Title of Invention

COMPOSITION AND PROCESS FOR THE SOLVENT EXTRACTION OF METALS USING ALDOXIME OR KETOXIME EXTRACTANTS

Abstract A solvent extraction composition comprising one or more orthohydroxyarylaldoximes and one or more orthohydroxyarylketoximes, and one or more equilibrium modifiers selected from 2,2,4-trimethyl-1,3-pentanediol mono-isobutyrate, 2,2,4-trimethyl-1,3-pentanediol mono- benzoate, 2,2,4-trimethyl-1,3-pentanediol diisobutyrate, 2,2,4-trimethyl-1,3-pentanediol di- benzoate, isobutyl heptyl ketone, nonanone, 2,6,8-trimethyl-4-nonanone, diundecyl ketone, and 5,8-diethyldodecane-6,7-dione, tridecanol, and nonyl phenol in an amount providing a degree of modification of the orthohydroxyarylaldoximes present of from about 0.2 to 0.61.
Full Text COMPOSITION AND PROCESS FOR THE SOLVENT EXTRACTION OF
METALS USING ALDOXIME OR KETOXIME EXTRACTANTS
The present invention concerns a solvent extraction composition, a solvent
extraction process and especially a process for the extraction of metals, particularly
copper, from aqueous solutions, especially solutions obtained by leaching ores.
It is known to extract metals, especially copper, from aqueous solutions containing
the metal in the form of, for example, a salt, by contacting the aqueous solution with a
solution of a solvent extractant in a water immiscible organic solvent and then separating
the solvent phase loaded with metal, i.e. containing at least a part of the metal in the form
of a complex. The metal can then be recovered by stripping with a solution of lower pH
followed for example, by electrowinning. Most commonly, the aqueous metal-containing
solutions for extraction are the result of the acid leaching of ores. However it is known that
some metals, especially copper, can be leached from certain ores with ammoniacal
solutions. This has the advantage that solutions containing especially high concentrations
of copper are derived and that there is little contamination of the solution with iron.
Solvent extractants which have found favour in recent years particularly for the
recovery of copper from aqueous solutions include oxime reagents, especially
o-hydroxyaryialdoximes and o-hydroxyarylketoximes. Whilst such reagents have been
found to work well in the recovery of copper from solutions, one problem which has been
encountered in the application of such reagents is that the aldoxime and ketoxime
reagents can strongly bind metals to the extent that the efficiency of metal transfer from
leach solution to strip solution can be impaired. In order to overcome such problems,
modifiers have frequently been used with an aldoxime and ketoxime reagent to effect the
binding efficiency of the extractants. Typical modifiers are disclosed in W096/25525, and
in particular a class of highly branched ester modifiers are disclosed in EP-A-0202833.
Solvent extraction processes are employed in diverse situations, and much work
has been done to identify suitably extractant compositions.
In particular US 4507268 and US 4544532 disclose that by employing aldoxime
compositions that additionally comprise a ketoxime reagent, efficient copper recovery can
be achieved when much lesser amounts of kinetic and equilibrium modifiers are employed
than would be used with purely aldoxime compositions. Further, according to US 4507268
and US 4544532, it is preferred that no modifier is present with aldoxime compositions that
additionally comprise a ketoxime reagent.
However, it has surprisingly been found that compositions comprising aldoxime /
ketoxime mixtures should contain at least comparable and often greater amounts of kinetic
and equilibrium modifiers as would be required if aldoxime was used alone.
According to a first aspect of the present invention, there is provided a solvent
extraction composition comprising one or more orthohydroxyarylaldoximes and one or
more orthohydroxyarylketoximes, and one or more equilibrium modifiers in an amount

providing a degree of modification of the orthohydroxyarylaldoximes present of from about
0.2 to 0.61.
The compositions preferably also comprise a water immiscible organic solvent.
Compositions according to the present invention may facilitate higher copper
transfer in solvent extraction circuits. Higher copper transfer can be translated into
increased metal recovery which may result in lower O/A ratios, or lower reagent
concentrations for a given recovery. Composition according to the present invention may
find particular use with lower acid concentration strip solutions.
The orthohydroxyarylketoxime compounds employed in the present invention are
substantially water insoluble and preferably have the formula:

