3,872,209 Ion exchange process for the recovery of metals

Patent Number/Link:

United States Patent [19]

Hazen et al.

[II] 3,872,209

[45] Mar. 18, 1975

3,592,775 7/1971 Swanson 260/566

13 Claims, 7 Drawing Figures

Primary Examiner-M. Weissman

Attorney, Agent, or Firm-Sheridan, Ross & Fields

A process for recovering copper values from an acidic

aqueous medium which comprises contacting the medium

with a mixed extraction reagent. The reagent

comprises an organic solvent having dissolved therein

a 2-hydroxy benzophenoxime or mixtures thereof and

an organo phosphoric acid in an amount up to about 4

percent by volume of the solvent. The invention includes

the composition comprised of the substituted

hydroxy benzophenoxime and the organophosphoric

acid.

[57] ABSTRACT

[54] ION EXCHANGE PROCESS FOR THE

RECOVERY OF METALS

[75] Inventors: Wayne C. Hazen, Denver; Enzo L.

Coltrinari, Arvada, both of Colo.

[73] Assignee: Hazen Research, Inc., Golden, Colo.

[22] Filed: Mar. 17, 1972

[21] App!. No.: 235,623

[52] U.S. CI•.................. 423/24,75/101 BE, 75/117

[51] Int. CI. COlg 3/00

[58] Field of Search 423/24; 75/101 BE, 117;

260/566 A

[56] References Cited

UNITED STATES PATENTS

2,992,894 7/1961 Hazen et al... 423/24

3.872,209

2 3 4 5

CONTACT TIME - MINUTES

234 5

CONTACT TIME - MINUTES

EFFECT OF AND VERSATIC ACID ADDITION TO

L1X64N ON. COPPER EXTRACTION RATE

LEGEND

--0-- L1X64N, 10%,NO DEHPA

-G- . lIX64N, 10% + 1% DEHPA

-A- L1X 64N,10% + 5% DEHPA

LEGEND

-<:l- lIX64N, 10%+1% VERSATIC ACID

~ L1X64N, 10% +5% VERSATIC ACI D

LOADING RATES OF L1X64N WITH

AND WITHOUT DEHPA ADDITIVE

"- ""

0'-.. ---------- .

(;)

'GJ"",

z 1.0

u::

l.L..

0::

~ 0.8

0::

Wn.

n. 0.6 0u

...J

l':>

0.40

1.2

i:L

l.L..

0::

~ 0.8

0:: wn.

u0 0.6

...J

"- l':>

0.4

EFFECT OF OLEIC ACID ADDITION TO L1X64N

ON COPPER EXTRACTION RATE

LEGEND

-0- lIX64N, 10% - NO OLEIC \CID

......,.&- L1X64N, 10% + 1.5% OLEIC ACID

-0 ..

--fr.-

tJ.q:. 5

4 6 8 10

CONTACT TIME - MINUTES

! !

22 23

F1\TENTEO MARl 81975 3.872,209

SHEET 2 Of 3

EFFECT OF DEHPA ADDITION TO KELEX 120

ON COPPER EXTRACTION RATE

1.6 .

1.4

1.2 w....

Zl-J.. 1.0

lJ..

0::

-z 0.8

0::

Wa.

a. 0.6 0u

lJ..

0.4

...J ......

0.2

0 2

LEGEND

----0- KELEX 120, 12.5 % , NO DEHPA

----tr- KELEX 120, 12.5% + 1% DEHPA

t.lq: 6

-0- I ,

4 6 8 ,10 22 23

CONTACT TIME - MINUTES

100

EFFECT OF DEHPA CONCENTRATION IN L1X64N

ON COPPER STRIPPING

2 90

en 80

t.lg: 7

70 f a I

~ I

a. I

a:: 60 f

I- I

en I

50,

0::

Wa.

~ 40L.---'-----'----'-----'----L o 2 345

VOLUME % DEHPA

3.872,209

SHEET 3 O...F.. 3.

