DOCTORAL DISSERTATION SERIES

The (olloidil State And Precipifihon O f
Certain Metd))ic Hydroxides In Concentrated

TITLE

a

^

Solutions
AUTHOR

- _

A i

%

A

—

»

*

»

*

Of Nickel Sulfate

Harold Jerome h//<?sn<?r

UNIVERSITY. M i c h i g a n
DEGREE

-*

HlD

S ta te

DATE m

C o lle y e

PUBLICATION NO.
Mil i mm
'l

\U

576

1111111 imm 1111111

__2

UNIVERSITY MICROFILMS
ANN

ARBOR

-

MICHIGAN

u

The w r i t e r 'w ishes t o
tio n to,D r,
• 1
w h i c h made t h i s

express h is

T . ‘ Ewing f o r h i s
work

possible.

sincore

guidance

and

apprecia­
suggestions

' , v :: c o l l o i d a l
HYLHO.yTBKU I "
j. s t u d y
form ation

of

tHu f f - : c : i f i t : . u : on op cezTj.i:: j2s t a l l t c
:: o r r -” ”? R A T tf) SOLUTIONS OF ITICK3L SULFATE

he s

h ~ c n rincie o f t i e

the

hydroxides

v a l e R t K.nd h c x a v a l e r . t
and

ferric

sulfate,
object
ides

iron,

boric

of

acid

c i r c w : ‘u n ,
zinc

to

removed

previous

nickel

of

reported

ir

the

i n v e s t i r u t i ons

A tkins

(3)

found

cclorinetrice.lly

precipitated

ferrous

iron

alkaline

H iller

from f e r r o u s

find 7 . 6 ,

be more

(5)

with

w hile

specifically

observed th " t
'-ad
to

F atten

occured

of m etallic

sim ilar

(1)

end
that

sulfate

but the
to

the

of B r i t t o n

solutions

and M ains

(4)

b e t w e e n pH 5 . 5

pH v f a - r e

ide

found

end 6 . 0 .

owplete p ro c ip -ita tio n

?.t t h e

cf

solution

p i e n o l p h t 1' n l e i n .

(C} invest? y fed

the

co'i-rr i t i o n

of the t r e -

f r o ? t a l um s o l n t " ' o n s u o n a d d i t i o n o f

alkali.

6. 5 (colorim etric)

« pH o f

(£)

ferrous

c-i * f t r t . e s f o r b a d

v; l u e a t w h i c h t h e
co- s l et : * o n .

the

t v e y w-'ro cor.-

literatu re

of H ildebrand

Pickering

of nickel

so.lfate

precipitation

those

to

ferrous

ot w hich th e hydrox­

^ro

rsnye

tri-

from s o lu tio n .

extensive

b e t w e e n pH 5 . 1

was

solutions

one

hydroxide

the

st.rony

cooper,

p r e e l n i t ? t o , .end o t ’' . t i e r

h y d r o x i d e s Hove l ^ e n

present

cupric

and b u f f e r e d

F o r i on s nil s t u d i e s

only

in

e f f e c t in.fr t h e

r l u r r n u n , cadmium,

of

d e t e r * " : r i m ; id o pH v- l u e s

be r n

pletoly

end

factors

pm ci' i f tion

Hlum ( 7 )

war:

-Iven a s t h e

of elu-Unuw a p p r o a c h e s

s t u d i e d th ^ r r e c i p i t . ' - t i f '

of a lu ­

minum. a s o x i d e a n d f r o m o t s o r v ? t i . o n s m?" d e v;i t h a n h y d r o -

nen e l e c t r o d e
red,

and

found t vr t

suitable

t-e

indicators,

precipitation

for

exemple, m ethyl

o f aluminum h y d ro x id e

from ' luwinum

c 'io ritie

solution?

UTS i c _ t j *5 t o

1CT7 ’ 5 .

.Toffe end McLean (P )

in

the

presence

It.

s o l u t i o n v;rr t r - n s f o r m e d

pF 4 . 7

to

of

A.8 .

vas

s u lf ' te-ions

However,

the

’o m n l e t e w h e n II*

tie

into

a l u m i n u m p r e o i a i tm t i o n o c c u r e d

Price?ux

and K e n a e s s

of hydrous
from t h e

aluminum o x id e

sulfate

a b o u t pH 0 . 5
."rile
v? l u e s f t

in

solution
chloride

there

ie

tigations

it

are

is

occurs

This

supports

the

ion has

a yroster

colloid

th

H ildebrand

th eir

ide.

r

pi. 4 , h. ut n o t u n t i l

• tout

uyrcement as

m olar

rule

zinc

st: r t r

to

fate

solution?,

preci

st- r t s

that

f . 5.

precipitate
above

of

from

inves­
sul-

chloride.

bivalent

sulfate

t'w

ion.
z i n c was r e ­

a n d Ka medn

zinc

of z irc

from

respectively.

of

pH

from the

chloride
found

hydrolysis

itrte

to

exact

upon p o s i t i v e

K olthoff

pH v a l u e ?

the

the

t^e

effect

(10)

concert w t ions

They o b ta in e d

precipitation

precipdt' tion

mo n o v : l e n t

and P o w e r s

of th e

to

from s o l u t i o n ,

con p u l a t i n y

pH o f a b o u t

studies

various

ft

a l o w e r pH t h a n

general

n dce"! the

r.reci p i t - . t i o n

visible

little

at

nj[ o . 4 .

resorted

in r yreement t h a t

solution

pel a t

solution.

removed

to

at

studying the

v;h i ch. n l u mi n u . m h y d r o x i d e

o r a t which

moved a t

in

the

.007:;

".re ser.ee o f c h l o r i d e - i o n

com plete

(9)

that

aluminum from a

com rlately

in

found

sulfate

w ith

G.17

and

.051.' a n d
B ritton

(1 1 ) in
titrated

sodium h y d ro x > ',4 0

,-t w h i c h

.01H z i n c

( V. ) r e p o r t e d

culn pH

(4)

Experim ent,”1
H rt.ericlr
nickel

rr.d A p r s r n t u e : -

su lf-'to

- t

b a k e r * a .one l y z e d
t^ r.

This

trotted

C.P.

rod i n n h y d r o x i d e

hour at

to

divided

PT..70 z *

?. l i t e r ?

•• n t o

n i'

two

of

of d i s t i l l e d

. c -t,ions;

f " r o r ium l y e r o . v r , t h e

os

solution,

. 511, u n t i l

d>. 0 .

90°C,

war

solution

by d i s s o l v i n g

N i 8 0 A *GHp0 i n

solution
v.dtf

pH v;nr. G . 7

prepared

s

A stocB

The

allowed

eyorcxinr-toly

-s

s o lu tio n s were h e a te d

to

stand

one

neb

for

the

one

tw enty-four hours,

then

filtered .
T h e m e t a l a v.-er-- rdd.eci i n t l . e f o r ”! o f
except

in

content
icals

the

of

of hexavalent

r.pp r o x i m r t e l y

w»re used

sulfates,
The

case

^he

sulfates

Boric

recrystallized
.•analyses

acid

zinc

o m etal

yive

iron

were

prep- red

was B a k e r ’ s C . P .

C h e m­

end n i c k e l

5>IpC a n d C r O g w e r e C . P .

copper and

sulfates,

Taker* s A nalyzed

f o r clurr.inun, cccmium,

of

pure m e t a l s .

chromium, t o

,5 y ./l.

Cr»? ( SO 4

their

grades.

from t h e

g r a d e , and was

from w a t e r .
for

cadmium,

copper,

and

zinc

w e r e made

enr.3 o y i n g n L e e d s a n d J’o r t h r u p E l e c t r o - C h e r i o p r a p h .
lie?surer*, e n t s
(G)

Beckmn
!!ethod

m ination

of

tion

served

zir.o

and

half-!'-'vc

of

pH w e r e m a d e w i t h

a laboratory

model

pH m e t e r .
of A nr-lysis:cadmium and
es

nickel

s

cory®r,

sum r e n t i n g
wa v e s

" o t ' - ' n t i r' 1

For the

cowe
the

the

polr.rorraphic
nickel

sulfate

e le c tr o ly te , hut
■t

since

so v r o x i w ; t ” l ,r t h e

sulfate

solution

deter­
solu­
the

- no

th;e z i n c

was

(5)

f i r s t ^ r a r r t - r ! fro - . +.:■.a n i c k e l by t h e method of F a l e s
and h a r e ( 1 9 ) , t h e s u l f i d e ' ^ r d i s s o l v e d i n cold 1 : 1
h y d r o c h l o r i c n c i d , e v e p o r a t e d t o d r y n e s s , t a k e n uy i n
hl> n il. o f r. s o l u t i o n .111 a-'•.’non ium a c e t a t e and ,0?5N p o t ­
a s s i u m th3 ocyr.nr.te, a s s u y y e r t e d hy hoed and Cumminvs (£0) .
j . l u r . i i n u r . v-T.r d o t e m i n e d
lic

acid

of

aurin

y o n vor--- d e t e r m i n e d

volum etric- l l y

. O h o n cl . 01:1 i o t r o o j u n d i c ’n *or ' r t o

a. -' ir. c s o d i u m

sulfonate

as

indicator,

3 -.in ’.var o x i d i z e d

to

persulfate,

then

t- e a b o v e

ferric

iron

-vc r

solution
tered,

tricarboxy­

( f 6 ).

Chromium m e
main;;

by u s e

t to iteFVv l ^ n t

b y m o o f m. e x c e s s . o f

dissolved.

in v m

!i i m n e m a n - R e i n h a r d t
iron

'..'an f i r s t

■ on

rroxide,

method

oxidized
then th e

a m ' o r . i u ’i h y s . r r . x i d o

to

si

te

of
t :■

hydro h

c ’ rom-

m i t h a'-morhun

procedure

from th e

follo*vod.

nickel

analysis
•m r i c

acid

used .
ok to

and th e
lerrouc

v:3 t h h y d r o -

y r e c i . it.-.to.-'. v : i t h

M i v ^ h u n d *ed m l .

of

i u :*i f i f'd n:' c c l s u i f a t e r . o l t t o n ’.vao oc id I f i c c t o
by a d d i t i o n

v/ei. *hod r u m t i t y

v/hile

tie

o f a -lot o r

r:h t:

ho m l .

rcid.

solution.

m i nr

c tirre r.

in

the

a sk
Vho
the

G'” " ' h e r me r e v; i t h' . r o o m f o r

hydroxide

sol'.it io n '''.r
driven

’ sulfuric

o f 'no t r l l ~ : o . - v. l t v;r,s d i r s o l v e d

r’ o] u t ' o r . , t • <^n t ' r e e
r rv'lyr.j s .

f il­

.

hxrorii'ientr 1 P r o c e d u r e : -

o f h .0 -3 .0

sulfate

r r . -o n i u m h y d r o x i d e ,

hydrochloric

1:1

diphenyl-

h 'riv slen t

mentioned

r.roci r it. a t e d

• -1 t h

(1:4)
-tirrec'

v/m

added drocv/ine

v i t o r o u s l y b y n e r ns

.. p m l oci o f

five

m inutes

of

U)

stirring

was a l l o w e d

sam pling.

At 0.1-C.?,

were w ith d r; an and
One

r. f t e r

series

of

tem perature

sam ples

the

hr t h

thr^e

’ours.

scries

off

in

7"x

w ith

one

air

£5 m l .

b e f cr e
samples

5/ 8 " t e s t

to

stand

r 4 h o u rs with

n he t e s t

ever o r a tio n .

a flame

two

o t h e r was h e a t e d

’•’■-■re f i t t e d

m inim ize

into

was s l l o v / e d

( 2 :5 0 . 0 7 0 0 ) f o r

v/hile

for

pi I i n t e r v a l s

pipetted

shnkir.'',

t h e in I , OK a d d i t i o n s

in

tubes

at

room

occasional

a b o ilin g w ater
in t h i s

condensers

tubes.

in

second

order to

T h e s e vrere made by a l m o s t

end

of a s ix

inch

piece

closing

of

s e v e n aim.

observations

w e r e made

t u b i n m.
.it

the

end

of

c-.r t o

the

tered

throupii h o .

of

the

condition

earlier

The a b o v e
hydroxide
the

to

in

the

the

in which
shove

tim es

during the

run

the

boric

A nickel
m etals

-

suit-to

ph.

the

in

ocid

solutions

fil­
nature

in

th e manner

thesis.

case

atm osphere

series

solutions

it

with

0.2a

solution

sodium

solution

exception
to

in
of

ke ep, a n

and s a m p l e s

at

all

prevent oxidation.

and b u f f e r e d

cor.tr i n e b

the

was n e c e s s a r y

order to

c l u w i n u n , c: b n i u n ,

using

r i s e ’-1 n e t a l w a s t r o t t e d

described

inert

the

samples

a n d ph m e a s u r e m e n t s a g a i n

r u n on t h e

manner p re v io u s ly

In

the

o r 4 1 ?/h e t m a n p a p e r ’w h e n t h e

p r o c e d u r e mm s r e p e a t e d

raise

f e r r o u s .i r o n

solutions,

perm itted,

A nalyses '/ere

described

periods

of the

to

precipitate

made.

these

57.5

nickel
;./l.

containing

coy. e r ,

iron,

sulfate
of
the

boric

acid.

follow ing

magnesium,

and

zinc

in

concentrations

sodiur.i h y d r o x i d e

of 0.5

g ./l.

anct p r o c e d u r e

was

already

treated
described

The a n a l y s e s "/ero made s p e c t r o g r a p h i c n l l y .
rorented

carbonate

buffered

determ ine

obtained

when t h e

?5°f

when h e a t e d

and

and

tee

sam p les were
for

of th is

equilibrium

precipitation

hydroxyl

it

sometimes

recuired

was d e c id e d

m inutes

be

collected

that

allowed
mo

pi I v a l u e s

for

their

after

librium

Heaourem ents

the

second

d a t■ are

scries

recorded

was h e a t e d
in

from a p r a c t i c a l
t' o s o lu t io n
amount

of

must

in

the

of

at

question

since

the

during
sol­

reac­

five

sam ples were

pH’ s o f t h e s e

standing
to

of

A ccordingly,

of base

The

order

f 4 hours

obtain the

at

equi­

pH w e r e a l s o m a d e a f t e r

5 hours

at

100°C.