Wherein
R1 is an optionally substituted hydrocarbyl group
R2 is an optionally substituted ortho-hydroxyaryl group,
and salts thereof.
The orthohydroxyarylaldoxime compounds employed in the present invention are
substantially water insoluble and preferably have the formula:

wherein
R3 is an optionally substituted ortho-hydroxyaryl group,
and salts thereof.
Whilst the invention is described herein with reference to compounds of Formula
(1) and (2), it is understood that it relates to said compound in any possible tautomeric
forms, and also the complexes formed between orthohydroxyarylaldoximes of
orthohydroxyarylketoximes and metals, particularly copper.
Optionally substituted hydrocarbyl groups which may be represented by R1
preferably comprise optionally substituted alkyl and aryl groups including combinations of
these, such as optionally substituted aralkyl and alkary! groups.
Examples of optionally substituted alkyl groups which may be represented by R1
include groups in which the alkyl moieties can contain from 1 to 20, especially from 1 to 4,

carbon atoms. A preferred orthohydroxyarylketoxirne is one in which R1 is alkyl, preferably
containing up to 20, and especially up to 10, and more preferably up to 3 saturated
aliphatic carbon atoms, and most preferably R1 is a methyl group.
Examples of optionally substituted aryl groups which may be represented by R1
include optionally substituted phenyl groups. When R1 is an aryl group, it is preferably an
unsubstituted phenyl group.
Optionally substituted ortho-hydroxyary! groups which each independently may be
represented by R2 and R3 include optionally substituted phenols. Examples of optionally
substituted phenols which each independently may be represented by R2 and R3 include
those of formula:

wherein R4 to R7 each independently represent H or a C, to C22, preferably a C7 to
C15, linear or branched alkyl group. Particularly preferably only R6 represents a C1-22 alky!
group, most preferably a C7 to C15 alkyl group, with R4, R5 and R7 representing H.
When any of R1, R2 or R3 is substituted, the substituent(s) should be such as not to
affect adversely the ability of the orthohydroxyarylaldoxime or orthohydroxyarylketoxirne to
complex with metals, especially copper. Suitable substituents include halogen, nitro,
cyano, hydrocarbyl, such as C1-20-alkyl, especially C1-10-alky!; hydrocarbyloxy, such as C1-
20-alkoxy, especially C1-10-alkoxy; hydrocarbyloxycarbonyl, such as C1-20-alkoxycarbonyl,
especially C1-10-alkoxycarbonyl; acyl, such as C1-20-alkylcarbonyl and arylcarbonyl,
especially C1-10-aIky!carbonyl and phenylcarbonyl; and acyloxy, such as
C1-20-alkylcarbonyloxy and arylcarbonyloxy, especially C1-10-alkylcarbonyloxy and
phenylcarbonyloxy. There may be more than one substituent in which case the
substituents may be the same or different.
In many embodiments, the orthohydroxyarylketoxirne is a 5-(C8 to C14
alkyl)-2-hydroxyacetophenone oxime, more often a 5-(C9 to C12
a!kyl)-2-hydroxyacetophenone oxime, and particularly 5-nonyl-2-hydroxyacetophenone
oxime.
In many embodiments, the orthohydroxyarylaldoxime is a 5-(C8 to C14
alkyl)-2-hydroxybenza!doxime, more often a 5-(C9 to C12 alkyl)-2-hydroxybenzaldoxime,
and particularly 5-nonyI-2-hydroxybenzaldoxime.
The compositions may often comprise more than one different
orthohydroxyaryialdoximes and/or more than one different orthohydroxyarylketoximes in
which the nature of the substituent groups represented by R1 and R2 differ between

component orthohydroxyarylketoximes and/or the substituent groups represented by R3
differ between component orthohydroxyarylaldoximes, especially where the component
orthohydroxyarylaldoximes and/or orthohydroxyarylketoximes are isomeric. Such
isomeric mixtures may have better solubility in organic solvents than when a single
orthohydroxyarylketoxime and a single orthohydroxyarylaldoxime is present.
The orthohydroxyarylaldoximes and orthohydroxyarylketoximes are often present
in a total amount of up to 60% by weight of the composition, commonly no more than 50%,
and usually no more than 40 % w/w. Often, the total amount of orthohydroxyarylaldoxime
and orthohydroxyarylketoxime comprises at least 1% by weight, commonly at least 2.5%
by weight and usually at least 5% by weight of composition, and preferably comprises
from 7.5 to 20%, such as about 10%, by weight of the composition.
Equilibrium modifiers employed in the present invention are substantially water
insoluble. Suitable equilibrium modifiers can be alkylphenols, alcohols, esters, ethers and
polyethers, carbonates, ketones, nitriles, amides, carbamates, sulphoxides, and salts of
amines and quaternary ammonium compounds.
Alkylphenols which may be used as modifiers in conjunction with the extractant
include alkylphenols containing from 3 to 15 alkyl carbon atoms, for example 4-tert-
butyiphenol, 4-heptylphenoi, 5-methyI-4-pentylphenol, 2-chloro-4-nonylphenol, 2-cyano-4-
nonylphenol, 4-dodecylphenol, 3-pentadecylphenol and 4-nonylphenol and mixtures
thereof. The preferred phenols contain alkyl groups having from 4 to 12 carbon atoms,
especially the mixed 4-nonylphenols obtained by condensation of phenol and propylene
trimer.
Alcohols which may be used as modifiers in conjunction with the extractant include
saturated and unsaturated hydrocarbon alcohols and polyols containing 14 to 30,
preferably 15 to 25 carbon atoms. The alcohols are preferably highly branched with the
hydroxyl group located approximately midway along the hydrocarbon backbone.
Especially preferred are the branched chain alcohols that may be made by condensation
of short chain alcohols by the Guerbet process, such alcohols sometimes being referred to
as Guerbet alcohols. Optionally, the alcohols may contain an aromatic group or other
functional group, particularly an ester group.
Especially useful alcohols may be synthesised from highly branched precursors
leading to very highly branched Guerbet alcohols containing a large number of terminal
methyl groups. Examples of particularly efficient alcohol modifiers include highly branched
isohexadecyl alcohol and iso-octadecyl alcohol, the latter being 2-(1,3,3-trimethylbutyl)-
5,7,7-trimethyloctan-1 -ol.
Esters which may be used as modifiers in conjunction with the extractant include
saturated and unsaturated aliphatic and aromatic-aliphatic esters containing from 10 to 30
carbon atoms. The esters may be mono-esters or polyesters, especially di-esters. The
esters are preferably highly branched. Optionally, the esters may contain other functional

