MXPA01002457A - Process for extracting and recovering copper - Google Patents

Abstract

A process for extracting and recovering copper from an aqueous solution containing copper values comprising:(a) contacting the aqueous copper bearing solution with an organic phase comprising a water insoluble and water immiscible solvent solution of an extraction reagent formulation to extract at least a portion of the copper values into the organic phase;(b) separating the resultant copper pregnant organic phase from the copper baren aqueous phase;and (c) recovering the copper values from the copper pregnant organic phase;wherein the extraction reagent formulation comprises (i) an oxime extractant and (ii) an equilibrium modifier in which the modifier is a linear diester or polyester of an unbranched dicarboxylic acid and an unbranched alcohol.

Description

PROCESS TO REMOVE AND RECOVER COPPER Field of the Invention: This application relates to a process for extracting copper from aqueous solutions containing copper by contacting the aqueous solution with a solution of a water-insoluble hydroxyaryl oxime (ketoxime or aldoxime or mixtures thereof). ) in an organic solvent insoluble in water and immiscible in water to extract the metal of the aqueous solution in the organic phase in the form of a chelate of the metal with the hydroxyaryl oxime and then separating the organic phase charged with the metal from the aqueous phase by virtue of the inability of the organic phase and the aqueous phase . The metal can then be recovered from of the organic phase by purifying with an aqueous acid solution followed, for example, by electroextraction. The general process of extracting copper from aqueous solutions such as acid solutions and the recovery of the metal by purifying the phase Organic followed by electroextraction is taught in US Patents 4,507,268; 4,544,532; 4,978,788; and 5,281,336 all the contents of which are incorporated herein by reference. The reaction that leads to the metal chelate compound It also forms acid and causes a decrease in pH. This The reaction is reversible and proceeds to a point of equilibrium that will favor the formation of the chelate compound as the pH increases. Aqueous solutions containing metal salts from which the metal, for example copper, will be extracted will often be leaching liquors obtained by extracting metal ores with acid and will in some cases have a low pH. Since the amount of the chelate compound formed in equilibrium is lower as the pH increases, only those o-hydroxyaryl oximes having a strong chelating power will be able to achieve a high degree of extraction of those aqueous leaching liquors that They have very low pH or high copper content. The advantage of the high copper extraction shown by these very strong chelation oxygens is to a certain extent out of bounds by the large amount of copper remaining as a chelate in the solvent after debugging with acid of suitable strength. As long as this residual copper is not lost as a chelate, since it can be recycled in the extraction step, a reduction in the amount of residual copper chelate in the absence of any comparable reduction in the degree of copper extraction from the aqueous solution, would bring an improvement in the total effectiveness of the process. United Kingdom Patent No. 1549615 teaches that j§¡g¡¡ IT. the amount of copper removed in these cases from the solvent phase in the purification step is significantly increased if the solvent phase contains a "purification modifier" such as a phenol. This patent also teaches that certain aliphatic alcohols, such as tridecanol have similar beneficial effects. The purification modifiers will not only influence the strength of the extraction solvent, but will also affect the hydrolytic stability, the selectivity of the extraction of copper on the extraction of iron, the level of drag, the kinetics of the extraction and the stages of purification in the generation of impurities. A suitable modifier will therefore often result in a compromise. 'Impurity' is a term applied to the undesirable foreign matter formed at the organic-aqueous interface or in the organic phase in the settler compartment of mixing settlers used in the solvent extraction process. It is usually an oil-water emulsion stabilized by the presence of finely divided solid material which may be either aluminosilicates present in the crude ore, or colloidal silica precipitated during the solvent extraction operation. It can accumulate in sufficient quantities to seriously reduce the workload of a settler leading to overflow. Where large quantities are produced, it has to be removed and the emulsion cracked by centrifugation. Impurity can also be a source of reagent loss. U.S. Patent 5,281,336 discloses the use of C-10 to C-30 aliphatic-aromatic or highly branched chain aliphatic esters or C-14 to C-30 alcohols that provide unexpected benefits as depuration modifiers. By "highly branched" it is indicated how the ratio of a number of methyl carbons to non-methyl carbons is greater than 1: 5. The good and unexpected selectivity for copper over iron can be achieved and the above disadvantage having to do with the formation of impurities and the level of entrainment can be solved using such compounds, particularly highly branched derivatives when compared to the straight chain compounds .