These

tables.

standpoint

bo r a i s e d

i m p u r i t y would

tim e.

before

pH d e t e r m i n e d .

(ff-£3°C)

be

re.mov-.*d f r o m

addition

stirrin g

room t e m p e r a t u r e
values.

the

This p r e c ip ita tio n

each

s a m p l e s vrere a g a i n m e a s u r e d

agitated

arose,

being

considerable

after

could

of A e s u i t s

investicetior

pi:.

t vn t

in

u.t 1 0 0 ° C .

io n s were

changing th e

added

solutions

thoroughly

5 hours

obtaining the

tion

sulfate

and D i s c u s s i o n

course

thus

nickel

m x i m u m y>]\ v a l u e s

the

Data

ution,

r u n was

c n lc i u n h y d ro x id e were

and u n b u f f e r e d

order to

In

The

follow ed.

u s i n g cmnonitim h y d r o x i d « .

H ickel
to

w ith

in

the

ph v a l u e

o rd er to

most u s e f u l .

remove

t o which
a certain

The e c u i l i b r i u n

f':
( n)

nil v a l u e s
are

do n o t

usually

V'-I n e s .

clw ays

give

from 0 . 2- 0 .5

Thus,

tli.it

inf creation

pH u n i t s

in p l o t t i n c

^he

low er than

graphs

the

since
the

they

in itial

in itial

values

v/ere r e c o r d e d .
.-iluninun: of

either

buffered
sulfate

Initial

appearance

a mm o n i u m o r
nickel

sodium h y d ro x id e

sulfrte

v:or o b s e r v e d

solution

at

pH 4 , 0 .

upon f u r t h e r

pH 4 . 0 - 4 . 7

coagulation

noted,

ms

seen from T a b le s

tion

the

of

standing
heavy
the

for

P4 h o u rs.
at

a l u m i n u m v;s s n o t
be o b s e r v e d

The

solutions
cf“ b a s e

vreci

drop

itatio n

and a t

(c)

(d)

and

the

in

the
at

pH 4 . 4

low er;

removed a t
case

the

concentra­
upon

scruples produced

pL u n i t s

the

vac

rapidly

alum inum o x i d e was

0.3-0.4

in

buffer

hydrous

H eating

that

or un­

aluminum

although

addition

com pletely

sr mp3. es a c o n s i d e r a b l e
no v i s i b l e

I

buffered

a lum inum was m a r k e d l y r e d u c e d

precipitation

ma y a l s o

of the

to

uron a d d itio n

contoining

ph. - i . 4 k o . l

at

. a c t i o n wc.s e n c o u n t e r e d
became v e r y t u r b i d

of tu r b id ity

pH 4 . 9 .

of the

It

heated

pH o c c u r e d

In e v id e n c e ,

however,

even where

indicating

h y d ro ly s i s had t rken p l a c e .
S o me d i f f i c u l t y
tricerboxylic
In order
the

to

r-ralysis

sulfate
lake
tubes

ac?

have

so t h a t

for

it

frequently

aluminum

samplers w e re

causeci

in

the

lev; c o n c e n t r a t i o n s

sufficient

P O ml .

content

v/as e n c o u n t e r e d

was n e c e s s a r y
w h i l e n? k i n g

to

o f aluminum.

nnc

The h igh
settling

shams t h e

chock

aurin

( C. 1 - 0 . 5 n g . ) f o r

taken.

cor.gul-t i o n

use of

nickel
of

the

colorim eter

readings.

4 .9 0

4 .5 0

3.70

160
l i l l l i f f m m a p a r L l t ^ r o f Aln...lnu ;5
r i g . 1 - Alus.iimiffi l r b u f f a r p f p i n e a l m i i r r t * r r - l u t i o n - t < M f f « r p n t
pH t p 1u» s : 1 , NsOH tT-«r.t,-i*>nt, 3 h r ? r t 1 0 0 ° C . ; f , Hh.OH trr~t_i**nt
7 h r n r t 1 0 0 nC . ; 3 , KpOH t r » f > t n » n t , ?4 h r? r t -’5 ° C . ; 5 ,
OH t r p r t r .rn t,
h r s r t Pf^Pc. .
1
*

m

I

Rem • ' v s l o f A l u m i n u m f r o m
Nick®! A ulf • t e S o l u t i o n
Table I
pH a f t ^ r
rc’f i t " or.
o f ’ i : - oi*
(ori.v

noln)

T r ~ c f 1n e r . t

(a)

pH o f t e r
treatm ent

none

’ ’' T/ I A1
in soln
50C

4.18
4 .69
4.54
5.0?

?4 h r s
a t f5°C
II
If
II

4. IP
•1 . l b
4 . 46
4.67

6.68
458
665
18

3.60
.->.89
4.08
4 .18
4 .40
5.0?

3 hrs
a t 1 0 0 °G
II
II
It
II
II

3.08
6.08
6 . lo
3.06
2.61
0.74

500
500
480
350
41
17

R e m o v a l o f ^ l u T r i n u 1! f r o m
B uffered N ickel
Table
pK a f t e r
; c.d i t i o n
o f d i n*-roh
(orig
3.85
3.93
4.01
4.1?
4.38
4.49
4.7?
4.88
3.42
3.58
3 . 8 id
3.93
4.07
4.8?
7r
hra • OO
4.49
4.7?
4 . BP

soln)

r!’ o P >r r, p

none
24 h r s
a t ?5°0
II
II
It
Tt
1?
II
II
3 hrs
a t 100°C
II
II
It
If
II
n
IT
IT
IT

pH a f t e r
t r « ! tm ert
-

mg/1 Al
in soln
485

3.05
3.93
6.05
4.13
4.3?
6.45
4.7?
4.0.4

485
485
485
431
79
83
90
0.6

3.13
3.14
3.10
3.15
2.75
? . 51
*".. • O
AIc
L
o
t >• nt 11
2 .8?
2.0 0

49?
407
476
445
09
38
f
c>o
?1
20
19

' "p’ti ov. ' 1 o f f l i i r i n u n f
B u f f o T ' t f ?Ti o V o l S u l r ' t o S o l - t t '■n
Totlo
r I T ■ ■ f t " 1"
•°7 G i t i
o f Nr'or

t.

ic

pH r f t P T

.'•

C ’i-cr, n o l n )
' * a» *L
* . 00
.09
.?o
■t. ; 8
A • '■‘O •
' • 6-:>
'■ . 8 5
5.10

I

none
?*■ h r s
- t ?5°C
It
ft

tt
!T
It
tt
tt
Tt

mg/1 . .
in rol:
47?

6.89
9.96
/■ . 06
A .r
"/ • f* t»-■
<.-7
A. Go
■
.BG
5.08
g

■87?
4-7 ?
/I ™
8 60
78
79
7 5
GO

V i r n

of
5.7?
.

• —

• got.

•
* .00
-1 . 0 9
* .ro
8.f8
,1 • A O
*8 .65
A m0 F>

r t

1 0 0 OC
tt
tt
tt
tt
tt

tt
tt
tt
tt
tt

5.1?
8.19
5 .IP
8.17
8 .1^
? .2 *
8 . 6?
? .87
? . of
8.75
P .80

*-70
8 15?
8-88
8 5
107
77
48
50
PA
?A

ovr-YT]?;ry o f Dad a o n
Table

I

(e)

n p p e : f-’n c '1 o f T u r i i n i t y
A o lu tio n

a - f t e r

o d ti.itio n

o f

b a s e

NeOIT
i

NiSOA
b u f f e r e d

#/

A f t e r
f ’4 h r s
«*>o
r* r> O '"1
4. t . * & / ^

n t i4 o h

NnOH

4 .4 -

4 . 3 -

" .3 -

4 .5

4 .4

4 .4

4 . o

k h

4

a t

A f t e r

NaOH

o h

o

h r s

s t

NH4 0 !i
3 .8 3 .9

4 . 4 -

4 .3 -

4 .0 5 -

4 .0 -

3 .5 -

4 .5

4 .4

4 .1 5

4 .1

5 .9

r i s e ,
4.

3

100°G

3.91.0

H e a v y P r e c i ir>’ t r- t i on
h o l o t , j or.

f t e r f do i t i n n
c f Vp p. p
No Oil

. . f t e r ?.4 h r s
f. ?■■■-£7 °C

n h 4 oh

No Oil

at

a f te r 3 hrs
IOC oc

n h 4 oh

at

NaOH

n h 4 oi i

NiS0A

a bove
PH ' 1 . 5

above
pH A . 5

above
above
. a .! 5 pi: 4 . 4
F*-

a bove
pK 4 . 3

above
pH 4 . 3

Buffered
I ! i 8 C ht
,

a love
■^pr ,1 >o

above
pi l 4 . 5

v. b o v e
pH 4 . 5

above
pH 4 . 0

above
pH 4 . 1

above
pH 4 . 4

Removal o f .iluninum
3oluti.cn

A fter

f:4 h r s

MaOH
trace at
pH 4 . 9
ri304

Buffered
Ni304

78ns/l ro ­
n e i n pH 4 . 4
00 u : / l r e ­
g a i n nil 5 . 1

nt

P?-H7°0
Nil/ OH

t r a c e rit
pH 5 . Oc
trace at
pH 5 . 3 7 .
P6 -n - /l r e na. i n pH 4 . 9

A fter

3 hrs

NaOH

lOOOC

m i 4 o:e

t r a c e .at
pH 4 . 9

50 r p / l
n a j.n pH
94 n p / ' l
ur . i n pH

at

re4 - . 4ro4.85

trace at
pH 4 . 0 3
abs. at
pH 5 . 0 6
05 n- p /l
a r i n pH
19 mtr/l
•rta i n pH

re­
4.4
re4.68

(9)

Gc.d77i3.um: -

Csdmiuis we s n o t

o u lf- to

nickel

.‘- e l u t i o n

nppr^ciably

with

am- o n i u m h y d r o x i d e u p t o

a pit o f 7 . 0 ,

even upon h e a t i n g

*. bove pH 7 . P

-

II

7.3

t h e r e wee

(a)),

but

at

solution

war

greatly

have

been

the

curried

the

reduced,

c- s o

tion

would have

v lues

since

that

the

umd

required

to

aim ilorly,

m erely

3n t h e

case

out using

only

acid

The
pH a t
II

It

roxide,

and

only a v ery
w ith

occurs

-.•/ill b e n o t e d

that

to
at

r, pH o f 7 . 1
the

/’• i n t

a solution,

O . H.

end o f

the

since

nickel

the

titrate

pH

is

in

r

boric

o r 3g i n n l

volume
the

boric
factor

upon t h e

out

acid

of

in Table
solution

no p r e c i p i t a t j on

PA ’’ o u r s a t
the

carried

dilution

brought

upon a d d i t i o n

at

sulfate

concentration

500 m g . / I .

turbidity

solu­

c admi um, w o u l d h a v e

a considerable

th e m etal

of

in

the desired

s t u d i e s were

to

precipitation

was 1400 m y . / I . ,
and

of

a cadmium c o n t e n t

oc c u r e d u p

require

introduced

im portance

wticli

(g).

w ith

a r m 3urn h y d r o x i d e

would have

hydroxide

of buffered

r. n u m b e r o f p r e c i v i t w t i o n

sodium h y d ro x id e

cadmium m iy

by d i l u t i o n .

solutions

dilute

of the

r. : r o c i r i t r n t

attain
the

content

hydroxide.

volume o f

c o n c e r . t r n t i on o f

b o o n y r o r - t l y lov/ercw

as

100°C.

(see Table

the

the n ic k e l

such a l a r g e
been

at

nickel

so t h a t

.iodiun h y d r o x id e was n o t
this

fo r 3 vrs

s o me r e m o v e d

same t i m e

d o wn w i t h

rem oved from a

of

a mmo n i u m h y d ­

E5°G t h e r e

was

same pH, v / h e r e e s ,

codwin^

’. av-c i - i t a t 3 o n st-- r t o a

content
Votueen

o f which
0.7

(10)

Notew orthy a ls o
(c)

end

(f).

was v e r y
sulfate
heavy
the

In

little

ere

the

case

precipitation

heated

of

precipitation

started

b e t w e e n pH 6 . 0

boric

c a d m i u m c o n c e n t r a t i o n ’.'.'as r e d u c e d
pH 7 .

