Solvent extraction of metals with a cyclic alkylene carbonate

Claim 2

A PROCESS FOR THE SOLVENT EXTRACTION OF METAL VALUES SELECTED FROM THE GROUP CONSISTING OF SALTS AND COMPLEXES OF GOLD, PLATINUM, PALLADIUM, RHODIUM, IRIDIUM, COBALT, COPPER, VANADIUM, URANIUM, BISMUTH, CADMIUM, MERCURY, AND CERIUM, COMPRISING THE STEPS OF PROVIDING AN AQUEOUS MEDIUM CONTAINING AT LLEAST ONE OF THE SAID METAL VALUES, SAID MEDIUM HAVING AN ACID PH, AND CONTACTING SAID MEDIUM WITH A COMPOSITION COMPRISING A CYLIC ALKYLENE CARBONATE, SAID CARBONATE COMPOSITION BEIGN AT LEAST PARTIALLY INSOLUBLE IN SAID MEDIUM.

Claim 3

A process as defined in claim 1 wherein the salt is a halide.

Claim 4

A process as defined in claim 2 wherein the halide is a chloride.

Claim 5

A process as defined in claim 1 wherein the cyclic alkylene carbonate is propylene carbonate.

Claim 6

A process as defined in claim 1 wherein the cyclic alkylene carbonate is ethylene carbonate.

Claim 7

A process as defined in claim 1 wherein the cyclic alkylene carbonate composition includes an organic liquid that is miscible with the carbonate and is from only slightly soluble to insoluble in the medium.

Claim 8

A process as defined in claim 6 wherein the organic liquid is selected from the group consisting of benzene, o-xylene, m-xylene, p-xylene, diethyl ether, 4-methyl-2-pentanone, 2,4-pentandione, ethyl acetate, n-heptyl alcohol, and chloroform.

Claim 9

A process as defined in claim 7 wherein the cyclic alkylene carbonate is propylene carbonate.

Claim 10

A process as defined in claim 7 wherein the cyclic alkylene carbonate is ethylene carbonate.

Claim 11

A process for the solvent extraction of a metal selected from the group consisting of gold, platinum, palladium, iridium and uranium comprising the steps of: a. providing a halide of the metal to be extracted in a suitable aqueous medium therefor; b. adjusting the pH of the medium to a range of about -0.6 to about 3.0; c. contacing the medium with a composition comprising an organic alkylene carbonate, said composition being at least partially insoluble in said medium; whereby a phase separation occurs, the metal being located in the carbonate phase; d. separating the carbonate phase from the remainder of the medium; and e. recovering the metal from the carbonate phase.

Claim 12

A process for the solvent extraction of a metal selected from the group consisting of gold, platinum, palladium, iridium and uranium comprising the steps of: a. providing a halide of the metal to be extracted in a suitable aqueous medium therefor; b. adjusting the pH of the medium to a range of about -0.6 to about 3.0; c. contacing the medium with a composition comprising an organic alkylene carbonate, said composition being at least partially insoluble in said medium; whereby a phase separation occurs, the metal being located in the carbonate phase; d. separating the carbonate phase from the remainder of the medium; and e. recovering the metal from the carbonate phase.

Claim 13

The process as defined in claim 10 wherein the metal is recovered from the carbonate phase by an electrowinning process.

Claim 14

A process as defined in claim 10 wherein the carbonate is propylene carbonate.

Claim 15

A process as defined in claim 10 wherein the carbonate is ethylene carbonate.

Claim 16

A process as defined in claim 10 wherein the carbonate composition includes an organic liquid that is miscible with the carbonate and from only slightly soluble to insoluble in the medium.

Claim 17

A process as defined in claim 14 wherein the organic liquid is selected from the group consisting of benzene, o-xylene, m-xylene, p-xylene, diethyl ether, 4-methyl-2-pentanone, 2,4-pentandione, ethyl acetate, n-heptyl alcohol, and chloroform.

Claim 18

A process as defined in claim 14 wherein after the carbonate phase is separated from the medium, the organic liquid is volatilized from the carbonate prior to recovery of the metal therefrom.

Claim 19

A process as defined in claim 15 wherein the carbonate is propylene carbonate which is present in the composition in a range of from about 5 to about 40 per cent and the organic liquid is benzene which is present in the range of from about 95 to about 60 per cent.

Claim 20

A process as defined in claim 17 wherein the metal is recovered from the carbonate phase by electrowinning.

Claim 21

A process for the solvent extraction of a metal selected from the group consisting of gold, platinum, palladium, rhodium, iridium, cobalt, copper, vanadium, uranium, bismuth, cadmium, mercury, and cerium, comprising the steps of: a. providing an aqueous medium of a thiocyanate of at least one of said metals; b. adjusting the pH of the medium into the acid range; c. contacting the aqueous medium with a composition comprising an organic alkylene carbonate, said composition being at least partially insoluble in said medium whereby a pHase separation occurs, the metal being located in the carbonate phase; d. separating the carbonate phase from the remainder of the medium; and e. recovering the metal from the carbonate phase.

Claim 22

A process for the solvent extraction of a metal selected from the group consisting of gold, platinum, palladium, rhodium, iridium, cobalt, copper, vanadium, uranium, bismuth, cadmium, mercury, and cerium, comprising the steps of: a. providing an aqueous medium of a thiocyanate of at least one of said metals; b. adjusting the pH of the medium into the acid range; c. contacting the aqueous medium with a composition comprising an organic alkylene carbonate, said composition being at least partially insoluble in said medium whereby a pHase separation occurs, the metal being located in the carbonate phase; d. separating the carbonate phase from the remainder of the medium; and e. recovering the metal from the carbonate phase.

Claim 23

A process as defined in claim 19 wherein the metal is electrowon from the carbonate phase.

Claim 24

A process as defined in claim 19 wherein the carbonate is propylene carbonate.

Claim 25

A process as defined in claim 19 wherein the carbonate is ethylene carbonate.

Claim 26

A process as defined in claim 19 wherein the carbonate composition also includes an organic liquid in admixture therewith, said liquid being miscible with the carbonate and from only slightly soluble to completely insoluble in the aqueous medium.

Claim 27

A process as defined in claim 23 wherein the organic liquid is selected from a member of the group consisting of benzene, o-xylene, m-xylene, p-xylene, diethyl ether, 4-methyl-2-pentanone, 2,4-pentandione, ethyl acetate, n-heptyl alcohol, and chloroform.

Claim 28

A process as defined in claim 24 wherein the carbonate is propylene carbonate.

Claim 29

A process as defined in claim 24 wherein the carbonate is ethylene carbonate.

Claim 30

A process as defined in claim 23 wherein prior to recovery of the metal from the carbonate phase, the organic liquid is volatilized from the carbonate composition.

Claim 31

A process as defined in claim 23 wherein the carbonate composition comprises from about 5 to about 40 per cent propylene carbonate and from about 95 to about 60 per cent benzene and the organic liquid.

Claim 32

A process as defined in claim 28 wherein the metal is removed from the carbonate phase by an electrowinning process.