groups, particularly a hydroxyl group or ether group. Where the ester is a product of the
reaction of an alcohol and a mono-carboxylic acid, it is preferred that the alcohol is an
alkyl alcohol and comprises from 1 to 6 carbon atoms, and the mono-carboxylic acid
comprise from 2 to 16 carbon atoms. Where the ester is a product of the reaction of an
alcohol and a di-carboxylic acid, it is preferred that the alcohol is an alky! alcohol and
comprises from 1 to 6 carbon atoms, and the di-carboxylic acid comprises from 4 to 12
carbon atoms. Where the ester is a product of the reaction of a diol and a mono-carboxyiic
acid, it is preferred that the diol is an alkyl diol and comprises from up to 6 carbon atoms,
and the mono-carboxylic acid comprises from 6 to 16 carbon atoms. Where the ester is a
tri-alkyl phosphate, the alkyl groups each commonly comprise from 4 to 14 carbon atoms.
Examples of useful esters include isodecyl acetate, methyl decanoate, 2-pentyl octanoate,
n-hexyl hexanoate, methly isooctanoate, 1,4-butanediol dihexanoate, di-butyl adipate, di-
isobutyl adipate, di-pentyl adipate, di-hexyl adipate, bis-2-ethoxyethyl adipate, dipropylene
glycol dibenzoate, propylene glycol dibenzoate, tributyl phospate, trioctylphosphate,
triethylhexylphosphate, 2,2,4-trimethyl-1,3-pentanediol mono-isobutyrate, 2,2,4-trimethyl-
1,3-pentanediol mono-benzoate and particularly 2,2,4-trimethyl-1,3-pentanediol di-
isobutyrate and 2,2,4-trimethyl-1,3-pentanediol di-benzoate.
Ethers which may be used as modifiers in conjunction with the extractant include
hydrocarbon ethers and polyethers containing 12 to 30, preferably 15 to 25 carbon atoms.
Examples of useful ethers and polyethers include benzyl 2-(2-butoxyethoxy)ethyl ether
and benzyl 2-butoxyethyl ether.
Carbonates which may be used as modifiers in conjunction with the extractant
include carbonates containing from 4 to 16 carbon atoms. Commonly, the carbonates are
alkyl carbonates. Examples of useful carbonates include isobutylcarbonate,
isotridecylcarbonate and a carbonate mixture comprising a mixture of C3 and C10 alkyl
groups.
Ketones which may be used as modifiers in conjunction with the extractant include
alkyl ketones in which the alkyl group contains from 1 to 20 carbon atoms. Examples of
useful ketones include isobutyl heptylketone, nonanone, 2,6,8-trimethyl-4-nonanone,
diundecyl ketone and 5,8-diethyldodecane-6,7-dione.
Nitriles which may be used as modifiers in conjunction with the extractant include
aliphatic and araiiphatic hydrocarbonitriles which comprise from 10 to 36 carbon atoms.
Examples of useful nitriles include undecylnitrile and oleonitrile.
Amides which may be used as modifiers in conjunction with the extractant include
amides containing from 8 to 20 carbon atoms. Amides comprise products which may be
derived from the reaction of a primary or secondary amine with a mono- or di carboxylate
acid or equivalent, in particular phosgene or equivalents. Examples of useful amides
include N,N'-bis-2-ethylhexyl urea, N,N'-bis-2-ethylhexy! 2-ethylhexanamide, N-hexyl 2-