In

the

c e d m i u n ’" a s

6.07

after

5 hours

7.rh i l e

making t h e

a buffered

"-educed

at

solution

pH C . P

and

the

wes

larqe

about

nickel

0.6

solution.
fered

hydroxide.
in Hiq.
In

fluence
that

pH 0 . 3 ,

sulf-te
of t ! e

nickel

the

and

approximately
sulfate

to

a,re

that

solu­
pH

between

became v e r y t u r b i d

the

in

and

above

p r e c i ^p i t a t e d .
value

precipitate

solution

The r e s u l t s

view of th e

sore

It

and 6 .5

in buffered

w= o o b s e r v e d

low er than

started

sulfate

solution

in

a t which
on u n b u f f e r e d

which t h e

was r a i s e d

pH o f

with

shown i n T a b l e

This

a buf­

a mm o n 1 urn

II

(h)

and

PA.

ide above
nickel

cedmiun

A r u n v:es t h e n m ade

nickel

acid

b y 5 0 mc~ . / I . a t

o f N i ( 0 K ) cC~> w a s

pH u n i t

hydroxide

it

solution

quantity

to

nickel

only

run w ith

s u l f rto

6) . 3 a

there

100°C.

nickel

6.5

(a),

c a d mi u m, from n i c k e l

in th e

at

II

samples

whereas

tion

to

of th e

in T ables

b e l o w pH 7 ,

40 n c . / l .

the

differences

is

heavy p re c ip ita tio n

the

removal of

solution
boric

c'nr.ot

acid

since

of nickel

cadmium from t h e

be a t t r i b u t e d
it

is

o f t.' e c? u n i u s -war. a d s o r b e d

to

entirely

hydrox­
buffered

the

in­

probable

from s o l u t i o n

by

hydroxide,
evident

pH v a l u e s

also

that

any v i s u a l

a t which m e t a l l i c

observ? t i c n

hydroxides

as

c o me dov/n

r

6 .0 0

0

160

320

480

m i l l i g r a m s p e r L i t e r o f Cadmium
F i g . 2 - Cadmium i n b o r i c a c i d , n i c k e l s u l t e t e , a nd b u f f e r e d n i c k e l
s u l f a t e s o l u t i o n e a t d i f f e r e n t pH T e l u e s :
1, b o ric acid so lu tio n
a f t e r NH4 OH t r e a t m e n t , 3 b r a a t 1 0 o ° C . ; 2 , b o r i c a c i d s o l u t i o n a f t e r
b'h.oil t r e a t m e n t , 24 h r s a t 2 4 ° C . ; 3 , N i c k e l s u l f a t e
so lu tio n a f te r
!5il0H t r e a t m e n t , 3 h r s a t 1 0 0 ° C . ; 4 , N i c k e l s u l f a t e
so lu tio n a f te r
,. h J0!: t r e e t . - . e r . t , 24 n r s a t 2 7 ° C . ; 5 , B u f f e r e d n i c k e l s u l f a t e s o l u t i o n
r f t e r i.li O'- t r ^ e t . . i e n t , 3 h r s a t 1 0 0 * 0 . ; 6 , b u f f e r e d n i c k e l s u l f a t e
a o l ' i t i o r . P i t e r NH4 01' t r e a t m e n t , 2* h r s r.t 2 3 ° C . ;

7.00

6 .6 0

6.2 0

pH

5 .4 0

5 .00

20

40

60

U rP is s p e r L i t e r o f w l e k » l

F i g . 2 A - N i c k e l c o n t e n t o f b u f f e r e d n l c n e l s u l f < t # p o i n t ton f 't 6 l i f e r ­
e n t pH v e l u e s :
1 , M' OH t r « f i t : s e n t , 3 h r s r t l o o ° j . ■ p : o : , o l t r e i t e r t
24 h r s n t ? 5 ° C .
’
'r

r o9 J 1 “ 8 J" vi '
aO'lIW ' * '■' 0 o 9 i
H ‘ a u a - j .i»j»
• *DoOOT »» 8 JH £ ‘ »U«u»«tfcX» HOvHiJ '«; 1‘ 00001 »« H H £

*t

:s«nxuA ;iJ 1u«'J.ajJtP %» uoxinxoa

!0 ».: t
>i0-«

oi^o*; 'o; ^.t>xu.yu; - j *>;£

utv[iupvO JO -iaitx a^J eiuu.ii<fXT?1'1
OOOT

009

00*

0

00

R e m o v a l o f Cadmium f r o m
N ickel S u lfa te S olution
Table
pH a f t e r
addition
o f NH4 OIT
(oris

scln)

6.85
6.07
7.18
7.48
0.83
6.97
7.18
7.48

II

Treatm ent

(a)
pH a f t e r
treatm ent

none
£4 h r s
a t 27°C
"
"
"
3 hrs
r.t 100°C
"
”
"

-

r a g / 1 . Cd
in soln.
485

6 .8 8
6.97
7.15
7.47

485
470
490?
460

6.75
6.75
6.6?
7.0?

478
478
470
4??

R e m o v a l o f Cadmium f r o m
R o r i c .^cid S o l u t i o n
Table
pH a f t e r
addition
o f NaOH
(ori"
6.95
7.09
7.24
7.40
6.05
C.P5
6.41
6.58
6.75
6.95
7.09
7.24
7.40

soln)

Treatm ent

none
?4 h r s
a t 74°G
11
”
"
3 hrs
a t IOOOC
"
"
"
"
"
"
"

II

(c)
pH a f t e r
treatm ent

-

^ s / l . Cd
in soln.

513

6.93
7.1?
7.27
7.44

513
40?
258
163

6.13
6.24
5.34
6.5?
6.70
6.93
7.13
7.32
7.47

513
357
245
150
85
45
29
19
10

R e m o v a l o f Cadmium f r o m
Eo- o i c A c i d S o l u t i o n
TablpH a f t n r
add i t i o n
Of MH^OH
( o T‘i g

soln)

TT',D? t m = n t

II

pH a f t e r
trortm ent

nonft
?4 h r s
tt
II
9 hrs
a t 100°C
tf
ft
tl
tt
tt
tt
tt
ft
tf

.•'0
O . O' ■■
5.6 0 . SP
5.95
6 . OP
6.50
6 . i' 4
6.70
6.79

T ;a b l e
pH r [ ' t o r
r d d i t *on
Of NnOH
(o^ig
6.6?
6.74
6.90
7.09
5 . OF
9 . 79
5.98
6.18
6 .98
6.6?
6.7/.
6.90
7.09

soln)

m g / 1 . C<
in soln
14-00

0
0
<0
cu
•p

G. AA
0.70
6.79

(d)

6 . A5
6.79
6.79

14-00
1 ? 04980

5.90
a
A
5.6?
5.7P
5.76
5.05
6 . O'7
6.17
3.4 0
C. 6

14 0 0
1400
1995
I P 56
1070
69?
47?
P56
?98

II

(°)

Tr . - h t m e n t

pH a f t e r
t1"k*6v

rrnn
r 4 h^s
f-t ? 6 ° C
ft
ft
tf
9 hrs
a t 100°C
tt
ft
tt
tf
ft
tt
tf
tt

-

mg/1. C
in so lr
1-890

6 .9 7
6 . 7?
6.91
7.19

IP 18
916
580
958

r .69
6.70
9.70
rt
•>« OK'
6.08
6.^5
6.50
6 .80
: .95

17^A
1160
98?
740
518
17?
101
59
97

"anovnl of Cormium from Buffered
Hickol Sulf'to Solution
T*ble II (f)
pH o f t o r
f: c'd i t i o n
o f BBOiOU
o^ig
-.17
6 . SO
U
6 . 57.
G. 70
6.79
6.87
■-*

•

A
• : i.:

n.Hf
o.97

p.nln)

tm ^nt

nono
r 4 hrs
• t r?»oo
ii
tt
tt
tt
tt
tt
6 b r-s
o t 100°C
?!

pH r>f t o r
t^o- tm o r t

«•

m g/1 .
i n on]
■A- 5 9

(' • kr' A
6.40
6 .^ 0
6 . 56
6 .6 6
o.77
6.79

■6^5
4 If
8P9
nn
66?

5.70
5.78

A6 ?
/ni.s

•

660

T f b l ® IT ( T) c o n t .
R e m o v a l n f o- . mi urn
S olution

After

e 'A

hro

r- o i :
MiR04

: ' u f f (irod
'■ io04

none
removed

-

500 ms :/ l
Gd i n '
] r;.;B0 ry

1 6 ,; m ~ / l Go
" ri l a i n
pH 7 . / 0

l-inr r u r / i
Go i n
K:-B0 r,

rl r P rri ' * / !
r» -o-'-jn j n
r] I 7 . 0 9

at f g - r ' 7 ° J
in:, o r
Gd

780 m r /1
ir.
pH 6 . 8 7

>

1 5 m ^ / l Ca
-■-moved
.1. 7 . 0 9

-O ’.’ —/P
:-v i n H T
1 0 T- - / I
' i r tH

-

' ;

•A ‘ n p / 1 Gd
- ■ in
;1 7.5

1: - - / I Go
in
: T: ■•■.67

-

r

100°G

hh 4 oh

N*0H

478 m p /l
rer-i in
pH 6.8:-.

n >.■
•’>jf-./ i
v ~mn i.n
'H 6 . 8 0

V \ ° "• t

A fter

pp7.1
ro7.4

-

•’9 v'_, ”/ 1
- " '0 ■ n - / l
*11.' i n y ll
. 9 r»r'Tn; i xi
pH 6 . no
"7 m - '/ l r e
’- i r i n pH 7 . 1

Cd

(12)

He x s . v e l e n t
were r u f e

Chromium: w ith

In n ic k e l

concentrations

shows t h a t
pH r a n g e ;
r e uired

curve

the

1 in F ig .

break

occurs

nam ely,6 . 5 - 6 . 6 .
in

voth

cases

pletely

from s o l u t i o n .

true

w ell

as

sulfate
the

that

solution

tend

t- t i o n

does

t l,nt,

since,

r

the
tion

of

case

of

in

fig.

pH o f

solution

t^e

pIT.

reached,

one

another.

as liable
to

7.1

yellov; as

sane
7.0

acid

III

(d)

also

nickel

sulfate

whereuyon th e

has any

is

is

the

more

solution
two c u r v e s
precipi-

solution

it.

It

in

shows, hexavolent
acid

pro­

seems

influence

at. r . l l f r o m a b o r i c

in

sulfate

The v o lu m in o u s
buffered

nickel

break

(upon h e r t i n s )

nickel

is

con-

buffered

N oteworthy

in the

this

chromium

solution

u s i n g a mmo n i u m h y d r o x i d e .

hydroxide

as

yellov' n eed les
had

a pH o f

6 ; however th e

is

boric

in th e

5

st; tem ent h o ld s

from b u f f e r e d

been h e ted

changed p r o g r e s s iv e ! p

a light

1 in F ig .

down some c h r o m i u m w i t h

sodiu^

Ij.-'t,

curve

chromium i n

n lover

hydroxide

precipit;

;.’i t h
tity

6 .8

pH.

remove chrnrr'iim a l m o s t

in u n b u ffe re d

of nickel

not

up t o

than

carries

4 w ith

a mmo n i u m h y d r o x i d e

approach

doubtful
case,

rt

the

apyroxinntely

of
^

raise

The p r e v i o u s

precipit' tio n

e pH o f
to

bably

occurs

w ith

efficient
until

the

r.r i n d i c a t e d

curve

fact

in

runs

to

Furtherm ore,

to

solution

o f 500 and 1000 m g . / l .

c h r o n i u m u s i n g ammonium h y d r o x i d e
com parison of

sulfate

prscipit; nt
wr - n o t e d
5 hours

at

at

a sm ell
p . ] 7.0

100°!.

from an o ra n g e -re d

sodium h y d r o x i d e s

added,

quan­
after

The
at

solu­

pH 5 t o

indicating

the

c o n v e r s i on o f t h e

T r i v a . l e n t Chromium: upon

solution

observed

very

producible
nr:d t h e

near

if

the

solution

different

veil

etc.

The

interesting

v 'lu e s

for ri ckol

range

of

100°C

all

heated

3.4-4.9
drop

gained
In

case

'•/ns c o n s i d e r a b l e

occurs

after

hydroxide
that

sistent

the

the

and

in

that

after
0.1.

"as

IV

(a),

f .7,

Thus,

e t w hich th e

a series
the

(b),

(c),

3 hours

pH’ s o f

only

pH

approxim ate

for

the

col-

initial

in t h e

.Then t h e

re­

slow ly

of

where th e
lie

wos

cuite

ncidity

he? t i n a

above

rapiuly.

of the

samples

difficulty

r e r. q e i s

of

sulfate

Upon h e a t i n g

solution

rise

in

at

the

concentration
a n a. j. p r o x i m o -

chromium, i s

the

the

removed

is

V.'encott

(1?)