PREVIOUS ART The surprising discovery has now been made that the copper extraction solvent formulations based on linear diesters yield similarly to the formulations based on branched diesters. This is surprisingly in the clarity of the claims made in US 4,978,788 and 5,281,336 that linear esters do not yield as do highly branched esters in terms of entrainment and impurity formation. Thus, the invention is a process for recovering copper from an aqueous solution containing copper indexes comprising the steps of: (1) contacting the aqueous solution with the water-insoluble extraction reagent composition which comprises an aldoxime, a ketoxime or combinations thereof and a diester or polyester of an unbranched monocarboxylic acid or unbranched dicarboxylic acid and a mono- or diol not branched to extract at least a portion of the copper indices within the organic phase; (2) separating the resulting impregnated organic phase from the resultant sterile copper aqueous phase; and (3) recover the copper indices of the organic phase impregnated with copper. DETAILED DESCRIPTION OF THE INVENTION. Different than the operation examples, or where indicated otherwise, all the numbers that express quantities of ingredients or reaction conditions used herein will be understood as modified in all examples by the term "approximately". Thus, in its broadest scope, the present invention is directed to a process for recovering copper from an aqueous solution containing copper indexes. comprising: (a) contacting the copper-bearing aqueous solution with an organic phase comprising a water-immiscible, water-insoluble organic solvent solution of an extractive reactive jd formulation to extract at least a portion of the copper indices within of the organic phase; (b) separating the copper impregnated organic phase resulting from the sterile copper aqueous phase; and (c) recovering the copper indexes from the organic phase impregnated with copper: wherein the extracting reagent formulation comprises a hydroxyaryl oxime and an equilibrium modifier in which the modifier is a linear diester of an acidic polyester dicarboxylic and an alcohol, or diol. Copper indexes are preferably recovered from the organic phase (d) by contacting the organic phase impregnated with copper with an acidic solution of aqueous purification, whereby the copper indices are purified from the organic phase within of the acidic solution of aqueous purification; (e) separating the aqueous clearance acidic solution from the organic phase; and (f) recovering the copper from the aqueous acidic purification preferably by electroextraction; Reagents of the extraction solvent for use in the extraction of the copper step include those which contain one or more hydroxyaryl oxime extraction solvents of the hydroxyaryl aldoxime type or #hydroxyaryl ketone oxime. A general formula for such oximes is formula (I) below; in which A can be: i. (ni) H where R and R 'can be individually similar or different and are saturated aliphatic groups of 1-25 carbon atoms, ethylenically unsaturated aliphatic groups of 3-25 carbon atoms or OR '' where R '' is an aliphatic group tot-ga "itt¿ftAiaa '• ^^^^^^^^^^^^ and * ethylenically unsaturated or saturated as defined, n is 0 or 1, a and b are each 0, 1, 2, 3, 4 , with the proviso that both are not 0 and that the total number of carbon atoms in Ra and R'b is from 3 to 25, R '' 'is a saturated aliphatic group of 1-25 carbon atoms or a ethylenically unsaturated aliphatic group of 3 to 25 carbon atoms, with the proviso that the total number of carbon atoms in Ra and R '' 'is 3-25.The preferred compounds where A is (i) above are those in which a is 1, b is 0, R is a straight or branched chain alkyl group having from 7 to 12 carbon atoms and where R is attached in a para position to the hydroxyl group. Among those, the most preferred compounds are those wherein R1"is methyl and R and a are as appointed. Compounds wherein n has an a value of 0 (ie, hydroxybenzophenone oxime compounds) can be suitably prepared according to the methods described in Swanson, U.S. Patent Nos. 3,952,775 and 3,428,449. Because of easy solubility in diluents organic commonly employed in solvent extraction and desirable properties of complexes of the compounds with copper, preferred benzophenone compounds are those having an alkyl group of 7-12 simple carbon atoms in a position to the hydroxy group, who The alkyl group is a mixture of isomers. Examples of such • ^^^^^ a ^ Mk¡ ^ Amtá £ ^ sjiM compounds are 2-hydroxy-5-nonylbenzophenone oxime and 2-hydrox? -5-dodecylbenzophenone oxime, which are obtained as mixtures of the isomeric forms when commercial nonylphenol and dodecylphenol are used respectively in their