ethyihexanamide, N,N'-dibutyl benzamide, N,N'-dibutyl octanamide, N,N'-dimethyl
octanamide and N,N'-bis-2-ethylhexyI versatamide.
Carbamates which may be used as modifiers in conjunction with the extractant
include alkyl and aryl carbamates. Examples of useful carbamates include N-octyl
isotridecylcarbamate and isotridecyl N-tolylcarbamate.
Sulphoxides which may be used as modifiers in conjunction with the extractant
include alkyl sulphoxides. An example of a useful sulphoxide is di-2-ethylhexyl
sulphoxide.
Salts of amines and quaternary ammonium compounds which may be used as
modifiers in conjunction with the extractant include tertiary amines and quaternary-
ammonium compounds containing alkyl groups having from 8 to 18 carbon atoms and
sulphonic acid salts thereof. Examples of sulphonic acids include dinonyinapthalene
sulphonic acid and toluene sulphonic acid.
In the context of the present invention, 'highly branched' as applied to the alcohols
and esters means that the ratio of the number of methyl carbon atoms to non-methyl
carbon atoms is higher than 1:5 and preferably higher than 1:3.
If desired, mixtures of compounds selected from the group consisting of
alkylphenols, alcohols, esters, ethers, polyethers, carbonates, ketones, nitriles, amides,
carbamates, sulphoxides, and salts of amines and quaternary ammonium compounds
may be employed as modifiers. Particularly preferred are mixtures comprising a first
compound selected from the group consisting of alkylphenols, alcohols, esters, ethers,
polyethers, carbonates, ketones, nitriles, amides, carbamates, sulphoxides, and salts of
amines and quaternary ammonium compounds and a second compound selected from
the group consisting of alkanols having from 6 to 18 carbon atoms, an alkyl phenol in
which the alkyl group contains from 7 to 12 carbon atoms, and tributylphosphate.
Preferably one or more equilibrium modifiers selected from 2,2,4-trimethyl~1,3-
pentanediol mono-isobutyrate, 2,2,4-trimethyi-1,3-pentanediol mono-benzoate, 2,2,4-
trimethyl-1,3-pentanediol di-isobutyrate, 2,2,4-trimethy!-1,3-pentanediol di-benzoate, di-
butyl adipate, di-pentyl adipate, di-hexyl adipate, isobutyl heptyl ketone, nonanone, 2,6,8-
trimelhyl-4-nonahone, diundecyl ketone, 5,8-diethyldodecane-6,7-dione, tridecanol, and
nonyl phenol are employed. One or more equilibrium modifiers are present in an amount
that provides a degree of modification of the orthohydroxyarylaldoximes present of from
about 0.2 to 0.61, more preferably from about 0.3 to 0.59, and most preferably from about
0.4 to 0.6.
As employed herein, "degree of modification" designates the inverse ratio of (a) the
stripped solvent copper level of an hydroxy aryl aldoxime extractant at equilibrium
(expressed in terms of grams per liter of copper) extracted with an aqueous solution
containing a fixed concentration of copper and sulfuric acid to (b) the stripped solvent
copper level of the same extractant under the same conditions when a selected

equilibrium modifier additive is present. Consistent with this definition, the presence of
relatively small quantities of an equilibrium modifier will shift the extraction equilibrium
slightly, resulting in minor diminution of aldoxime stripped solvent copper level at
equilibrium, as will be reflected by a degree of modification value closely approaching 1.0,
e.g., 0.99. Increased effective quantities of modifier under otherwise identical conditions
will result in a more pronounced shift in extraction equilibrium and a more pronounced
diminution of aldoxime stripped solvent copper level at equilibrium, as will be reflected by a
degree of modification corresponding less than 1.0.
Expectedly, the degree of modification resulting from a given molar ratio of
equilibrium modifier to aldoxime in a reagent will vary depending on such factors as the
degree of purity of the extractant composition employed in formulation of the reagent, the
aromaticity of the solvent, and, perhaps most significantly, the chemical identity of the
equilibrium modifier employed. It will also depend significantly on the conditions involved
in determination of stripped solvent copper levels. Consequently, for purposes of
determining degree of modification of an aldoxime by a given equilibrium modifier, the
following test conditions should be adhered to. The temperature at which the
determination is made should be about 24 °C. The molar concentration of aldoxime (or
mixture of aldoximes) in the diluent should be about 0.184 as determined by copper
loading and titration and an aldoxime stock of approximately 94 percent purity (with the
remainder being substantially alkyl phenol starting material residue) should be employed.
The diluent should be Escaid 100 or a mixture of aliphatic and aromatic hydrocarbons
closely approximating the constitution of Escaid 100. An atomic absorption methodology
should be employed for determining copper content. The composition of the strip solution
should be 150 g/l sulfuric acid and 30 g/l Cu2+. The foregoing conditions are employed in
determining degree of modification according to the invention because they represent
conditions closely resembling those commonly extant in commercial solvent extraction
facilities for recovery of copper.
Organic solvents which may be present in the composition include any mobile
organic solvent, or mixture of solvents, which is immiscible with water and is inert under
the extraction conditions to the other materials present. Preferably the organic solvent has
a low aromatic hydrocarbon content.
Preferred organic solvents are hydrocarbon solvents which include aliphatic,
alicyclic and aromatic hydrocarbons and mixtures thereof as well as chlorinated
hydrocarbons such as trichloroethylene, perchloroethylene, trichloroethane and
chloroform.
Highly preferred organic solvents having a low aromatics content include solvents
and solvent mixtures where the amount of aromatic hydrocarbons present in the organic
solvent is less than 30%, usually around 23% or less, often less than 5%, and frequently
less than 1%.