100°C t h e r e
consistent

data

which p r e c i p i t a t i o n
trials

best

inform ation

using

b o l o w pH P . O .

to

chromic

at

five

probably

m ,a t h o u g h t

heated

obtaining

at

after

precipitant

of h y d ro ly sis

is

minimum p o i n t

results

B ritton

value

r, n i c k e l

ir.ec.s u r o m e n t s .

3 hours.

as

of turbidity

o f b a s e w e r e made

values

be air. t o

from t h o s e

concerning

fact

pH P . 6 t

pH v; l u e

the

This

agitated.

sulfate

chromium d e c r e a s e s

sodium c h ro m e te .

chromic

shown i n T a b l e s

the

to

samples

of t i e

the

p b v -. l u e s , i r c r e e s e
or

to

sodium h y d ro x id e to

additions

noted

is

appearance

pH 4 . 0 .

"rs

tion

Initial

containing

utinn

of

ricid

o d d i n .;; a m m o n i u m o r

sulf' to

at

chromic

bo a s s o c i a t e d

a mmo n i u m
available

The
w ith

incon­
rate

sulfate.
curried

out

titratio n s

of

(14)

increase

ir. a c i d i t y

shown by t h e

fact

upon h e r . t i n r t h e

that

to

Inspection
relation

f-'te .

in

as

to

boiling

and

cooled,

a

th e

pH l . P .

of Table

IV

o h r r - ’V.uri h y d r o x i d e

l o w e r pT; t h a n

solution

a. O . b i l G r C l g . 611^0 s o l u t i o n h a d

pH o f 2 . R 5 , b u t w h e n b o a t o d
yr. h a d d r o p p e d

nr.lt

the

( p ) shows t h a t
starts

buffered

to

in

boric

p ro c ic it'to

and u n b u f f e r e d

acid

-t

nichel

su l -

7.4C

7.00

6.20

5.4 0

0

160

480

m i l l i g r a m s p e r L i t e r o f Chromium
F i g . 4 - H e x e y e l e n t chrom ium I n n i c k e l s u l f a t e s o l u t i o n a t d i f f e r e n t
pH r e l u e s :
1 , Nh^OH t r e a t m e n t , 3 h r s a t 1 0 0 ° C . : P , NaOH t r e a t m e n t , 3
h r s n t 1 0 0 oC . ; 3 , NH4 OH t r e a t m e n t , 24 h r e a t 2 3 * 0 . ; 4 , NaOH t r e a t m e n t ,
24 h r s a t 2 2°C.

L» O

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800
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1?00

L l t a r o f C hrnraJun

F i g . E - H e x a v s l e n t chrom ium I n n i c k e l a u l f a t e s o l u t i o n a t d i f f e r e n t
pH r a l u e a :
1 , NH.OH t r e a t m e n t , 5 h r a a t 1 0 0 ° C , ; ? , MLiOh t r e - t r s e n t ,
£ 4
h r e a t E4°C.

<~vTi r v ; 1 o f
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u l l l l g m m a p e r L i t e r o f Ch rom ium
F i g . C - H » x a T e l e n t chrom ium i n b u f f e r e d n i c k e l s u l f a t e s o l u t i o n a t
d l r f e r s n t pH T e l u e s : 1 , NH4 OH t r e a t m e n t , 8 h r s a t IOOOC.; ? , Nh.jOH
t r e a t m e n t , ?4 h r s a t £4 °C .

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IToOH

Ml^OH

No OH

n h a oii

O • 0) **
0 .7

0 .6 0 .9

6.£ 0.-

0 .1 6 .?

el-r r
pH 7 . 0

1 0 0 0 r r ^ / l 07i n Mi f-0 ..

-

o .9 7 .0

H u f f n^'-'d
7.iSQA

*=t

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?

o.l - r r
pTI 7 . 1

i f t o r f/' h r s
100°0

Ml!/i 01 !

500
Or
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M; • ’' °

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rr-?7°C

o le-r
pH 7 . 1

-

6 .r 0.A

o lo -r
pH 7 . 1

cln.- r
pH 7 . 1

-

••

bolov;
pH 6 . 0

cl^r r
pH 7 . 1

c1ea r
pH 7 . 1

-

ro^vy F r ^ c i r itv tio n
S o l u t - on

A f t » " n H(' 5 t i o n
of base

500 n . p / l Or
i n H i S 0 /(
1 0 0 0 mg/ 1
i n N H ,oA

A f t e r ? d h r r. r t
rF-F7°C

NaOH

NIT, OH

Mr OF

- bove
pH 7 . 0

cl -r
pH 7 . 0

r bove
6 •Q

none
pH 7 . 0

nune
pTT 7 . 1

—

above
pH G . 7

none
pH 7 . 1

none
pH 7 . 1

none
pH 7 . 1

Cr

H t.EO,.

none
pH 7 . 1

Huf f
HidO .

-

-

k h a ok

' f t o r r/ h r s
1 0 0 oc
Mo OH above
rH 6 , 6

at

NH4 0K
; bove
pH 6 , 6
^bove
pH 6 . ^

none
pH 7 . 1
-

pone
pH 7 . 1

f:'r"bio I I I

(f)

O er.oval o f
d o l ’i t l o n

A fter

f/i- It s

I If OH
1300 r v / I
Or i n
NiHO^.
1 00C " - - / I
Or i n
NiKC 4
H.-POr,
o
O

Buf f e n d
iTiao4

50 ~* t/ 1 O r
TPnOYPli
r jr
none
rem oved
j’■
->tr
- * 7' • 1
-

ft

cont.

Ohromium
ff-?:7°0

A fter
NaOH

Hr:,- oil
17 T " / l
rem oved
pH 6 . 9 8

Or

1 7 0 mtp / l
rema i n
pH 0 . 9

3 hrs

at

100°0

NTHAOK
Or Of m.p/1 O r
rem ain
pH 6 . 9 6

7 7 0 me / 1
rem ain
pH 7 . 1

-

16 m ; / l
rema i n
pH 7 . 0

none
rem oved
pH 7 . 1

none
rem oved
pH 7 . 1

none
rem oved
pH 7 . 1

1 F 0 m‘* / l
removed
pH 7 . 0

-

4? m p /l
m a i n pH
24 inp / 1
m a i n pH

Or

re­
6 .8 5
re­
7 .0

5 .0 0

4 .2 0

3 .8 0

3 .4 0
160

3 EC

480

M i l l i g r a m s p e r L i t e r o f C h r o m iu m
F i g . 7 - T r i v e l e n t c h r o m i u m ir. n i c k e l s u l f e t e s o l u t i o n a t d i f f e r e n t pH
v alu es:
1 , N«0H t r e a t m e n t , 3 h r e a t 1 0 0 ° C : 2 , NH4 OH t r e e t a e n t , 3 h r s
a t 1 0 0 ° C . ; 3 , NaOH t r e a t m e n t , 2 4 h r e a t 2 5 ° C ; 4 , NH4 0H t r e a t m e n t , 2 4
h r s a t 24°C.

T?f'T’i o ' 1 o f T ■"iv .-1 ° r .t Cb'"'VP3 nm
1‘rorq H i o ^ l

Sulw te

T- M pH - f t r v
'■’rid i t i on
o f ;v'4oi;

m^r. *• -t-rr' ri P P

( o ’i K o n l n )

non-1

. ''6
*. 5
v . •■■■9
. DO
4 .6 8
' .98
o .l7
>.8 7
. -0

IV

Solvitn^n

(; )

pH n f t o r*
t ^ n r t r^ n t

505
pp
• >...
rz. 8 8
8 .9 £
4 .08
4 .10
4 .8 1
4 .0 b
b . or

- f -*°C
tt
t»
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ft
ft
tt
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487
504
505
8 58
£56
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T ’vwi t m e n t .

pH p f t e r
t.ro r t n e n t

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a

. 18

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58 £
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0

160
f c . i l l l g r e m s p e r L i t e r o f C hrom ium

rig .

e - T r l r a l a n t c h r o m i u m I n b o r i c a c i d s o l u t i o n f i t d i f f e r e n t pH
▼ n lu e a :
1 , NH^OH t r e a t m e n t , 3 i r e a t 1 0 0 ° C . ; 2 , NaOH t r e a t m e n t , 3 h r r
e t 1 0 0 ° C . ; 3 , NlLiOH t r e a t m e n t , 24 h r e e t r i ° C . ; « , NaOH t r » r t n e n t ,
b r a a t 24°C.

’V m o v o l o f ' f - i v n 3 e n t C h r o n i u n
f r o n B o r i c A cid S o l u t i o n
A b le
pH ? f t e r
add i t i o n
o f NaOH
(o"i&

-.21
”' . 7 0
/

•

T r,en trr-*nt,

so ln )
89
at

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I t .

/

‘V,
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-.9 8

9' . 9 C

'• . K5

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2.60

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tt
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1.00
8.20
8 . 65
8 .92
5.12
5 .. 5
3.7 0
5 .8 9
A .08
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A . 23
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A. 52
9 .0 7
9 .98
2 .18

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in s o ln .

585
488
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160
M i l l i g r a m s p a r L i t e r o f Chromium
r in - ^

- T r l v e l e n t ch ro m iu m I n b u f f e r e d n i c k e l s u l f a t e s o l u t i o n a t
d i f f e r e n t pH r e l u e e :
1 . NaOH t r e a t m e n t , 3 h r s a t 1 0 0 ° C . ; 2 . NH4 OH
t r e c t m e n t , 3 h r s a t 1 0 0 6 C . ; 3 , NaOH t r e a t m e n t , 24 h r s e t 2 3 * C . : ^ 4 ,
NH4 0H t r e a t m e n t , 24 h r s a t 2 3 ° C .

?p^ovrl of
vr.lert C h r o m i u m from
Ruffor^u R i cko l Sulfate Sol ut ion
Toble IV (e)

pH o f t e r
rdclitio n
of HU03r

T v,n! t m o n t

O -±cr ^ o l n )

none
p/i Jjr n
r . t S 5°C

* .5 5
A .50
. 70
* .90
&. SO
5 . 00
r .70
'• >• *-1(c■
s . 78
s . 95
5 .55
A. 80
1.70
o .90
o .. 0
S. . C 0

tt
tf
tf
ft
tt
tt

5 h'-s
o t 100°G

pH - f t or*
f ^ r tT '°r:t

m p/1. C r
in o nIn .

* .00
*.1 6
4. 6
4 .79
5 . r r7
5 . OS
5 .78

515
561
156
77
55
■X/!.
57

S . OS

r>r*

tf

s . 65

tf

O

tt

? . 64
S . 68
? . 9 rS .8S
f .90
5 .8 0

tt
tt
tf
tf
It

t\ r>

• w u

*71
spoiled.
Si4
ll*
r r ■*

co
0

B^rrov^l of' T ^ i v o l ' n t Oh -oral run f"om
Buff^rrd N iok ol S u l f a t e S o l u t i o n
j?nhl*
r hjl^ IV
XV \( f1)1
tm ^nt

p lr f f t * 1”
a d d i t i on
ol* No OH
o t ’i g
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Suwmmry o f ] > t e

on T r i v a l e n t

T ^bi«

r;

C hroV um

(g)

■■pp®'- ’••anor o f T u r b i d i t y
S o lu tio n

A fter ad d itio n
o f be.e^

A fter

ITaOII

m i4 0 H

N iS04

' .5 A .6

4 .5 4 .7

.4 5. 5

HrsBO^

3 .7 3 .8

3. 84 .9

B uffered
NiSO^

U. 64 .7

4 .8 4 .9
v

S o lu tio n

envy

24 hre a t
P -»2 7 °C

Nr 0II

A fter 5 h rs
1 0 0 °G

NH4 OH

Nr OH

NHa 0H

A
A.'o

3 .1 3 .4

b^low
pH 3 . 0 '

i.'. 6 •4.7

3*-• • 3
•S. 5

1 .8 2 .0

below
pH 2 . 0

4 .4 4 .5

4 .3 5 4 . SO

2 .8 0 .9

3 .4 3 .7

P r pc i p i t a t i o n

A f t « r s id i t i o n
o f be s e
1T.-0F

T!K4 °H

M iS04

-1 . 6 •* . 7

- .5 * .7

H ^O .;