synthesis. Compounds wherein n has a value of 1 (ie, hydroxyphenylbenzyl ketone oxime compounds) can be suitably prepared according to the methods described in Anderson US Patent 4,029,704. Preferred oximes fenilbencilcetona as above benzophenone oximes observed are those having an isomeric mixture of alkyl groups of 7 to 12 carbons as a single substituent on the ring to the hydroxyl group. These preferred compounds are exemplified by the compound, 2-hydroxy-5-nonylphenylbenzyl ketone oxime, when manufactured from a commercial nonylphenii comprising a mixture of nonyl isomeric forms. Compounds of the oxime type of Hydroxyphenyl alkyl ketone can be suitably prepared according to the procedures described in United Kingdom Patent 1,322,532. As noted with respect to the benzophenone and phenylbenzyl ketone compounds noted above, the preferred compounds of this type also are those that have an isomeric mixture of groups ^^ gÉt ^ ÉMiiÉ ^^ íÉ alkyl of 7 to 12 carbons as an individual substituent in the ring for the hydroxyl group. Also preferred are those in which the alkyl group R '' 'is methyl. Accordingly, illustrative of such preferred compounds is 2-hydroxy-5-non-phenylmethyl ketone oxime manufactured by the use of commercial nonylphenol. The hydroxaryl aldoxime extraction solvents that are employed are those in which A is H. These hydroxybenzene aldoximes also called "salicyl aldoximes" can be suitably prepared according to the methods described in Ackerley et al US Patent 4,020,105 or 4,020,106 or by oximation of aldehydes prepared according to Beswick US Patent No. 4,085,146. Again, the preferred compounds are those having an isomeric mixture of isomeric alkyl groups of 7 to 12 carbons as an individual substituent for the mixed hydroxyl group of alkyl isomeric forms of aldoxime of 2-hydroxy-5-ethylbenzene, aldoxime of 2- hydroxy? -5-octylbenzene, 2-hydroxy? -5-nonylbenzene aldoxime and 2-hydroxy-5-dodecylbenzene aldoxime are preferred, most preferred for the purposes of the present invention where A is H, are the nonyl compounds and dodecyl. The reagents can include a chemical individual extraction solvent as illustrated in the above '? ^^^ ^^ ^ t ^ St ^^^^^^^^ "***' * '" ^^ or different extraction solvents can be of the type illustrated in US Patents 4,507,268; 4,544,532 and 4,582,689. A particularly useful oxime in the mixture with another oxime is an acetophenone tais oxime such as 5-alkyl-2-hydroxyacetophenone oxime., wherein the alkyl group contains from about 6 to about 12 carbon atoms, such as 5-nonyl-2-hydroxyacetophenone oxime or 5-dodecyl-2-hydroxyacetophenone oxime. Reagents also useful in the practice of the invention may include kinetic additives. Preferred kinetic additives include alpha-hydroxy oximes described in Swanson US Patent 3,224,873 and alpha-beta dioxims described in Koenders et al., US Patent 4,173,616. Kinetic additives are often referred to as "accelerators", "catalysts", "kinetic catalysts" or "kinetic synergists" and are generally defined as chemical substances that increase the transfer ratio of the metal indices between the organic and aqueous phases without affecting materially the equilibrium position. As previously indicated, the oxime reagent which is water-soluble, is dissolved in a water-immiscible liquid hydrocarbon solvent and the resulting organic solution is contacted with the copper-containing aqueous phase to extract at least a portion of the water. copper indices within the organic phase. The phases are then separated and the copper indices are purified from the charged organic phase (LO) by the use of an aqueous purification medium. Prior to debugging, it is not usual to wash the organic phase, particularly when the trace metals can be loaded onto the organic extraction solvent. One or more washing steps may therefore be employed depending on any of the trace metals present, the amount of entrainment and the purity required of the final nickel-laden debug solution. In the extraction process, a plurality of liquid hydrocarbon solvents immiscible in water can be used in the copper recovery process to form the organic phase in which the extraction solvent is dissolved. These include aliphatic and aromatic hydrocarbons such as kerosene, benzene, toluene, xylene and the like. A choice of essentially water-immiscible hydrocarbon solvents or mixtures thereof will depend on factors, including the design of the solvent extraction plant, (mixer-settler units, extractors) and the like. Preferred solvents for the use of the present invention are aliphatic or aromatic hydrocarbons having ignition temperatures of 130 degrees Fahrenheit and higher, preferably at least 150 degrees and solubilities in water of less than 0.1% by weight.

