THE MECHANICAL ENGINEERING
0F MINES AND MILLS

THESIS FOR THE DEGREE OF M. E.

James L. Morse

1932

 

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THE MECHANICAL ENGINEERING
of
MINES.ANDVMILLS

A PRACTICAL SURVEY OF THE CONDITIONS
GOVERNING THE SELECTION AND OPERATION
OF THE MECHANICAL EQUIBVIENT EMPLOYED

IN MINES AND MILLS

A Thesis Submitted to
The Faculty of

MICHIGAN STATE OOL‘IECE

By
James L. We
Candidate for the Degree of
MECHANICAL ENGINEER

June, 1932.

 

INTRODUCTION

Some years ago while engaged in teaching mechanical
engineering in a mining school, the writer endeavored to find
a suitable text covering the application of mechanical engi-
neering principles to the equipment of the mine and mill.
However, the complete lack of any such co-ordinated information
in book form, prompted the writer to secure the desired informa-
tion by means of a field survey of the principal mines and mills
in Colorado and.certain other states in the Rocky'Mountain
Region; and to deduct from.the material collected during this
survey, the basic principles involved in the selection and ar-
rangement of mechanical equipment peculiar to the mining and

milling industry.

The following pages contain, in condensed form, the
co-ardination of the fundamentals of processes and equipment, by
first outlining the principles involved in the process, and fol-
lowing this, the application of the necessary mechanical equipment

to produce the required result.

The mechanical engineering of mines and mills is a
phase of mechanical engineering practise requiring constructive

imagination and creative thought.

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THEMINE

There is a general misunderstanding among the major-
ity of people living at a distance from the mining fields in
regard to the significance of the term "MINE". They think of
it as an inexhaustible treasure vault in Nature's great store-
house of wealth, from which the fortunate owner may draw fabulous
quantities of easy money continuously and constantly. To them
the idea of an interest in a mine is a vision of luxury, ease,

influence, and immunity frcnn present or future want.

It is this popular opinion which has enabled unscrupu-
lous promoters to defraud thousands of people by selling them
worthless mining stock which existed only on paper, or, stock in
old mines which were worked out and worthless, but which may have

been productive of profit at one time.

As a matter of fact the best ,mine has a limited life,
and every ton of ore taken out means one ton less of valuable
mterial remaining as available, or potential profit. In this
respect it differs entirely from a factory, where the raw material
my be replenished and the process go on indefinitely as long as
the demnd for the product continues. A mine is a deposit of
definite amount and its contents cannot be renewed. When, there-

fore, the deposit is worked out the enterprise ceases permanently.

2.

There are nany deposits of are that cannot be mined at
a profit on account of their geographical location which renders

transportation so expensive as to over reach the value of the

product.

Other deposits more favorably situated may contain such
a small percentage of valuable mineral in proportion to the amount

of worthless material to be handled that they cannot be worked at

a profit.

Still other deposits may contain such a complex variety
of different minerals so intimately combined that they cannot be

separated at a profit.

These three examples represent the unprofitable class of
mines upon which it would be unwise to'spend money for mechanical
equipment for their operation, but the fact that they actually
contain valuable minerals nukes them a ready bait for the unsuspect-
ing purchaser of mining stock who buys without investigating the

validity of his purchase.

The orebody which is easily accessible from the standpoint
of transportation; which yields readily to ordinary methods of
mining and milling, which contains a high percentage of valuable
mterial, and which is extensive in volume, represents the "bonanza"
mine which is the dream of the prospector, and the investor. For-
tunately there are several such mines in existence, and new ones are

being developed, but there are a large number of extinct mines today

which yesterday were of the bonanza type, and which paid their
owners millions in net profits during their productive life, but
they are forever closed as a result of their valuable contents be-
ing entirely depleted. In recent years, mines of this kind have
reached the limit of production more rapidly than new ones have
been discovered, and as time goes on the trend will be more and
more towards the development of processes which will reclaim the

unprofitable ore bodies of today.

Ore deposits usually exist in rough or mountainous coun-
try, and their discovery is effected in various ways. Sane are
found protruding through the surface and are known as outcrops.

These are the easiest to find, and some of the best producers have
been of this type. Other deposits exist at variable distances from
the surface and their existence may be indicated by geological forma-
tions. These indications do not always prove true, and there are
valuable deposits that have been accidentally discovered under
conditions entirely contrary to geological indications. The presence
of ore deposits other than outcrops may be proven or disproven by
boring test holes, or by driving a shaft or tunnel to the point where

the deposit is supposed to exist.

When an outcrop is discovered, or the presence of an ore
body is indicated or suspected, the first step is to secure a legal
title to the property the same as would be done in securing a title

to a factory or business site, and it is as necessary that this be

done in the case of a mine as in any other instance of property
ownership. The legal title to the ownership of a mine site is
known as a patent, and serves the same purpose as a deed to ordi-
nary real estate. A mine claim.must be surveyed by an authorized
mineral land surveyor who has been directed by the surveyor gen-
eral to survey the particular claim.in question. Without this
authorization the results of the survey will not be considered
legal. The record of the survey must be filed in the office of
the surveyor general and duly approved in order to protect the
owner of the mine site in the peaceful possession of his property.
For the details of this procedure the reader is referred to
”Mineral Land Surveying" by J omes Underhill, U. 8. Mineral land
Surveyor for the State of Colorado, published by the Mining

Science Publishing Company, Denver, Colorado.

When the formal legal rights to the property have been
secured the actual work of developing the mine nay'begin, and as
this involves the use of machinery, the mechanical engineer becomes
a part of the personnel at this phase of the mining work. .As a
rule each mine constitutes a separate problem and the conditions

met with must be carefully considered in each individual case.

If the ore deposit is of the outcrop type the breaking
and removing of the ore may begin at once, but if the ore body is

buried at some distance from the surface a certain amount of

5.

preliminary, or development work must be done in opening a pas-
sageway to the ore body. One of three general types of entrance

may be employed depending on the topographical situation.

THE SHAFT
When the ore body is directly under the point of delivery,
a vertical shaft is sunk and a hoisting system of some kind is em-

ployed to raise the ore to the surface. 12, 2
Fig.2

THE INCLINE
If the ore body is inclined and in the form of a slab, the
incline is generally preferred as it follows the general direction
of the deposit. The incline, like the shaft, requires a hoisting sys-

tem and in addition, a track on which the hoisting skip runs. 2. 2
Fig.1

THE ADIT

When the ore deposit is contained in a mountain at some
distance above the surrounding country, the deposit is usually reach-
ed by driving a passageway practically horizontal to connect the
surface with the underground workings, this is known as an edit, and
is similar to a tunnel, except that a tunnel extends through the
elevation and is open at both ends, while the adit has but one open
end. However, an adit is sometimes referred to as a tunnel in the

description of a mining property. 2. 2..
Fig.5

Practically all of the mines in the Cripple Creek district
in Colorado, and the mJority of the mines in the Leadville district

are reached by means of the vertical shaft, although there is in the

        

  

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Leadville district an adit over five miles in length which connects
with a few of the very shallow mines in that vicinity, and serves
the double purpose of drainage and for the removal of ore. The
great majority of the mines were too deep to be benefitted by this

adit, and had to employ hoisting equipment to remove the ore.

The adit is preferred where the topographical position
of the ore deposit will permit its use on account of the elimina-
tion of expensive hoisting equipment required in the case of both
the shaft and incline. There are many mines in the state of
Colorado of this kind. The majority of the mines in the famous
Telluride district as well as several in Idaho Springs, Georgetown,

Silver Plume and other localities are of this type.

The incline is less common than either the shaft or adit
but there are examples in various parts of the country. One of
the large copper mines in the state of Michigan is of this type,
and there are a few in the state of Colorado. The old Stanley

line near Idaho Springs is a good example of this type.

In sinking a shaft, or in driving an incline or adit,
the method which is satisfactory in one locality may be entirely
unsatisfactory in some other place. In one instance loose earth
and gravel may be met with which is easy to remove but which
necessitates expensive lining to prevent caving. On the other hand,

the passage may continue through solid rock which is difficult to

remove but needs no protection against caving. .Again, alternate

layers of hard rock and loose earth and gravel may be encountered
which requires a change of tools and methods every few feet. The
engineer in charge of this work must be resourceful and ingenious

if he is to meet these conditions successfully.

Some are bodies lie near the surface and are covered
with a few feet of earth. In cases of this kind the earth is re-
moved by steam.shovels and the ore is scooped up by the same shovels
and dumped into cars for transportation to the mill. This method
of mining is known.as the stripping and open pit system. The huge
copper mine of the Utah Copper Company at Bingham, Utah, is a good
example of this system.of mining. In this mine the ore bed is sev-
eral hundred feet in depth and the deposit is worked on different
levels or steps simultaneously. Shovels and are trains are on each
level. Standard gage cars and commercial sized locomotives are
employed in this mine. Some of the shovels have dippers of twenty-
five cubic yards capacity, and are the largest machines of their
kind in existence. An enterprise of this kind requires a staff of
engineers, mechanics, and laborers to maintain the mechanical and

electrical equipment, p. IQ, illustrates this immense mine.

Iron are in the Lake Superior district is mined in this
way. Some of the iron ore beds have no earth covering and no strip-
ping is necessary in such cases. The famous Homestake mine at Lead,

South Dakota, combines the open pit and underground systems on account

\

 

VOL. 33, NO. 11

 
 

 

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NOVEMBER, 1930

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“The hills are shadows. and they flow They melt iiike mist. the solid Imuls.
From form to form. and nothing stands: Like rlmuls. they shape themselres and go."
, Train-mu

Shovels, however. work quicker than Nature when the mountem romaine copper!
(See p. 6'00)

 

 

 

 

 

 

of the position of the ore deposit.

THE SURFACE PIANT

An essential feature of a mine of any consequence is the
so called ”Surface Plant" composed of the surface machinery and
the buildings which house this equipment. In addition to the build-
ings containing the mechanical equipment, the surface plants of many '
mines include quarters for the employee, the mine offices with the
drafting and napping departments, assaying and sampling laboratories,
locker and shower rooms, hospital and first aid service.

Surface plants, like power plants or factories vary greatly
in type, size, construction, and equipment, according to the size and
location of the mine. In the case of snall mines situated near a
town, the surface plant is usually limited to the mechanical equipment
only, as the men have living accommodations in the town. On the
other hand, mines which are remote from the larger centers must be
sufficiently self contained to service and renew the operating equip-
ment.

The shop equipment of some of the larger mines is very
complete and represents a good sized industry; the mchine shop con-
taining lathes, boring mills, planers, shapers, milling machines,
grinders, drill presses, Keyseating machine, hub press, power punch,

plate bender, plate roll, and a complete set of hand tools.

The forge shop is equipped with steam and power hammers,
power saws, punches, dies, tempering and heat treating furnaces, drill

forging mchines, and a complete set of hand tools common to a first

class forge shop.

The power plant is equipped.with.boilers, engines, gen-
erators, and in the case of the mine with shaft or incline the
hoist is an indispensible feature of the equipment. .Also in the
case of all hard rock mines the air compressor is of equal impor-
tance to the hoist. In most of the mines in the Leadville district
the air compressor is not required, as the mines are of the "Soft
Ground" type and the ore itself is of a clayey consistency. It is
usually broken by means of a bar or pick, and drilling and blasting
is unnecessary. In contrast to this condition the mines in the
Cripple Creek district only eighty miles distant are of the "Hard
Rock" variety, and the best quality of drill steel is required to
pierce the flinty ore and surrounding rock to provide for the high

power explosive necessary to break down the ore.

The recent expansion in the field of electric power has
'phaced current within the mining field to such an extent as to
bring about an abandonment of steam.powar entirely in.many mine
power plants. In the earlier days of mining the steam.hoist was the
accepted type, while today a trip through the mining districts re-
veals many disused boiler plants capable of giving many years of
service, but which cannot function in competition with electric
power. These mines have installed electric hoists, and electric

driven air compressors, as well as numerous motors to drive the

auxiliary nachinery.

 

10.

The internal combustion engine is coming into rather
wide use in the mining localities near the petroleum.fields.
The Diesel type being the common preference during the last few
years. However, in the northern portions of the country where
the winters are long and severe, the steam plant is more common,
as the steam.may be used to heat the buildings after furnishing
power to the engines. The question of choosing the power ma-
chinery for a mining property is a rather serious one, and.requires
a careful consideration of all the conditiOns involved in the

economic analysis of the enterprise.

Radical improvements in the design of existing equip-
ment may make it necessary to discard the machinery with which any
enterprise is begun, and the mining industry is no exception to
the rule. An interesting example of this fact occurred in the case
of the old Portland.mdne in the Cripple Creek district. 'When the
mine began operations, a large duplex, tandem, cross compound, steam
driven air compressor was installed at a cost of $20,000.00 The
air cylinders were 22” and hO” by #8" stroke. This compressor was
automatic in its operation and the rate of consumption of air would
determine the speed. The machine would shut down.when no air was
being used and start again.when the air pressure in the receiver
dropped slightly; with no attention from.an attendant. The service
was ideal but the thermal efficiency was extremely low at slow speed.

Hewever, at the time of the installation coal and labor were both

ll

cheap, the ore was near the top of the ground and the hoisting
expense was smll. The mine was making money and little atten-
tion was paid to operating economy as long as the service was
satisfactory. Soon after the war the price of coal and labor
advanced rapidly. The workings had deepened to such an extent
that hoisting became an item of considerable expense, and the
profits begn to diminish. Coal .to produce steam suffered a
freight charge alone of $5.00 per ton from the nearest source of
supply to the railroad yards in Cripple Creek, and it had to be
hauled by truck up a steep hill to the mine plant. The total

cost of coal at the boiler house was about $12.00 per ton which
was a prohibitive price. The company investigated the cost of
electric power and decided upon three electric driven comessors
with a combined capacity equal to the steam unit which was sold for
$2500.00. The new compressors were automtic in their regulation
and would cut in or out as the demand for air varied. For instance,
if the denand for air was within the capacity of one machine the
other two out out, or, if two were needed they would cut in as re-
quired, while for maximum demand all three would operate. This ar-
rangement provided higher load efficiency by enabling each machine
when in operation to work near its rated load. The saving realized
in the reduction in power cost fulL'Ly Justified the change. This
example is but one of mny that might be mentioned, but it illus-
trates the pressure of economic conditions which are continually

demanding the attention of the engineer in almost any field of

activity, as well as that of mining.

Air compressors have the disadvantage of reduced out-
put and efficiency at altitudes above sea level. For example
a compressor which.will deliver 100 cu. ft. of air in a given
time at sea level will deliver about 85 cu. ft. in the same time
at an altitude of 5,000 feet for a gage pressure of 100 pounds
per sq. in. .At 10,000 feet above sea level the output would be
about 70 cu. ft. Therefore, if the compressor were to deliver
100 cu. ft. of air at 10,000 feet the cylinder would need to be
h3% larger than for sea level performance. The benefit realized
from.stage compression is much greater at altitudes than at sea
level. .Another significant fact is that the high pressure cyl-
inder in a stage machine must decrease in diameter relative to
the low pressure diameter as the altitude increases. The selec-
tion of an air compressor for high elevations is an important
matter if the most economical results are to be Obtained. The
reader is referred to Peele's Compressed.Air Plants, Wiley and

Sons, for comprehensive information on the subject of air compres-

ears.