LEGEND

---{)- KELEXI20, 12.5%

~ LlX64 ,10%

--e- L1X64N ,10 %

~ L1X70 ,7.5%

4 6 8 10

CONTACT TIME - MINUTES

COPPER EXTRACTION RATES FOR KELEX 120, L1X64, L1X64N

AND L1X70 WITHOUT DEHPA ADDITIVE

<l:

<l: a:::

a:::

0- 0.8 0-

-l

("!-) 0.6

0.4

o.2()

<l: a:::

tt:

00o

-l

"(!)

EFFECT OF DEHPA ·ADDITION TO L1X70

ON COPPER EXTRACTION RATE

LEGEND

~ L1X70, 7.5 %, NO DEHPA

-b- L1X70, 7.5 % + 1% DEHPA

o 234 5

CONTACT TIME - MINUTES

7 8

fJ.g:. 3

3,872,209

SUMMARY OF THE INVENTION

DETAILED DESCRIPTION OF THE INVENTION

phenoxime) is quite slow, commonly requiring as long

as four minutes to reach equilibrium in a batch agitated

system at room temperature. Because the solution flow

rates in a copper leaching plant are very large, the size

5 of the mechanically agitated vessels required for a mixing

system to contain and mix the required solvent and

aqueous for this long a time are large and expensive. In

addition, in a continuous mixing system it is not possible

to achieve the true chemical equilibrium that is

10 achieved when materials are agitated in a batch. This

is because of the well known phenomenon of short circuiting.

In fact, as a practical matter, a mixer designed

for copper extraction is calculated on the basis of only

80 percent of the extraction equilibrium that would be

15 achieved in a batch tank having the same residence

time.

The dollar value per unit volume of a copper leach

solution containing a few grams per liter of copper is

very low, thus the capital investment for an appropriate

20 mixing system is quite high for the amount of copper

which is being treated. The depreciation costs, therefore,

per pound of copper are high and to that extent

it diminishes the value of the solvent extraction process

for the copper industry.

Much of this disadvantage would be overcome if it

were possible to accelerate the rate of transfer of copper

from an aqueous leach liquor to the solvent and its

reverse, the stripping of copper from solvent into an

acid electrolyte. This objective is achieved through the

30 present invention through which the rate of extraction

of copper from an acid solution by the specified copper

extractants, LIX-64, LIX-64N and LIX-70, is enormously

accelerated by the addition of small quantities

of organic phosphoric acids.

The invention relates to the use of organophosphoric

acids as additives to the 2-hydroxy benzophenoximes

represented by the trade name products LIX-64, LIX40

64N and LIX-70 sold by General Mills, Inc., to greatly

increase the rate at which these products are loaded

with copper when used as ion exchange extractants to

recover copper from acid solution. It comprises a

method for recovering copper values from acidic aqueous

solutions by contacting the solution with awaterimmiscible

organic phase comprised of an organic solvent

having disclosed therein as an active extractant a

2-hydroxy benzophenoxime or mixtures thereof and an

organophosphoric acid in an amount up to about 40

percent by volume of the organic solvent. The invention

includes the composition comprised of the 2hydroxy

benzophenoxime and the organophosphoric

acid.

Two-hydroxy benzophenoximes operative for the invention

include those disclosed in U.S. Pat. No.

3,428,449 issued to Ronald R. Swanson on Feb. 18,

60 1969. These compounds are ion exchange extractants

for copper values in acid solutions. Individual compoqnds

or mixtures thereof may be used. Methods for

making these compounds are disclosed in the same patent.

As disclosed in the above patent, 2-hydroxy benzophenoximes

having the basic structure,

< ~8:~->,

BACKGROUND OF THE INVENTION

ION EXCHANGE PROCESS FOR THE RECOVERY

OF METALS

The solvent extraction process is finding increasing

application in the field of extractive metallurgy. It is

commercially used for the recovery of uranium, copper,

tungsten, molybdenum, rare earths, beryllium, and

other metals. Its wide application is because of the

availability of organic solvents with specifically selective

properties for a given element. The specific organic

solvent can be used to extract from an aqueous

solution and purify one metal element from a mixture

containing many contaminants.