»bove
rlT 4 .1

a bove
pH 1 . 0

B uffered
NiSO^

above
' .7 - 4 .9

above
5 .0 -5 .1

A fte r f 1 hre a t
” P - 27°C
Ha OH

t.h :4 o n

A fter 3 h rs
100°C
He OK

above
1 .5 -4 .6

A fter

ps-

hrs

NaOH

at

above
r-H 3 . 8

above
".8 -2 .9

above.
above
Q
: > . 9 - i . O *f *

above
2 .8 --.9

above
pH 2 . 8

above
pH 4 . 6

above
3 .6 -3 .7

above
:: . 8 - 3 . 9

A • ao
—

22-27°C

above
4 .6 -4 .7

A fter

0 h]?s a t

NaOH

NH4 OH
Gr

at

EH^OK

R em o v al o f Chrom ium
S o lu tio n

et

100°G

NH4 OII

5 m g/1 Gr
T*---mr;in
pH 5 . 2

T,e m o v e d
pH 5 . 1 5. 2

9 m g/l r e ­
m a i n pH 5 . 0
3 m g/l r e ­
m a i n pH 5 . 3

7 m g/1 r e ­
m a i n pH 4 . 7
Cr rem oved
4. 7 -4 .9

7 m g/l r e ­
m a i n pH i . 6
C r T,=>moved
4 .7 -* .8

N1S04

3 a mg / 1
rem ain
pH 5 . 1 5

H^.BOg

20 n g / l r e ­
m a i n pH 5 . 0
one 5 . 5

16 m g / 1
ma i n pH
PS mg / 1
m a i n pH

re5 .1
re­
5 .4

B uffered
NISO,;

16 m g / l r e ­
m a i n pH 5 . 3
- mg / 1 r e ^ a j n pH 3 . -A

m g/1
m a i n pH
37 m g / 1
m a i n pH

re­
9 m g/l r e ­
34 m g / l r e 3 .5
ar: j n pH -1. 9 ma i n pH 1 . 7
Q-y, ’' . r , T r 0 Y a J
re­
5 m g/l r e 3 . 7 a a . 0 - 5 .2
m.0 3 n pH 4 . 9

6.00

5.00

5.00

160
i.‘ i l l l p ; r a m s

per L i t e r

o f Copper

F i g . 1 0 - C o r ' e r I n b u f f e r e d end u n b u f f e r e d n i c k e l s u l i u t e m i u t l n n s
a t d i f f e r e n t pH v l u e s :
1 , n i c k e l s u l f r . t » s o l u t i o n u f t - T ” hOH t r e a t ­
m e n t , 3 h r s « t 1 0 C n C . ; f , n i c k e l r u l f a t e r n l ' i t ' o n t f t » r NeOF t r e a t m e n t ,
l \ h r r t:t f 7 ° C . ; 0 , n i c k e l « . , i f - t » r e j u t i o n » f t » r FHiOH t r e - t m e n t , ‘
h r s » t 1 0 0 PC . ; 4 , n i c k e l s u l f a t e s o l u t i o n “ f t " IT!:,,01! f e ' t c e n t , P* h r s
e t P 5 0 C . ‘, 5 , b u f f e r e d n i c h e l P U l f e t e s o l u t i o n r f t s r JS' .01! t r e t t « » n t ,
5 h r s e t 1 0 0 ° C . ; 6 , b u f f e r e d n i c k e l s u l f r t e s o l u t i o n a f t e r Nh .Oh t r e a t ­
m e n t , P4 h r * e t P4 C.

>

0

Romovr.l o f C o r r - ' r f r o m
nickel S u lfrte Solution
Tobio V (o)
pH » ' t o .■.do 31 o n
o f n h aoh
( o ’' i g

r*

nono
r ^ ii"o
fit n ° C
♦1
It
tt
tt

tt
Tt

r-Q

tt

6 . •' 7
6 .6 9
o .e r
- .98

^ . G5
<■ ,9'1
5 .1 7
•"'.•’• I
un • r•' o

tt
tf
tt

:

h^S
t 1 0 0 °C
tt

tt

pH p f t " "
t
t ’Tl«nt

8.ir

5.05
p' . 07
n . 80
6 .0 7
6 . .'-.0
6 .6 0
6. 9
6 . 8'

7 .or
'

o.er.

tl

.-l
6 . '8
6 ,8 9
6 .-7
6 .0 9
6 . 88:
6 .9 8
6 .9 8

tt
tt
ft
tt
tt
tl

165
5)8
A"V;
rA r»p
fl8
'•01
5; 9 0
.75.0
n r
15 6
50

a

a

-» rs
• U KJ

• -i o
•■
kj

A
-

.68
# '/. ■«i“,

A 78
<’ 67
'1 78
A"I A

A

tt
tt

m g / l . Cu
in o o ln .
/i.8 o

cc
•
U

s . 17
: . ’1
o .o f
5 . 6r
5.8 1
e .08

ooln)

T t'" '-tr.o n t

/> n r
' . S'*
. -1fj
c-.- '0
6 .1 5
6 . ^9
6 .6 6
6 .69

sqa

198
5 .8

14
r"

O
o

tf

r

5
r*

tt

6 .75

tl •

n 8*
t; • / •'

i
4.?0

3. 4<J
iu'illigrBfiiB p e r L i t e r o f C o p p e r
F l f , . 1 1 - C o p p e r I n b o r i c e c i d s o l u t i o n e t d i f f e r e n t pH v e l u e s :
1,
tieOH t r e f t : n e n t , 3 h r 9 e t 1 0 0 ° C . : ? , NH^OH t r e e t r a e n t , 3 h r e e t 1 0 0 ° C . ;
3 , NeOH t r e j t i i . e n t , ? 4 h r e e t P3- C . ; 4 ,
t r e r t m e n t , 24 h r s e t P 5 ° C .

r
. ' r'Tn. o v r' l o : O np T" '1'' v •*->n
o o ' ’*io A o i ' ‘ S o l u t i o n
n

pH r. ft'--'"
vO O ition
o-r : 7 7 0 ’ '
( o r io* c’o l n )
A . 65-'
. r :•
5 .0 4
L . 1 '•
o.'O'"
5 .5 8
.8 0
.. 0
/.o 8
u.SO
o .7 o
7 .no
7 .1 :
5 .

6

rvnp
r • hro
' i t ?'5°G
»
"
"
"
"
"
"
"
"
"
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"
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tt
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tt

.

v

( C)

rH r rt^'T
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-

r ip ; /1 . Cu
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*

^-70

5 .:;c
: .''1
5 . Of
••' . 9 8
5 .0 t
'’ . 0 9
■■ . 0 5
,:. r o
: .7 1
C . 5 ‘i
0 .0 1
7 .08
7 .0 1

•*0 7
4 '7
W
7-98
: o
fS9
97
17
7
9
10

'■50
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5 . 9 ^

1.

r 6

75

468
/ 85
-

5 .0 0
5 .1 0

585

tt

5 .1 0

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5 .7 '

196

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•- • ' ' 5 .5 0

IT

5 .50

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.05

50

tt

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tt

o . 683
6 .5 0

tt
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6 .7 3

5
7

•

.

68

6 .: 0

6 .7 5
7 .1:

7 .1 5

'7

U e - i o v r l o r Cop. o f f r o m
r c ' i c A cid ' o j u t i o n

V (d)
pH o f t e r
ad d itio n
o f IHOTT
( or ip

4.7^
R.O f
'■'.I?

f . ‘C1

./ r.

•

<7^

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tt

«

/

r" * r : \

/

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Q t-;

410
o .o -’l

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210

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.19
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■■17
407

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.71

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ff

> . 7 R

r o'*

tt

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tf

ft

tf

ri

A?Q

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?t

100°C

r , 6 r:

•''07

/

f!

•t
.05

m g / l . Cu
in c o in .

tt

*

o n

pH ' f t o r
i . n t

,O p

K

(A, O

!t n r
0 .40

tf

r,- ' 7 0

:

p

o

?!

*1 r -1

7.07

t?

n

r- q

,1

R w i o v r l o f Copper f r o n
B u f f o — d Nickel Sulf'to Solution

T ^b lr v
-Tr j.-,
Pi I e J. t e r
•°dr i t i o n
o f ! l v OF.
orig

00

•

d .n o
4,9 7
• .10
5.?-7
5 .5 5
• ’o<' ■
5 .n n
: .90
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6.1 9
6 . 41
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pH f f t o - ’
t r o r t — 'n t
-

m g /l.
i n so:
4 85

4 .62
4 . 8 r5 .0 ?
5.20
-.2 8
: . '5
5 .-7
5.7 0
-.7 5
QO
6.0 0
6 .25
-•

4 91
AC) A
A f*A.
48?
.1 r-P
554
268
201
16 6
r i
106
61
•5A

4 .1 0
4 .1 2
• V4 . 65

hj"
4 24
4-15
8 A1
501
197
85
n7

hrs
o
o
c1—I
-p

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4 .6 9
4 .8 0
■1 . 9 7
5 .10
5.r7
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5 .6 8
5 .9 0
6 . 00
O' . 1 9
6.4 1
6 .6 2

tt
t!
tt
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A ./ P

tf

^ ;5
4.7 ?
5.1B
5 .56
5 , 68
5 . p?
5.97
6.07

tt

tf
tt
tf
tt
ft

ft

AA

2.7
o

8
11

Sur.vrry o f - a t e on ' ; o r ; - r
T able V (f)
A ppearance
S o lu tio n

A f t e r -■de.ii : o n
**■ *' , r» /
O 1* V

niso,.

of T u rb id ity
A fter

r

f
*•

hrs
r; 0 ri

t

ITa Oil

jUI^OII

F a OF

I!H_r OH

5 .0 5 .1 0

5 .1 n • <i

4.0.9

4 o_
5 .1

O* “

5.A I • '

5 .0 5 .1

5 .0 5 .1

1 6'
:'130.4

5. f::. 7

—

’ . 0

-

■

.1

«•»

A fter L hrs
lot. i°C
ITaOH
bi l o .v
nIT 4 . 9
.

5

-

.

7

at

FH.'OII

Y;
4 .6 4 .0
belov;
pH 4 .

.

}{r v y P m o ^ a i t ' t i on

or

A f t e r r-Cu i t , i o n
r .t b a op
no on

T^i Ob'
J*4 -

ITi 3 0 4

above
pF 5 . 3

above
pF 5 . 6

F 330g

above
pB 5 .

a hove
pF

Bufferec!
: i 304

/ -

14 h r s

ru i'f e re d
HiSCr

at

c
o

r*
•

A ftar s hrs
100°C
F a OH

above
pi! 5 . 5

above
pH 5 . 3

above
pH 5 . 6

••bove

above
pi: 4 . 9

above
pH 4 . 9

>>T7
*. , ..

t;
o

o
• ✓

11b o v e

-rJr £ 7

-

above
•pT' 3 A

-

o f C onp e r

" - ~^7°C

A fter
He OH

5 hrs

at

100°C

HFA0 F

5Ai n r / 1 m - • i n pH 7 . 0

50 r . ~ / l
n - i n -H
11 n r / l
17-■i n rH

f o : p ~ / l I' t - i n ph 4 . 4
7
;/l m 7T i n pH •' , 0

17 n , r / i r e ' r: pH
.7
1 C rr p / 1 m •'■:•' i n r F 7 . 1

-'C m t / l m 5 'I t/l
v- i n pH :?.u 'V i n pi!
.4
6 r.r/I
w i n pH 5 . 7

-

=-t

F in o o

t*e4 .0
m 0 .4

r ‘/ I
i n if"
1 5 7i' 7 1
r'-a i n pH
°1

t

i: b c 3

bove

r .T T
I - 1 I

/nr
n*T
‘■j 4 U

F a OH

F i3 0 4

'

above
pT: 5 . 0

am ove!
a fte r

t r r op
4

i n.oi-r

above
pF 5 . 7

-

S o I n t i on

A f t « r a y hr>r, r. t
; n-p7°C

6 '■ n p / 1 r
rr in'pH . 6 . 4

-

re- ; . r n- i n pH 6 . 1
re- 5 n r/ 1 re­
6 . * s t i n pH 6 . 5

5 7 T lt'/l
r i - i n pit
11 n r / I
w 4 n ri!

re —
'3.0
re4 .6

(16)

F errous I r o n :under th e

K eeping f e r r o u s

co n d itio n s

of

so me d i f f i c u l t y .

it

war p o s s i b l e

adopted

to r

passed

lected .

o b tain

stream

through

fa irly

acid ,

soon a s

th e

placed

in t e s t

to
th e

f -

to

per

iro n

pit 6 . 8

although

neck
genera­

being c o l ­
of a lk a lin e
d istille d

in

flask

series

to

o f g a s was b u b b l e d
th en th e

second
th ese

occurea.

show d e f i n i t e l y

and

from th e

connected

stream

Bven w i t h

ferric

how ever,
at

3 b ubbles

th ree

w ith t h e K ipp g e n e r a t o r ,

f o r tw o m i n u t e s ,

treatm en t,

tio n

series

A rap id

so lu tio n
about

perm anganate

tu b es

re su lts.

from a K ipp

c o n sistin g

s a m p l e s v:ere w i th d r a w n

of n itro g en .
th e

in

w e r e made b e f o r e

sam ples w ere

train s

state

r u n s was a m a t t e r

in a one l i t e r

w h jle th e

p o tassiu m

w a te r w ere p la c e d

w ere

it

reduced

co n sistan t

o f hydrogen

Two p u r i f i c a t i o n

p y ro ,g allic

th e

A number of t r i a l s

to

end a r a p i d

in

fo r th ese

The s o l u t i o n was p la c e d
flask

iron

th at

for

rate
th e

th ey
a tan k

th ro u g h

was r e d u c e d

d u ratio n

p recau tio n s

of

som e o x i d a ­

C urves 1 and

2 in F ig .