The selection of machinery for a mine shop is similar
in many respects to equipping a Jdbbing shop, in that the machines
should.be general purpose, rather than of the highly specialized
type. For example, a lathe for a mine shop should be adaptable to

a great variety of operations in order that it may be used on many

13.

different Jobs. It would be folly to install a battery of au-
tomatic lathes in such a shop. Not that the quality of the
machine should not be the best but because there is not enough
duplicate work to Justify the investment in complex machinery
which is capable of turning out large quantities of the same-
piece. 'What has been said in regard to the lathe applies also

to the other equipment as a general rule.

The question of investment in mine shop machinery is a
matter of the economics of the enterprise. The majority of mines
have a life of a few years, and in.many instances the equipment
which was purchased for one mine may be acquired by a new mine in
the same locality when the old one has reached the end of production.
However, in a transaction of this kind the purchasing engineer should
be able to Judge closely of the value of the used equipment, and of
its adaptability to the new requirements. On the other hand in the
case of a mine like the Homestake, which will probably have an oper-
ating life of a century or more, it would be poor economy to consider
anything but the best grade of new machinery Obtainable. The same
reasoning applies to every feature of the surface plant and the
underground equipment as well. The investment in operating equipment

must be less than the value of the product if a profit is to be made.

There is probably no more outstanding example of a complete

mine surface plant than the one owned.by the Homestake Nflning Company

11+ .

at Lead, South Dakota, and for this reason a brief sunmery of

the major portion of the mechanical equipment will be given here.
For the air service in the mine and shops, nine compressors with
a total capacity of 21,250 cu. ft. of free air per minute at

100% gage pressure constitute one group; while for the compressed
air locomotives, of which there are at present, thirty-five,
ranging in weight from 3% to 1h tons, a group of three compres-

sors with a total capacity of #600 cu. ft. of free air per minute,

furnish air at 1000# per sq. in.

The hoisting equipment, which was entirely steam.in the
past, is now practically all electric, with the exception of the

Nordberg compound, condensing, skip hoist, installed in 1915.

The machine shop is 60 x lhO feet, and has an electric
traveling crane. The shop is equipped with a full set of machine
and hand tools. As an adjunct of the machine shop there is an
automotive repair and service department for the fleet of 85 trucks,

tractors and cars used for company transportation service.

The blacksmith, boiler, sheet metal, and tinsmith shops
are housed in a building 60 x 170 feet. Thirty-seven men are em»
ployed in this building. The equipment consists of seven forges,
two gas fired furnaces, two forging machines, three power hammers,

threading machine, power punches, shears, and power rolls, electric

rivet heaters, and an electric spot welding machine recently de-
veloped for the making of the many thousand feet of galvanized

iron air conduits required for mine ventilation.

At the drill sharpening shop twenty-five men are emr
ployed. About 5,000 hollow drills are sharpened daily on eleven

drill sharpening machines.

A special shop is devoted entirely to the repair and
service of 1600 end dump, and 1200 side dump mine cars, as well

as additional cars used in surface transportation.

An unusual feature to be met with in most mine surface
plants is a foundry 72 x 168 feet served by an electric crane.
Two he" and one 22" cupolas are used for the iron castings, and
two tilting, natural gas fired furnaces are used for the non-

ferrous castings.

During the year 1950 the servicing and repair of the
h90 rock drills employed in the mine involved an expenditure of
$7,86h.00. Drill bits made and sharpened during the year total-
ed 1,017,858 at a cost of $57,967.00 to which was added $51,807.00

for the new steel required to replace worn out bits.

The output of the foundry for the year was 1,115 tons
of iron castings, and 12% tons of bronze, copper, and aluminum

castings. The iron castings made numbered 26,h88 pieces while the

number of non-ferrous pieces produced amounts to 5,hh3.

The mechanical engineering department has a personnel
of 260. The offices of the department constitute a bureau of
information. Complete records are kept of all work, material,
equipment, repairs, replacements, new machinery, and supplies.
Frequent meetings of the department personnel are held for the
discussion of matters pertaining to the business of the enter-
prise, with suggestions for possible improvement in operating
methods. From the above figures it is evident that the mechan-
ical engineering of a large mine is fully equal to that of a large

industry.

In addition to the mechanical engineering features of
this mine, a most important adjunct is the matter of health pro-
tection, and hospital service maintained by the company; A modern
hospital representing an investment of $125,000.00 is equipped
with the most modern surgical, X-ray, physiotherapy, and laboratory
facilities. The staff consists of six full-time and two part-
time physicians, six graduate nurses, and non-professional help,
making a total of nineteen employee. The hospital and medical
service is available to the families of the mine employee as well
as to the men themselves. During the year 1930 the cost to the
company for maintaining the hospital and medical service was

$66,715.55. While this feature is somewhat outside of the

17.

engineering field, it is too important to escape mention in con-

nection with the rest of the surface plant.

MDIE OPERATION
Although the surface plant is the source of energy for
the underground operations within the mine, there is much of an

engineering nature concerned with the removal of the ore.

In mines of the so called "Hard Rock" type it is neces-
sary to employ some kind of high explosive to dislodge the ore.
Dynamite being the agent generally used, and for the proper plac-
ing of this explosive to enable it to break down the maximum
ammmt of ore per pound of explosive, a series of holes are dril-
led in the rock at variable angles with the surface, the arrange-
ment being the result of experience and trial with different grades
of rock. After being placed in the holes and securely tamped the
dynamite is fired either by means of a fuse or by electrical
means.

THE ROCK DRILL

The mechanism employed for this drilling is known as the
air drill, on account of the operating medium being compressed air
at a pressure of from 80 to 125 pounds per square inch. The air
pressure acts on a reciprocating piston similar to the action of
steam in a steam engine. The piston terminates in a piston rod

which strikes the end of the steel drill bit a succession of rapid

blows, the energy of which is transmitted to the cutting end of
the bit by vibration, although in the early type of rock drill the
piston rod was attached directly to the bit, and the piston and
'bit moved as a single unit. Recent practice has discarded the

old pistol drill almost entirely in favor of the hammer drill.

For general mining work the drill bit is made hollow
and a stream of water is forced through it while in operation.
This serves to wash the cuttings out of the hole and allays the
dust which is injurious to health if breathed. In the early days
of rock drilling mny drill operators contracted what is known as
miners' consumption by breathing rock dust produced by drilling
the rock dry. When the drilling is done in wet rock an air con-
nection is attached to the drill and air instead of water is used
to remove the cuttings from the hole. For general outside work
the drill bit is solid instead of hollow, as it is much cheaper to

mks and is satisfactory for work of that kind.

‘.-‘.’hen in operation on general mining work the drill is
supported on a vertical column made of heavy pipe with a screw ad-
Justment at the bottom which enables the operator to wedge the column
between the top and bottom of the passageway with sufficient force
to hold the drill in position. The vertical column is fitted with
a swiveling arm which permits the drill to be pointed in any con-

venient direction. In some cases a horizontal bar is used and two

19.

or more drills carried on the same bar. The illustrations on
pages 12 A-B-C show various set-ups for mine drilling, and also
a cross section of a drill. It will be noticed that these drills

each have two lines of hose. One is for air and the other for

“later 0

CWEE’RESSED AIR PIPE LINES

To furnish air for the operation of the drills, the
compressor plant referred to in connection with the surface plant,
discharges compressed air into a receiver or storage tank from
which a pipe line is run into the mine near the point where the
drilling is going on. A hose is employed to transmit the air from
the pipe to the drill in order to provides flexible connection to
facilitate handling and moving the drill. The air pipe must be
provided with moisture traps and drains to prevent the condensate -
in the air line from reaching the drill and interfering with its
proper operating by slugging, and washing out the lubricating oil.
It is necessary that the air line be large enough to avoid serious
drop in pressure between the compressor and the drills, and, as the
length of the pipe line is a factor in the pressure loss it is
necessary to estimte as nearly as possible the mximum length
that will be required and calculate the diameter accordingly. .How-
ever, in cases where capital is limited, or the extent of the work-
11188 cannot be foretold, the initial installation may be smaller

in diameter than will be later required, and as the workings extend

! __________—________Ee_¢a_/9/i
{-

 

1" ".c'- «'5 mm- fill-omt .
I - -- It . 7 .g - . .- . .
‘ “Ira-M .' '- ‘sfl- 4‘" ”‘4 2f“ ‘
. I4". - ; y. ,A ‘ .
. - . _, Q -\'\‘.~. ,-

 

 

 

 

 

 

 

 

 

Even the most difiicult drilling jobs around a mine are easily handled by an 8-7!) drifter. The drill
illustrated is working in a heading on the sixth level of a mine in Tenn.

 

 

 

 

 

SIX SIZES OF DRIFTER DRILLS

HE six sizes of I-R drifter drills covered in

this bulletin range in weight from 117 lbs.
to 222 lbs. They are suitable for a wide range
of drilling conditions.

Durability is one of the first requisites of an
I-R drill. Along with this durability, we have
emphasized light weight in one machine; me-
dium weight and low air consumption in another;
fast drilling speed, exceptional hole-cleaning
capacity, etc., in others.

Every l-R drill must pass a certain speed
test with a specified air consumption before it
is allowed to pass through our drill testing de-
partment. Each drill is given several three-

minute runs in hard granite. and the average
speed per minute must equal or better the speed
set for that machine.

Because of the great differences met in the
field—ground conditions. air pressures. etc.—
the machines are apt to do a great deal more
work or a little less work that the record de-
manded in our test department. Rock drill
users can be sure. however. that by using the
LR drill best suited for their particular condi-
tions, they are getting the highest possible
drilling speed and economy.

Descriptions and essential details of each
of the six sizes will be found on pages 16 to 24.

 

The light weight and power of the N-75 drill make it an ideal machine for the majority
of drilling jobs around a mine.

 

 

 

 

 

 

 

.‘ I I
await——

F%7g£ Hi5

 

 

 

 

.0
-vgfi—whl J.

 

_~’ w," 4

 

 

N-72 Drifter on the 700’ level of a mine at Schumacher, Ontario. The rock at this property is exception-
ally hard. Note the large amount of quartz present.

14

 

 

 

 

 

 

The X-71 Drill mounted on tripod will easily drill and clean holes to 35’ in depth. The above is a View of
a granite quarry in North Carolina.

(1) Dimension Stone

In the quarrying of dimension stone, the
operation consists of drilling and broaching; or,
as it is generally known, channelling by the
hammer drill method.

The X-71 is used mounted on a quarry-bar.
This mounting facilitates the proper spacing of
a straight line of parallel holes. After the holes
have been drilled to the proper depth with the
regular 1%” hollow round steel, a special
broaching steel is inserted in the chuck and the
webs between the holes are broken down.

Not only has this method proved to be much
faster and cheaper, but the blocks can be taken
out in the exact size wanted. This eliminates
much waste and also keeps a straight, even face.

(2) Crushed Stone

In the field of hard rock quarrying for crushed
stone, the X-71 drill is used on a tripod. Such
an outfit is light enough to be moved about
easily, yet is very economical and efficient. It

 

can be used either on a bench or on a full face
that does not exceed 35 feet.

The holes can be spaced in such a way as to
eliminate secondary drilling almost entirely.
This saving is important, as secondary drilling
has always constituted a large part of the total
operating expense in a crushed stone quarry.

Limestone

In limestone or other formations which run
from soft to medium-hard, either the 8-70 or
the X-71 drill with a wagon mounting is most
practical. This outfit is particularly suitable for
rock formations that allow changes of steel in
excess of 36”.

The weight of the drill with slab-back is
sufficient to feed it down as fast as the machine
will drill. The drill is raised by either a winch
or an air-operated “Little Tugger" Hoist.

Our wagon drills are making excellent records.
200 to 300 feet of hole per shift constitutes an
ordinary run. We have on file numerous records
of drills that have made 300 feet in five hours
overall drilling time.

13

 

 

I'UJUE’ 17b

 

 

 

 

   

. .- z«wiv‘wummr.~1idm\~WWWM-¥H«Wet-IMkfi'hMW‘MI-HM‘W'V«'Mi4“N nu».

 

 

 

 

 

 

 

 

 

 

 

\

. a} ‘
_“" ,—_

 

At this large silver mine in the Republic of Mexico, the shaft bar mounting has proved very
popular. This illustration shows Ingersoll-Rand N-75 and R-72 drills on a single bar.

 

22

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

und machine is of all-steel con- cylinder porting is so arranged that the pistoi

THE R-72 DRILL

 

R-72 Drifter with 24" feed solid guide shell.

 

 
     

tion revo u ionize me o s in o ‘tne crusneu
stone and dimension stone quarries. Mounted
on a quarry—bar, it makes possible the successful
taking out of granite blocks by the drilling and
broaching method. With the wagon drill mount-
ing, this machine is making enviable records in
the limestone quarry field. Mounted on a tri-

-—__

   

resembles the butter-fly type in its smooui,
positive action. The longer the valve is run,
the better the seat becomes. It is light in weight,
and the construction is such that it insures a
negligible amount of wear on both valve and
seat. This is due to its cushioned action and its
unusually large port openings and short travel.

 

X-71 Drifter with standard 30" feed solid guide shell.

_21

 

20.

farther imder ground, and profits from the mine accrue, the
small pipe is replaced by a size ample for the transmission of
air through the greater distance. Pipe line formulae my be
found in Peele's "Compressed Air Plants" or Kent's or Mark's

handbooks .

ORE Hill-IDLING UNDERGROUND

After ore has been broken down its removal from the
mine becomes a materials handling problem of considerable mgni-
tude. By far the most common method is the mine car; a very
commonly used type of which isithe one ton capacity, although both
larger and smaller sizes are in use. This type of car has but
four wheels, placed well towards the center of the car body, being
from one-third to one-fourth the length of the car body apart. This
arrangement enables the car to negotiate sharp curves, and in cases
of derailment one man can usually retrack a one-ton car by lifting
one end and utilizing the overhang of the opposite end of the car
similar to a see-saw. ~One pair of wheels can be placed on the
track by lifting one end of the car, after which the other pair my
be replaced by. lifting the opposite end. The wheels being so near
the middle of the car act as a fulcrum, while, if they were at the

ends of the car a ,jack would be required to lift the car on the

track.

Mine cars are made in several types. One type is ar-

ranged with the sides hinged at the top to facilitate unloading.

21.