The most recent wide use of solvent extraction is for

the recovery of copper from dilute sulfuric acid solutions

such as those obtained by leaching a copper oxide

ore. This use has been made possible principally by the

development of specifically copper selective solvents

such as the extractants sold by Ashland Chemical Co.

under the trade name Kelex, and those sold by General

Mills Co. under the trade names LIX-63, LIX-64, LIX64N

and LIX-70, the latter three inclUding substituted

2-hydroxy benzophenoximes as the active extractant. 25

The copper selective solvent sold under the trade

name LIX-63, an alpha hydroxy oxime, is not operative

in solutions of the acidity normally encountered in acid

leaching while certain other types such as the sulfonates

and organo phosphates are non-selective and thus

have no present use in copper recovery.

The equipment for the application ofsolvent extraction

to extractive metallurgy has usually consisted of

multiple stage countercurrent mixer-settler systems in

which the barren organic solvent and the pregnant

aqueous stream (usually a leach liquor) are mixed together

for a given period of time after which they are

permitted to separate in a settling reservoir. The solvent

and aqueous then flow in opposite directions to

the next stage of contact.

During the mixing step in conventional systems for

copper recovery, the driving force for the transfer of

the copper from· the aqueous to the organic phase (or

in the case of stripping, the transfer from the organic 45

to the aqueous phase) depends upon the difference in

concentration of copper in the aqueous and the organic

phases. If agitated long enough, eventually a chemical

equilibrium is achieved and no further transfer of copper

takes place between the aqueous and the organic. 50

The concentrations at which equilibrium is reached will

be dependent on the organic solvent, the acidity of the

solution, temperature, etc. In order to achieve maximum

efficiency in the system, it is highly desirable to

have each mixer come as close as possible to this chem- 55

ical equilibrium before the material leaves the mixer

and flows to the settling tanks.

The size of the mixing equipment which is required

to achieve chemical equilibrium within a given time

will depend fundamentally on the extraction rate of the

particular organic solvent being used. It is known that

those solvents which have been developed specifically

for the extraction of copper are much slower in their

extraction rate than are the solvents used specifically

for extraction of some other metals, as for example, 65

uranium. The extraction of uranium with a tertiary

amine in acid solution of pH 1.5 isvery fast, a matter

of seconds, whereas the extraction of copper from acid

solution of that pH by LIX-64N, (a substituted benzo3,872,209

wherein R anaR/maybehydrc>gen,-aliphatiC~-aryl,

50 aralkyl and wherein not more than one R is hydrogen.

The term aliphatic includes branched chain radicals

and alkyl or aryl substituted radicals. The term aryl includes

alkyl substituted aryl radicals.

The organophosphoric acids which can be used in-

55. c1ude di(2-ethylhexyl) phosphoric acid, octyl phosphoric

acid, dodecyl phosphoric acid, amyl phosphoric

acid, isoamyl phosphoric acid, heptadecylphosphoric

acid, die I-methylheptyl) phosphoric acid, di-isooctyl-

60 phosphoric acid, die 2-ethyl-4-methylpentyl) phosphoric

acid, di(2-propyl-4-methyl-pentyl) phosphoric

aC\d, octylphenyl phosphoric acid, .di-phenyl phos.

phoric acid, the isooctyl or stearyl derivatives of alkyl

acid phosphates and others. Of course, these com65

pounds can be used in the form of their phosphates.

It has been found thatthe tri-substituted organophosphoric

acids, such as, triphenyl phosphate are inoperative

for the purpose of the invention.

such as halogen, ester, amide, and the like. Likewise,

the aromatic nuclei can contain inert substituents. By

inert is meant that the said constituents do not affect

the solubility, stability or extraction efficiency of the

5 compounds to any significant extent.

