Recovery of gallium

Claim 2

A PROCESS FOR TREATING SOLUTIONS CONTAINING GALLIUM IN ADMIXTURE WITH ALUMINUM AND CAUSTIC IN ORDER TO ENHANCE THE GALLIUM CONCENTRATION WHICH COMPRISES: A. ADDING A SOURCE OF SILICA SUFFICIENT TO REACT WITH 50-98 PERCENT BY WEIGHT OF THE TOTAL SODA PRESENT IN SAID SOLUTION IN AN AMOUNT SO AS TO PROVIDE 2 MOLES OF SILICA PER MOLE OF SODA TO BE REACTED; B. ADDING A SOURCE OF ALUMINA IF THE NA2O:ALO3RATIO OF THE SOLUTION IS ABOVE ABOUT 1 TO LOWER THE RATIO TO ABOUT 1 OR LOWER; C. HEATING THE SOLUTION AT TEMPERATURES OF FROM ABOUT 212* TO ABOUR 400* SO AS TO CAUSE ALUMINA AND CAUSTIC TO SELECTIVELY REACT WITH SILICA TO FORM A PRECIPITATE AND LEAVE THE SUBSTANTIAL PORTION OF THE GALLIUM IN SOLUTION; D. SEPARATING THE PRECIPITATE FROM THE SOLUTION;AND E. EVAPORATING THE SOLUTION SO AS TO INCREASE THE GALLIUM CONCENTRATION THEREOF

Claim 3

The process of claim 1 wherein the source of silica and alumina in steps (a) and (b) is clay.

Claim 4

The process of claim 1 wherein the solution from step (e) contains at least 2 moles of free soda per mole of alumina.

Claim 5

IN A PROCESS FOR ENHANCING THE GALLIUM CONCENTRATION OF A SOLUTION CONTAINING CAUSTIC, ALUMINUM AND GALLIUM WHEREIN SAID SOLUTION IS TREATED WITH CARBON DIOXIDE AT CONDITIONS TO SELECTIVELY PRECIPITATE THE MAJOR PORTION OF ALUMINUM, FOLLOWED BY REMOVING THE PRECIPITATE AND SUBJECTING THE REMAINING SOLUTION TO A SECOND TREATMENT WITH CARBON DIOXIDE SO AS TO PRECIPITATE A MIXTURE OF SODIUM ALUMINUM COMPOUNDS AND SODIUM GALLIUM COMPOUNDS, THE IMPROVEMENT WHICH COMPRISES: A. CALCINING SAID PRECIPITATE OF ALUMINUM AND GALLIUM COMPOUND AND DISSOLVING THE SAME IN WATER TO PROVIDE A SOLUTION HAVING A NA2O: AL2O3 RATIO OF ABOUT 1; B. CONTACTING SAID SOLUTION FROM STEP (A) WITH SILICA IN AN AMOUNT EQUAL TO ABOUT 2 MOLES SILICA PER MOLE OF ALUMINA TO BE REACTED AT ELEVATED TEMPERATURES OF FROM ABOUR 212* TO ABOUT 400*F SO AS TO CAUSE THE SILICA TO SELECTIVELY REACT WITH CAUSTIC AND ALUMINUM AND FORM A PRECIPITATE AND LEAVE THE SUBSTANTIAL PORTION OF GALLIUM IN SOLUTION; C. SEPARATING SAID GALIUM SOLUTION FROM SAID PRECIPITATE; AND D. CONCENTRATING SAID GALLIUM SOLUTION BY REMOVAL OF WATER.

Claim 6

IN A PROCESS FOR ENHANCING THE GALLIUM CONCENTRATION OF A SOLUTION CONTAINING CAUSTIC, ALUMINUM AND GALLIUM WHEREIN SAID SOLUTION IS TREATED WITH CARBON DIOXIDE AT CONDITIONS TO SELECTIVELY PRECIPITATE THE MAJOR PORTION OF ALUMINUM, FOLLOWED BY REMOVING THE PRECIPITATE AND SUBJECTING THE REMAINING SOLUTION TO A SECOND TREATMENT WITH CARBON DIOXIDE SO AS TO PRECIPITATE A MIXTURE OF SODIUM ALUMINUM COMPOUNDS AND SODIUM GALLIUM COMPOUNDS, THE IMPROVEMENT WHICH COMPRISES: A. CALCINING SAID PRECIPITATE OF ALUMINUM AND GALLIUM COMPOUND AND DISSOLVING THE SAME IN WATER TO PROVIDE A SOLUTION HAVING A NA2O: AL2O3 RATIO OF ABOUT 1; B. CONTACTING SAID SOLUTION FROM STEP (A) WITH SILICA IN AN AMOUNT EQUAL TO ABOUT 2 MOLES SILICA PER MOLE OF ALUMINA TO BE REACTED AT ELEVATED TEMPERATURES OF FROM ABOUR 212* TO ABOUT 400*F SO AS TO CAUSE THE SILICA TO SELECTIVELY REACT WITH CAUSTIC AND ALUMINUM AND FORM A PRECIPITATE AND LEAVE THE SUBSTANTIAL PORTION OF GALLIUM IN SOLUTION; C. SEPARATING SAID GALIUM SOLUTION FROM SAID PRECIPITATE; AND D. CONCENTRATING SAID GALLIUM SOLUTION BY REMOVAL OF WATER.

Claim 7

The process of claim 4 wherein the silica added in step (b) is 2 moles for every mole of alumina desired to be reacted and the alumina reacted is 50-98 weight percent.

Claim 8

The process of claim 5 wherein sufficient silica is added to react with 90-98 weight percent of the alumina present in a ratio of 2 moles of silica per mole of alumina.

Claim 9

The process of claim 5 wherein the gallium solution of step (c) contains at least 2 moles of free soda per mole of alumina.

Claim 10

The process of claim 6 wherein the gallium solution of step (c) contains at least 2 moles of free soda per mole of aluMina.