ferrous

is

p re cip itatio n

iro n

started

as

not

12,

rem oved

b e t w e e n pH 5 . 0

and 5 . 4 .
B ecause

of th e

of th e

fact

p letely

to

in

form ,

th is

th a t
th e

d ifficu lties

ferrous

ferric
fu rth er

w ere a b e n d o n e d .

iro n

state

is

in v o lv e d ,
read ily

and b e ca u se

oxid ized

co m­

and rem oved fro m s o l u t i o n

e x p e r i m e n t s v.H t h

ferrous

iro n

)

6 .8 0

6 .4 0

6 .0 0

S . 60

5 .2 0

4 .8 0
160

320

M illig ra m s p e r L i t e r o f Iron
Tig. 12 - F e r r o u s I r o n i n n i c k e l s u l f a t e s o l u t i o n a t d i f f e r e n t
v alu ss:
1 , NH4 OH t r e e t m e n t , 24 h r s e t 2 6 ° C . ; 2 . NH4 OH t r e - t i a e n t ,
5 h r s a t 100°C.

n o v e l o f F e r r o u s I r e n from
N irk ^l S u l f ' S o l u t i o n
T -'b le VI
T

tm o n t

pH r f t n ~
* r e ; fro? o t

m g/1 .
in sol

o

§J
O

p! T 'r f t o - ' o d i f f on

(p)

oric;
A. . ^-8
■v . 7 c
.0
* . 50

coin)

none
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'■t ‘H ’OO
ft

11
11

* 85

mm

a1 *

■*

o:

*.67
* .S*
r: • -l *-

09 6
*'
AA o
090
/ r-i /r
•• • r

5 . 78
0 . 10

e n r
• * 2.

ft

G

;* r

fl

6 . 58

6 .78

ft

^02
279
270

Q C-■

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0 .8 0
6 . •■'■■ 2

ft

■*

t0

• ‘

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. r< ' *

t_>

•

n c
f »

a

.

50

r /

5

h ~ s

£
a . 78
8 . Go
5 .-0
5 .9 8
6 . £0
6
2
6 .0o
G . 78
. 2

P t

100°C
If
ft

-:•

.90
.on

ft

eV « ‘V
- ,C,

ft

5 . 80
6.02
6 .2 5

ft

ft
tl
tf

6 . ^ 0

o . 55

406
470
A 2 S

42>6
,110
r/ 7 2

2 28
«:»<-

856

(17)

F erric

Iro n :-

A boric

ferric

iron

at

pi! 1 . 4 - l . f ;

raised

w ith

r. nunon:>un o r

colorstion

appeared

changed

darl: orange

node.

to

Ho v i s i b l e

a pH o f

f.C -f.7

betw een

i' ll 1 . 9

additions
ferric
tost

tho.

and

above
the

pH w a s

sodium h y d ro x id e

a light

yellow

as

1.9,

was

observed

although

the

rem ove d .

five

.°t

in

■'( r i p l e a .

H hours

the

p recip itatio n

down t o

pH l . t - 1 . 7 .

the

solutions

were

we s

present.

At

The
fered

rpret ranee

and

tm buffered

much h i g h e r
The

value

solutions

Above

in

yellow

range

rather

to

bring

more

w ithout

' T h e n pH 5 , r - t ?

effecting

green

large

ferric
tin

co s e

wqs
st

of

base

^ r. d

Over

pH s h o w e d

pH 1 . 5

and

1.6

precipitate

in

the

buf­

solutions

sea

at

of

ge

boric

betw een

sulfate

vw a r e a c h e d , h e a v y

un til

clear.

seditions

pH t o

hydrous

sam ples

th is

settled

sulfate

the

a ll

Between

colloidal

of

wst-'-r b a t h .

below

sam ple

nickel

than

became

the
the

th is

la rg e ly

state

of

but.no

F urther

solution.

coagulation

the

un til

effect.

the

in

w ere

solutions

cuantities

pi!, o f

10C°G

of

pH 1 . 4

the

w*- r. o b s e r v e d

turbid,

base

pH a p p r e c i a b l y

the

m inutes

of

precipitation

Sm all

in

rapidly

how ever,

T yndall

about

raising

- c r 1e r

w hich

additions

showed, t h e

pro c it it''.ti or

period

p”

further

increases

r f t or

5 0 0 r ag / 1

As t h e

brought

a

containing

colorless.

about

f .6

was

large

pH 1 . 9

was

reached,

w ithout

Upon, i con t i n g
volum inous

solution

tu rb id ity

was

iron

caused

at

alk ali

oxide

of

then

of

acid

any

of

into

acid

pH ? . 8
alk ali
the

alone.
and

b.O .

served

colloidal

appreciable

turb id ity

e

was

extent.
noted

(18)

nnd

furtherm ore,

narked

decrease

Curves
there
in

is

36

to

im ately

w ell

or

of

oxid.e

F igs.
80k

of

13,

of

nearly
th is

-

15 a r e

alk ali

caused

in terestin g

pH r a n g e

hydrous

On e i t h e r
in

less

in

nickel

a

betw een

ferric
side

than

3.0

oxide

of

sulfate

is

th is

£4 h o u r s .

in

that

and

3.1

stable

range

pre­

C olloidal

solution

did

hy­

not

stab ility .

14,

the

pH £ . 0

above

F ig.

a narrow

occured

degree

lovr a s

plete

4

of

acidity.

colloidal

ferric

In

additions

the

48 h o u r s .

shov; t h i s

os

3 and

the

cip itatio n
drous

in

actu ally

w hich

for

sm all

and

15

it

iron

is

£.1;

how ever,

com plete
range.

may be

removed

rem oval,

in

in

noted
the

order

the

that

heated
to

pH m u s t

approx­
sam ples

effect
be

com­

raised

10

30

l.VO

1 .5 0
3F0

480

lllifrro iu s y e r L i t e r o f Iro n
F i « . 1 3 - F e r r i c I r o n I n . : i c k e l s u l f e t e s o l u t i o n e t d i f f e r e n t pH r e l u e s :
L . N»0H t r e r t n e n t , 3 h r s e t 1 0 0 ° C . ; P . NH4 0 r t r e e - t m e n t , 3 h r s e t 1 0 0 ° C . ;
3 , *J*OH t r e e t . i o n t , P 4 h r s e t ? 4 ° C . ; 4 , KH^OH t r e a t m e n t , P 4 h r s e t 8 « ° C .

O’o n i o v ' 1 o f F e r r i c I ' ”on f r o m
Nickel s u lf a te Solution
'Tpblo V I I
It ' f t o '1
nd i t I on
o f I'7K4 OH .
( c ” i /3 c o i n )
2.68
s . Of

Treatm ent

n o n- 2 * hrs
et

.18
.. 0
•V

1

2 6°G
"
"
*’
"

* '

tt

2

"

( o r 38 c o i r )
l . a o
1 . .19
1 .7 5
1 . 9 1

ir after
t'-oatrnor.t
2 . G"
2.78
2.7'-.
2.08
8.09

^ v 1!

100°C
"
tT
"

n g / 1 . Fo­
in coin.
420

^

none
8 hr-S
*-t

(a)

-

^17
869

10 108
r<6
0?
8

52.0

1 .^ 7

520

1 . 5 5
1 . 6 5
1 . 7 5

510
4-00
1 2 '1

1 . 9 8

"

1 . 7 4

100

7.1
2 . 5 4.
2.5 9

"
"
"

1.88
1 . 9 4?>.C2
2 . 1'1
2.78
2 .7:
%. 1 5
8.06

1 0 '*
90
58
*7
28
10
7
0

tt

2.12

"
t.

:~.59
tr

"
tt

Re mo v a l o f F e r r i c i r o n f r o m
' Ti c V o i - n i i v t e S o l u t i o n
7"bl^
pH r- f t e r
'•■da i t : o n
o f 'H'OH
orig
y .51
: .01
? .60
? .0?
r .90
5.01
5.10
5.18
5.58
0.60
1.65
1.68
1.88
r.o?

ooln)

VII

(b)

pH n f t ^ r
tre-fo^nt
-

none
F--1 h - ’O
? t ? '°C
tt
tt
It
tt

tt
tt
tt
tt
ft

6 h^ O
of, 1 0 0 c C
tt
tt
tt

£ .ro

tt

l . 51
? . . 68

tt
tt

460

y.* z
r . 53
i
? . 78
F.65
F.79
- .75
r .76
5 .r o
" . 11

AGO
/or
AGO
A5 8
AOO
?ro
f" ~. /*
10 A
17

1.61
1.65
1.70
1.80
1.9?
r.o^
? .09

A G O

<J P O
C • v.

tt

r

.90
: .01
: ■ . 10
> . 16
6.:-8
6 . 6?
r.75

tt

r.is
tr . • 0-o c.

?

♦t

tt

tt

*

r s **'

o ca
? .85
7 . 0^5.11
<-✓ • »

tt
tt

• J_ •

<r>

♦t

n g / l . ¥*'*'
in onin

*•

,

..

6

47?
1^7
98
spo:led
r o
* /

51
■1 4

rj8
r

o
f C
10
O
0

( f
r r

3 .40

3.00

2.60

2 .2 0

0

160
M illigr»m s

480
ppr L it» r of Iron

F i g . 1 4 - K e r r i o i r o n I n b o r i c n c l d s o l u t i o n f i t d i f f p r r n t pH v - I u p s :
1 , NH4 OH t r e a t m e n t , 3 h r s a t 1 0 0 ° C . ; 2 , NbOH t r p f i t Q p n t , 3 h r s f i t 1 0 C ° C ;
3 , NfiOK t r p r . t M P n t , ? 4 h r s n t 2 6 ° C . ; 4 , NH. OH t r p f i t - . f i n t , ?4 h r s fi t F 1 ° C .

He a j o v n l ol' f e r r i c I r o n f r o m
B c ' i c Acid o o l u t i o n
T-ble VII (c)
pH

' f t c v

T " r *.' t r j ^ n t

pH

r f t e r

o d d i t , : on
o f

i n

HIT,, O H

o ^ ip ;

coin)

non°
? /

r

r, n

r, t

hr-f.
« l 0 c

? . 7 0

tf

r . o o
o ■*
■- . o x

Tt
IT

f

Tt

.8 0

• • 0w 04

Tt

- . 1 5

Tf

^."•1

Tt
tt

c o - io

B o l n )

n o r.n

r/
1 . 5 6

r t

-

b o

]

a 6.1

r . r 0
? .7 0

' 9 n
8 5 1

? .0 9

• •? 7

? .0 8
0
r;p
• ^ «r- .*

8 0 8

0 . 7 ?
• O
» 'f

1 0 0

r'

.1.8 . 40

B'MA

r;0
r r

1 0

—

h r s

1 0 0 ° C

1 . 5 0

tt

l.G * *

TT

1 .7 A

»t

1 . 8 5

TT

1 . 9 ?

tl

r - .o ?

r a g /l.

Tt

1 . 3 2

A 6'?

1 .4 8

A I V

1 . 6 4

* 4 1

1 .G 9
1 . 7 ?

? 6 7
1 7 8

1 . 7 ?

1 1 9

1 . 6 ?

1 1 ?

1 . 06

7 4

? . 1 ?

tt

5 . r'C

tt

rC « , j cr>
r

tt

? . 7 0

tt

1 .8 6

?5

ft

1 . 9?

? 0

r .80
r .99

tf

A.1 5

tt
t?

1"O

tt

1 .

p .t >

"6

1 . 8 7

0.-5
? .45
r; r?
P . rtP

14

6
0
O

''e ; n o v r l o f Fr ^ ^io I r o n f r o i i
B o ric .'cid S o lu tio n
T - b l - V I I (6)
pH r f t ^ r
addition
o f N r OH
(orig
r
■.-o
£.63
0
C * r*/ £c
r..9±
3.00
1

3.35
3.65
1.48
1.60
1.78
1.9?.
£.01
T.ir
?.?o
£.39
£.63
£.7?
£.77
£.91
3.00
3.12
3.35
3.65

none
£ /! h ' - S
r t ?C°C
tf
tt
t?
tt

T1
tt
tt
tf

:7 a r s
a t i00°0
tt
ft
tt
tf
tt
tt
tt
tt
tt
ft
tt
tt
tt
tt
tt

m ^ / l . F°
in 0 0 In .

—

1 /. 0

£ .50
2.61
£.67
£.67
£.63
£.00

oe-i
S^l
313

0
0
•
CO

nr
i

soln)

pH ■ f t n r
t.re ' t r ^ n t

r< # c.
a t'p

«_v
...

.