The benzophenoximes, which may be used in the

present invention, are those which have sufficient solubility

in one or more of the above solvents or mixtures

thereof to make about a 2% solution and which are es-

10 sentially insoluble or immiscible with water. At the

same time, the benzophenoxime should form a complex

with the metal, such as copper, which complex,

likewise, is soluble in the organic solvent to at least the

extent of about 2% by weight. These characteristics are

15 achieved by having alkyl, ethylenically unsaturated aliphatic

or ether substituents as described on either ring.

It is necessary to have substituents which total at least

3 carbon atoms. This minimum may be obtained by

means of a total of 3 methyl groups distributed on ei-

20 ther one or on the two rings, by means of a methyl and

an ethyl group, by means of a propyl group, etc. Usually

it is preferred not to have more than 25 carbon

atoms total in the substituents since these substituents

25 contribute to the molecular weight of the oxime without

improving operability. Large substituents, therefore,

increase the amount of oxime for a given copper

loading capacity. In general, the branched chain alkyl

substituents effect a greater degree of solubility of the

30 reagent and of the copper complex and, accordingly,

these are preferred.

The above compounds are suitable as the copper ion

exchange extractant component of the mixed solvent

extraction agent of the present invention which in35

c1udes as the other component an organophosphoric

acid in addition to the solvent.

The organophosphoric acids used as additives to the

2·hydroxy benzophenoximes as represented by the formula:

are tailored with substituents to provide the required

solubility in suitable organic solvents, the extractants

including 2-hydroxy benzophenoximes in which thc

substituents arc alkyl radicals, cthylenically unsaturated

aliphatic radicals and alkyl or ethylenically unsaturatcd

aliphatic ether radicals.

The preferred 2-hydroxybenzophenoximes are those

represented by the formula:

OH ONOH - -~-< ~

Rm R'n

in which Rand R' may be individually alike or different

and are saturated aliphatic groups, ethylenically unsaturated

aliphatic groups or saturated or ethylenically

unsaturated ether groups (I.e. -OR") and m and n are

0, 1,2,3 or 4 with the proviso that m and n are not both

O. The total number of carbon atoms is Rm and R'n is

from 3-25. Rand R' contain I to 25 carbon atoms

when saturated aliphatic and 3 to 25 carbon atoms

when they are ethylenically unsaturated groups. Preferably,

the position ortho to the phenolic OH substituted

carbon atom is unsubstituted and also preferably the

positions ortha to the oxime carbon atom on the other

aromatic nucleus are unsubstituted. Branched chain

saturated aliphatic hydrocarbon substituents are preferred.

Compounds of the above type useful in the present

invention include the following:

2-hydroxy-3'-methyl-5-ethylbenzophenoxime

.2-hydroxy-5-( I,l-dimethylpropyl)-benzophenoxime

2-hydroxy-5-( I,l-dimethylethyl)-benzophenoxime

2-hydroxy-5-octylbenzophenoxime

2-hydroxy-5-nonyl-benzophenoxime

2-hydroxy-5-dodecyl-benzophenoxime

2-hydroxy-2',4'-dimethyl-5-octylbenzophenoxime

2-hydroxy-2',3',5'-trimethyl-5-octylbenzophenoxime

2-hydroxy-3,5-dinonylbenzophenoxime

2-hydroxy-4'-( I, l-dimethylethyl)-5-(2-pentyl)benzophenoxime

2-hydroxy-4'-( I, l-dimethylethyl)-5-( 2-butyl)benzophenoxime

2-hydroxy-4-dodecyloxybenzophenoxime

2-hydroxy-4'-( I, I-dimethylethyl )-5-methylbenzophenoxime

2-hydroxy-4',5-bis-(l ,l-dimethylethyl) benzophenoxime

As indicated from the above representative compounds,

various alkyl groups can be used as Rand R'.