These are usually operated by hand. Other types have the sides
arranged to lift up and may be operated by means of a tripping
cam.mounted on a post which engages the lifting linkage as the
car is drawn past by the hauling motor. Other types are made
water tight for use in mines where the ore is mixed with water,
and the cars are dumped by a revolving car dumper which lifts
them off the track and inverts them. Cars of this type were a
necessity in the Tom.Boy Mine in the Telluride district, where
the metal bearing gravel was saturated with water to such an ex-
tent that it would flow like concrete. Another type of car has
the ends hung on hinges for dumping at the end instead of at the
side. This type is often used when the ore is hoisted in a skip.
The skip is lowered down the shaft and the car is tipped up on
one pair of wheels, allowing the contents to slide into the skip.
This is another reason for placing the wheels near the center of
the body. See illustrations, p;_21.A-B-C-D, for representative

types.

In some mines the broken ore is loaded into the cars by
hand shovels, and while this method is inefficient from.the come
nercial standpoint and requires considerable physical exertion, it
is the only means available in narrow passageways, especially while
following a narrow vein of ore which on account of its richness will
yield profit if mined in this way, while, if the passage were made
wide enough to accommodate mechanical loading equipment so much

barren rock would have to be removed that the expense of breaking

THE ATLAS CAR AND MANUFACTURING COMPANY .1, _A CLEVELAND, OHIO ' e

ROCKER SIDE DUMP CARS FOR CONTRACTORS,
QUARRIES, CLAY PITS AND GENERAL
INDUSTRIAL USE

 

   

No. 217-S No. 217-H
. . . No. 217-A
Side Rocker Dump Car, small Side Dump Car. heavy construction
capacity. Plain Wheels for steam shovel use Side Dump Car

     

No. 217-L

Side Rocker Dump Car. with foot
brake. Low sides
Side Dump Car Side Dump Car Automatic coupler

No. 217-C No. 217-B

     

No. 217-F

N . 233 No. 217-w . .
0 Side Dump with Flarmg Ends
Rocker Side Dump Garbage Car, Either Side Dump Car Permits nesting to make compact
A. R. A. Construction With scale package for export

These cars are furnished in various track gauges, with or without brakes; with roller
bearings or plain bearings, link and pin or automatic couplers, and in all capacities.

I

Variations in design to meet the individual handling conditions are readily available.

 

ll‘

 

 

THE ATLAS CAR AND MANUFACTURING COMPANY

SIDE DUMP CARS

 

No. 156-3

Side Delivery Car for Cement.
Ashes or Coal

No. 164
One Side Delivery Car

   

No. 161-A

Gable Bottom Dump Car.
with trip and brake

160

Gable Bottom Steel Car

 

No. l6l-P

Gable Bottom Pig Iron Car.
heavy construction, standard gauge

No.
Steel Gable Bottom Car, large

159

capacity. Standard gauge

BIRDSBORO TYPE CARS

 

 

‘ LEVELAND. OHIO

 

 

 

No 157

One Side Automatic Dump Car

 

No. 161-8
Steel Gable Bottom Car

 

No. 485

Side Dump Garbage Cat.
A. R. A. Construction

 

No. 258 No. 258-A

l

«a

i:

 

I .~
[—7 ' echSTt .7 .
( Afiiltlulwi‘ x ’ . _
L’ , ,, 3 L /
— x ; . £_ _

Showing various dumping methods.

 

a" 1
. J7 . . ',\ i . I . '
.I’ ' N A, iFfi i}
b J _ ‘ ‘ ; J .—

No. 253-“
70-Ton Capacity Birdsboro TYP‘

 

Built in all capacities and track gauges.

 

 

'17

 

I.

THE ATLAS CAR AND MANUFACTURING COMPANY

CLEVELAND, OHIO 0 .

ROTARY AND END DUMP CARS

 

No. 213
Rotary Steel Dump Car

 

End Dump Quarry Car

 

 

 

No. 201

Standard Scoop Car. with or

without Rotary feature

 

N0. 277

Steel Mine and Quarry Car

 

“-_;-_~-
vulAL‘H"cJ
. ~—’-l
.___._,...a-If"" ‘
1 .
V
a!”
.. J. :. ~ _
.

l-c r,

 

 

 

 

No. 240
Rotary Ore Car

 

No. 270
End Dump Mine Car

No. 203

Automatic End Dump Car

 

No. 173

End Rocker Dump Car. with brake,
large capacity

 

No. 278
Steel Mine Car

 

No. 271

End Dump Mine Car. with auto-
matic trips on door

 

Round Bottom All Steel Ore

Car

No. 272

End Dump Incline Car

     
 

    

ATLAS CAR AND MANUFACTURING COMPANY ’ CLEVELAND, OHIO

 

 

 

 

 

 

 

 

 

 

No. 150-C No. 150 No. iSO-H

Bottom Dump Car Bottom Dump Car Center Bottom Dump Car

IA‘J‘

5.
Q» 3-
“- Nf‘u‘." if

No. 159 A

     

70-Ton Gable Bottom Car with Special
collector arm for energizing bin
Bottom Dump Ore Car gate operating mechanism Bottom Dump Car

No. 150-A No. ISO-D

A FEW TYPES OF MOTOR DRIVEN CARS

 

   

No. 217-EH No. 214-E No. 160E
Large Capacity Side Dump Car Rotary Dump Car Side Dump Gable Bottom Car i

   

No. 181
' - ' N . 1 O-E
One Side Delivery Car No 212 C 0 5
F0! mines or quarries Rotary Slate or Refuse Car Bottom Dump Car

BULLETIN NO. 1223 GIVES COMPLETE SPECIFICATIONS AND DETAILS OF ELECTRIC ROTARY CARS

 

I‘D
R)
o

and removing this extra tonnage would consume the profits.

In cases where the ore body is of sufficient width to
permit the use of mechanical loading equipment it is usually
used, especially if the ore is of low grade, in which case large
quantities per man must be handled. There are several makes of
these leaders on the market among which the Nordberg, and.Allis-
Chalmers are leaders. Page 22 A-B illustrates types of these

machines.

When the orebody extends for several hundred feet in a
vertical or nearly vertical direction, as is the case in a large
number of mines, the ore is stoped, or broken down from.above and
allowed to accumulate on a temporary staging with openings, or
chutes, under which the ore cars are run, and the ore allowed to
fill them.by opening the chute doors. This gravitational method
eliminates the expense of loading either by hand or machine, but
cannot be employed in all mines. The method used must be adapted

to local conditions. P. 22-0.

The old Portland mine in the Cripple Creek district is
an excellent example_of the stoping method. Ore strata in this
mine extend from the top of the ground to a distance of more than
three thousand feet down. Levels are run from.the shaft, at
intervals of one hundred feet, one above the other. The ore is

then drilled and blasted from.overhead and allowed to run into the

 

Loading copper ore in the Pilarcs Mine of the Moctczuma Copper Company at Nacnzari. Sonora, Mexico.

Designed and Constructed for Hard Usage

_Light in weight yet sturdily built

Page 2 2.8

ALLIS-CHALMERS MANUFACTURING COMPANY

Cut 20797

 

 

 

 

 

HOAR SHOVELS

.VIodels No. 2 and No. 5-2

(Patented)

Klechanical mucking, as a means of reducing costs, and speeding the advancement
of the work in hand, has become a recognized factor in the mining fields, and in tunnel
construction work.

l\-’Iucking machines have passed their experimental stage, and the operator may now
install underground power shovels with the assurance of their successful operation. Hoar
Shovels, have proven themselves over a period of more than eight years. Their field of
use has been extended from the iron mines for which they were originally designed, to
include metallic mines of all classes; rock development work in anthracite and bituminous
mines; non-metallic mines; water, sewer, power and railway tunnels, and general excavation
in restricted operating space.

The Hoar Shovel is a fully revolving power shovel, weighing slightly over three tons,
that will dig any material that can be handled by standard power shovels of the familiar
surface type. The smallest size Hoar shovel will operate in a tunnel seven feet wide,

by seven feet high above the crown of rail. For further details on Hoar Shovels see
Bulletin 1824-A.

N0. 107-—A 104

 

 

— - -—— M- ..-

— -..._.' —-.

 

CONCENTRATIN.G EQUIPMENT

Cut 13050 Cut 16960

   

One of Three 375 H.P., Impulse \Vheels for QIhs-ChalmersdDingle-x CI?‘
1380’ Head and 325 Kv-A., 3 Phase. 50 ”“ICOWC‘C ‘0‘ ‘5' “
Cycle, 2300 Volt Generators built for La
Cumaca Hydro Electric Co., Venezuela, S. A.

For the power plant complete equipment “from prime mover to swit
by the Allis-Chalmers organization. This includes all types of prim
turbines, hydraulic turbines, steam, gas and oil engines, together with Cr
equipment. Condensers of all types, pumps, air compressers and many a
supplied. Allis-Chalmers equipment is used in plants of all sizes and incl
largest power units ever built. Allis-Chalmers NIanufacturing Comp
organization in the world furnishing complete power equipments of e.
built in the same shops and under one management.

 

 

Cut 15109

 

 

 

103

 

. fixixk 0 \O£\\3\\\t0 IN

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re
kN

cars from chutes. Several of the levels are worked simultan-

eously for quantity output.

UHDERGROUNU EAUILGE
he moving of ore cars any be accomplished by man,
animal or mechanical power, and all three are in use today in
various localities, even in this country some of the mines with
narrow, crooked passageways find the so called hand tramming the
most economical system to use. Some of the mines use mules for
this purpose, but animal haulage is found principally in coal

mines. The large mines employ mechanical haulage in nearly all

C8888.

For mines with low overhead room.the storage battery
locomotive finds a wide use. It has the disadvantage of high
first cost, and the batteries will deteriorate if not cared for
properly and recharged regularly. It has the advantage of not
Irequiring a trolley wire or third rail, and for gaseous mines it can-
Ilot cause ignition of the gas by trolley sparks. In wet mines the
Changer of short circuits from.the overhead trolley is entirely slime

Iinated by the use of the storage battery motor.

In mines with ample overhead room, that is, greater than
1:he height of a man, the trolley locomotive is widely used. It has
1Lhe advantage of lower first cost than the storage battery type,

51nd freedom from.storage battery ills. It is easily repaired and

the cost of upkeep is relatively low. One disadvantage is

the cost of the trolley wire, and the fact that the trolley wire
must be advanced.as fast as the track is laid, which requires

a lineman in addition to the track layers. However, the service
of this type of prime mover is so satisfactory that it has enjoyed

a wide use.

The compressed air locomotive is another type of prime
mover which is very convenient in mines where there is danger
from gas, as it is proof against producing sparks, and its ex-
haust aids ventilation. It has the disadvantage of requiring
a separate compressor unit furnishing air at from 1000 pounds
per square inch to 1500. For this reason it is usually found in
relatively large mines where the output will Justify the expense

of the extra compressor equipment.

The internal combustion locomotive has also found a lim-
ited use in underground haulage but the exhaust fumes are objec-
tionable in many cases. ‘When the internal combustion locomotive
is operated in.what is known as the return airway, that is to say,
the passage through which the air is leaving the mine, it has
proved successful in numerous instances. It has even been used
in coal mines, which is the last place such a machine would be
expected to be used. The C(florado Fuel & Iron Company used this

type of locomotive in one of their coal mines for over a year

TD
\fl
0

without accident, but in view of the possibilities of danger to
the workmen in case of a derailment and blocking of the passage-
way, and danger of fire from the ignition of gasoline, the company
officials decided to abandon this type of prime mover for under-
ground work. It may be stated in general that unless the ven-
tilation is known to be adequate under all conditions for this

type of motor, it should not be employed for underground service.

THE HOIST
In all mines where the ore is reached by an incline or
shaft the hoist becomes an important feature of the surface plant
equipment. On account of the fact that the men working in the
:mine are transported into and out of the mine by the hoist, it is
important that this machine be as perfect as human skill can make

it, and that the operator be thoroughly trained in its operation.

Hoists may be driven by steam, electric or internal come
bustion engine power. Electric power is gaining favor over the
other two where it is available at a reasonable cost. The steam
hoist was the universal type during the early days of mining, and
is reliable, dependable, and easily controlled. There are two
general types of steam.hoist; the "first motion" hoist and the
geared hoist. The former has the connecting rods direct connected
to cranks on the drum.shaft, at 90°like the locomotive, to enable

the machine to start in any position of the cranks. In the geared

hoist the crank shaft has a pinion meshing with a gear on the drum
shaft, and the crank shaft makes several turns to one of the drum.
This type is usually found in small, shallow mines where the
hoisting speed is relativelyislow; while the first motion hoist
was the accepted type for the large mine. It can be said of this
type of hoist that is representated the highest attainment of the

engine builders art. P. 26qA.

The electric hoist eliminates the boiler room.and fire-
man.but is usually higher in first cost than the steam hoist, and
in some localities the cost of current is prohibitive, but the
rapid expansion of electric service is placing cheap power in the
mining districts to such an extent that the steam.hoist is rapidly
losing ground, except in the coal mines where fuel is practically a
by-product. An additional advantage of the electric hoist is
that during intermittant hoisting service, there is no loss from
fuel consumed during the idle periods as is the case with the

steam.hoist. P. 2648.

The internal combustion engine has never found favor for
large hoists, as it is necessary to employ friction clutches and
reversing trains with this type of prime mover. It has been used
to some extent in small mines, and is convenient for preliminary

work on account of its portability.

The rope drum.is of two main types; the cylindrical

MILWAUKEE, WISCONSIN. U. S. A.

Steam Driven Hoist
Reynolds-Corliss Heavy Duty Type

Cut No. 15320

 

Built for
BRITISH-AMERICAN NICKEL CORPORATION
SUDBURY, ONTARIO, CANADA.

20,000-lb. Maximum Rope Pull, Double Drum Duplex Direct Acting Hoist.
Cylinders 22”x48”. Drums 7’ 0" dia.x5’ 6” face. Drums
mounted on the same crankshaft, one keyed and one loose
with friction clutch. Speed 800' to 1,500’ per
minute. Safety devices, etc.

107 No. 106-A

 

 

 

 

l faye 265

I

, : The World’s Largest Coal Hoist ; :

 

Chicago, Wilmington 82 Franklin Coal Company
West Frankfort, Illinois

WORLD’S record for coal hoisted from a single shaft is held by this

hoist ‘in service at the New Orient No. 2 Mine. This mammoth
electric hoist with its unusually large drum driven by two motors shows
the present day tendency toward larger and more efficient hoists as an aid
in the lowering of mining costs. Without attempting to make a record,
on three successive days the average daily tonnage hoisted was 12,444.
The maximum was 13,563, which is a record for coal hoisted from a shaft

mine. Two hundred and sixty-six railroad cars were required to load this
one day’s operation.