^

V-

1.52
1.64
i.ed
1.70
1.75
1.75
1.74
1.30
1.91
1.95
1.98
£ . 28
£.58
2.48

O rt 1
*’- • / 1
9
pr
1*. • ^ ^

64
43
34
19
8
406
349
140
1?9
97
64
76
37
21
£3
£0
14
O
7
6
4

3.5C

3.10

P . 70

1 .9 0 i

0

460

160
M illiprrns

par L its r of Iron

j ' ir' ,. 1 5 - i > r r r i c i r o n l r . b u f f r r s r f n l e k p l s u l f n t p s o l u t i o n s t d i f f e r e n t
pF vi l u r s :
1 , NsOF. t r p r t n r n t , 3 h r s s t 1 0 0 ° C . ; 2 , NH/OK t r s r t i p M l t ,
3 f i r s f t 1 0 0 ° C . ; 3 N»0ji t r » ; t ; , » n t , P 4 h r s » t
4 , NH.OH t r s a t n p n t , ?4 h r s n t "3*C.

■^or'DV* 1 o f

F ^ -ic
: Ti c k o l

T ^ o n f -om
S ulfate S olution

Trble VII
pH ; f t o r
•-1'■ ’ i t j o n
O f M i , ; 01 "

Tv°' t^ 'n t,

( o i - i ;3 r o l n )

non<=
:,1 h' -r
t *“ O'Of*

7.80
*' O"'
:•.(' •
7 . (V'u l°

• '

-/

If

pH p f t n f
trn r t'-^n t

tt

T?
tt

tt

7 . ?0
T oo

705
,1 77

o no
* .08
7.-R
•••.; 0
: .71

A-

'• l i r s

t io o ° :;
tt

1.7:tt

1 . 8 9

r.ci
T
c. • X
p .V I
7 . 0 - '■
7.80
97
'*. 0 :‘>
7.07.19
7.45
7.55
* )

A

t?

Tf
tr
tt

tt

n
tt
tt
tt
tt
tt

1.G7
l.fiF
1 . 6^
1.77
1.78
1.85
1.97
7 . 0*
r .10
7.17
7 . 18
r-

a

7 7

8”
70
17
17
17

t*

1 . 6
1.67

m ^ / l . Fe
in sn ln .
s 60

tt

tt

7 . 7a

M

4 ’6 5
< a.o
'* r>
C
^

67
71
49
69
4 ?.
79
79
7.0

r2

f. ♦ - 1 ■>
c~-

n

a

8 c5
■'. i )0

>3

T?pyn n v r l o f
I-ron fr o m
Ti uf f oT- oa I T j c k o 1 S u l f ' - t . o S o l u t i o n
T fblo
p!T n f t “ ‘>*
addition
o f N oor

( o ”i g p o l n )
£.43
£.70
£ .8?
£.98
S . 08
5.00
5.0.3 . 1 5
^

s.er
1.4 8
1.58
1.70
1.88
p . 06
P. rp
P.^7
.50
£.70
0?
O

Q P

7 , 1 08
3.06
3|l 5
3. A3
q qp

T'ppptE^-nt

n^ne
‘ 4 hrs
r.t ?3°C
"
"
"
”
”
"

V II

(f)

pi! ^ f t ° v'
tr o t^-nt

ms/ 1 I p
in so ln

-

455

P . 50
P . 74
p . 05
P . 70
^.OB

-15 5
^ 19
4?: p.
r 9f
408
580
365

P . 75

P. 85

"

" . 0 1

7£

If

3

P A

”
3 h'-s
r t 100°C
"
"
"
"
"
M
*'
"
«
».
"
"
«
"
n.

^

3.63
1.50
1.61
1 .6?
1.71
1.81
1 . 68
1.07
2 -OJ
?.H
f . 15
p . 19
?.77
'3 .3 6
£.69
2.05
3.13

°o
455
- ' 15
1^4
70
48
50
A P

"1
79
60
20
IP
6
12

Summary o f Th'to
Table
A’T e - r a n c e
S o l u t i on

A f t e r rul e i f i o n
o f bRse
NaOH

n h a oit

r

NiS04

3.43. 5

on F o ~ ~ ic

VII

Iron

(rr)

of T urbidity
A f t e r PA h r s
33 —7 7 Of}

et.

i f t e r 3 hrs
1 0 0 °C

at

He OH

n h a oh

NaOH

NH/i OH

3 .3

3.73. 8

r .5r.G

1.51.6

1.51.6

H.

7 . 63.7

P.73.8

3.43.5

C. 4 r- v

1.41.5

1.41.5

Buffered
:ri s o 4

■
■v• i cs
. —
• •o

■• rf
■■• A.“
/j *

r . 8r .9

3 . 6' ■. 7

1.51.6

1.41.5

n o r v y ?>••• c j ; i t

Solution

A f t r a 3 d i t i on
o f b; r o

tion

i f t e r ‘‘ 4 h r s
?P-f7°C

at

f'fter 3 h rs
io c°o

at

1H0H

^ar
... ^ Ury-T
j»

NaOH

HH4 OH

NaOH

»tt r /-yrr

TJ i S0 4

f'bnve
pH 3 . 3

above
pH 7 . 4

pfeove
pH ^ . 1

t bove
vLit
-.TJ- *v • r'

eibove
pH 1 . 9

above
pH 1 . 0

11*30^

above
pTI 3 . 7

nbove
pH ^ ' . 0

nbove
rTT ‘-•. 6

bo-.-e
pi:

above
nil 1 . 8

above
r Tr 1 . 8

NiS04

r bove
pK 7 . a

above
pH 7 . 3

above
r>T: ", "
f 11 • '

r. b o v e
pH 7 . 7.

above
rH 1 . 8

above
pH 1 . 8

R e m o v a l o f F^r-'-ic
Solution

in ter

34 h r s

NaOI-T

NiS0A

T' uf f e r e c
H i SO,

at

17

7° C

I ” on
ofter

3 hrs

NaOH

NK4 OII

at

100°C

NKa 0 H

1 0 my / 1 r e ­ 7 8 m y / 1 r e ­
m a i n pH
. 4 m a in til 3 . 1
7 my/1 r o ■'<. 3 - 0 . 7
rn: i n pH 3 . 5

17 r n y / l r e v a i n ] 11
3 m p/l re in rr
.5

8 m y / I F e -/
i'
in
pH ’ . 3

19 " ' p / l r e rn:- i n r l ! 7 .
8 m y/l ro n.' i n pT' 3 . 7

7 ' n:;/l r e ­
3 0 mp / 1 r n am i n pH
Tm i n pH 7 . 8
1 0 re v / l r o — 8 m y / l v e - n - i r - 1^ •-#o
a’- i n pH ' . 7

1 4 m y / l '-e m a i n pH 3 . 0
•' n v . / l -:*ovr>'. ^ n. T'^T • • • }

c 0 m .v/ l r<'n;; i n V] r 3. . P>

PC m y ' ]
'f" .in pH
13 m y / I
rn:. i n : :

3 7 '' -/].
m i n j'i'
3b m p / l
m a i n pH

re3.3
-•©7.9

7 0 o-’ / l
m a i n -■H
.1
1f ^ /1
—
v v
f
3.6

'*0 —
7.3
re­
■■..a

(19)

Zinc: -

Z i n c v/ns n o t

sulfate

solution

opprecicT ly

w ith

either

ide u n t i l

a pH o f

Tip;.

Id.

Thereupon th e

w ith

ammonium h y d r o x i d e

tion

com pletely

removed

ammonium o r

S .4 was re a ch e d ,

at

as

the

zinc

after

is

sodium h y d ro x ­

n a y be

curves break

ptT 6 . 8

from n i c k e l

quite

seen

from

rapidly

removed

and

from s o l u ­

b e in ’ heated

for

3 hours

at lon°c.
It

was

not

possible

to

c-'rry th e

sodium h y d ro x id e

to

a pH h i u h c r

derable

of

the

dilution

Amain i n
solution
showed
at

visual

that

in

case

the

solution

precipitated

tion

alone,

but

o .6 w ith o u t

buffered
were

of

nickel

than

possible

of

the

separation

r o l n r o f,,r a e h i c
points
here:

work w ith

conveniently

use

of

for

this

either

(1)

In

order
at

token.

III4 CI o r

the
(2)

of

o t h e r w i s e , an w e ll

to

lower
In

the

nickel
an

a combina­

Cummings

(19)

(20),

zinc

concentrations
form ic

and

and w i l l

sufficient

m ixture,

be
to

fifty
the

recommended, b u t

preferable,

since

ammonium s u l f a t e

some z i n c

of the

a n d 7/a r e

bo n o t e d

have

sul­

overlooked.

w h ich was

( NH4 ) P3 0 4 w e r e

c a s e MH4 C I w a s f o u n d

w a s a 1 ' mpe a m o u n t

be

of ra le s

should

in n ic k e l

effect

o f Heed and

im portance

m entioned

sam ples were

method

procedure

of

ml.

analysis,

A nalyses

was p r e c i p i t a t e d

n ic k e l hydroxide must not

c a r r y ins, o u t t h e

consi­

sulfate

no v a l u e .

zinc

solution

the

with,

concentration.

sam pler

this

In

several

ted

of the

heated

flan

ion

observations

a m u c h l o w e r pi I i n

fate

the

the

zinc

precipitation

there

precipita­

cn;.:oni.ura s u l i a t e .

(?0)

(3)

It

was

essential

before

saturating

nickel

sulfide

p recipitation
sulfide
he

is

wa.
was

not

dissolved

in

that

the

solution

bo a t

pH £ . 0

w ith hydrogen

sulfide

gas,

otherw ise

e r e c i t it.a t e d

and th e

zinc

sulfide

incom plete.

objectionable
cold

A sm ell
since

the

1 : 1 KC1 l e a v i n g

amount o f n i c k e l
zinc

tlie

sulfide

nickel

may

sulfide.

7 .0 0

160
fc.llllt;roi».s p e r L i t e r

3?0

480

o f Zlno

f i g . 16 - Z in c In b u f f e r e d e r f 'i n b u f f e r e d n i c k e l s u l f n t e s o l u t i o n a t
d i f f e r e n t pH v r l u e s :
1 , N i c k e l s u l f a t e s o l u t i o n e f t e r HH.OK t r e a t m e n t ,
3 h r s f i t 1 0 0 ° i J . ; £, N i c k e l s u l f a t e s o l u t i o n a f t e - NH.OH tre>'t.T,ent, ? 4
h r s e t P 6 ° 0 . ; 3 , N i c k e l s u l f a t e s o l u t i o n a f t e r NaOH t r e a t m e n t , 3 h r s
e t 1 0 0 n C . ; 4 , N i c k e l s u l f a t e s o l u t i o n a f t e r NnOH t r e " t . : . e n t , P 4 h r s a t
g r ° C . ; f ' . B u f f e r e d n i c k e l r u l f e t a n o l u t ’ o n e f t . - T I . H. Oh t r e ■ ■ t i e n t , 3
h r s a t 1 0 o ° 0 . ; 6 , b u f f e r e d n i c k e l s u l f r t e s o l u t i o n a f t e r NH.OH t r e a t ­
m e n t , P4 h r s e t £ 5 c C .

Removal o f Z inc from
H i o k o l SuVi'nte S o l u t i o n
V I I I

pH r f t n ~
^ d d it'o n
o f NlfOK
(c 'i"

Trni

o-'ln)

5 .''?
5.15

? '
at,

5

5.15
! ,?5
5*A5
5.00
5.89
5.10
6.50
6.58
6.85

pH p f t ^ '
t ~ r.tHpnt

n^np
hno
26°C

6 no

”

?■.■'7
S . 59
' . 9r

Pr 0
*10
A 10

"
"
«

0.20
6 . -HI
6.7?

~9G
^0
10C

J l I ’S

r, t 1 0 0 ° 0
"
«
"
”
"
"
"
"

5.09
r .?l
5.55
5.58
5.01
6.0?
6.r;l
6.58
6.67

Trble VIII
pH o f t e r
addition
o f H p OH
(o' ^’i . p s r l n )
6.6
6 .98

Tvor.tn.ent

nor.p
?a I n s
7a t ? ? ° 0
"
”
tt
TT

6.1?
6 . T9
G »^ 7
6 .5 5
6.65
C . 65

^g/l •
in s o ln .

-

"

5.59
6.50
6 .59
0.95-'

( r )

•V l O °G
ii

"
i’

A ■
A'/>/
150
550?
400
r<90
590
80
0

( 1>)

pH p f t e r
t T*' ■ t ' m n t

m g / l . Zn
in °o ln
00

6.08
6..'0
.rd
5.60

6.0?

A9 8
n o6 ‘
/ 50

- 9P

o . 19

"' 8 .-'

6 .6 . ‘'-5

.'■■ro
960
26?

R^novr.l of Z in c from
Buffovor1 H i c k o l S u l f r t e H o l u t i o n
fpfle
pH f i ' t o v
■ dd i t ^on
o f NIT,-LOil

T

V IIT(c)
pH
t " “ r. t m ^ n t

m g / l . Zn
in " d n .

(21)

M ixture
The

of

results

en tirely
Ferrous
pH o f
not

M etallic
obtained

in

using

rem oved

plained
the

for

at

fluence
that

of

expressed
study

of

in

sam ple;

/

p -

tio n

then

ab

ion

-

the

th is

upon

in

ion

original;

removed

from

v/hereas

alone

it

was

-

partially

of
a

from

adsorption,

the

ex­

as w ell

S im ilarly,

ion.