And as set forth above, such groups may be branched

or straight chain. Various ethylenically unsaturated

groups can also be used as Rand R' and the same may

be branched or straight chain. Representative of such

groups arepentenyl, hexenyl, octenyl, decenyl,

dodecenyl, octadecenyl and the like. It is preferred that

such groups contain less than about 2 double bonds and

more preferably a single double bond. The R" portion

of the ether groups can be the saturated and ethylenically

unsaturated aliphatic groups as described. The R"

portion of the said ether groups is preferably an alkyl

group. In addition, the saturated, ethylenically unsaturated

and ether groups may contain inert substituents

--··-----------R-.-------

R'-O-~=o ' 6H

3,872,209

TABLE I

% of COPPER EXTRACTED

Test Mixing NO .5% 1% 2% 4%

No. Time DEHPA DEHPA DEHPA DEHPA DEHPA

Min·

utes

I .25 32% 62% 65% 65% 58%

2 .50 47 69 73 72 62

3 1 58 77 73 73 63

4 4 77 77 73 73 61

From the above results it can be seen that the addition

of an amount of DEHPA equal to 1%increased the

extraction rate so much that 15 seconds of mixing extracted

more copper than a minute of agitation without

the DEHPA. This means that a solvent extraction mix-

50 ing system would only need to be one quarter as large

if the DEHPA is added to the LIX-64N. It will also be

noted from these examples that adding more than an

amount of about 4 volume percent of di-2-ethyl hexyl

phosphate impairs the loading capacity of the LIX64N.

The examples presented in the following tables illustrate

that the rate of transfer of copper from one phase

to another is accelerate'.\not only in the extraction but

in the stripping operation also. For all examples in

Table 2 a 10% by volume LIX-64N solution in kerosene

containing various percentages of DEHPA was

loaded with copper by agitating with an acidic copper

sulfate solution. Portions of the loaded solvents were

agitated for 15 seconds with 3 Normal sulfuric acid at

an organic to aqueous ratio of 2 to 1 at room temperature.

The percentage of the copper stripped was determined

by analysis of the separated phases.

The organophosphoric acids are used in amounts ception of the example of FIG. 7 in which an 01A ratio

with the substituted 2-hydroxy benzophenoximes up to of 2/1 was used. In all the graphs except FIG. 7 contact

about 4 percent by volume of the organic solvent. time in minutes is plotted on the abscissa against gil of

Above this amOunt no further acceleration in rate is Cu in the raffinate on the ordinate. All percentages are

found and in fact a decrease in total leading capacity 5 in volume percentages;

occurs. Up to 20% by volume of LIX-64N and LIX-70 The graph of FIG. 7 is based on examples of stripping

may be used. In addition to increasing the loading rate LIX-64N loaded with copper when varying amounts of

of the hydroxy benzophenoximes it was found that the DEHPA were added to the LIX-64N. 3N H2S04 was

presence of the organophosphoric acids in the amounts used for stripping. The organic was loaded to 1.2-1.4

stated also increases the rate at which metals can be 10 gil copper.

stripped with acid from the 2-hydroxy benzophenoxime The examples presented in Table I were performed

extractant. to show the increase in the rate of extraction of copper

It was found that use of other cation exchange mate- from an acidic copper sulfate liquor with LIX-64N as

rials as additives to the 2-hydroxy benzophenoximes, the extractant to which was added varying quantities of

such as, versatic acid, oleic acid and naphthenic acid, 15 di-2-ethyl hexyl phosphoric acid (DEHPA). For these

had little effect on the loading rate. Also, the use of the tests, a given amount of the copper solution analyzing

orgailophosphoric additives with other conventional 1.98 gil Cu, 1 gil Fe, 10 gil Na2S04 at pH 2.0 was mixed

copper extractants, such as Kelex-120, an alkylated hy- with an equal volume of solvent for the time noted. The

droxy quinoline, has no noticeable effect On the loading phases were then separated and the amount of copper

rate of copper. 20 extracted was determined by analysis. The solvent in all

The water-immiscible organic solvents in which the of the examples contained 10 volume % ofLIX-64N in

extractant mixture is dissolved to form the organic kerosene (AMSCO 175) to which was added varying

phase are the conventional ones, such as, aliphatic hy- quantities of di-2-ethyl hexyl phosphoric acid as specidrocarbon

solvents including petroleum derived liquid fied in volume percent.

hydrocarbons, either straight chain or branched, such 25

as, kerosene, fuel oil, etc. Various aromatic solvents or

chlorinated aliphatic solvents may be used, such as

benzene, toluene, xylene, carbon tetrachloride, per"

chloroethylene and others. The solvent must be substantially

water-immiscible, capable of dissolving the 30

extraction reagent, and must not interfere with the

function of the reagent in extracting the metal values

from acid solution. The benzophenoxime component

of the organic extractant mixture must have a solubility

of at least 2 percent by weight in the hydrocarbon sol- 35

vent in the organic phase and is insoluble in water.