Examples of suitable hydrocarbon solvents include ESCAID 110, ESCAID 115,
ESCAID 120, ESCAID 200, and ESCAID 300 commercially available from Exxon (ESCAID
is a trade mark), SHELLSOL D70 and D80 300 commercially available from Shell
(SHELLSOL is a trade mark), and CONOCO 170 commercially available from Conoco
(CONOCO is a trade mark). Suitable solvents are hydrocarbon solvents include high flash
point solvents and solvents with a high aromatic content such as SOLVESSO 150
commercially available from Exxon (SOLVESSO is a trade mark).
More preferred are solvents with a low aromatic content Certain suitable solvents
with a low aromatic content, have aromatic contents of hydrocarbon solvents such as ESCAID 110 commercially available from Exxon (ESCAID
is a trade mark), and ORFOM SX 10 and ORFOM SX11 commercially available from
Phillips Petroleum (ORFOM is a trade mark). Especially preferred, however on grounds of
low toxicity and wide availability, are hydrocarbon solvents of relatively low aromatic
content such as kerosene, for example ESCAID 100 which is a petroleum distillate with a
total aromatic content of 23% commercially available from Exxon (ESCAID is a trade
mark), or ORFOM SX7, commercially available from Phillips Petroleum (ORFOM is a trade
mark).
In many embodiments, the composition comprises at least 30%, often at least 45%
by weight, preferably from 50 to 95% w/w of water-immiscible hydrocarbon solvent.
Advantageously, it may be preferred to make and supply the composition in the form of a
concentrate. The concentrate may then be diluted by the addition of organic solvents as
described herein above to produce compositions in the ranges as described herein above.
Where the concentrate contains a solvent, it is preferred that the same solvent is used to
dilute the concentrate to the "in use" concentration range. In many embodiments, the
concentrate composition comprises up to 30%, often up to 20% by weight, preferably up to
10% w/w of water-immiscible hydrocarbon solvent. Often the concentrate composition
comprises greater than 5% w/w of water-immiscible hydrocarbon solvent. In certain high
strength concentrates it may be necessary to employ a higher than normal aromatic
hydrocarbon content. In such cases where a high aromatic hydrocarbon containing
solvent is used in the concentrate, solvent of very low aromatic hydrocarbon content may
be used to dilute the concentrate to the "in use" concentration range.
According to a second aspect of the present invention, there is provided a process
for the extraction of a metal from solution in which an acidic solution containing a dissolved
metal is contacted with a solvent extraction composition, whereby at least a fraction of the
metal is extracted into the organic solution, characterised in that the solvent extraction
composition comprises a water immiscible organic solvent, one or more
orthohydroxyarylaldoximes and one or more orthohydroxyarylketoximes, and one or more
equilibrium modifiers in an amount providing a degree of modification of the
orthohydroxyarylaldoximes present of from about 0.2 to 0.61.