ML? &? Solvents are essentially chemically inert. The commercially available representative solvents are Orfom® SX7, distilled petroleum available from Phillips Petroleum Company, which has an inflation temperature of 160 degrees Fahrenheit; Escaid ™ 100 and 110 (available from Exxon-Europe) that has an inflation temperature of 180 degrees Fahrenheit; Norpar ™ 12 (available from Exxon-USA) with an inflation temperature of 160 degrees Fahrenheit; Conoco ™ 120E (available from Conoco) with an inflation temperature of 180 degrees Fahrenheit; and Aromatic 150 (an aromatic kerosene available from Exxon-USA that has an inflation temperature of 150 degrees Fahrenheit), and various other kerosenes and petroleum fractions available from other oil companies. In processes, the volume ratios of organic to aqueous phase (0: A) will vary widely since the contact of any amount of the organic oxime solution with the aqueous solution containing copper will result in the exaction of the copper indices within of the organic phase. However, for commercial practicability, the organic: aqueous phase ratios for extraction are preferably in the range of about 50: 1 to 1:50. It is desirable to maintain an effective 0: A ratio of about 1: 1 in the mixing unit by recirculating one of the streams. In the stage of ^ - [< : F, t, * ^ - -ii »-PÍÜlmm ** /? '8 depuration, the phase of organic purification medium: aqueous preferably will be in the range of approximately 1: 4 to 20: 1. For practical purposes, extraction and purification is normally conducted at ambient temperatures and the pressure, although higher and lower temperatures and pressures, can be fully operated. While the whole operation can be carried out as a batch operation, more advantageously the process is carried out by continuously employing one or more extraction stages (E) followed by one or more purification steps (S) with the various streams or solutions that are recycled to various operations in the process for the recovery of copper extraction and the purification stages. In the extraction process, solutions of the organic solvent may contain the oxime extraction solvent typically in an amount of about 5-25% by weight, generally on a percentage of Volume / Volume (V / V%) with respect to the solvent of about 5-40%, typically around 10-20 V / V%. The extraction reagent formulation will therefore contain an aldoxime, a ketoxime or a combination of such oximes, a diester and / or a polyester as described herein in an aliphatic hydrocarbon solvent. Typically, the extraction reagent will be comprised of an aldoxime, a cetoxima or a combination and ^ Sm? ^^. , of such oximes in relative amounts ranging from about 1/100 to about 100/1 at an aldoxime concentration of about 1.00 mol / liter to about 1.50 mol / liter and a concentration of 5 ketoxime ranging from about 0.25 mol / liter to about 0.75 moles / liters and from about 0.3 to about 0.75 moles / liters of a diester. In the case of polyester, they will be used in an amount sufficient to provide a degree of modification equivalent to the diester as set forth in the above. Preferably a formulated extraction solvent will be comprised of 1.25 moles / liter of 5-nonylsalicyl aldoxime, approximately 0.51 moles / liter of 5-noml-2-hydroxyl acetophenone oxime, 0.3 to 0.75 moles / liter of an ester as is described in Example 2 below in the solvent SHELLSOLD® D70. The diesters according to the invention are those resulting from the esterification of an unbranched dicarboxylic acid and an unbranched mono-ol. The unbranched polyesters can also be used in the process according to the invention. Such polyesters can be made by the reaction of an unbranched dicarboxylic acid and an unbranched diol. The unbranched dicarboxylic acid can be a saturated or unsaturated aliphatic carboxylic acid or it can be an aromatic dicarboxylic acid. 25 Examples of aromatic and aliphatic dicarboxylic acids are not Branches according to the invention include, but are not limited to, oxalic, malonic, succinic, glutaric, adipic, maleic, fumaric, italic, terephthalic, and isophthalic acids respectively. A commercially available mixture of dicarboxylic acids is a mixture containing about 5-31% succinic acid, 11-65% glutaric and 4-25% adipic. Examples of linear mono-oles include, but are not limited to, ethanol, n-propanol, n-butanol, n-hexanol, n-octanol, n-decanol, cyclohexanol