SPECIFICATIONS

Type of Drum ................... Cylindro-conical Size of Motors ................... Two 2000 H.P.
Size of Drum .............. Small diameter 10 feet Arrangement of Drive ................ First motion

Large diameter 17 feet Number of Brakes .......................... Two
Size of Rope ................... 2 inches diameter Size of Brakes ................... 11 feet diameter
Total lift ............................... 607 feet Method of Brake Operation .....................
Weight of Skip .................... 17,000 pounds Vertical hydraulic thrust cylinders
Weight of Coal .................... 26,000 pounds Number of Trips per Hour ................. 138%
Rope Pull ......................... 46,820 pounds Normal Hoisting Capacity. . . . 12,000 tons in 8 hours
Rope Speed ................. 4,000 feet per minute Maximum Hoisting Capacity.l4,400 tons in 8 hours

~ , v—vw

C.
‘._A " A ‘ 1“

" n
Page two

Nordberg Electric Mine Hoists

A Standard by Which Others Are Compared

" ORDBERG Electric Mine Hoists are
designed and built for those who
desire the best in hoisting equipment.

As more is built into them in the way of
superior design, construction and the use
of better materials, more can be obtained
from them in performance and long life.
No mining equipment carries more respon-
sibility than the hoist. Should the hoist
fail there is no spare to take its place.
Mining operations may be at a stand still.
Because of this great responsibility every
precaution should be taken to make the
hoist absolutely dependable at all times.
This of course adds to the cost but if there
is any equipment that warrants the best
that can be obtained, it certainly holds
true of the hoist.

Engineering Experience

Nordberg Hoisting Machinery, because of
its many years of predominance, needs no
introduction to mining men. It has been
built in all types for every conceivable con-
dition of load, depth, speed and driving
power. This has meant the solving of
many difficult engineering and hoisting pro-
blems for which the Nordberg organization
is amply qualified due to its corps of highly
trained engineers, many of whom are
specialists in their respective fields. When-
ever difficult hoisting problems are encount-
ered, Nordberg Engineers are invariably
consulted. Their efforts in this direction
have led to many advancements and im-
provements in hoist design and construc-
tion. It is one of the reasons why N ordberg
hoisting equipment leads the field today.

Manufacturing Facilities

Our facilities for building large hoists are
unexcelled. A complete modern plant
equipped with the latest machine tools for
the building of a high grade product, to-
gether with a force of highly skilled
workmen experienced in the building of
better grade hoisting equipment, assures a

 

product that is superior in regarc
workmanship and construction.

World’s largest steam and electric h.
have been produced in Nordberg Sh

The Present Day Tendenc;
In Hoists

The increased use of electricity for
ions mining operations, particularly
adaptability and economy for the drivix
mine hoists, has led to its receiving 1
favorable consideration in every mi
field. Until a comparatively few years
practically all hoisting was done with st
equipment. The development of c
hydro-electric power and the extensic
power lines into most mining districts
resulted in a rapid growth in the us
electric hoists.

At one time only smaller hoists
considered applicable for electrical 0]
tion but now there seems to be no lirr
size. This change is due to some extei
the development of large motors
better methods for their control.

The application of electric drive is
ticularly suited to hoisting service.
ability of electric hoists to handle a
tonnage at exceptionally low costs, tog
with their case of control and mini
maintenance expense is of special inter<
mining officials endeavoring to reduce
duction costs to the minimum.
present day close competition in the m'
industry necessitates the use of only
equipment that will perform with gre
economy. For this reason many ur
nomical steam hoists are being replace
more efficient designs arranged for elect
operation.

Safety

One of the first considerations in 1
design should be an adequate provisio:
safety at all times and for all condition
operation. This is important not only

h)

drum, and the cone drum. The cylindrical drum is of uniform
diameter throughout its length, and is widely used for medium and
small hoists. It has the disadvantage of imposing a peak stress
on the power supply during the acceleration period. While the
cone drum begins winding the rope on a small diameter during the
acceleration period and gradually winds on an increasing diameter
as the load gains speed. The cone drum is usually limited to
large, first motion hoists in large, deep, mines. Another type
of winding device is known as the reel, on which a wide flat
cable wraps upon itself like a clock spring. This cable is made
by laying several round wire ropes side by side and lacing them
together with wire. The width varies from four to eight inches
and the thickness from half to five-eighths of an inch. This type
of cable is used for very heavy hoisting where the diameter of an
equivalent round cable would be so great as to require a drum of
unwieldly diameter to avoid kinking the round cable at the inner

portion of the bend as it wraps around the drum. See Pp. 26 A-B

for drums.

In the great majority of the larger mines the hoist is
provided with two drums or reels with the hoisting cables arranged
so that one goes down while the other is being raised. This ar-
rangement is known as hoisting in balance, on account of the fact

that the descending cage helps to raise the ascending load. The

illustrations on P. 26—A-B show this type of hoist.

In some mines the ore cars are run directly into
the hoisting cage which is fitted with rails, and the car and
are hoisted to the surface together. This arrangement is
preferred where the care must be run for an appreciable dis-
tance from the hoist to the mill or shipping point. In other
mines the ore is hoisted in a skip into which the ore is dumped
from.the car, which is usually of the end dump type. The skip
is usually arranged to dump automatically when it reaches the
surface, similar to the charging skip serving a modern blast
furnace. This arrangement is preferred when the ore can be
discharged from.the hoist into railway cars for shipment, or,

directly into the mill.

SURFACE TRANSPORTATION
When the mill or shipping point is at a distance of
from approximately half a mile to several miles from.the mine,
the ore must be transported over the intervening space by one

of the several systems of carrier available for this kind of

work.

One of the simplest methods is the team.and.wagon
which is still employed in some localities; usually in the

case of small mdnes, with limited output.

Where the roads are suitable, the truck us used to

some extent in localities where the life of the mine is not be-
lieved to be of sufficient duration to Justify the expense of
laying a track for cars. The truck like the wagon cannot be
profitably employed for handling large quantities of low grade
ore, but is suitable for mines yielding a relatively small quan-

tity of ore high in value.

When the mouth of the mine is at an elevation.above the
mill, or loading station, the aerial tram, or the surface tram.is
generally employed for distances of from.a few hundred feet to
several miles. The principal mines in the Telluride district are
so situated with respect to the mills or shipping points, that

the aerial tram system.is exclusively employed.

The aerial tram consists of a cable supported on towers of
steel or wood, carrying metal buckets of from.one-tenth to one-half
cubic yard capacity; This type of carrier has the advantage of
immunity from.trouble and delay from.the heavy snowfall usually
encountered in the mountain districts, and is independent of irreg-

ular or rough country.

There are two principal types of aerial tram. One in
which a single, traveling cable carries and propels the buckets,
and a second, and much more used type, in which two cables are
used, one being stationary and acting as a monorail track for the

supporting sheaves of the buckets, the other cable known as the

50.

traction cable which propels the carriers by means of detachable
grips. In the single cable tram.the cable is endless and runs

on a large sheave at either end of the system. In the other

type the traction cable is endless but the stationary cable may

be either endless or free at the ends. Neither the stationary

or traction cables are constrained rigidly at the ends of the
-_system, but are maintained at the proper tension by large weights
to allow for the change of length of the cables due to seasonal
changes of temperature. The traction cable sheaves are supported
on sliding ways to allow for this take up, and are placed with
their axes vertical or inclined such that they are perpendicular to
the plane of the two branches of the cable. In most of the modern
tram.systems, the buckets dump automatically as they come to the

unloading point.

‘When the inclination of the tram is sufficient, as is
often the case, the weight of the loaded buckets is sufficient to
return the empty buckets without the expenditure of power other
than gravity, and in some cases the inclination is such as to re-
quire a braking system to prevent overspeed. In other cases the
inclination is not sufficient to overcome the frictional resistance
and some additional power is necessary to operate the system.

There are exceptional cases where the tram.is level or up hill in
the direction of the load but these conditions are avoided where

possible. The topography of the locality is the deciding factor

31.

in each case.

The surface tram.is similar in its operation to the
aerial tram.except that it requires a track laid on the surface
of the ground on.which cars or skips are drawn. When the in-
clination of the line is sufficient to enable the cars to oper-
ate by gravity, preferably over 5%, the usual arrangement is to
use two cars, one attached to each end of a cable running over a
sheave or capstain at the upper end of the track. The cable
being of such length that one car will be at the top of the incline
when the other is at the bottom. For the sake of economy in the
cost of the track it is usually made with a turnout midway between
the ends and the portion below this is a single track, while the
portion above the turnout consists of three rails. The center
rail forming a common side for each car. he three rail arrange-
ment above the turnout is necessary to enable the returning car to
avoid contact with the cable of the other car. While below the
turnout there is never more than one car and no interference is
possible. In cases where the inclination of the line is less than
the above, a tail rope is attached to the lower end of each car
and carried over a sheave at the lower end of the track. .A motor
is employed to drive the winding sheave, and the tail sheave insures
the descent of the opposite car. These systems have the disadvan-

tage of interference from snow but are otherwise very satisfactory.

See Pp. 32 AAB-C-D-E for illustrations of aerial trams.

MINE DRAINAGE
The subject of mine drainage is of a rather serious nature
in many mines. The great majority of mines form.natural sumps for
the accumuhation of water. In some mines the amount is relatively
small while in other cases the problem of drainage has been the
direct cause of abandonment of mines on account of the expense in-

volved in this phase of the operation; long before the ore deposit is

exhausted.

Like every other phase of mine operation the removal of water
from.a mine is influenced by local conditions, and requires careful

consideration of the details involved in this branch of hydraulics.

The mine which is so situated that it is entered by means
of an adit which inclines downwards from.the workings to the mouth,
is particularly fortunate with regard to the matter of drainage, as
the water which accumulates will flow out of the mine by gravity, and

the expense of pumping is avoided entirely.

The Tomboy, Liberty Bell, SmuggleréUnion, Black Bear, and
other mines in the Telluride district enjoyed this advantage, as have
nunerous other mines in various parts of the country. The majority
of mines are so situated that the workings are below the level of
natural drainage facilities, and the water must be lifted in some man-

ner to the point of disposal which may be at the top of the shaft, or

 

 

 

 

 

 

 

 

The Leschen Systems

Catalog No.T ‘25

were
1&7?

{3:

Designed and Maz'ua‘acwred by
A. LESCHEN & SONS ROPE CO.

ESTABUSHBD 1857

5909 Kennerly Avenue
ST. LOUIS. u.S.A.
New York Chicago Denver

San Francisco

 

 

.Poge 32/4

in "I

 

 

Page 32 5

The Leschen Systems of Aerial Tramways

 

 

 

 

'4 Firm:

 

For the disposal of mine waste, the only available location here was a ravine between two
almost parallel ridges. Quite a problem was presented as unusually high towers would have
been necessary to secure sufiicient dumping area. The problem was solved b designing aerial
saddles which are sugported by ropes stretched across the ravine from hi lside to hillside.
This is on one of the ve Leschen tramways of the Fordson Coal (30.. located near Stone. Ky.

Page Twelve

 

Page. 32 C

The Leschen Systems of Aerial Tramways

 

The Hugh Nawn Contracting Company. who built the Gilboa Dam of the New York City Water

Supply System. used three Leschen Tramways for handling crushed rock. sand and cement.

The installation here shown carried crushed stone from quarry to mixing plant. It is approxi-
mately one mile long and its capacity is 150 tons per hour.

 

Page Fourteen

 

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. Page 32 D

 

interior of a loading terminal showing the double groove drive sheave and idler.

Page chcnleen

 

 

 

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Frequently the only available space for disposing of mine waste is on the o posite side of a
ridge from the tipple. An aerial tramway is then the perfect solution of t e problem. An
example is this installation of the Consolidation Coal (10., at Coalwood. W. Va.

 

 

lodge 32 E

The Leschen Systems of Aerial Tramways

 

 

 

 

A group of miscellaneous carriers. showing the variety of material that can be handled with an
aerial tramway.

Page Twenty

 

to some point between the workings and the top. Both of these

conditions are met with in the mines of the Cripple Creek district.

The Portland mine in this locality had the advantage of
being near enough to an outlet known as the Roosevelt Tunnel, to
utilize this outlet by driving a lateral to connect the mine with
the tunnel. This lateral was driven from the twenty-first level
(2100 feet below the surface). This plan eliminated twenty-one
hundred feet of lift in draining the workings after the mine had
reached this depth. Previous to this the water had to be raised
to the surface. The lowest portion of this mine is now thirty-
three hundred feet below the surface, or about twelve hundred feet

below the drainage lateral.

The Vindicator Mine in the same district was at such a
distance from.the tunnel that it was out of the question to try to
connect with it, and the water which collected in this mine in large
quantities had to be lifted to the surface. At the time of the
writer's visit to this mine, water was being pumped eighteen hundred
feet to the surface in the amount of about five hundred gallons per
minute at a cost of over one thousand dollars per month. The pump
room of this mine was excavated in the solid.rock, similar to the
illustration on PI ii A, and contained three horizontal, triplex,

motor driven pumps similar to the one shown herewith.

 

. .
.eh

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N..Vv.\k7l> ,flv. 4 pa.

 

51+.

The expense of installing pumps of this type at such
a distance underground is a large item. First, the pump parts
must be designed to keep the weight and size within certain
limits to accommodate the dimensions of the hoist cage and the
load it will safely carry. This means that such parts as the
frame, sub-base, main gear, and similar parts must be section-
alized and provided with bolt sockets and flanges to facilitate
assembly. Design of this kind is very different from that for
surface operation, as the mine passages limit the size of parts to
the existing space, and the clearances must be determined and
the measurements furnished to the pump designer before he can be-

gin his part of the work.

The variety of pumps employed.in mines in different
localities include practically every type of pump on the market,
as well as special designs. In the earlier practice the plunger
pump with driving crank on the surface with long rods extending to
the cylinders which were placed at the collecting sump, was the
comon choice. These pumps had the advantage of surface instal-
lation for the driving machinery and could utilize any convenient
type of power available. They would operate successfully with
the cylinders submerged and gave very little trouble, but the
great'weight of the long rods often necessitated counter weights
which added to the inertia of the reciprocating parts. The speed

of these machines was necessarily very slow. The first cost was

also high. A striking example of the cost of installation
and operation of this type of pump comes from a large mine

in California where a battery of these pumps were installed
at a cost of 91,500.000.00 exclusive of the foundations, to
lift 5hoo gallons per minute, a distance of 1070 feet. The
cost of operation was $59,200.00 per month. The weight of
the moving parts including the pump rods was 360,000# for
each pump. There were eleven pumps in the complete installa-
tion. Some of these old pumps are still in operation in
different parts of the country but they are being replaced by
turbine centrifugal pumps, or self contained plunger pumps of

the triplex, or quintiplex type, with motor drive.

The direct connected, motor driven, multi-stage tur-
bine pump is the most compact type as regards floor space and
is fact becoming the general preference in modern mine service.
Pumps of this type are capable of raising water 3500 feet, but
it is generally found desirable to relay the water by means of
a series of pumps one above the other and avoid the tremendous
pressures imposed on the stuffing boxes and pipe connections in
deep mines. Lifts of from.five to eight hundred feet are satis-

factory.