The aqueous phase from which the desired metal is

extracted is ordinarily the acidic leach solution resulting

from leaching of an ore. During the extraction

phase the mixed extractant becomes loaded with cop- 40

per or other desired metal.

It is well known that LIX-64, LIX-64N and LIX-70

exhibit a selectivity for copper over other metals at pH

values below about 4. The most efficient organic to

aqueous ratio can be arrived at in accordance with pro- 45

cedures well known in the art. After separation of the

loaded organic phase from the aqueous phase copper

is stripped from it with a mineral acid, such as sulfuric,

in a stripping circuit.

The liquid-liquid extraction may be performed by

continuous countercurrent or batch methods.

The extraction with the extractant mixture is performed

at a pH in the acid range. Leach solutions of

copper ores ordinarily have a pH range from about 1.7 55

- 3.0.

The invention is illustrated by the following examples

and the graphs of FIGS. 1-7 illustrating the results of

various types of examples including comparative examples

and stripping examples. 60

In the examples on which the graphs are based, except

those for FIGS. 3 and 7, sulfate solution was used

for the aqueous containing 2.0 gil Cu + 10 gil Na2S04

at pH 2. For the examples of FIG. 3 the composition of

the sulfate solution was 1.9 gil Cu, 0.9 gil Fe+3, 10 gil 65

Na2S04' The solvent for all examples was kerosene

(SACO SOL 175). An organic to aqueous ratio of III

was used at temperatures of 25°C and 23°C with the ex"

3,872,209

4 2 .26 1.74

5 4 .16 \.84

6 \.0 0.25 0.48 1.52

7 0.5 .24 1.76

8 I .14 1.86

9 2 .14 1.86

10 4 .16 1.84

G/LCu

Test DEHPA LOADED STRIPPED % Cu Stripped

No. VOL.% ORGANIC ORGANIC In 15 Seconds

I 0 1.53 \.70 7.1

2 1.0 1.76 \.26 28

The results of Table 4 show that DEHPA greatly improves

the stripping rate of LlX-70.

The examples in the following Table 5 show copper

loading by LlX-64 at various volume percentages of

DEHPA and LlX-64N. The aqueous for the examples

contained from 1.50 to 6.20 gil Cu and 2 gil of sodium

sulfate. The solvent was kerosene and an alA ratio of

1.2/1 was used.

TABLE 4

For the following stripping examples, 7.5 volume percent

of LlX-70 in kerosene with and without DEHPA

was loaded with copper by contacting with ,simulated

copper leach liquor. The loaded extractants were

stripped with 3N H2S04, Stripping contact time in each

example was 15 seconds.

TABLE 3

Test DEHPA CONTACT G/L Cu

TIME

No. Vo\.% MINUTES RAFFINATE ORGANIC

I 0 0.25 1.18 0.85

2 0.5 .84 1.16

3 I .54 ),«5 40

TABLE 2

g/ICu %Cu

Test DEHPA LOADED STRIPPED Stripped in

No. VOL% ORGANIC ORGANIC 15 Seconds 5

1 0 \.43 0.94 34

2 0.50 1.40 0.23 84

3 1.0 1.33 0.11 92

4 2.0 1.30 0.082 94

5 4.0 \.10 0.027 98

It can be seen from the above table that stripping is

essentially complete in 15 seconds from a loaded sol- '

vent which contains the proper quantity of DEHPA

where it is incomplete if the additive is absent. This 15

clearly demonstrates the acceleration of stripping rate

when the solvent contains DEHPA.