and cyclopentanol. Examples of linear diols include, but are not limited to, ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol. Particularly preferred is the di-n-butyl, di-n-pentyl or di-n-hexyl or di-n-octyl ester of adipic acid or the mixture observed above. Esters made by esterification of diols as set forth above and monocarboxylic acids are also contemplated. Examples of linear monocarboxylic acids include, but are not limited to butanoic acid, pentanoic acid, hexanoic acid, acid decanoic, octanoic acid. One can use the esters according to the invention either individually or as mixtures with each other. A preferred mixture is the result of the esterification of a mixture of these diacids which is commercially available as a manufacturing by-product. of nylon. This mixture of diacids, as stated in above, typically consists of approximately 5-31% succinic acid, 11-65% glutaric acid, and 4-25% adipic acid. An example describing a typical preparation of a diester is found below. These diesters can be used as equilibrium modifiers in mixtures with strong copper extraction solvents such as the alkyloxy alkyximes to give mixtures having varying degrees ranging from 0.2-0.95 with the preferred degree of modification range being 0.4-0.9. . They can also be used as equilibrium modifiers in mixtures with strong copper extraction solvents such as alkyloxy alkoximes and a hydroxyaryl ketoxime such as 5-nonyl-2-hydroxyacetophenone oxime where the ratio of moles of alkylaryl aldoxime to ketoxime alkylaryl, the diester would be present in sufficient quantity to give a degree of modification of alkylaryl aldoxime components from 0.2 to 0.95. As used herein, "degree of modification" designates the inverse relationship of (a) the level of purified solvent copper of an extraction solvent of hydroxyaryl aldoxime in equilibrium (expressed in terms of grams per liter of copper) extracted with an aqueous solution containing a fixed concentration of copper and sulfuric acid a (b) the level of copper of purified solvent of the same extraction solvent under the same conditions ís », S í- -. Yes, yes? Á: «? &I when a selected balance modifier additive is present. Consistent with this definition, the presence of relatively small amounts of an equilibrium modifier will change the equilibrium extraction slightly, resulting in a lower decrease in copper level of purified solvent of aldoxime in equilibrium, as will be reflected by a degree of value of modification that reaches approximately 1.0, for example, 0.99. Increased effective amounts of modifier under identical conditions will otherwise result in a more pronounced change in equilibrium extraction and a more pronounced decrease in copper level of purified solvent of aldoxime in equilibrium, as will be reflected by a degree of modification that corresponds to less than 1.0. Another variation of an oxime would involve the substitution of the 5-nonyl-2-hydroxyacetophenone oxime component of the mixture with an improved product derived from a modified manufacturing process comprising heating at least one phenol ester containing an unreacted phenol. in an inert liquid organic solvent with a Lewis acid and a monocarboxylic acid halide or anhydride to obtain a ketone by transposing Fries; (B) isolating the ketone reaction product from the reaction mixture; and (C) by reacting hydroxylamine or a salt thereof with the ketone obtained in step (B) to produce a ketoxime of the ketone. The invention may be further illustrated by means of the following examples, in which all parts and percentages are by weight unless otherwise indicated. The "degree of modification" has been referred to in the foregoing. The "Degree of Modification" is further defined as the inverse relationship of (a) the copper concentration of the purified solvent of an equilibrium aldoxime extraction solvent (g / 1 Cu) extracted from an aqueous solution containing 30 g / 1 Cu 150 g / 1 H2SO a (b) the concentration of purified solvent copper from the same extraction solvent under the same conditions when the selected equilibrium modifier is present. The following example of the present invention establishes that the use of the linear diesters results in the yield of at least the equivalent to that of the highly branched diester, 2,2,4-trimethylpentane-1,3-diol diisobutyrate (TXIB) .

