Isolation of nickel sulfide

Claim 1

A METHOD OF LEACHING A NICKEL-BEARING ORE CONTAINING AT LEAST ONE OTHER NON-FERROUS METAL VALUE, IRON SULFIDES AND ACID-INSOLUBLE GANGUE, WHICH COMPRISES THE STEPS OF: PASSING A QUANTITY OF NICKEL-BEARING ORE CONCENTRATE INTO AN OXIDATION LEACHING SYSTEM IN WHICH IT IS SIMULTANEOUSLY SUBJECTED TO: (A) OXIDATION IN THE PRESENCE OF WATER AND A GAS SELECTED FROM OXYGEN, OXYGENENRICHED AIR AND AIR, (B) THE ACTION OF A SUFFICIENT RECYCLED AMOUNT OF ACID PRODUCED IN THE OXIDATION LEACHING STEP TO PROVIDE A PH LESS THAN ABOUT 3.0 AND (C) TO A TEMPERATURE OF ABOUT 275-750* F., THE WATER BEING SUFFICIENT IN AMOUNT TO PREVENT THE ACID CONTENT DURING REACTION FROM EXCEEDING 15%; REMOVING OXIDIZED SLURRY FROM THE OXIDATION LEACHING SYSTEM; FILTERING THE SAID RECOVERING SLURRY; DISCARDING THE SOLIDS RESIDUE; DIVIDING THE CLARIFIED FILTRATE INTO TWO PORTIONS; TREATING ONE SAID PORTION WITH (A) A SUFFICIENT AMOUNT OF AMMONIA TO PRODUCE A PH OF 4.0-6.8 IN THE PRESENCE OF (B) SUFFICIENT AMMONIUM SULFATE AFTER PH REDUCTION TO CONVERT ALL THE NICKEL CONTENT OF SAID ONE PORTION TO NICKEL SULFATE-AMMONIUM SULFATE DOUBLE SALT IN THE PRESENCE OF A SOLUTION CONCENTRATED WITH AMMONIUM SULFATE; COLLECTING THE RESIDUAL RESULTANT NICKEL-BEARING PRECIPITATE; TREATING THE REMAINING PORTION OF SAID CLARIFIED FILTRATE AT ABOUT 275-750* F. WITH A SOLUBLE REDUCING AGENT AND ADDITIONAL AMOUNTS OF ORE CONCENTRATE HAVING AN IRON AND SULFUR CONTENT EQUIVALENT TO THE NON-FERROUS METALS CONTENT OF SAID REMAINING PORTION OF FILTRATE; CONTINUING THE TREATMENT UNTIL REPLACEMENT SUBSTANTIALLY CEASES; COLLECTING THE SOLIDS CONTENT OF THE RESULTANT SLURRY; PASSING THE RESULTANT CLARIFIED LIQUID FROM THE SYSTEM AND FEEDING THE COLLECTED SOLIDS TO THE OXIDATION LEACHING OPERATION, TOGETHER WITH WATER, ADDITIONAL ORE CONCENTRATE AND A PORTION OF RECYCLED ACID PRODUCED IN THE OXIDATION LEACHING STEP.

Claim 2

A METHOD OF LEACHING A NICKEL-BEARING ORE CONTAINING AT LEAST ONE OTHER NON-FERROUS METAL VALUE, IRON SULFIDES AND ACID-INSOLUBLE GANGUE, WHICH COMPRISES THE STEPS OF: PASSING A QUANTITY OF NICKEL-BEARING ORE CONCENTRATE INTO AN OXIDATION LEACHING SYSTEM IN WHICH IT IS SIMULTANEOUSLY SUBJECTED TO: (A) OXIDATION IN THE PRESENCE OF WATER AND A GAS SELECTED FROM OXYGEN, OXYGENENRICHED AIR AND AIR, (B) THE ACTION OF A SUFFICIENT RECYCLED AMOUNT OF ACID PRODUCED IN THE OXIDATION LEACHING STEP TO PROVIDE A PH LESS THAN ABOUT 3.0 AND (C) TO A TEMPERATURE OF ABOUT 275-750* F., THE WATER BEING SUFFICIENT IN AMOUNT TO PREVENT THE ACID CONTENT DURING REACTION FROM EXCEEDING 15%; REMOVING OXIDIZED SLURRY FROM THE OXIDATION LEACHING SYSTEM; FILTERING THE SAID RECOVERING SLURRY; DISCARDING THE SOLIDS RESIDUE; DIVIDING THE CLARIFIED FILTRATE INTO TWO PORTIONS; TREATING ONE SAID PORTION WITH (A) A SUFFICIENT AMOUNT OF AMMONIA TO PRODUCE A PH OF 4.0-6.8 IN THE PRESENCE OF (B) SUFFICIENT AMMONIUM SULFATE AFTER PH REDUCTION TO CONVERT ALL THE NICKEL CONTENT OF SAID ONE PORTION TO NICKEL SULFATE-AMMONIUM SULFATE DOUBLE SALT IN THE PRESENCE OF A SOLUTION CONCENTRATED WITH AMMONIUM SULFATE; COLLECTING THE RESIDUAL RESULTANT NICKEL-BEARING PRECIPITATE; TREATING THE REMAINING PORTION OF SAID CLARIFIED FILTRATE AT ABOUT 275-750* F. WITH A SOLUBLE REDUCING AGENT AND ADDITIONAL AMOUNTS OF ORE CONCENTRATE HAVING AN IRON AND SULFUR CONTENT EQUIVALENT TO THE NON-FERROUS METALS CONTENT OF SAID REMAINING PORTION OF FILTRATE; CONTINUING THE TREATMENT UNTIL REPLACEMENT SUBSTANTIALLY CEASES; COLLECTING THE SOLIDS CONTENT OF THE RESULTANT SLURRY; PASSING THE RESULTANT CLARIFIED LIQUID FROM THE SYSTEM AND FEEDING THE COLLECTED SOLIDS TO THE OXIDATION LEACHING OPERATION, TOGETHER WITH WATER, ADDITIONAL ORE CONCENTRATE AND A PORTION OF RECYCLED ACID PRODUCED IN THE OXIDATION LEACHING STEP.