Metals that may be extracted in the process according to the second aspect of the
present invention include copper, cobalt, nickel, manganese and zinc, most preferably
copper.
The orthohydroxyarylaldoximes, orthohydroxyarylketoximes, the equilibrium
modifiers and the water immiscible organic solvent are as herein described before.
The aqueous acidic solution from which metals are extracted by the process of the
second aspect of the present invention often has a pH in the range of from -1 to 7,
preferably from 0 to 5, and most preferably from 0.25 to 3.5. Preferably, when the metal to
be extracted is copper pH values of less than 3 chosen so that the copper is extracted
essentially free of iron, cobalt or nickel. The solution can be derived from the leaching of
ores or may be obtained from other sources, for example metal containing waste streams
such as from copper etching baths.
The concentration of metal, particularly copper, in the aqueous acidic solution will
vary widely depending for example on the source of the solution. Where the solution is
derived from the leaching of ores, the metal concentration is often up to 75g/l and most
often from 1 to 40g/l. Where the solution is a waste stream, the metal concentrations can
vary from 0.5 to 2g/l for a waste water stream, to somewhat higher for those from other
waste streams, for example Printed Circuit Board waste streams, and can be up to 150g/l,
usually from 75 to 130g/l.
Preferred solvent extraction compositions are those which comprise a 5-(C8 to C14
alkyl)-2-hydroxybenzaldoxime and 5-(C8 to C14 alkyl)-2-hydroxyacetophenone oxime in a
ratio of from about 90:10 to about 50:50 aldoxime to ketoxime, and contain one or more
modifiers selected from 2,2,4-trimethy!-1,3-pentanediol mono-isobutyrate, 2,2,4-trimethyl-
1,3-pentanediol mono-benzoate, 2,2,4-trimethyl-1,3-pentanediol di-isobutyrate, 2,2,4-
trimethyl-1,3-pentanediol di-benzoate, butyl adipate, pentyl adipate, hexyi adipate, isobutyl
heptyl ketone, nonanone, diundecyl ketone, 5,8-diethyldodecane-6,7-dione, tridecanol,
and nonyl phenol in an amount sufficient to provide a degree of modification of 0.61 or
lower.
The process of the second aspect of the present invention can be carried out by
contacting the solvent extractant composition with the aqueous acidic solution. Ambient or
elevated temperatures, such as up to 75°C can be employed if desired. Often a
temperature in the range of from 5 to 60°C, and preferably from 15 to 40°C, is employed.
The aqueous solution and the solvent extractant are usually agitated together to maximise
the interracial areas between the two solutions. The volume ratio of solvent extractant to
aqueous solution are commonly in the range of from 20:1 to 1:20, and preferably in the
range of from 5:1 to 1:5. In many embodiments, to reduce plant size and to maximise the
use of solvent.extractant, organic to aqueous volume ratios close to 1:1 are maintained by
recycle of one of the streams.

After contact with the aqueous acidic solution, the metal can be recovered from the
solvent extractant by contact with an aqueous acidic strip solution.
The aqueous strip solution employed in the process according to the second
aspect of the present invention is usually acidic, commonly having a pH of 2 or less, and
preferably a pH of 1 or less, for example, a pH in the range of from -1 to 0.5. The strip
solution commonly comprises a mineral acid, particularly sulphuric acid, nitric acid or
hydrochloric acid. In many embodiments, acid concentrations, particularly for sulphuric
acid, in the range of from 130 to 200g/l and preferably from 150 to 180g/l are employed.
When the extracted metal is copper, preferred strip solutions comprise stripped or spent
electrolyte from a copper electro-winning cell, typically comprising up to 80g/l copper,
often greater than 20g/l copper and preferably from 30 to 70g/l copper, and up to 220g/l
sulphuric acid, often greater than 120g/l sulphuric acid, and preferably from 150 to 180g/l
sulphuric acid.
The volume ratio of organic solution to aqueous strip solution in the process of the
second aspect of the present invention is commonly selected to be such so as to achieve
transfer, per litre of strip solution, of up to 50g/l of metal, especially copper into the strip
solution from the organic solution. In many industrial copper electrowinning processes
transfer is often from 10g/l to 35g/l, and preferably from 15 to 20g/l of copper per litre of
strip solution is transferred from the organic solution. Volume ratios of organic solution to
aqueous solution of from 1:2 to 15:1 and preferably from 1:1 to 10:1, especially less than
6:1 are commonly employed.
Both the separation and stripping process can be carried out by a conventional
batch extraction technique or column contactors or by a continuous mixer settler
technique. The latter technique is generally preferred as it recycles the stripped organic
phase in a continuous manner, thus allowing the one volume of organic reagent to be
repeatedly used for metal recovery.
A preferred embodiment of the second aspect of the present invention comprises a
process for the extraction of a metal from aqueous acidic solution in which:
in step 1, the solvent extraction composition comprising a water immiscible organic
solvent, one or more orthohydroxyarylaldoximes and one or more
orthohydroxyarylketoximes, and one or more equilibrium modifiers in an amount providing
a degree of modification of the orthohydroxyarylaldoximes present of from about 0.2 to
0.61 is first contacted with the aqueous acidic solution containing metal,
in step 2, separating the solvent extraction composition containing metal-solvent
extractant complex from the aqueous acidic solution;
in step 3, contacting the solvent extraction composition containing metal-solvent
extractant complex with an aqueous acidic strip solution to effect the stripping of the metal
from the water immiscible phase;