Example 1 A series of solvent extraction circuit comparisons were carried out at a mine site located in the Southwestern United States. These comparisons were carried out in a side-by-side manner in two circuits consisting of a parallel stage of - • y- Á ~ g ^^ extraction, two stages of extraction in series and one stage of purification with a charged organic balance tank. In this configuration, the purified organic makes contact with the fresh aqueous raw solution in the parallel stage to generate a partially charged organic plus a refined parallel stage. The partially charged organic then enters the extraction stage E2 where it makes contact with the partly spent copper refining of the extraction stage. The watery refining of E2 comes from system as the final refined. The partially charged organic carrying the additional copper leaves E2 and enters where it makes contact with the fresh aqueous crude solution. The resulting charged organic phase then proceeds to the charged organic equilibrium tank from where it is pumped then to the purification stage where it makes contact with the lean electrolyte to give the purified organic and the impregnated electrolyte which in turn returns to the tank. The circuits were adjusted as close as possible to give the identical performance. The aqueous crude solution contained 2.3 gpl of copper and 5.6 gpl of iron. The lean electrolyte typically contained 210-220 gpl of sulfuric acid and 33-35 gpl of copper. The organic phases consisted of the following components as shown in Table 1 diluted to give 35 liters of the total organic with Conoco 170 Exempt ^^ «toa ^^ Solvent. TabJ ^ a 1 Organic Phase Components Alloxime Ketoxime E 42073 TXIB A 2674 g 891.3 g 1040 g 0.0 B 2920 g 0.0 1966 g 0.0 C 2920 g 0.0 0.0 1871.1 g 1) 5-Nonilsalloximide 2) 5-oxime ninil-2-hydroxyacetophenone 3) diester derivative of the esterification of a mixture comprised of 5-31% succinic acid, 11-65% glutaric acid, and 4-25% adipic acid with a mixture of n-hexanol and n-octanol. Measurements of organic entrainment in aqueous were made during the course of a comparison run using the methodology described in Henkel Red Line Bulletin - "Aqueous Entrainment in Organic Solutions Centrifuge Method". The organic samples were collected at the El landfill. The results of a comparison of the aqueous trawl indices in the loaded organic leaving El are summarized in Table 2. As the data in Table 2 show, the Linear diester based on the formulations gave better performance in terms of drag when compared to the highly branched diester TXIB. and Table 2 Comparison Organic Phase Aqueous Drag (ppm) 1 -C 1125 2 A 875 3 B 617 Example 2. Preparation of Di-n-pentyl Dicarboxylate Method A (p-toluenesulfonic acid): a deep round neck flask 4, of 5-1, equipped with a mechanical stirrer, a thermometer, a Dean Stark trap, and a condenser was charged with Dibasic Acid (DBA, Dupont) (1426.5 g, 5.296 moles) and n-petyl alcohol (1403.3 g, 15.92 moles) water (550 mL) was removed from the reaction mixture. After cooling to room temperature, p-toluene sulfonic acid (50 g, 0.26 mol, 5% mol) was added. The resulting reaction mixture was heated for 8 hours while stirring 908 ml of water (908 ml). The cooled reaction mixture was transferred to a 4L separatory funnel and washed with 1L of water and 4x1L of brine until the pH was neutral. The organic phase was then washed with 1 L of 0.0938N NaOH followed by 4xlL of brine until the pH was neutral. The crude product was transferred to a 3L RBF for distillation, and distilled in vacuo to obtain di-n-pentyl dicarboxylate in 94.8% yield. ^^ g am i ^^^ m Method B (stannous oxalate): DBA (132 g) was added to a round 250 ml deep flask and the water present in DBA was evaporated until the weight of the DBA solution was 87.63 g. Amyl alcohol (105.6 g), 1.2 moles was used to transfer the tempered DBA solution to a 500 ml round neck deep flask 4 equipped with a mechanical stirrer, a thermometer, a Dean-Stark trap, and a condenser. A 1.0 g sample of the DBA / amyl alcohol mixture was titrated with 5.1 ml of IN NaOH (acid value = 286). Tin (II) oxalate (115 mg, 0.06%) was added to the mixture, and the resulting mixture was heated under vigorous stirring. The esterification was continued until the theoretical amount of water (41.5 g H20) was collected in the trap. The reaction mixture was cooled, and then treated with 50% NaOH solution (570 mg) to neutralize any remaining acid species. The crude product was distilled in vacuo (150-155 ° C (0.6-1.6 tor) to obtain di-n-pentyl dicarboxylate in 90.7% yield.

