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
8
8
7
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
"- ""
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...J
"-
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1.2
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<!
0::
~ 0.8
0:: wn.
n.
u0 0.6
...J
"- l':>
0.4
0
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....
<t
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0::
-z 0.8
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0
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Cl
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
o
to
z
2 90
zo
u
w
en 80
t.lg: 7
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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
2
COPPER EXTRACTION RATES FOR KELEX 120, L1X64, L1X64N
AND L1X70 WITHOUT DEHPA ADDITIVE
W
f-
<l:
Z
LL
LL
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"(!)
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
2
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.
35
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
1
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.
4
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:
40
3
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
45
--··-----------R-.-------
Io
R'-O-~=o ' 6H
5
3,872,209
6
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
8
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.
35
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
7
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
LOADING
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
LOADING
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.
I2
3
4
5
6
7
8
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
1.44
.32
.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
11
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:
35
40
45
50
55
60
65