in step 4, separating the metal-depleted solvent extraction composition from the loaded
aqueous strip solution.
The invention is further illustrated, but not limited, by the following examples.
Examples
An extractant composition was prepared by mixing 25g of 2-hydroxy-5-
nonyisalicylaldoxime (an aldoxime), 25g of 2-hydroxy-5-nonylacetophenone oxime (a
ketoxime), and varying amounts of 2,2,4-trimethyl-1,3-pentanediol di-isobutyrate (a
modifier) in 1 litre of Orfom SX7.
100ml of the extractant composition was then stirred with 500ml of an aqueous acid
copper ion containing solution for 30min to simulate extraction. After 30min the extractant
composition was. separated and then contacted with fresh aqueous acid copper ion
containing solution. This procedure was repeated until there was no longer a change in
the aqueous or organic copper concentration. A sample of the organic phase was then
analysed for copper content.
The procedure was repeated with various aqueous acid copper containing solutions to
simulate extraction and stripping conditions.
The Experiments below shows the equilibrium organic Cu loading and Cu stripping values
obtained.





During the simulation experiments, there was no evidence of crud formation when
modifiers were employed.

WE CLAIM:
1. A solvent extraction composition comprising one or more orthohydroxyarylaldoximes
and one or more orthohydroxyarylketoximes, and one or more equilibrium modifiers selected
from 2,2.4-trimethyl-1,3-pentanediol mono-isobutyrate, 2,2,4-trimethyl-1,3-pentancdiol mono-
benzoate, 2,2,4-trimethyl-1,3-pentanediol diisobutyrate, 2,2,4-trimethy]-1,3-pentanediol di-
benzoate. isobutyl heptyl ketone, nonanone, 2,6,8-trimethyl-4-nonanone, diundecyl ketone, and
5,8-diethyldodecane-6,7-dione, tridecanol, and nonyl phenol in an amount providing a
degree of modification of the orthohydroxyarylaldoximes present of from about 0.2 to 0.61.
2. A solvent extraction composition as claimed in Claim 1 wherein the degree of
modification is from about 0.4 to 0.6.
3. A solvent extraction composition as claimed in any one of Claims 1 or 2 wherein the
orthohydroxyarylketoximes are compounds of formula:

wherein
R1 is an optionally substituted hydrocarbyl group
R2 is an optionally substituted ortho-hydroxyaryl group, and
sails thereof,
and the orthohydroxyarylaldoxime are compounds of the formula:

wherein
R3 is an optionally substituted ortho-hydroxyaryl group, and
salts thereof.
4. A solvent extraction composition as claimed in Claim 3 wherein the
orthohydroxyarylketoxime is a 5-(C8 to C14 alkyl)-2-hydroxyacetophenone oxime, and the
orthohydroxyarylaldoxime is a 5-(C8 to C14 (alkyl)-2-hydroxybenzaldoxime.

5. A solvent extraction composition as claimed in Claim 1 wherein the
orthohydroxyarylketoxime is 2-hydroxy-5-nonylbcnzophenone oxime, and the
orthohydroxyarylaldoxime is 2-hydroxy-5-nonylsalicylaldoxime and equilibrium modifier is
2,2,4-trimethyl-1,3-pentanediol di-isobutyrate.
6. A process for the extraction of a metal from solution in which an acidic solution
containing a dissolved metal is contacted with a solvent extraction composition, whereby at
least a fraction of the metal is extracted into the organic solution, characterised in that the
solvent extraction composition comprises a water immiscible organic solvent, one or more
orthohydroxyarylaldoximes and one or more orthohydroxyarylketoximes, and one or more
equilibrium modifiers selected from 2,2,4-trimethyl-1,3-pentanediol mono-isobutyrate, 2,2,4-
trimcthyl-1,3-pentanediol mono-bcnzoate, 2,2,4-trirnethyl-1,3-pentanediol diisobutyrate, 2,2,4-
trimethyl-1,3-pentanediol di-benzoate, isobutyl heptyl ketone, nonanone, 2,6,8-trimethyl-4-
nonanone, diundecyl ketone, and 5,8-diethyldodecane-6,7-dione, tridecanol, and nonyl phenol
in an amount providing a degree of modification of the orthohydroxyarylaldoximes present
of from about 0.2 to 0.61.
7. A process as claimed in Claim 6 wherein the metal is copper, cobalt, nickel,
manganese or zinc.
8. A process as claimed in Claim 7 wherein the degree of modification is from about 0.4
to 0.6.
9. A process as claimed in any one of Claims 6, 7, or 8 wherein the
orthohydroxyarylkeloximes are compounds of formula:

wherein
R1 is an optionally substituted hydrocarbyl group
R2 is an optionally substituted ortho-hydroxyaryl group,
and salts thereof,
and the orthohydroxyarylaldoxime are compounds of the formula:


wherein
R3 is an optionally substituted ortho-hydroxyaryl group,
and salts thereof.
10. A process as claimed in Claim 7 wherein the orthohydroxyarylketoxime is a 5-(C8 to
C14 alkyl)-2-hydroxyacetophenone oxime, and the orthohydroxyarylaldoxime is a 5-(C8 to
C14 alkyl)-2-hydroxybenzaldoxime.
11. A process as claimed in Claim 10 wherein the orthohydroxyarylketoxime is 2-
hydroxy-5-nonylbenzophenone oxime, and the orthohydroxyarylaldoxime is 2-hydroxy-
5nonylsalicylaldoxime and equilibrium modifier is 2,2,4-trimethyl-1,3-pentanediol di-
isobutyrate.


A solvent extraction composition comprising one or more orthohydroxyarylaldoximes
and one or more orthohydroxyarylketoximes, and one or more equilibrium modifiers selected
from 2,2,4-trimethyl-1,3-pentanediol mono-isobutyrate, 2,2,4-trimethyl-1,3-pentanediol mono-
benzoate, 2,2,4-trimethyl-1,3-pentanediol diisobutyrate, 2,2,4-trimethyl-1,3-pentanediol di-
benzoate, isobutyl heptyl ketone, nonanone, 2,6,8-trimethyl-4-nonanone, diundecyl ketone, and
5,8-diethyldodecane-6,7-dione, tridecanol, and nonyl phenol in an amount providing a
degree of modification of the orthohydroxyarylaldoximes present of from about 0.2 to 0.61.

Documents:

01910-kolnp-2005-description provisional.pdf

01910-kolnp-2005-drawings.pdf

01910-kolnp-2005-form 1.pdf

01910-kolnp-2005-form 2.pdf

01910-kolnp-2005-form 3.pdf

01910-kolnp-2005-form 5.pdf

01910-kolnp-2005-international publication.pdf

1910-KOLNP-2005-ABSTRACT.pdf

1910-KOLNP-2005-CANCELLED PAGES.pdf

1910-KOLNP-2005-CLAIMS.pdf

1910-kolnp-2005-correspondence.pdf

1910-KOLNP-2005-DESCRIPTION (COMPLETE).pdf

1910-kolnp-2005-examination report.pdf

1910-KOLNP-2005-FORM 1 1.1.pdf

1910-kolnp-2005-form 18.pdf

1910-KOLNP-2005-FORM 2 1.1.pdf

1910-KOLNP-2005-FORM 3 1.1.pdf

1910-kolnp-2005-form 3.pdf

1910-KOLNP-2005-FORM 5 1.1.pdf

1910-kolnp-2005-form 5.pdf

1910-KOLNP-2005-FORM-27.pdf

1910-kolnp-2005-gpa.pdf

1910-kolnp-2005-granted-abstract.pdf

1910-kolnp-2005-granted-claims.pdf

1910-kolnp-2005-granted-description (complete).pdf

1910-kolnp-2005-granted-form 1.pdf

1910-kolnp-2005-granted-form 2.pdf

1910-kolnp-2005-granted-specification.pdf

1910-KOLNP-2005-MISCLLENIOUS.pdf

1910-KOLNP-2005-OTHERS PATENT DOCUMENTS.pdf

1910-KOLNP-2005-OTHERS PCT FORM.pdf

1910-KOLNP-2005-OTHERS.pdf

1910-kolnp-2005-others1.1.pdf

1910-KOLNP-2005-PETITION UNDER RULE 137 1.1.pdf

1910-KOLNP-2005-PETITION UNDER RULE 137 1.2.pdf

1910-KOLNP-2005-PETITION UNDER RULE 137.pdf

1910-KOLNP-2005-REPLY TO EXAMINATION REPORT.pdf

1910-kolnp-2005-reply to examination report1.1.pdf


Patent Number 248954
Indian Patent Application Number 1910/KOLNP/2005
PG Journal Number 37/2011
Publication Date 16-Sep-2011
Grant Date 14-Sep-2011
Date of Filing 26-Sep-2005
Name of Patentee CYTEC TECHNOLOGY CORP.
Applicant Address 300 DELAWARE AVENUE, WILMINGTON, DE 19801, U.S.A.
Inventors:
# Inventor's Name Inventor's Address
1 SODERSTROM, MATHEW, DEAN 9 JUNIPER DRIVE, WHITEHOUSE STATION NJ 08889, U.S.A.
PCT International Classification Number C22B 3/00
PCT International Application Number PCT/US2004/009545
PCT International Filing date 2004-03-29
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 60/463,330 2003-04-17 U.S.A.