,,, ^ ^^ ..J¿ * £? *? J ?? *! * -. ^^. ^^^^^^^ a., ^^^,

Claims (31)

1. CLAIMS 1. A process for extracting and recovering copper from an aqueous solution containing copper indexes comprising: (a) contacting the copper-bearing aqueous solution with an organic phase comprising a solution of water-immiscible solvent and insoluble in water of an extraction reagent formulation to extract at least a portion of the copper indices within the organic phase; (b) separating the copper impregnated organic phase resulting from the sterile copper aqueous phase; and (c) recovering copper indices from the organic impregnated copper phase: wherein the extraction reagent formulation comprises an (i) oxime extraction solvent and (ii) an equilibrium modifier in which the modifier is a linear diester or polyester of an unbranched monocarboxylic acid or unbranched dicarboxylic acid and an unbranched alcohol, or diol.
2. 2. A process as defined in claim 1, wherein the recovery of the copper indices in step (c) comprises: (d) contacting the impregnated organic phase of copper from step (b) with a solution watery * ^^^^^ - ^^^^^ acidic purification, whereby the copper indices are purified from the organic phase within the aqueous solution of acidic purification; (e) separating the aqueous purification solution containing the copper indices from the organic phase; and (f) recovering the copper from the aqueous acidic clearance solution.
3. 3. A process as defined in claim 2, wherein the copper is recovered from the aqueous acidic clearance solution by electroextraction.
4. 4. A process as defined in claim 1, wherein the extraction solvent is a hydroxyaryl oxime.
5. 5. A process as defined in claim 1, wherein the hydroxyap oxime is a ketoxime.
6. 6. A process as defined in claim 1, wherein the hydroxyaryl oxime is an aldoxime.
7. 7. A process as defined in claim 1, wherein the hydroxyapic oxime has the formula: in which A is selected from the group É Éfa | & £ W (ii) R '' 'and (üi) H where R and R' may be individually similar or different and are saturated aliphatic groups of 1-25 carbon atoms, ethylenically unsaturated aliphatic groups of 3-25 carbon atoms or OR ' 'where R' is an ethylenically unsaturated or saturated aliphatic group as defined, n is 0 or 1, a and b are each 0, 1, 2, 3, 4, with the proviso that both are not 0 and that the total number of carbon atoms in Ra and R'b is from 3 to 25, R "is a saturated aliphatic group of 1-25 carbon atoms or an ethylenically unsaturated aliphatic group of 3 to 25 carbon atoms, with the proviso that the total number of carbon atoms in Ra and R "is 3-25
8. 8. A process as defined in claim 7, wherein the hydroxyaryl oxime is a ketoxime selected from the group consisting of 2-hydroxy oxime. 5-alkyl benzophenone in which the alkyl group contains from 7 to 12 carbon atoms and the oxime of 2-hydroxy-5-nonylacetophenone .
9. 9. A process as defined in claim 7, wherein the hydroxyaryl oxime is an alkyxy alkyloxy in which the alkyl group contains from 7 to 12 carbon atoms.
10. 10. A process as defined in claim 5, wherein the hydroxyaryl oxime is an allyoxime salicylate is selected from the group consisting of 5-nonyl alkyloxy aldoxime and 5-dodecylsalicylic aldoxime.
11. 11. A process as defined in the claim 10 4, wherein the hydrocarbon solvent immiscible in water is selected from the group consisting of kerosene, benzene, toluene and xylene.
12. 12. A process as defined in claim 1, wherein the unbranched dicarboxylic acid contains 15 to about 12 carbon atoms and is selected from the group consisting of an aromatic dicarboxylic acid and a saturated or unsaturated aliphatic dicarboxylic acid and the unbranched linear alcohol is selected from the group consisting of a linear mono-ol and a linear diol which contains 20 to about 12 carbon atoms.
13. 13. A process as defined in claim 1, wherein the unbranched monocarboxylic acid contains up to 12 carbon atoms and the unbranched linear diol contains up to about 12 carbon atoms.
14. 14. A process as defined in the claim 13, where the unbranched linear diol is selected from the group consisting of ethylene glycol, 1,3-propanediol, 1,4-butanediol and 1,6-hexanediol.
15. 15. A process as defined in claim 5, wherein the unbranched, linear dicarboxylic acid is selected from the group consisting of oxalic, malonic, succinic, glutaric, adipic, maleic, fumaric, italic, terephthalic, and isophthalic acids.
16. 16. A process as defined in claim 10 12, wherein the linear unbranched mono-ol is selected from the group consisting of ethanol, n-propanol, n-butanol, n-hexanol, n-octanol, n- decanol, cyclohexanol, and cyclopentanol and the unbranched linear diol is selected from the group consisting of ethylene glycol, 1,3-propanediol, 1,4-butanediol, and 1,6-hexanediol.
17. 17. A process as defined in claim 15, wherein the dicarboxylic acid is a mixture of succinic, glutaric, and adipic acid and the unbranched, linear alcohol is n-hexanol.
18. 18. A process as defined in the claim 1, in which the equilibrium modifier is din-butyl adipate.
19. 19. A process as defined in claim 1, wherein the equilibrium modifier is di-25-hexyl adipate. u **** ^ ***** »*** ^ ..,. ~" ,, a ^,. ^^
20. 20. A process as defined in claim 1, wherein the equilibrium modifier is di-n-pentyl adipate.
21. 21. An extraction reagent composition comprised of an oxime extraction solvent and equilibrium modifier of a linear unbranched diester or polyester of an unbranched monocarboxylic acid or unbranched dicarboxylic acid and an unbranched alcohol or diol.
22. 22. An extraction reagent composition as defined in claim 21, wherein the oxime extraction solvent has the formula. in which A is selected from the group 11, R ' iMtiii m ^ (iii) H where R and R 'can be individually similar or different and are saturated aliphatic groups of 1-25 carbon atoms, ethylenically unsaturated aliphatic groups of 3-25 carbon atoms or OR' 'where R' ' is an ethylenically unsaturated or saturated aliphatic group as defined; n is 0 or 1; a and b are each 0, 1, 2, 3, 4, with the proviso that both are not 0 and the total number of carbon atoms in Ra and R'b is from 3 to 25, R "is a group saturated aliphatic of 1-25 carbon atoms or an ethylenically unsaturated aliphatic group of 3 to 25 carbon atoms, with the proviso that the total number of carbon atoms in Ra and R "is 3-25. of extraction reagent as defined in claim 21, wherein the unbranched dicarboxylic acid contains up to about 12 carbon atoms and is selected from the group consisting of an aromatic dicarboxylic acid and a saturated or unsaturated aliphatic dicarboxylic acid and linear alcohol unbranched is selected from the group consisting of a mono- or linear and a linear diol containing up to about 12 carbon atoms 24. An extracting reagent composition as defined in claim 21, wherein the dicarboxylic acid unbranched neal is selected from the group The family consists of oxalic, malonic, succinic, glutaric, adipic, maleic, phumapoic, italic, terephthalic, and isophthalic acids. 25. An extraction reagent composition as defined in claim 21, wherein the linear unbranched mono-ol is selected from the group consisting of ethanol, n-propanol, n-butanol, n-hexanol, n-octanol , n-decanol, cyclohexanol, and cyclopentanol and the unbranched linear diol is selected from the group consisting of ethylene glycol, 1,3-propanediol, 1,4-butanediol, and 1,6-hexanediol. 26. An extraction reagent composition as defined in claim 21, wherein the dicarboxylic acid is a mixture of succinic acid, glutaric acid, and 15 adipic and the unbranched linear alcohol is n-hexanol. 27. An extraction reagent composition as defined in claim 21, wherein the equilibrium modifier is di-n-butyl adipate. 28. An extraction reagent composition as defined in claim 21, wherein the equilibrium modifier is di-n-pentyl adipate. 29. An extraction reagent composition as defined in claim 21, wherein the equilibrium modifier is di-n-hexyl adipate. 30. An extraction reagent composition as ^^ j ^ a ^ to ^^^^^^^^^^^^^^^^^ defined in claim 21, wherein the branched monocarboxylic acid contains up to about 12 carbon atoms and linear diol branched contains up to about 12 carbon atoms. 31. A composition extraction reagent as defined in claim 29, wherein the linear unbranched diol is selected from the group consisting of ethylene glycol, 1, 3-propanediol, 1, 4-butanediol and 1,6-hexanediol. 10 ^^^^ jfe ^^ g ^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^