A special type of pump known as a "Sinker" is employ-
ed to unwater mines which have lain idle for some time and become

submerged. The sinker is a compact type of centrifugal, motor

\N
O\
o

driven pump with a vertical shaft, it is suspended from.a
cable and lowered to the surface of the water, and.gradually
lowered as the water level lowers. It is fitted with hose
for the discharge instead of pipe. In some cases where the
quantity of water to be removed is not great, as in the case
of lowering the drainage sump as the workings become deeper,
an ordinary duplex boiler feed pump is utilized by attaching
an air hose to the steam inlet, and another hose to the dis-
charge and lowering it into the water by means of a cable.
Such a pump will run submerged and mahes a very satisfactory
sinker for temporary work while the regular pump is being

lowered to the new level.

The selection of a pump for mine service often in-
volves a problem.in materials of construction. Many mine waters
are strongly acid and an iron pump which would be entirely sat-
isfactory in a domestic water supply would be rendered useless
in a short time if installed in a nuns to pump acid water. It
is usual to make an analysis of the water in each individual
mine before investing in the permanent pumping plant to ascer-
tain the conditions to be met. 'Various bronze and other alloys,
porcelain and.rubber linings, and certain special alloy steels
will resist the action of different impregnated mine waters.
Pump manufacturers can produce alloys suitable for mine service

if given the analysis of the water native to the given locality.

57.

In some mines the water carries sand or silt in
suspension, which condition is a serious one on the life of
a pump. In fact a reciprocating pump would be out of the
question in such a case, and a centrifugal pump has its life
shortened by the abrasive action of the gritty mediunn A
method has been employed in several mines which is prdbably
the simplest remedy for this difficulty, and consists in a
series of settling sumps through which the water travels so
slowly that most of the abrasive content settles out and undue
wear on the pump is to a great extent prevented. The soft
ground workings in the Leadville district proved troublesome
in this respect, as the water carried both sand and silt, and
the decantation method proved very satisfactory in this local-
ity. In the hard rock mines the water is apt to be relatively
' free from.abrasive matter, although it is met with in some

localities.

Displacement pumps operating on compressed air have
been used to some extent in the removal of mine water and
though simple and cheap to install they are expensive to
operate. A modification of the simple displacement pump
known as the return.air system is more economical in the use
of air but requires a complex system.of reversing valves. This
system.takes advantage of the work of expansion, while the

simple displacement system cannot utilize this saving.

58.

The air lift is employed to a limited extent in some
mines but is not as common as the mechanically operated pumps
previously described. Its efficiency is lower than the ordinary
pump, and the ratio of submergence to lift is such as to render
its use unsatisfactory in the case of a shallow sump and high
lift, although it is possible to operate the air lift on less
than two per cent submergence, as was determined in the Tire
Genera1.Nune, at Charcas, Mexico, where an air lift delivered
water at a height of ten hundred and seventy feet with twenty
feet submergence, or 1.8%. It required 29.7 cu. ft. of free
air per gallon and the efficiency was very low, being less than
ten per cent. ‘With a submergence of twenty per cent the ef-
ficiency was about thirty per cent. The reader is referred to
"Compressed.Air Plants" by Peele for information relative to

pumping by means of compressed air.

In some of the small, shallow mines, in which the ac-
cumulation of water is but a few gallons per day, the cost of a
pumping system is not Justified.and a simple expedient is to bail
the water out at intervals by means of a metal barrel with a
flap valve in the bottom. This barrel is lowered down the shaft
the same as a cage and as it descends into the water it fills
through the bottom and is hoisted to the surface. It is necessary
to have the sump as an extension ofethe shaft for this method of

water removal.

THE MILL
In the preceding pages consideration.was given to the
principal operations involved in the removal of ore from the
mine. Following this there is another series of operations
required to separate the valuable product from.the worthless
rock, or "Gangue" with which it is intimately combined in the
ore body, and to prepare it for market. The building and equip-

ment employed in this process is known as a mill.

Mills are divided into two classes relative to ownership
and management. One class representative of the mills owned.and
operated by the mine as a feature of the surface plant, and the
other class known as custom.mills, or mills separately owned and
purchasing ore from.mines on the same basis as a flour mill buys

wheat.

The custom mill is a necessary adjunct to small mines
which cannot incur the expense of individually owned mills, but
Can ship the ore to the custom.mill for treatment. .Another reason
for the existence of the custom.mill is that many mines are situated
in localities where water of sufficient purity for use in the mill
is not Obtainable, and one indispensable operating medium.in a
mill is an ample supply of good water. It is out of the question,
therefore, to establish a mill where good water is scarce, no matter

how favorable the other conditions may be.

ho.

In the case of large deposits of low grade ore, it is
usually necessary to construct the mill near the mine and if neces-

sary employ a pipe line to bring water to the mill for process work.

In general, the milling process is a complex problem.
involving both chemical and physical processes. It is unusual to
find gold or silver existing separately in an ore body, but it is
generally found in combination with such other minerals as copper,
lead, zinc, iron, etc., and the problem.of separation of these
metals from.aach other is sometimes more difficult than their sep-

aration from the ore.

The various processes employed in the mills of the coun-
try at large would require dozens of volumes to describe, and there
are many ore deposits still awaiting the discovery and development
of new processes as yet unknown, to render their recovery profitable.
The metallurgical chemist has a field in thta phase of industry which
is broad and interesting and productive of new methods and processes
that make possible the recovery of valuable minerals which the pro-

cesses of yesterday failed to recover.

Previous to the selection of the mill equipment a thorough
analysis of the ore must be made to determine the type of treatment
to which it will yield, and the kind and type of machines and pro-
cesses must be based on this information, 'Even.with these precautions

it may be necessary to make changes in the method of treatment from

#1.

time to time on account of changes in the nature of the ore as

the work in the mine advances.

Although each mill generally differs in some respect
to practically all others in size, proportions, arrangement of
equipment, and capacity, there are two basic classifications which
include milling practice in general, namely; the cyanide process
and the concentration process. Under certain conditions these two

processes may be combined.

The first step in the milling process in general, that
of crushing the ore is similar in either process when hard rock ore
is being treated. The selection of crushing equipment is a matter

requiring good Judgment and careful study of the nature of the ore.

The mechanism of crushing may be illustrated very simply
and effectively by the following experiment. Place a piece of
ordinary chalk about half an inch in length, on a table and strike
it with a light hammer. It crushes with a large portion of fine
particles among which are many small pieces not pulverized. If
given a second blow with the hammer the fine material packs and
very little additional crushing effect is produced on the coarser
particles. Succeeding strokes do relatively less in the way of
pulverizing the last few pieces. Repeat the experiment, but
after the first blow slip a spatula under the mass of fine and

coarse particles and transfer them.to a sieve. Screen out the

#2.

fine particles and place the remaining coarse particles on the
table, striking them.with the hammer. The second blow produces

a very complete crushing effect on account of not being resisted by
the bed of packed fine material as was the case in the first ex-
periment.- This demonstrates the all important fact that if the
crushed product is removed as fast as it is formed the work of
crushing is greatly diminished, and the cost of this expensive
operation is diminished accordingly. Consequently crushing is
usually performed as a series operation. When the ore is brought
into the mill it is dumped on a "Grizzly" which is a heavy screen
consisting of bars much the same in arrangement as the grate of a
hand fired.boiler furnace, and so inclined that the chunks which do
not fall between the bars will roll off the end to the coarse
crusher. The portion which goes through the grizzly being trans-
ferred to the intermediate crusher, or if it contains a relatively
large proportion of fine material it may be again screened and the
finer portion transferred past the first intermediate crusher to a
third stage in the series. This eliminates the lost work which
would occur if all the material were sent through the first crusher.
When the product has been reduced to the consistency of coarse sand
it is usually finished in ball or tube mills which reduce the
particles to a size such that they will pass a two hundred mesh

screen, that is, one having h0,000 openings to each square inch.

hi.

Not all ores require such extremely fine pulverization, but the

majority do when the cyanide process is employed.

The first crusher to receive the ore when it comes
to the mill is known as a JaW'crusher. One make of which is
shown on.Pag§ hfieA. This type of crusher is economical in
first coat and easily repaired. Another type which is often
used when the ore comes to the mill in suitable sized pieces is
the gyratory crusher shown on P, hi B-C. This type of crusher
is usually employed as a second crusher following the Jaw
crusher, but may be used as the primary crusher in localities
where the ore is suitable. The ball and tube mills are shown
on PI hi-D and are used for fine grinding. The stamp, which is
one of the oldest types of crusher is still employed.with certain
kinds of ore, and performs the crushing in one stage. It is emr
ployed in the Homestake mill at the present time on account of the
nature of the ore found in that locality. Its use was almost uni-
versal in the early milling practice but experience proved other

methods of crushing better adapted to many of the ores. See illus-

trations P, hfiéE.

Screens for classifying the crushed ore from.the coarse

and intermediate crushers are illustrated on P, h: F-G.

Following the crushing process the ore proceeds to

either the cyanide process or the concentration process. The

Page 43/4

Over
CONCENTRA TING EQUIPMENT

...—A1.- ___V‘_...

Cut 15271

f w p . ._ '.
l \Ih' ‘
.~ I

'pw

.‘d‘.

 

'i.’ .‘.J ' .

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84' x 66" All Steel Jaw Crusher, Rear View and Fly Wheel Side.

ALL STEEL JAW CRUSHER

In some locations conditions may exist which make it desirable to use a crusher where
a large receiving opening must receive first consideration due to the steam shovel opera-
tions in order to solve the labor problem, and the demand for finished product does not
warrant the installation of a gyratory crusher having a receiving opening large enough
to take care of the steam shovel feed on account of its large capacity.

Therefore after a careful study of these conditions, and with the knowledge gained
from the many years of experience in manufacturing crushing machinery to guide us, we
have designed a jaw crusher which has met these conditions to the entire satisfaction of
the many users of this class of crushing equipment. For further information and a more
complete description of the jaw crushers manufactured by the Allis-Chalmers NIanufac-
facturing Company, send for Bulletins 1810—A, 1827 and 1451-C.

21 No. 107—11

Page 43 5",

LLIS-CIIALMERS MANUFACTURING COMPANY

 

 

World’s
Record
Crusher

. 17..» .‘
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60" A-C Superior McCully Gyratory Crusher.
Two of these were built for Chile Exploration Co., Chuquicamata, Chile.

No. 107—A ' 22

 

 

\OmVQLfl-fitht-I

JIILTVAUKI'JE,

Cut No. 9270

IVISC'ONSIN, U. 8.

Page 43 C

 

General Sectional View of Style “K” Gates Rock and Ore Breaker.

LIST OF PARTS FOR STYLE “ i” GATES ROCK AND ORE BREAKER

Bottom Plate
Bottom Shell

Top Shell

Bearing Cap

Oil Nipple and Cap
Spider

Hopper

Eccentric

Bevel Wheel

Brass Wearing Ring
Bevel Pinion

Band Wheel

Oil Bonnet

Dust Ring

Dust Cap

Head

Concaves

Wearing Plates
Upper Wearing Plate

Main Shaft

Upper Ring Nut

Lower Ring Nut

Countershaft

Spout

Oiling Chain

Outboard Bearing Base

Outboard Bearing Cap

Outboard Bearing Oil Nipple
and Cap ‘

Countershaft Collar

Dust Door

Bottom Plate Cover

Spider Bushing

Shaft Bushing

45A Shaft Split Nut

46
47
49

 

Gil) Key for Split Nut
Clamp Bolts for Split Nut
Oil Plug in Dust Cap

fi?‘;

 

Concave Supporting Ring

Main Shaft Collar

Zinc Keys—Poured in Place
by Owner

Key Concave

Narrow Ke}r Concave

Babbitting Sleeves

Babbitting Mandrel for
Countershaft Bearing

Side Dust Door

Side Dust Door Handle

Split Nut for Clamp Bolt

Oil Feed and Drain Pipe

Oil Pump

Telltale Pipe for Eccentric
Filling Pipe

Telltale Pipe for Countershaft
Headeenter or Core

Mantle

No. 106-A

A L L I S - C H A I. J! E R S J! .1 N L' I" .1 C T L5 In’ I N (1' C 0 .ll 1’ A .V Y

GATES ROCK AND ORE BREAKERS

The Gates Rock and Ore Breaker was designed to overcome some of the objections
to jaw crushers, such as limited capacity, unbalanced crushing stroke, etc. Some of the
first Gates Breakers built are still in regular use at the older metallurgical works which
is the best evidence that these machines were originally well designed, of good work-
man ship and materials.

The Gates Breaker is a better balanced machine than the jaw crusher, and crushing
throughout the entire movement of the gyrating crushing head. is more economical of
power. By reason of the large bearings and well designed head. heating is reduced to
a minimum. The Gates Breaker will crush more rock for the same horsepower than
any breaker on the market.

The total area of the feed opening is greater in the gyratory breaker than in the
jaw crusher for the same maximum size of feed, and consequently gyratory crushers are
more economical to install for large capacities, one gyratory often doing the work of
several Blakes. The head room for a single gyratory crusher is less than that required
for several Blake crushers of equal capacity if the feed or product has to be spouted
from or to one place.

Large gyratory crushers are often arranged so that mine cars can be dumped di-
rectly into the hopper. They cannot be choked by the spider being covered and the
dumping can easily be arranged from any angle.

This breaker can be procured in either the right angle or regular drive. The regular
drive is shown on page 34. The right angle drive can be made left hand or right hand.

WHY A STYLE “K” GATES ROCK AND ORE BREAKER IS BEST:

REQUIRES LESS PO\\'ER TO OPERATE. This machine will break more
rock per horse-power than any other ever made.

EASE OI: l“El.£l)IN(i. The style of Spider gives large and unobstructed feed
openings. which does away with clogging and consequent loss of time in working.

UNOBSTRUCTED I)ISCI‘-I.~\RGE. No limit of capacity at this point.

HIGHEST RANGE O l“ ADJUSTMEN'I‘. Provides ease in changing the size of
product and great facility for taking up wear of the breaking surfaces.

TOP SUSPENSION OF SHAFT. Prevents the bottom bearings running hot un-
der the hardest work and makes adjustments easy.

STRENG'I‘II ANI) lx’I(_}ll)l',l‘Y. Due to the liberal prcq‘mrtioning of the parts.

C(Z’)(i)l, RUNNING. Because of extra large bearings.

EASEVOI“ MAINTENANCE. Every detail has been carefully worked out and
every part particularly designed to do its work. Each part is accessible.

CONCAVES CAN BE CIIANGEI) \\'I'l‘_ll(")[,"l‘ l‘)ISTURBlNG TlIE SPIDER.

Impossible with any other kind of breaker.

N 0. 106-.»‘1 3 6

CONCENTRA TING EQUIPMENT

 

Cut 21683

 

 

I

' ‘ o i
”an..-” ,_

 

 

 

 

6 - 5'x10' Allis-Chalmers Motor Driven Rod Mills, The Homestake Mining Co., Lead, S. D.

Cut. 16958

i
' l
| $

{fill

. ‘9

Mining”) ’
'1

 

 

Cut No. 5529

‘W‘ 2'. ’ .‘k'.‘ ‘A 1
’ . O. . ‘ ‘fi’
Q

 

.f%a76"¢£7£f

 

Front View Showing Stamps and Table Plates
Goldfield Cons. Mining Co.