The beneficial result from the addition of an organic

phosphoric acid is found not only with LlX-64N but

also for LlX-70. In the example presented in the follow- 20

ing table, the extraction rates are compared for LlX-70

with and without di-2-ethyl hexyl phosphoric acid additive.

For these tests, a given amount of copper solution analyzing

1.9 gil Cu, 0.83 gil Fe, 10 gil Na2S04 was mixed 25

at pH 2.0 with an equal volume of solvent for the time

noted. After separation of the phases the amount of

copper extracted was determined by analysis. The solvent'

forall examples contained 7.5 volume % LlX-70

in kerosene to which was added 1.0 volume % of 30

DEHPA. An organic to aqueous ratio of I: I was used

at a temperature of 25°C.

The results of Table 3 show that DEHPA is an effective

for accelerating the loading of LlX-70 with copper

--------------------- 10 as it is for LlX-64N.

The following table presents results showing the effectiveness

of DEHPA on the stripping of copper from

LlX-70.

TABLE 5

COPPER LOADING BY L1X·64N AT VARIOUS PERCENTAGES

OF DEHPA AND L1X-64N

TEST VOL 0/< VOL 0/< CONTACT gil Cu 0/< OF MAXINO.

L1X-64N DEHPA TIME, MINS RAFFINATE ORGANIC MUMCu

I 5.0 NONE .25 1.22 .23 28

2 .5 1.12 .32 36

3 I .97 .44 53

4 2 .80 .58 70

5 4 .62 .73 88

6 8 .50 .83 100

7 5.0 0.25 .25 .59 .76 86

8 .5 .49 .84 95

9 I .45 .88 100

10 2 do. do. do.

II 4 do. do. do.

12 8 do. do. do.

13 5.0 0.5 .25 .52 .82 94

14 .5 .48 .85 98

15 I .46 .87 100

16 2 do. do. do.

17 4 do. do. do.

18 8 do. do. do.

19 5.0 3.0 .25 .60 .75 97

20 .5 .59 .76 99

21 I .58 .77 100

22 do. do. do.

D J do. do do.

l" B .59 .7h 99

::!~ 30 NONE .2~ 3.hO l.17 q

26 .5 .1.22 lAB 62

27 I 2,(,8 l.93 n

3,872,209

9 10

TABLE 5 -Continued

COPPER LOADING BY L1X-64N AT VARIOUS PERCENTAGES

OF DEHPA AND L1X-64N

TEST VOL 'if VOL 'if CONTACT gil Cu '* OF MAXINO.

L1X-64N DEHPA TIME. MINS RAFFINATE ORGANIC MUM Cu

28 2 2.04 3.47 87

29 4 1.60 3.83 96

30 8 1.41 3.99 100

31 30 1.5 .25 1.88 3.60 91

32 .5 1.66 3.78 95

33 I 1.46 3.95 99

34 2 1.44 3.97 100

35 4 do. do. do.

36 8 do. do. do.

37 30 3.0 .25 1.83 3.64 94

38 .5 1.65 3.79 98

39 I 1.56 3.87 100

40 2 do. do. do.

41 4 do. do. do.

42 8 do. do. do.

43 30 18 .25 2.50 3.08 98

44 .5 2.48 3.10 99

45 I 2.46 3.12 100

46 2 2.44 3.13 do.

47 4 2.44 do. do.

48 8 2.46 3.12 do.

The results of Table 5 show that DEHPA additive is 25

highly effective on the loading on LIX-64N at various

percentages. The results of Tables 1 and 5 demonstrate

that at about 4% by volume and above of DEHPA the

loading capacity of LIX-64N is seriously impaired.

They further show that comparatively small percentages

of DEHPA are highly effective in accelerating

loading rate. Amounts as small as .25% by volume are

shown to be effective.

The operable ranges are up to about 4% DEHPA by

volume of the solvent and upto about 20% ofLIX-64N 35

by volume of the solvent.