The

as

solu­

other
or

in­

fact

investigation

com parison w ith

are

the

d ifficu lt.
(a)

and

scheme:

but
tr

a

single

concentration

present,

at

occured,

to

any

IX

trace

was a d s o r b e d

m etals

T ables

to

ions.

a

oxide.

makes

follow ing

same

it

portion

individual

may he

oxidation

S olution: -

o f m e ta ls were n o t

reduced

attrib u ted

ions

the

the

of

This

alum inum

individual

approxim ately

was

some o f

q u alitatively

to

S ulfate

m ixture

those

6 .6 .

th^t

thet

sym bols

according

/

fact

other

the

The

w ith

pH o f

may be

results

the

exam ple,

hydrous

discrepencies

/

a

by t h e

by t h e

N ickel

ammonium h y d r o x i d e ,

p o ssib ility

tion

in

w ith

agreem ent

iron,

5.4

Ions

in

as

P in

are

ion
the

of

the

i

used

present

in

original

a much l o w e r

a trace

solution.

(b)

concentra­
ion

present;

K irtu re of N e t e l l i c I n p u r i t i e s in
N ic k e l Sulf- t e S o l u t i o n
T a b l e IX (a
PH
after
NH4 0H
adan

FepH
48 hrs 3 hrs 48 hr
after
48 hrs
at
at
et
at 25°C ?5 C 100°C ?5°C

4.90
5.40
5.82
5.98
6.18
6.35
6.4?
6.50
6.60
6.75
6.93
7.00
7.1?

4.68
4.78
5.10
5.44
5.93
6.17
6.35
6.3?
6.60
6 .7 3
6.93
7.00

7.1?

P
tr
ah
!l
tt
tt
tt
tt
tt
tt
tt
tt
ft

P
ab
tt
tt
tt
tf
tt
ft
tt
tt
tt
tf
tt

ab
tt
tt
tt
ti
tt
tt
tt
tt
tt
tt
tt
tt

Zn
Cu
3 hrs 48 hrs 3 hrs 48 hrs 3 hrs
at
at
at
at
et
100
1C0°C
100°G ?5°G
?5°G
ab
tt
tt
tt
t»
tt
tt
t»
tt
tt
n
t*
it

P
F
P
F
r
p
a
tr
ah
i.

v
tt

TT
TT

F
F
P
P

F
F
P
P

Tt'

•p

V>

r>
F
p

P
ab
tt
tt
tt
tt
tt

1-

P
P
P
F
P
r
p
p
x

is

p
tr
P

ab
tr
ab

Table IX (b)
PH
after
NaOH
addn

Cu
Zn
pH
A1
Fe++
3
hrs
3
hrs
?
4
hrs
84
hrs
3 h
3
hrs
24
hrs
after
84 hrs
at
at
at
at
at
at
24 brs
at
at
100°G
26° J
86°C 100°C 86 °C 100
at 1 6°0 86°G 100°C

4.97
5.25
5.45
5.80
6.00
6.42
6.65
6.80
6.90

4.
4.39
4.47
4.41
4.52
4.54
5.05

P
p
V

p
r
Y'

r

p
p
r

tr
tr
tr

tr
tr
ab

rb

tf

Tt

tf

tt

r> n
• ( f -

tt

tf

ft

t»

5. GO

tf

f?

t?

tt

cr

tt
Tf

T*.

tr
tr
ab

ab
tf

T>
j.

}'
.

P
T:
P
T)

V

ab

p
P
P
P
P
P

tr
ab

P
r
P
P
P
P
P
y
tr

P
P
T>
X

p
p
p
i '
v>

a
ab

i£

ti
Cr . . ( OH) r

are

b; t h s

it

that

of

obtained

this

u;on

It

w ill

the

to

in

6.0

the

allow

the

fact

that

are

much l e e s
in

at

Table

Ca(OIT)-

at

and m a i n t a i n i n g
solutions
'’d d e d ,
in

Table

the

X (c)

th e n to

were
w ith

s t - no

’u n b u f f e r e d

at

solution

6 .0 .

Ca(0]Or

did

s auapd. es b u t
data
to

attain

in

the

is

(27)

o f Ce(0Ir) r

for

Vi e ?. t i n y , c o n t i n u e d

for

in

to

buffered

This

1C0°C, th e

obtained.

pH 5 . 4

pH

m a x i m u m pH i s

re a c t w ith

tem perature

the

very d e f in ite ly

the

out

XiCOg

raise

only to

indicate

carried

the

e i t h e r ITiOOg o r Go (Oi l ) 5, .

room t e m p e r a t u r e , t h e n

wore

X shows th e

solution

was

to

and un­

solutions

higher tem peratures.

th is

ma x i m u m

shaking.

solub ilities

v/e^e h e a t e d

and

allow ing

C n ( 0 H ) oc. t o

X (b)

the

buffered

T-ble

plating

sulfute

The

the

determ ine

sulfate

room t e m p e r a t u r e .
the

nickel

nickel

unheated

TTiCO-,•„ o r

NiC03 and

in Table X (a)

6.0 w ith

proper procedure

the

data

in th e

pK t o

sam ples.

at

and

that

above

the

the

solution

series

The

nickel

of

w ith

study.

buffered

raise

heated

that

obtained

solutions.

seen

in- t h e

to

sulfate

raised, w e ll

How ever,

above

bo

kince

purification

interm ittent

be

a n d IlmO: -

desirable

trea tin g

f. 7o 0 w i t h

failed

in

Or. ( 0' T) i and. TfgO a n d
~

l Ti C O f. ,
».*)

r-H w a s

used

could

nickel

results

-T -

often

Ca(OH)..

v/as t h o u g h t

pk V ' l u e s
buffered

N i OQ, ,

2)

accordance

with

n n d HiCO^

The h e a t e d

by a d d i n g
heating
3 hours.

I Ti C0 3 a n d

t h e NiC03

to

100°d

. . lien t h e
' Js ( O h )

b b o u rn , the

data

pH V a l u e s o f N i c k e l
C ontainins l.n s/1

S u l f a t e S o l u t i o n (300 s / 1 )
o f N i C 0 3 , C a ( 0 K ) g a n d MgO

Table

Time
1 hour
? days
1 week

X (a )

Ni00s

G a ( OH )

pH

pH

pH

6 .34
6.4?
6.4?

6.59
6 . 6?
6.61

6.67
6.69
6.68

p

MgO

pH V a l u e s o f B u f f e r e d a n d U n b u f f e r e d N i c k e l S u l f a t e
S o l u t i o n s T r e a t e d w i t h 5 s / 1 o f NiCO^ a n d C a ( 0 H ) g
Table
olution

SubSt.
added

I!iS04

NiCO'/.

pH b e f o r e
t r e ritment

NiS04

Ca ( OH) 8>'.

?.. 8 9

B uffered
j Ti SO^
B uffered
HiSO.
B uffered
NiSO.
Buff ered
N iS04

NiGOrr,
kJ

3.70

Mi CO^

2.70

G a ( O H ) ft
c

?

C a ( O F ) £«•.>‘

? .70

2

. 70

T elle

NiS04
B uffered
WiS0 4
IJiSC4
B uffered
TTi S 0 ^

pH a f t e r
treatm ent
6.42

at 2b C
3 hrs
a t 100°G
6 hrs
a t 25°G
3 hrs
a t 1 0 0 °G
6 hrs
a t 25°C
3 hrs
a t 100°G
6 hrs
e t 35°C
3 hrs A
a t 100 G

. 89

NiSO .

o

O
("H

? . 89

23

N i C O r,
o

Subst.
added

Treatm ent

? . 89

N i S O 'i
,

S o l u t : on

X (b)

6.52
6.71
6.63
5.80
5.22
6.30
5.40

X(c)

pH b e f o r e
treatm ent

Treatm ent

pH a f t e r
treatm ent

3 hrs
a t 1 0 0 °C

6.39

MiGOg

3.18

N i CO^

3.00

ti

o • 12

C a ( OH) f

2.97

H

6 . 58

Gc

2 .04

tt

5.3?

( OH)£

(T3)

C V e n e m ! C o n c l u s i o n s :-.
ception
end

of hexevalent

p recip itatio n

values

In

from

prenerel

chromium)

a fte r

heating,
solutions

unbuffered

nickel

sulf

te

rem oval

im purities

et

sulfate
more
in

low er

in

those

solutions.

rem oval

sol.viti.ons

the

that

th at

of
were

were

nickel

case

allow ed

for

to

or
the

sulfate

be

im purities

heated

pH

of unbuffered

As m i y h t

the

low er

Furtherm ore,

from b u f f e r e d
in

ex­

from b u ff e re d

solutions.

pTT t h a n

fo r heated

efficient

the

than

a

than

notable

p recipitation,

occur at

acid

starts

the

in itia l

boric

of

(w ith

expected,

was

effected

3 hours

stand

nickel

et

100°C ,

P8~P7°G

at

for

P4 h o u r s .
In
and
in

the

ferric
the

tins;

esses
iron

heated

to

of

the

alum inum ,
hydrolysis

sam ples

0 .3-P .5

in

the

triv alen t
process

form

of

chrom ium ,

m anifest

a drop

in

copper

itself
pH a m o u n -

units.
ultima r y

1.

The

valent
fron

rem oval

of

chrom ium ,

buffered

alum inum ,

copper,

and

ide

and

sodium h y d ro x id e

2.

The

rem oval

tion

3.

was

The

of

copter,
studied

ferrous

unbuffered
!, 7°C a n d

r 1' r o r i u u

c-dm iun,

at

and
a tt

nickel
100°C

whenever

cadmium,

m a x i m u m pH v a l u e s

f 7°C

iron
and

and

hexa-

ferric

iron

and

sulfate

have

been

zinc

nmonium hydroX '

vising

possible.

trivalent

ferric

PP. -

arh

trivalent

and

from
at

hex& valcnt

boric

100°G

acid

usinp

soluam noniun

( r.4 )

unbuffered
C ./l»
G hours

nickel

sulfate

solutions

o f N i C 0 j5 a n d C a ( O K ) r .
at

obtained.

??. -

and

L-7°G o r h e a t e d

were

treated

thoroughly

for

Z hours

with.

stirred
at

for

100°G w e r e

L iterature
1.

K ild ebrand , J .J .

.Am.

2.

B ritton,

J .

3.

nt.kins

•*.

P atten

5.

P ickorir.r,

9.

IT iller,

7.

Blum,

P.

Joffe.
(1228)

9.

P ridesur,

K .T .S .

Chem.
Chen.

T ra n s. Faraday
and

Soc.

Soc.

Assoc.

S.U .

J.

Chem. J o e .

J.

Public

An.

J.S .

end

Chen.

310

O ff.

A'<r.
91,

H ealth

3oc.

1282

J.R .

10.

H ildebrand, J.
(1913)

end

Bowers

J.

Ain.

11.

L o l t h o f f , 1.1',
832. ( 1 9 3 1 )

end

K e n ad r . , 7 .

J.

12.

B r itto n K .T .S.
£ 7 , 809 (1931)

end

W escott,

13.

liecl!oU fhton,
491 (1930)

14.

Thomas

nnd

I*.J.

Blum

and Kannond

Trans.

Chem.

4,

38,

Chen.

1995

8 6 .,

05,

Soc.

An Chem.

Trans.

E lectrochen.

83

Soc.

Faraday

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48,

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Soc.

4 5 , 249

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Trans.

E lectrochen.

Soc.

4 6 , 107

(1924)

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E vans,B .S.

P inner,
, S o d e r b e r g , G. and B a k e r , E .K .
E le c tro c h e n . Soc.
8 0 , 554-574 (1941)

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K ales, K . a
487 (1919)

20.

Re°d,
A nal.

7 / n r o , G-.P.

Soc.

£6 ,

(1925)

(1921)

IP.

and

53.

Soc.

C lectrochem .

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785

Faraday

Trrns.

36

(1940)

38,

I'adsen

46,

(1923)

47-59

15.

A nalyst

(1920)

(1916)

A nalyst

Trams.

£33

(1907)

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O.B.

(1925)

(1923)

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one K e n e ss,

(1913)

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Perorts

38,

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J.

U .S.

35,

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tains

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C ited

J.

J . F . a n d Cur:i;:iin{?s? A . A .
Ed. 12, 48.

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Ind.

and

Trans.

Soc.

Enj.

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r.l. L a m b , A . B . e n d -’or. Aa , G . R .

( c.ont)

J.

' An.

Chen.

Soc.

4-3,

I l f >4 ( 1 9 2 1 )
22.

M o n t e - H a r t i n i , G. a n d V e r n a z z r , E .
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25.

Denham

24.

Thom pson, !'.R . and Thomas,
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4 5 , 79 (1922)

25.

n i u n and Uo.uatoon
’’P r i n c i p l e s o f E l e o t r o n l a t i m p
D lectroform inr;”
PS 2 3 3 - 2 3 3 ( 1 9 3 0 )

and

2G.

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(1936)

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Z.

anory.

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Chem.

J57,

G .T.

M ethods

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V ol. 1

of

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Industria

C hinica

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Trans,

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Inorganic

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f oa .

E lectro-

V ol.

1,

O rganic

Com­