 

 

'fllflarnooiltlj-

1m m.»

 

 

 

w ~— wfl’

Page 431‘

Over
ALLIS-CIIALMERS MANUFACTURING COMPANY

Cut. 4227

h,

       
 

.‘ . ,z' a. ‘
:'.' ii; ., ' g
9‘ Q ~ ‘
. s...
f l
‘3'

Plain Cylindrical Revolving Screen arranged for delivering
Three Products

TROMMELS OR REVOLVING SCREENS

Trommels, screens and sizers are used in every mill to a greater or less extent. They
must have capacity and efficiency with minimum power and mill space. The size, shape and
velocity, as well as the kind of screen covering, are dependent upon the character of the ore
and the machines following the trommels. Our trommels are made cylindrical, conical,
double conical, hexagonal, parallel, double hexagonal parallel and hexagonal tapering
and are designed for large capacity and good wearing qualities. They can be furnished
completely equipped for running in series from a single drive. Complete details given in

Bulletin 1436-B

\

I 7 -"‘.‘F
uunnuun. unzan‘nlfi.
uuonounnluuw.vthuelt

HHHHH’.‘ anuwututi.{'\§

o H.“ nu... c I‘ 1.! .i
.;1.“-L'IN lift

H ‘5 L. (HUILFHHICDOCQI'H
"" “‘"l-“Huuuouu
.,., 'd‘v“ .‘ 1

Am \,'\\. It;

. "all“

 

Perforated Sheet Metal
Information given in Perforated Metal Bulletin l425-A

N 0. 107—11 34

——~ O- ~ ~69“ MM_.A—. _.

 

Page 4.3 G

("ONCENTRA TING EQI'IPMl-JNT

GATES CLOSED END REVOLVING SCREEN

(Patented)

Cut 20114 I'CCdmL’ End

’

f

i I i 'i ' “Si'éfisa‘i‘éf-{i/I
wmssmsww / . .

 

.-\LLlS-CII;\I..\IIL'RS GATES CLOSED END Rl’A'OIA'lNG SCREENS
TABLE OI“ DIMENSIONS AND SPEEDS

 

 

 

 

 

Diameter RPAI. R.l’.\l.
in Inches Length in Feet Screen Drum Pinion Shaft
24 4, 6, 8,10,1‘2 2212 45
32 6. S, 10, 12, 14, 16, 13,20 2‘2 3")

40 8, ll), 12. 14, 16, 1S, 2“, 2‘2, ‘24 IS 45
48 S. 10, 12, 14, 16, 18. ‘20, 2‘2, ‘24 lti 40
60 8, 10, 1‘2, 14, 16, IR, 20, 2‘2, '24 12 41)
72 S, 10, 12. 14, 16. 18, 20, 2‘2, ‘24 ll 36

 

Cut 20116 .
Discharge End

 

33 No. 107—A

hh.

cyanide process will be considered first, and comprises four dis-

tinct steps as follows:

1. Preparation of the ore

2. Dissolving of the precious metal content by means of
a cyanide solution

3. Precipitation of the precious metal

h. Reduction of the gold and silver to bullion

Step number one has already been described under the

operation of crushing.

In step number two the pulverized ore is placed in large
tanks equipped with stirring or agitating‘mechanism, with sufficient
water and cyanide to carry the finely divided ore in solution. The
agitating mechanism.produces a violent stirring and circulation of the
mixture, which must continue anywhere from.a few hours to two or
three days, depending on the nature of the ore, before the metal is
separated from.the dross, or barren rock. This process is carried on
in two ways: the batch method where the solution is agitated in the
same tank for the period of treatment, or the continuous method.where
the solution travels from.one tank to another in series during the

process. he continuous process is favored in large mills.

When the gold and silver is dissolved in the cyanide solu-
tion the mixture is filtered to remove the pulverized rock content.

The filtrate is then run to the zinc box, consisting of a long trough

with cross partitions forming pockets in which zinc shavings are
placed. The zinc shavings precipitate the gold and silver from.the
cyanide solution which is then available for use in the further

treatment of ore. This constitutes the third step in the process.

The fourth step consists in the smelting of the precipitate
into bullion, after which it is ready to be sent to the mint for
coinage, or to the industries for manufacturing purposes, or employed

in the plating industry.

One cubic foot in volume of zinc shavings per ton of solu-
tion to be precipitated per twenty four hours is the usual allowance
for computing the size of zinc boxes in gold plants and a little less

volume for silver recovery.

The mechanical equipment of the cyanide mill consists in
general of: Grizzlies, crushers, conveyors, screens, agitators, pumps,
filters, precipitators, washers, and compressed air equipment for the
agitators. The selection of the correct size and number of units for
each operation in a large mill is not a simple problem, but a complete
~laboratoryanalysis of the ore is made to determine its properties as
regards crushing qualities, dissolving time rate, precipitation re-
quirements, etc. For example, if the ore is of such a nature that the
agitation will be complete in five hours, the agitation unit will be
relatively small, while, if the agitation period takes fifty hours to

complete, as is the case in some localities, the agitation equipment

M6.

would be ten times the former capacity. One serious consequence

of failing to properly proportion the equipment of a mill is tlat
the output of the entire mill is limited to the capacity of the most
inadequate feature of the entire installation, and the under loaded
portion of the equipment is operating at a loss, at the same time
representing over investment. It is true that changes and exten-
sions may be made after the mill is completed but such changes are
'usually expensive to make, and, as a general rule disturb the oper-

ating equilibrium of the plant.

A portion of a cyanide plant of small size is shown on
PI h6qA. Owing to the small scale and the single view the complete
equipment of machinery is not all shown but the general sequence of
the process is apparent. The ore car, (1) dumps upon the grizzly (5),
which feeds the jaw crusher (h). The chute (5) conveys the product
of the crusher and the fines from.the grizzly to the elevator
.boot (6), from which it is carried to the top of the building as
shown. From there it descends through screens and sampling machines
and the fine particles are separated, while the remainder is deposited
in the ore bin (9)," and fed from this to the stamp mill (11), prev-
iously described. From the stamp mill the ore goes to the tube mill
(1}), which discharges into the classifier (16), from which the fin-
ished fines are sluiced out in suspension with water while the coarser
sands are returned to the tube mill for regrinding. The classifier

as the name indicates acts as a separator for the finished product

 

Page 4% A

MILIVAUAE'E, WISCONSIN, U. S. A.

are drawn into the transfer-pipes and spouted on the surface of the pulp in the “agita-
tion circle.” In the usual treatment mixture, two of solution to one of the solids, the.
pulp has a specific gravity of 1.26. This pulp stands in hydrostatic balance with the
clear solution within the diaphragm, and thus the level of the clear liquid is above that
of the pulp outside the diaphragm. This clear solution overflows continuously into an
annular launder around the upper edge of the diaphragm, from which launder a pipe
connection conducts it to the next adjoining tank toward the head of the series.

The pulp flow in the series of tanks is from head to tail and the separated solution
from tail to head. The solution becomes richer as it flows from tank to tank and the
solids become more barren as they proceed towards the last tank. The pregnant solu-
tion flowing from the head tank goes through the clarifying boxes and thence to the
zinc room, where the values are precipitated out of the solution which is then returned
as “barren” solution to counter-flow again against the pulp as before.

These tanks are designed for any daily capacity from 5 tons upwards. There are
no bridges, or side structures, belts, gears, interior or exterior moving parts, or centri-
fugal pumps.

Vertical Section
CYAN I I) E P LANT

for the

 

 

 

Bunker-Hill Mines Co.,
Tombstone, Ariz.

The Parral Tank System of Agitation used

 

 

Cut No. 12719

 

 

 

 

 

 

 

 

 

 

 

 

 

This cut illustrates the flow line through the machinery and
apparatus of a typical stamp mill and cyanide plant. The ore is crushed
in stages to pass a 200 mesh screen. passing in sequence through Blake crushers.
the stamp batteries and tube mill. The pulp is then thickened to the proper consistency
in Dorr Thickeners. from which it flows continuously into and through the No. 1 and No. 2
Parral Tanks where it is subjected to continuous agitation. All the soluble metals are dissolved
out of the solids and are brought into the solution in passing through these two tanks. The object
now is to separate the pregnant solution from the barren solids. This is done by alternate settlement, decanta-

 

 

 

tion and washing in three other tanks, two of which do not appear in the line shown in the cut. The decanted
pregnant solution 8098 t0 the zinc room for precipitation and the pulp to an Oliver filter which completes the treatment.
When properly designed a cyanide plant runs with the highest economy and efficiency from the first start—no “tuning up"
or alterations are required.

85 No. 106-11

ALLIS-CHALMERS MANUFACTL'RING COMPANY

Cut No. 10317

 

 

 

ZINC BOXES

We are prepared to furnish zinc boxes of any type or capacity, incorporating all
modern features in the design.

Cut No. 10332

 

ZINC LATHE

The Hampton zinc lathe is designed especially for cutting zinc shavings for zinc
boxes. It is automatic in operation and requires practically no attention.

No. 106-A 86

 

1+7.

which is so fine that it will remain in suspension with water and
flow to the large tank (22), which is the beginning of the cyanide
treatment described in the footnote under the illustration. The
filter (hh), is for the purpose of removing the gold or silver bear-
ing solution from the sands after the decantation is complete. The
zinc precipitation room is not shown in this illustration. .An imr
portant economic point in the construction of a mill is well illus-
trated in this installation, where advantage is taken of the gravi-
tational effect for working the material down hill, and the side hill
site permits of this with the minimum.of excavation for the building
and tank foundations. Many thousands of dollars can be saved in the
construction of a large mdll by the selection of a suitable side hill
location.
THE CONCENTRATION PROCESS

There are various low grade ores which owing to their come
plexity will not yield readily to the cyanide process, but are readily
recovered.by the concentration system. This method of treatment is
basically a mechanical separation rather than a chemical process, and
utilizes the specific gravity of the various minerals in the ore as the
operating:medium. The difference in specific gravity of various
minerals and their gangue, makes it possible to separate the constit-
uents of the are into their component parts, by agitation in water,
after having been liberated by crushing or grinding. The particles

of mineral and gangue arrange themselves in strata according to their

individual specific gravities. This is termed.gravity concentra-
tion and is more generally applicable to the majority of complex

ores than any other method.

Another property utilized in connection with concentra-
tion of minerals is the affinity between sulphide minerals and
emulsified oil, whereby the particles of sulfides are coated with
an emulsion of oil and air, causing them.to float in water. This
process is termed flotation and has found a wide application in

the treatment of sulphide ores.

In addition to the above, the magnetic properties of cer-
tain minerals may be utilized to separate them from.the gangue, or,
in some cases, to separate two minerals, one of which is magnetic

and the other non-magnetic.

In the concentration process the first step - that of
crushing - is the same as in the cyaniding process, except that in
some cases it is not necessary to crush the ore to the same degree
of fineness. A laboratory test will usually determine the degree
of fineness necessary to facilitate the separation of the minerals
from the gangue, and the minerals from.each other. One defect of
the concentration process is that it will not separate ndnerals
having the same specific gravity, and if an ore is encountered con-

taining minerals of like specific gravity some other process must

be employed to separate them, _ Fortunately this condition is not

of frequent occurrence, but when encountered it is sometimes dif-

ficult of solution.

Many of the ores treated by the concentration process con-
tain more or less earthy matter which when combined with water forms
what is called slime. The slimes are much like paint, or clay
wash, in that they'are not gritty like sand. The slimes are objec-
tionable in the concentration process and various methods are emr
ployed to separate the slimes from the sands. The fundamental plan
is to stir the mixture of sands and slimes'by some kind of a mech-
anism, at the same time running water through the mixture in such a
way that it will dissolve and dilute the slimes to such an extent that

they'will remain in suspension and flow out with the water.

One mechanism employed for this purpose is known as a clas-
sifier, a familiar type of which is shown on P h eA. The action of
the rakes in.mcving the sand towards the upper and opposite the direc-
tion of the water act both as agitators and conveyors and deliver the

mineral sands to the concentrating tables free from the Objectionable

slimes.

The concentrating table, P, #243 is an important feature of
the concentrating mill equipment. There are several different makes
on the market but all have the same action. The table top is given
a reciprocating motion by means of a linkage producing a variable

rate of acceleration. This motion will cause the mineral particles

[page 49/4

ALLIS-CHA LJIERS .lIANUFA CTURING COMPANY

Cut No. 10438

 

  

DISCHARGE

THE STANDARD DUPLEX DORR CLASSIFIER (PATENTED).
MODEL “C"

DESCRIPTION

The Dorr Classifier consists of a settling box in the form of an inclined trough open
at the upper end, in which mechanically operated rakes are placed to remove the heavy
material as fast as it settles, the liquid and slime overflowing at the closed end.

The rakes are carried by suitable hangers from bell cranks connected by rods to lev-
ers which terminate in rollers. The latter press against cams attached to the crank
shaft. The rakes are lifted and lowered at opposite ends of the stroke by the action of
the cams transmitted through levers and rods to the bell cranks. The horizontal motion
is produced by the cranks. The pulp is fed across the center of the trough and the sand
settles to the bottom after which it is advanced up the inclined bottom of the trough by
the scrapers reciprocating with a slow raking motion. After emerging from the liquid
the sand is discharged'from the open end of the machine with about 25 per cent moisture.

The present Standard Machine Model “C,” as shown above, has been designed with
a lifting device operated by a crank by means of which the lower end of the rakes can
be raised 10 inches to avoid draining the machine after a shut-down, when very heavily
loaded and started again from that position. The slime is prevented from settling by
the flow of the liquid as well as by the agitation near the bottom caused by the recipro-
cating motion of the scrapers, and overflows at the lower end of the machine.

The agitation produced, while ample to prevent the slime from settling, is not suf-
ficient to cause any sand to overflow with the slime.

The capacity of the duplex classifier depends upon the nature and per cent of the
solids in the pulp and the point of fineness at which the separation is to be made. When

No. 106-A 74

 

 

 

\\ MILWAUKEE, WISCONSIN, U. S. A.

Cut No. 12695

 

 

Cyanide Plant of the Russian Industrial Gold Co.,
Tschelabinsk, Siberia.
Furnished by Allis-Chalmers Mfg. Co.

Cyaniding Machinery

Cut No. 5530

 

 

 

 

 

 

 

‘ ‘
i ' ‘ , v _ n. '
M" . . --
. -

_’

 

 

 

Furnished by Allis-Chalmers Mfg. Co.
73 No. 1

 

 

 

 

-‘_

 

475x ‘ . ‘ ".

.l ll'ilflry in .lr‘lion

 

 

Phantom View of Wilfley Self-Oiling Head .Motion

 

 

 

 

 

 

 

zrwjuayuo

 

 

”xi/[€41 fl ”N

D

u.