The beneficial effect of the organic phosphoric acid

is found with both the mono- and di-substituted esters

of phosphoric acid, but is not evident with the neutral

tri-substituted product. In the following Table 6, the

rates of extraction of LIX-64N alone and with variously

substituteq organic phosphate ester additives are compared.

For the examples in the table, the aqueous contained

2.0 gIl Cu; 1.0 gIl Fe and 10 gIl Na2S0. at a pH of 2.0. 45

The organic was lOvolume % of LIX-64N in kerosene

to which was added 1.0 volume % of phosphate. A

contact time of 15 seconds was used and an 01A ratio

of Ill.

TABLE 6

Test PHOSPHATE ADDITIVE

No.

NONE

Di-2-ethyl-hexyl phosphoric acid

Didecyl phosphoric acid

Tridecyl phosphoric acid

Isoamyl phosphoric acid

Mono amyl phosphoric acid

Diamyl amyl phosphate

Triphenyl phosphoric acid

ORGANIC

.37

1.36

1.43

1.39

1.44

.32

gil Cu

RAFFINATE

1.62

.70

.'(;'3

.72

.55

.54

1.63

1.69

The results of Table 6 show that the tri-substituted

organophosphoric acids of tests 7 and 8 are inoperative

as loading accelerating additives for LIX-64N while the

mono- and di-substituted additives are highly effective.

Referringto Fig.!, the loadin~ rates of c()PPt:r_to

3,872,209

3-25 carbon atoms or -OR" where R" is a saturated

or ethylenically unsaturated aliphatic group as defined,

m and n are 0, I, 2, 3. or 4 with the· proviso that both

are not 0 and the total number of carbon atoms in Rm

5 and R'm is from 3-25.

4. The process of claim 3 in which R of the 2-hydroxy

benzophenoxime is an ethylenicallyunsaturated group.

5. The process of claim 3 in which R' of the 2hydroxy

benzophenoxime is an unsubstituted branched

10 chain aliphatic hydrocarbon group.

6. The process of claim 3 in which R of the 2-hydroxy

benzophenoxime is an unsubstituted branched chain

hydrocarbon group.

7. The process of claim 3 in which at least one R

15 group of the 2-hydroxy benzophenoxime is in the 5 position.

8. The process of claim 1 in which the 2-hydroxy benzophenoxime

is present in an amount up to about 20

20 percent by volume of the solvent.

9. The process of claim 1 in which the organophosphoric

acid is present in an amount of about I percent

by volume of the solvent.

10. The process of claim 1 in which the organophos25

phoric acid is di-2-ethylhexyl phosphoric acid.

11. The process of claim 1 in which the organophosphoric

acid is di-decyl phosphoric acid.

12. The process of claim 1 in which the organophosphoric

acid is isoamyl phosphoric acid.

13. The process of claim lin which the organophosphoric

acid is amyl phosphoric acid.

* * * * *

R6I

R-O-P=O ____k- _

~NOH

~--~-< ~

__R-"'- ' --!t.2'_

in which Rand R' may be individually alike or different 30

and are saturated aliphatic groups of 1-'-25 carbon

atoms, et~ylenically unsaturated aliphatic gr()lIps of

wherein R is selected from the group consisting of hydrogen,

alkyl, aryl, and aralkyl and wherein not more

than one R is hydrogen, to extract the copper values

from the aqueous to the organic phase, separating said

phases, and recovering the copper from the organic

phase.

2. The process of claim 1 in which the 2-hydroxy benzophenoxime

is a member selected from the group consisting

of alkyl substituted, ethylenically unsaturated

aliphatic substituted and alkyl or ethylenically unsatu- .

rated aliphatic ether substituted 2-hydroxy benzophenoximes.

3. The process of claim 2 in which the 2-hydroxy ben~~

phenoxime h.~s_~h.: formula:

a solubility of at least 2% by weight in the organic sol_'

J~nt allc!_~ll_~!~~~~p_'!.()_sphol"i.c__~~i~ ha~i~~_th:.f<:lrmula: