Separating metal values by selective extraction

Claim 2

A PROCESS FOR SEPARATING RARE EARTH METAL VALUES IN AN AQUEOUS SOLUTION CONTAINING SAID METALS WHICH COMPRISES CONTACTING AND MIXING SAID AQUEOUS SOLUTION WITH A FIRST IMMISCIBLE ORGANIC SOLVENT WHICH SELECTIVELY EXTRACTS AT LEAST A FIRST RARE EARTH METAL FROM THE METALS IN THE AQUEOUS SOLUTION, ALLOWING THE MIXTURE TO SETTLE INTO AN AQUEOUS PHASE DEPLETED IN THE FIRST RARE EARTH METAL AND A SOLVENT PHASE ENRICHED IN SAID FIRST RARE EARTH METAL, SEPARATING THE AQUEOUS PHASE FROM THE SOLVENT PHASE AND THEN CONTACTING SAID SEPARATED AQUEOUS PHASE WITH A SECOND IMMISCIBLE ORGANIC SOLVENT WHICH SELECTIVELY EXTRACTS AT LEAST A SECOND RARE EARTH METAL FROM SAID AQUEOUS PHASE, ALLOWING THE MIXTURE TO SETTLE INTO AN AQUEOUS PHASE DEPLETED IS SAID SECOND RARE EARTH METAL AND A SOLVENT PHASE ENRICHED IN SAID SECOND RARE EARTH METAL, SEPARATING SAID AQUEOUS PHASE AND THEN CONTACTING AND MIXING SAID SEPARATED AQUEOUS PHASE WITH SAID FIRST ORGANIC SOLVENT WHICH SELECTIVELY EXTRACTS AND ADDITIONAL AMOUNT OF SAID FIRST RARE EARTH METAL, ALLOWING THE MIXTURE TO SEPARATE INTO AN AQUEOUS PHASE DEPLETED IN SAID FIRST RARE EARTH METAL AND A SOLVENT PHASE ENRICHED IN SAID FIRST RARE EARTH METAL, SEPARATELY STRIPPING SAID FIRST AND SECOND SOLVENTS TO RECOVER A FIRST STRIPPING SOLUTION CONCENTRATED IN SAID FIRST RARE EARTH METAL AND A SECOND RARE EARTH METAL, AND SEPARATING A LAST AQUEOUS PHASE DEPLETED IN BOTH OF SAID FIRST AND SECOND RARE EARTH METALS.

Claim 3

A process for separating rare earth metal values in an aqueous feed solution containing said rare earth values which comprises contacting and mixing said feed solution with a first immiscible organic amine solvent which exhibits a selectivity for at least one of said rare earth metals, separating a solvent phase and an aqueous phase, contacting and mixing separated aqueous phase with a second immiscible organic phosphate solvent which exhibits a selectivity for at least one other of said rare earth metals, separating an aqueous phase and a solvent phase, alternately contacting said aqueous phase with said first solvent and with said second solvent to selectively extract into the respective solvents the metal values for which said solvents are selective and to thereby separate said rare earth values in said feed solution into said respective solvents, separating said metals from said solvents and recovering said metals.

Claim 4

A process for separating rare earth metal values in an aqueous feed solution containing said rare earth values which comprises contacting and mixing said feed solution with a first immiscible organic amine solvent which exhibits a selectivity for at least one of said rare earth metals, separating a solvent phase and an aqueous phase, contacting and mixing separated aqueous phase with a second immiscible organic phosphate solvent which exhibits a selectivity for at least one other of said rare earth metals, separating an aqueous phase and a solvent phase, alternately contacting said aqueous phase with said first solvent and with said second solvent to selectively extract into the respective solvents the metal values for which said solvents are selective and to thereby separate said rare earth values in said feed solution into said respective solvents, separating said metals from said solvents and recovering said metals.

Claim 5

thereafter contacting the aqueous phase with a second immiscible organic phosphate solvent which has a separation factor of about 2.5 for the higher atomic number metal values, separating an aqueous phase and a solvent phase,

Claim 6

thereafter contacting the aqueous phase with a second immiscible organic phosphate solvent which has a separation factor of about 2.5 for the higher atomic number metal values, separating an aqueous phase and a solvent phase,

Claim 7

A double solvent extraction process for the separation of rare earth meTal values from an aqueous solution containing said rare earth metals which comprises:

Claim 8

A double solvent extraction process for the separation of rare earth meTal values from an aqueous solution containing said rare earth metals which comprises:

Claim 9

then again contacting the aqueous phase with said first immiscible organic amine solvent, whereby said rare earth metal values are extracted from said aqueous solution preferentially into the two solvents, separating said metals from said solvents and recovering said metals.

Claim 10

then again contacting the aqueous phase with said first immiscible organic amine solvent, whereby said rare earth metal values are extracted from said aqueous solution preferentially into the two solvents, separating said metals from said solvents and recovering said metals.

Claim 11

The process of claim 3 wherein the alkyl amine solvent comprises a mixture of tertiary alkyl primary amines having 18 to 21 carbon atoms and the alkyl phosphate solvent comprises di-2-ethyl hexyl phosphoric acid.

Claim 12

A procedure for the solvent extraction of rare earth values present in an aqueous solution comprising successively contacting the aqueous solution with a first immiscible organic solvent containing an alkyl amine and subsequently contacting the aqueous solution with a second immiscible organic solvent containing an alkyl phosphate, then contacting the aqueous solution with said amine containing solvent whereby after each contact an aqueous phase and a solvent phase are separated and whereby the lower atomic number rare earth values are preferentially extracted into the alkyl amine solvent and the higher atomic number rare earth values are preferentially extracted into the alkyl phosphate solvent and the middle atomic number rare earth values selectively remain in the aqueous raffinate solution, separating the rare earth metals from said solvents and raffinate solution and recovering said metals.

Claim 13

A procedure for the solvent extraction of rare earth values present in an aqueous solution comprising successively contacting the aqueous solution with a first immiscible organic solvent containing an alkyl amine and subsequently contacting the aqueous solution with a second immiscible organic solvent containing an alkyl phosphate, then contacting the aqueous solution with said amine containing solvent whereby after each contact an aqueous phase and a solvent phase are separated and whereby the lower atomic number rare earth values are preferentially extracted into the alkyl amine solvent and the higher atomic number rare earth values are preferentially extracted into the alkyl phosphate solvent and the middle atomic number rare earth values selectively remain in the aqueous raffinate solution, separating the rare earth metals from said solvents and raffinate solution and recovering said metals.

Claim 14

A process for separating rare earth metal values in an aqueous feed solution containing Pr, Nd, Sm, Gd and Dy, and yttrium, which comprises contacting and mixing said feed solution with a first immiscible organic amine solvent which exhibits a selectivity for the lower atomic number rare earth metals, separating a solvent phase and an aqueous phase, contacting and mixing said separated aqueous phase with a second immiscible organic phosphate solvent which exhibits a selectivity for the higher atomic number rare earth metals and yttrium, separating an aqueous phase and a solvent phase, alternately contacting said aqueous phase with said first solvent and with said second solvent to selectively extract into the respective solvents the metal values for which said solvents are selective and to thereby separate said rare earth values and yttrium in said feed solution into said respective solvents, separating said metals from said solvents and recovering said metals.

Claim 15

A process for separating rare earth metal values in an aqueous feed solution containing Pr, Nd, Sm, Gd and Dy, and yttrium, which comprises contacting and mixing said feed solution with a first immiscible organic amine solvent which exhibits a selectivity for the lower atomic number rare earth metals, separating a solvent phase and an aqueous phase, contacting and mixing said separated aqueous phase with a second immiscible organic phosphate solvent which exhibits a selectivity for the higher atomic number rare earth metals and yttrium, separating an aqueous phase and a solvent phase, alternately contacting said aqueous phase with said first solvent and with said second solvent to selectively extract into the respective solvents the metal values for which said solvents are selective and to thereby separate said rare earth values and yttrium in said feed solution into said respective solvents, separating said metals from said solvents and recovering said metals.

Claim 16

The process of claim 6 wherein the rare earth metals Pr, Nd and Sm are concentrated in the amine solvent, the rare earth metal Dy, and the metal yttrium are concentrated in the organic phosphate solvent and the rare earth metal Gd is concentrated in the remaining aqueous phase.

Claim 17

A process for separating metals in an aqueous solution selected from the group consisting of solutions of vanadium and uranium; hafnium and zirconium; molybdenum and tungsten; zinc and copper; cobalt and nickel; and columbium and tantalum, said process comprising contacting and mixing said aqueous solution with a first immiscible solvent which selectively extracts at least a first metal from the metals in the aqueous solution, allowing the mixture to settle into an aqueous phase depleted in the first metal and a solvent phase enriched in said first metal, separating the aqueous phase from the solvent phase and then contacting said separated aqueous phase with a second immiscible solvent which selectively extracts at least a second of tHe metals in said aqueous solution, allowing the mixture to settle into an aqueous phase depleted in said second metal and a solvent phase enriched in said second metal, separating said aqueous phase and then contacting and mixing said separated aqueous phase with said first solvent which selectively extracts an additional amount of said first extracted metal, allowing the mixture to separate into an aqueous phase depleted in said first metal and a solvent phase enriched in said first metal, separately stripping said first and second solvents to recover a first stripping solution concentrated in said first metal and a second stripping solution concentrated in said second metal and a last aqueous phase depleted in both of said first and second metals.

Claim 18

A process for separating metals in an aqueous solution selected from the group consisting of solutions of vanadium and uranium; hafnium and zirconium; molybdenum and tungsten; zinc and copper; cobalt and nickel; and columbium and tantalum, said process comprising contacting and mixing said aqueous solution with a first immiscible solvent which selectively extracts at least a first metal from the metals in the aqueous solution, allowing the mixture to settle into an aqueous phase depleted in the first metal and a solvent phase enriched in said first metal, separating the aqueous phase from the solvent phase and then contacting said separated aqueous phase with a second immiscible solvent which selectively extracts at least a second of tHe metals in said aqueous solution, allowing the mixture to settle into an aqueous phase depleted in said second metal and a solvent phase enriched in said second metal, separating said aqueous phase and then contacting and mixing said separated aqueous phase with said first solvent which selectively extracts an additional amount of said first extracted metal, allowing the mixture to separate into an aqueous phase depleted in said first metal and a solvent phase enriched in said first metal, separately stripping said first and second solvents to recover a first stripping solution concentrated in said first metal and a second stripping solution concentrated in said second metal and a last aqueous phase depleted in both of said first and second metals.