97qu .3

50.

and sands to move along the table in the direction of its stroke.

water is allowed to flow continuously across the table at right

angles to the stroke and this causes the particles of lesser spe-

cific gravity to deflect from their straight line motion more than
those of greater specific gravity, resulting in a series of streaks of
mineral particles of different colors. Each color representing a par-
ticular mineral. The illustration on PI kg B-X shows by the wavy
lines the separation of the various products which.may be caught in
separate hoppers and transferred to bins by means of sluices or con-
veyors. The product of the table is not perfect but each.mineral
usually has minute particles of the finely divided rock adhering to

it, hence the name concentrate. It is necessary to smelt down the
mineral in order to refine it and this is usually done in a custom.mill
to which the concentrate is shipped from the concentration mill. The
prime object in concentration at the mine is to make a commercial sep-

aration to reduce the weight to be shipped and save on freight charges.

Another type of separator is known as a "Jig" and is employed
to separate slimes from sands and to separate sands of varying degrees
of fineness. pne type of Jig consists of a tank with a dividing
partition which does not extend to the bottom. On one side of the
partition is a stationary screen on which the sand, mineral, and slime
mixture is fed. On the opposite side of the partition is a plunger
or displacer which is raised and lowered by an eccentric at such a

rate of speed that it causes the water to surge up and down through

51.

the screen, washing out the slime which flows over a discharge
weir with the water. A second type of Jig has moving screens
which are rocked back and forth in the water as it flows

through the tank. The separation is practically as complete

in one type as in the other. The reason for the difference in
construction.being mainly a question of patents, although the
latter type is usually made in larger sizes than the former, and
for mills of large output a smaller number of units would be

installed.

The complete flow sheet of the new Homestake Mill,
P, fil-A, illustrates the sequence of the various operations in-
volved in the treatment of the ore peculiar to this district.
An exterior view of the mill is shown on P, 514B. The number
and size of the various units are shown on the flow sheet. The
three Traylor Jaw crushers (upper left) have a combined
capacity of seven hundred fifty tons per hour and are driven
by three one hundred twenty-five horsepower motors. The
two Simone crushers are each driven by a two hundred fifty horse-
power motor, while the six gyratory crushers opposite are
driven.by motors having a total of two hundred eighty horse-
power. The stamps require about five horsepower each, and the
rod.mdlls about one hundred horsepower each, while the tube mills
and classifiers require somewhat less than the rod.mills. This mill

employs a special cyanide process, while the Alaska Juneau

Metallurgy

Elli-en Sheff
ORE

(From hone-Fer runes)

   
 

8 t M Shaft
'ORE
(From skip. and Ohrcvgn
12' undergmund gnuznes)

i Surface crushing plan‘l' a+ am we

pp

EOrQ bm m headfmm

 

 

 

(Three underground 3 T |or jaw crushers
crush: etc-Hons) Was? is open ’
"9 M are. m9 2 NobAms- Chalmers
gyro-wry crushers.
. A 4" z’disc have. opening
x”) -
0a f \
k +
poc . s 2 Symon. 7'cone crushers. ‘ QMG‘All'3;C:;T‘¢n
~ °P“" ea or», r .
Ore shp 2V2 agharg. . "‘9 4'2 ydschorge opening
‘ Stewrlvskmagnehc
f f - ‘O ' I ' 'fi ' ' 0
Com rested-cur locomotive. E
hon 8

train: 0‘ 30 four-ion can

 

 

  
   
     
       

 

 

7100-90" sou». Hill
mill bin
Dorr
classlfier
' I20 fiat-ape
g
2 5'.“ Aim-out...
“" lubcfimus
. DO"
0 Tm"! classifier
B S'ufl'AlliI-Onlmen
red milk _
i 5.114 Allis'Cl'vlmrs
we»: 1 _ tube mill
1 E 16‘ Harding: hub:
mill

 

 

 

 

 

   

  

   
 

    

 

 

  
 

   
  

 

 

 

 

2920*“ Amicus mm moo-van gpxahwm
"Ml hrl ' '
mull bm "u”
Mercury ‘ . Mercury ~ ‘
| ‘7 240 sfamszJOO It | 5‘60 slump-95° lb-
AW‘MF "Chuck “x“ AMALGAM 4— H‘Chuck block
l 48 a .4? l
omal a- 32 $14 6'
MLGN'u— ”+3" D AMALGAM ‘- amigo-Mien
plates plates
l + Chip screen,
35p ‘ com‘ E71!“ openings
‘— w) l . .
. Q' s K). 4 54Ifi4
5 hr clasmfiers Ie‘Hlm Sand leach-
s fube mus (om? ing «m smo RESIDUE
1; gxg‘Alfs-Choha . lufion (sluiced)
I is-(lulmers f pnec M
‘- 1 5"d40emer Engm- 3 7} odopaflmx
«ring 92"“ 1
c —*To mill “ply tanks
Sadly dew?!
and
Don thickener:
13% 54'er

 

 

 

 

 

 

 

‘

 

' Mel‘h’ng furnace

 

5. __l_
i from}, V

cones

20 4
hydraulic

COHCS

 

 

 

 

 

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r——llf

Lime stamp mill
7- mesh screen

i E 3 Buii’QVS’ Mam dusflibufors
19 “Ric's-canal vafi

$Lim¢ mixer

  
  

Slime receiving vofs

31 Merrill (Mgr presse
each 90‘rames, 6":4 n4

SLIME PESIDUE

l
W”

 

l SAND Rescue (sluiced)
GOLD (sluiced)
Crowe vacuum
w “3123.?“
BARREN SOLUTION e l c] J ' ;BA"£N SOLUTION
‘ Zinc dust
EU Merrill press
i
- PRECIPITATE
. Flowsbeet of q... “a...

. . . Dry"

MI”: and C yamde Plant: t

at Lead, 3. D. ,
and Vicinity

B'Iquefhng machine

Lead cupel furnace

 

I
Dore‘ bul lien

‘fi
LITHARGE

Melhng furnace

GOL D

.F'age .575

 

PRIMARY CRUSHING
AUXILIARIES

 

 

Cut 18531

b
O

:-' -5rk'M ’5‘!

6

’ _
-

 
  

--—__ ’43,-
d

,,,”..v,.;-u§;4!31* .I.T rt":

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“34’. "

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New Mill and Cyanide Plant of Homestake Mining Co., Lead, South Dakota.

6 - 5’ x 10’ Allis-Chalmers Rod Mills installed'by The Homestake Company in this new mill.

  
   

"‘ if, ’ If

    
       
  

 

 

 

 

31

No. 107—A

ALLIS-CHA lullERS .llA .\' ('I-‘A C TI’RING ('0 .1! PA .V 1"

McCULLY ALL ROLLER TYPE OPEN END REVOLVING SCREENS

Cut2flfl2

Mounted on.‘\Vood Frame

 

Discharge End
Cut 20070

Mounted on Steel Frame

 

Discharge End

Al.LlS-Cl’l.\.l..\ll".RS .\lcCL’l.l.Y ALI. ROLLER 'l‘Yl’l‘l ()l’l‘lX l“..\'l) Rli\’()l.\'lX(} SCREENS
TABLE OI" .l)l.\ll"..\°Sl().\'S .‘\.\'D SPEEDS

 

 

 

 

 

 

l
Diameter R. P. .\1. R. P. M.
in Inches l Length in Feet Screens Pinion Shaft
48 ‘ 8, IU, 12, H. 16, 13, 20, 2'2, 24, 2O, 23 16 Sf)
60 10, 12, 14, 16, 18’, 20. 22, 24, 26, 28, 30 12 89.5
72 | If), 12, 14, 16. 18. 20. 22, 24, 26, 28, 30 11 S2
84 1 12, 14, 16, 18, 2f), 22, 24, 26, 28, 30, 32 9.5 72

 

N0. 107—;1 3'2

52-

mill, P. fiEeA, employs the concentration process. The flow sheet
of this mill illustrates the delivery of the ore to the mill and
the crushing equipment which is similar to the same feature shown
in connection with the Homestake Mill, but in place of the
amalgamation and cyanide apparatus the concentrator tables prev-
iously shown on P, hQAB constitute a prominent portion of the
equipment. It will be noted, however, that each of these mills
are so situated as to take advantage of the side hill location

for the advantage both in economy of construction, and gravity

flow of the product.

TEE CONCENTRATION OF COPPER ORES
The milling processes described in the preceding par-
agraphs are mainly for the recovery of the precious metals, but
the basic principles of concentration, and of precipitation from
solution, may be employed in the recovery of some of the baser

metals, of which copper is a good example.

The Utah Copper Company employs the concentration pro-
cess on account of the copper existing in what is known as the
sulphide state. The ore contains between one and two per cent
of copper, and must be handled in Large quantities to yield even
a small profit. 'Upwards of twenty five thousand tons of ore per
, day are handled.when the mill is operating at capacity. The ore
is crushed to a size of eighty to one hundred mesh and sluiced upon
vanners, which consist of machines carrying wide rubber belts on

rollers which are given an endwise motion perpendicular to the

F3793 52,4

ALLIS-CHALMERS MANUFACTURING COMPANY

Cut 139.39

 

 

 

 

Concentrating Mill, Alaska juneau Gold Mining Co.,
juneau, Alaska.

(‘ut 13893
(c‘ ”9'“. ”first new

    
  
 

 

      
     
  

     
 
  

 
 

 

   
   
  
  

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

z-Foul on r*
o'xs' mu MILLS i 5 ELEVATOR
@ 1001;? 51m 205R _ : - ‘aenspeea
on: an (gut --, ~ 4 - SHOVnyWHEELS
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Flow Sheet of Alaska Juneau Mill, Juneau, Alaska.
Example of Class 1, 3-1 Ores.

No. 107—A 10

 

 

Page 52 5

Flow Sheet Magna Mill,

CONCENTRA TING

Utah Copper Co., Garfield, Utah.
Examples of Class 1. 8-3 Ores.

Cut 13939

 

 

 

 

 

 

  

c0~cL~T!.AVt~Q
at

B "A? 0::
er.“ 02!. .ithi an

  

l—Mine Ore in R. R. Cars.
2—Car Dumper.
3——(irizzly 6' Opening.
4—N0. 27 Gates Crusher.
fr—t Apron Feeders.

6—2 - 60' Conveyors.
7—Grizzly.

8—3 No. 8 Gyratory Crushers.
9—60' Belt Conveyor.
10-—2 - 72'x20 Rolls.
ll—l2' Belt Conveyor.
12—8 Shaking Screens.
13—2 - 72'x20' Rolls.
14—36' Belt Conveyor.
15—2 - 36' Conveyors.
l6—Distributing Conveyors

over Bins.

17—Storage Bin.
18—2 Apron Feeders.
19—2 Shaking Screens.
20—12 Garfield Tables.

  
 
  
  

7. no.1],

21—2 - 37}~j'x15'
222—Bucket Elevator.
23—4 Shaking Screens.
24—Bucket Elevator.
25—«1 Wilfley Tables

(Cleaning Concentrate).
26—30' Bucket Elevator.

27—4 Primary Richard
Janney Classifiers.

28—2 - 6’ Chilian Mills.

29—2 Dorr Classifiers.

30—2 - 7’x10’ Ball Mills.
31——4 Secondary Richard

Janney Classifiers.
32—40 Vanners.
33-——Bueket Elevator.
34—2 Richard Janney

Classifiers.

35—8 Wilfley Tables.
36—8 Vannens.

IBQYAfiflgn D5l~1 ——

Rolls.

..__1

EQFIPMENT

‘ .

06

noes-hfi

Flow Sheet Britannia Concentrator,

Britannia Beach,

B. C.

Examples of Class I, A-3 Ores.

Cut 13938
@013

01" Q, “o.

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CD" might???

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l——2 Ore Bins.
2—C‘hain Bucket Sampler.
3—3 - 24'x12' Plunger
Feeders.
4—3 - X'x-t' Trommels,
1 [2" opening.
5—2 Pickimz Belts.
6—3 - 20'x10' Blake Jaw
Crushers.
7—2 - 48'x16' XX Crushing
Rolls.
8—3 - 40'x15' Anaconda
Type Crushing Rolls.
9—5 - 6’x3’ Trommels,
h” holes.
10—2 - 10' Bucket Elevators.
11—5 - 6’x3' Trommela
(1.5 m. m. holes).
12—2 - 14' Bucket Elevators.
13—2 Hancock Jigs.
14—5 Overstrom Tables.

 

V ozv lL‘L‘I‘ - A"

lS—Shipmcnt Bins.
16—10'x7' Bucket El-
lT—Two Compartmei
Dewatering Tank
lS—Slime Tanks.
19—4 - 36'x15' Style
Crushing Rolls.
20—8 - 7’xl2’ Granul:
21—16’ Bucket Eleva
222—3 Hydraulic Clas
23—4 Rougher Flotati
24—1 0 Cleaner Flotati
25—Shipment Bins.
2ti—Slime Tanks.
27—2 - 50'3”” Dorr '
era.

N o. 107—.

530

direction of the belt. This reciprocal motion of the rollers
combined with the movement of the belt produces a washing action
on the ore which removes the slimes and a portion of the barren
porphyry leaving the copper sulphide in a concentrated form
from.which it may be smelted into what is known as copper matte-'
an impure mixture of copper and sulphur - and the matte refined
to pure metallic copper. Page fifi-A illustrates the immense

mill in the upper view, while the two lower cuts given an idea

of the extensive equipment installed; a portion only of which is
shown. (See P, 32-13 for Flow Sheet). Fifty steam locomotives
were employed to transport the ore to the mall and the waste from
the mill, for several years, but recently the motive power is be-
ing changed over to electric locomotives, and the former steam

shovels are being replaced by electric shovels.

A class of low grade copper ores known as carbonates
are abundant in some localities, and are treated by what is known
as the leaching process, consisting of immersing the ore, which
has been crushed to about one-fourth inch mesh, in,a weak solution
of sulphuric acid, and allowing it to stand for several days until
all of the copper is combined.with the solution. The liquid is
then drawn off and the vats emptied of the residue. Fresh ore

is then placed in the vats and the process is repeated.

The production of copper in large quantities from.low

grade ore is attended by the necessity of loading enormous

Page JJA

 

CONCENTRATING TABLES
AND VANNERS

 

 

 

(‘ut 13R“?

 

 

 

 

 

 

 

Magna Mill, Utah Copper Co., Garfield, Utah
Cut 13885 Cut 13882

 

Lower Vanncr Floor, lsbcll Vannors Magma Mill, Second Vanner Floor looking west from section No. 1,

Utah Copper Co., Garfield, L'tah Isbcll Yanncrs Magna Mill, L’tah Copper Co., Garfield, Utah
75 No. 107—A

 

 

ALLIS-CHALMERS MANUFACTURING ('OMPAI

Cut 13873

 

Dcister—Ovcrstrom Diagonal Deck Table

DEISTER-OVERSTROM DIAGONAL

DECK CONCENTRATING TABLES
(Patented)

In the Deister-Overstrom Diagonal Deck type of concentrating ta
those principles of deck construction developed and perfected in the
and Overstrom tables.

The primary features of this construction are the Diagonal Dec
riflling. The combination of these gives the highest efliciency in .
high grade concentrate, a small middling and a clean tail.

High extraction and clean tails are secured:-- first, by the diagonal
line of travel naturally taken by the pulp, of the principal concentrating s.
which insures the pulp being retained thereon for the longest possibl:
rifles are placed parallel to the line of motion and at an angle to the tail
serving the advantage of deflected rifiles without the whipping action, ;
stratified mineral particles a free and unobstructed movement towar:
edge of the table.

High grade concentrates are produced by the spreading out in a thi
of the concentrate bed, thus exposing all of the fine sand or silica to the ac1
water. This “spreading out” feature is of special advantage in the prod
more mineral concentrate (as in the case of a lead-zinc separation),
minimum the middling between two minerals by eliminating the tro
lapping of the two kinds of concentrates.

Complete bulletin describing Deister—Overstrom Tables furnished (

 

- No. 6 No. 6 1 No. 7 No. 8
DEISTER ovmts'rnom TABLES Sud. Slime. ' Cm” Sam,
Size Feed ........................... +60 Mesh —60 Mesh —%" +60 Mesh —
Capacity Tons per 24 Hrs ............. 20+ 8-16 6-10 15+
Maximum Power .................... l H.P. l H. P. 1.5 H. P. .75 H. P.
Recommended Solids in Feed ......... 2070 20-25% 35’7n 20%»
Shipping Weight per Table Lb ....... 2675 2675 3400 2550
Shipping Weight Ocean Shipment ..... 3175 3175 3950 3050
Cubic Feet for Ocean Shipment ....... 173 , l73_ . _23§ __ 144

 

No. 107—A 76

 

 

51+.

quantities of materials into the vats for leaching, and the re-

moval of the residue.

Pagg fihqA illustrates a type of equipment in common
use for filling and emptying leaching vats. The upper illustra-
tion shows the filling bridge in the foreground, while the exca-
vating bridge is shown immediately back of it. The lower illus-

tration shows the excavating bridge in position to empty a vat.

In this particular installation each vat is one hundred
fifty feet long, one hundred ten feet wide, and.nineteen feet

deep, with a capacity for ten thousand tons of ore.

The filling:bridge has a span of one hundred fourteen
feet and is supported by towers on trucks similar to a gantry
crane. It is driven'by a one hundred horsepower motor. In the
foreground is shown the thirty-six inch trunk line conveyor, which
passes over tripper pulleys and discharges the ore through a chute
onto a transverse conveyor fitted with a traveling tripper which
enables the operator to discharge the ore at any point in the area
of the vat. The transverse conveyor and tripper are driven by'a
twentybfive and a five horsepower motor respectively. This ma-
chine operates on a five hundred volt, three phase, fifty cycle
circuit, and has a rated filling capacity of seven hundred tons

per hour.

The excavating bridge has a span of one hundred eighty

feet and is so proportioned that it will pass over the filling

THE \\ELI.“-\V-SIC\\'I‘ZIl-\l()n(3\V (I()\IP\VY. CI.IC\'ICI.\\'D. ()IIIU, li.S.\.

\I
\

 

 

 

 

55-

bridge to enable the two machines to change places for filling

and emptying the vats. The excavating bucket shown under the
truss has'a capacity for twelve tons of ore, and is provided with
two motors of two hundred twenty-five horsepower each, while the
bridge is driven by two one hundred horsepower motors. At the
farther and are two hoppers of sixty tons capacity each, which
receive the residue from the bucket and discharge into cars under-
neath. The hopper gates are controlled by twenty-five horsepower
motors. This machine will handle from seven hundred to one
thousand tons per hour, with a current consumption of approximately

one-half Kw. hour per ton of ore handled.

The mining methods of the Utah Copper Company are repre-
sentative of the low grade, large tonnage, open cut, copper mine.
There are other copper mines in which the ore is mined underground
by drilling and blasting, similar to the mining of gold and silver.
In these mines the ore contains a much larger percentage of copper
than is found in the Utah and similar properties. In other words
it is economically impossible to work underground copper deposits
of low grade on account of the extra expense of handling and hoist-
ing. Consequently, low grade copper deposits which are at a con-
siderable distance beneath the sm'face, await future economic
development in mining methods now unlmown, but there is every reason

to believe that the progressive engineer will solve this problem

as he has other problems which are now history.

The following table gives the output of the leading

 

 

 

gold mines of the world, listed in the order of output: (1950)
YIELD OZ.
NAME LOCATION OUTPUT TONS PER TON OF
_ Film 07.. 122.2.de 8:.
Government Gold...........Transvaal 11070k6 2&58658 .h6
Crown Mines............... " 92298 2905000 .52
New Modderfontein. . . . . . . . . " 862506 1811000 .h8
Randfontein Estates....... " 652575 2575000 .25
Hollinger Consolidated....0ntario h9h552 1625875 .50
East Rand Pty.............Transvaal #91095 2088852 .25
New State Areas........... kh5917 950000 .h8
Springs Mines............. " h08208 856700 .k9
Homestake'Mine............South Dakota h06000 156kh56 .50
Brakpan Mines.............Transvaal 591785 10h0200 .55
Lake Shore................Ontario 578690 550591 .69
Robinson Deep.............Transvaal 565781 1559000 .26
Langlaagte Estate......... " 526598 961500 .5h
Geduld Proprietary........ " 52288h 1011000 .52
City Deep................. " 506825 1157500 026
SUb N183100000000000000090 It 301l915 557200 085
Van Ryn Deep.............. " 297602 771000 .58
Modderfontein.B........... " 295517 8h0000 .55
West Rand Consolidated. . . . . " 290671 1087000 .25
Modderfontein Deep........ " 27h251 550800 .52
Took-Hughes Gold..........0ntario 260775 558555 .77
Consolidated.Main.Reef....Transvaal 258856 755900 .55
311111118]? 86 JaCko o o o o o o o o o o o 0 250,485 916700 027
‘Moddorfontein East........ " 2k21h9 855000 .29
McIntyre Porcupine........0ntario 225786 565510 .hO
Nourse Mines..............Transvaal 225198 760700 .29
'West Springs.............. 21805h 815800 .27
Geldenhu18 Deep. 0 c o o o o o o o 0 " 186256 811900 '25
Durban ROOdBPOOI‘to o o 0 o o 0 0 o u 172562 520000 03.5
AlfiSkfl Juneafig. o o o o o 0 c o o o 0 .Alaska 165512 59214-1460 .Oll2
R083 Deep...ooooooocooooooTransml 1558,41 733,400 .21
Ashanti Goldfields........Gold Coast 151666 129579 1.12
Witwatersrand.............Transvaal 1h5555 659500 .22
New meiflonteino o c o o o o o o 0 155192 619200 .22
lake View & Star.........West.Australia 52578 157695 .8h
Cam 8!: lVlOtOI' o o o o o o o o c o o o o osoutththeSia. 128656 285000 a 14-5
St. John del Rey..........Brazil 121000 226800 .55
Van Ryn Estate............Transvaal 11902k M96000 .28
‘Wright Hargreaves.........Ontario 117hh5 220h50 .55
Noranda Mines.............Quebec 117258 755971 .16
Mysore Gold...............India 101551 215728 .hh

57.

From the foregoing table it will be seen that with
the exception of one mdne of the forty one listed, the recovery
of gold is less than one ounce per ton of ore handled. These
figures are for average output over a period of one year and are
representative of results for several years for the majority of
these pr0perties. A favorite trick of many mine promotors is
to exhibit a particularly rich piece of ore as representative of
the entire deposit and sell stock at a high price to unsuspecting
investors. The writer once saw a piece of ore from the Portland
Mine in the Cripple Creek district, weighing about fifteen pounds
which contained approximately three hundred dollars worth of
gold, or, approximately nineteen hundred fifty ounces per ton of
ore, which would mean nearly forty thousand dollars per ton of
ore. People marveled at the fabulous wealth indicated by this
sample, yet this mine averaged much less than one ounce of gold
per ton throughout its productive life, and was on the point of
abandonment several times because of the low grade of the ore be-
ing mined. The Cresson.Mine in the same locality contained a
"Vug" in which several hundred thousand dollars worth of nearly
pure, metallic gold was found, and yet this famous mine yielded
but a very low average profit over its operating life. Gold ore
is apt to be erratic in its distribution, but in the case of some
mines, among which the Homestake is a notable example, the quality
of the ore runs almost uniform.through the greater portion of the

deposit.

58.

PLACER MINING.

In some parts of the country large beds of loose
gravel and sand intermixed with particles of metallic gold are
found, and are known as placer deposits. In this case the gold
is in no way attached to or combined with the gravel and the re-
covery of the gold is merely a separation process. One common
method of placer mining is to employ a dredge, the hull of which
contains the screens, washers, and tables employed in the separa-
tion of the gold from.the gravel. To the front end of the dredge
is attached an excavating elevator which delivers the gravel to the
separating equipment, at the same time creating a canal in which the
dredge moves slowly ahead as the work progresses. The worthless
gravel is deposited at the stern of the dredge by a corveyor. In
working a placer deposit the dredge moves back and forth parallel
to each previous trip until the entire area has been worked. It
is necessary to have sufficient water to float the dredge and for
use in the separation process. Usually water exists in the deposit
in sufficient quantity, but if such is not the case it must be ob-

tained from.aome other source.

When the placer deposit exists on a hillside a method
known as hydraulic mining is usually employed. This consists in
playing a stream of water from.a nozzle on the bank, washing the
gravel down into wooden gutters with little pockets in the bottom
containing mercury. The mercury catches the gold particles, forms

ing an amalgam, while the gravel and sand is carried away by the

water.

59-

COAL MINING

A phase of the mining industry which is widespread in
its application is the mining of coal. In this field the mining
is practically the only operation required, as the product does
not require treatment in a mill, therefore, this latter feature
which is a necessity in metal mining is not found in the coal
fields. However, in the majority of coal mines the grizzly is
usually included to separate the slack from.the lump coal, and
in some cases the revolving screen is employed to grade the product
to a variety of sizes, to which the trade terms of buckwheat, pea, nut,

egg, lump, etc., are applied to indicate the size of the pieces.

The removal of coal from the mine is very similar to that
of ore in the metal mine as regards the handling and hoisting. Me-
chanical loaders are employed where space will permit, and cars pro-
pelled by animal or motor power are used. Some coal deposits may be

reached by means of an adit and hoisting is eliminated in such cases.

The breaking down of the coal is somewhat different from
the breaking of ore, although in.many oases blasting is employed, but
an auger is usually used to make the hole for the explosive, and black
powder is usually employed instead of a high explosive like dynamite.
A high explosive shatters the coal, while the slower burning powder
exerts more of a heaving action and produces less slack. Some at-

tempts are being made to develop pneumatic expanders similar to a

60.

piece of rubber hose without the fabric common to the ordinary hose.
This hose is closed at one end and the opposite end connected to the
compressed air pipe. It is then inserted in the auger hole and

the pressure applied, causing the hose to enlarge and break the

coal without shock. This method seems to be in the experimental

stage at present.

In mines where the coal exists in large beds, the coal
cutter is often used, one form of which consists of an endless chain
running on a sprocket wheel at each end of an arm.attached to a
wheeled base. This arm.is attached to the base by'a hinge which
enables it to be swung like the boom of a crane. The chain carries
cutting blades, and the base is wheeled along the bank of coal with
the arm.at right angles to the direction of motion of the base. A
slot is cut at the bottom of the bank and also at the top, after which
the monolithic chunk is broken by mechanical means. No explosive is

used in this system of mining.

Some coal deposits are so near the surface that they are
mined by the stripping and open cut system, similar to the method

employed in the iron mines and by the Utah Copper Company.

One hazard peculiar to coal mining is the presence of gas
in many of the mines which presents ventilation difficulties not com-

monly met with in metal mines.

61.

It will be seen from.what has been stated in the fore-
going pages that the selection, design, or operation of mechanical
equipment for mdnes or mills is governed by conditions peculiar
to the locality in question, requiring thorough analysis to de-
termine the steps involved in the various processes before an in-
telligent selection of equipment can be made. Therefore, the
mechanical engineer who is interested in the design or purchase
of mining or milling machinery would do well to devote sufficient
time to the study of conditions common to a particular locality,
to acquaint himself with the requirements for specific equipment
adapted to the work it is to perform, if satisfactory results are

to be expected.

-----000 .....

INDEX

Mine - General Discussion...........................
Location of Ore Deposits............................
ACQHiSition Of Title.-00000000000000.0000.0000......
Beginning of Operations.............................
Entrance to Ore BOdyooooooooooocoo0000000000ocean...
Conditions Encounteredooooooocoooooooooooooooooooooo
Stripping and Open Pit Mining.......................
Surface Plant.......................................
EleCtric vs. Steam.Power...........o................
Internal cambUStion.En81n380000000000000000000.0000.
Changes Due to Improvements.........................
Air Compressors at AltitudeSo00000000000000.00000000
Mine Shop MaChineryooo000000000000000000000000.-coco
' Description of Homestake Surface P1ant..............
Ore Breaking...o.................e..................
Drills and Drilling.................................
Ore Removal ' Mine Cars...000000000.000000000000000.
MeChanical Loading...-cocoa.000.00.00.0000000000{can
Gravitational Loading - Stoang"....................
Mine Car Propu131onoooooooooo00000000000000...000cc.
Hoisting'Equlpment..............................o...
Hoisting in Balance.................................
Surface Transpartationoooo00000000000000000000000000
Mine Drainage................o......................
M11180...0.0000000000000000...OOOOOOOOOOOOOOOOOOOOOO
Ba81c Processesooooooc0000000000{00000000000000.0000
MBChanism.Of CruShingooo00.0000000000000000000000000
CruSherBooocoooo000000coco00.00000000000000000000000
Screens.........o.........o........o....o..........o
Cyanide ProceSSOOOOIOOIOOOIOOOOOOOOOOOOOOOOOOOOOOOOO
Cyanide Null Equ1pmentoo00000000000000.0000...sococo
Small Cyanide Plant (Elevation)..............o......
Concentration Process...o.....................o.....
Flotation...........................................
Magnetic Separationooooooo000000000000000000cocoa...
Slimes............o....o...............oo...........
Classifier.......o.........o.................o......
Concentration Tableooooooooooo00000000000090.0000...
J18.co0000.0000000000000000000000000.0000...00900000
HomBStakB Mill Flow sheetooooooooooooo00000000000090
Juneau.Mill and.F10W Sheet..........................
Copper Milling (Utah)ooooooooooooooooo00000000000000
Flow Sheet.....-..........o..................o.....o
Magma M111 (Utah)...................................
LeaChingoooo9000000000000...ocoooooocooooooooooooooo
Filling and Excavating Bridges-000000000000000000000
Output Of Leadig’bMIHGSoococo-000000000000000000.000
Placer M1n1ng..............o........................
Coal Mining.........................................

Page

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20 8c QIA-B-C-D
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56

58

59

ROOM USE ONLY.

 

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