Copper, cobalt, and ammonium sulfate recovery from mineral leach liquors

Claim 1

IN THE TREATMENT OF SOLUTIONS OBTAINED BY OXIDATION LEACHING OF SULFUR-BEARING MIXTURES CONTAINING NICKLE, COBALT AND COPPER WHEREBY SUL FATES OF METAL VALUES ARE DISSOLVED, THE METHOD OF SEPARATING THE COBALT CONTENT OF THE SOLUTION WHICH COMPRISES: ADJUSTING THE PH OF THE SOLUTION TO FROM ABOUT 4-6.5 AND THE SULFATE CONTENT TO THE EQUIVALENT OF SOLUTIONS AS ABOUT 25* C. CONTAINING CONCENTRATIONS OF (A) COPPER AND COBALT NOT OVER ABOUT 10% AND 6% RESPECTIVELY AT ABOUT 10% AMMONIUM SULFATE AND 2% AND 1.3% RESPECTIVELY AT ABOUT 20% AMMONIUM SULFATE, AND (B) AMMONIUM SOLFATE OF AT LEAST 9%, AT WHICH SUBSTANTIALLY ALL OF THE COPPER AND COBALT REMAIN IN SOLUTION AND SUBSTANTIALLY ALL NICKLE PRECIPITATES; REMOVING ANY NICKLE-BEARING PRECIPITATE; HEATING THE RESIDUAL SOLUTION SUFFICIENTLY TO PRECIPITATE SUBSTANTIALLY ALL OF THE COPPER VALUES; USE AND REMOVING THE PRECIPITATED COPPER VALUES; ADJUSTING THE PH OF RESIDUAL LIQUOR TO ABOUT 3.5-5.5 AND MAINTAINING THIS ACIDITY; CONCENTRATING ADJUSTED LIQUOR TO CRYSTALLIZE AMMONIUM SALT THEREFROM, CONTINUING AMMONIUM SALT CRYSTALLIZING UNTIL THE COBALT SULFATE-AMMONIUM SULFATE DOUBLE SALT CONTENT APPROACHES THE SATURATION POINT AT THE OPERATING TEMPERATURE AND COLLECTING RESULTANT AMMONIUM SALT CRYSTALS; AND CONTINUOUSLY PASSING CONCENTRATED COBALT MOTHE LIQUOR TO A COBALT COOLER-CRYSTALLIZER, WHEREBY COBALTAMMONIUM SULFATE DOUBLE SALT IS CRYSTALLIZED, COLLECTING COBALT SALT CRYSTALS AND RETURNING RESIDUAL MOTHER LIQUOR TO THE A MMONIUM SALT CRYSTALLIZED TO BE FURTHER CONCENTRATED IN COBALT.