Treatment of nickel-containing sulfide ores

Claim 1

A PROCESS FOR THE SEPARATE RECOVERY OF NICKEL, COBALT AND IRON FROM NICKEL-CONTAINING SULFIDE ORE WHICH COMPRISES BENEFICATING THE ORE TO OBTAIN A NICKEL SULFIDE CONCENTRATE HAVING A RATIO OF IRON PRESENT AS SULFIDE TO NICKEL PRESENT SULFIDE RANGING FROM ABOUT 10 TO 1 TO ABOUT 1 TO 4, ROASTING THE CONCENTRATE IN AN OXIDIZING ATMOSPHERE AT A TEMPERATURE BELOW ABOUT 1600* F. AND NOT BELOW ABOUT 1300* F. TO PRODUCE A CALCINE CONTAINING LESS THAN ABOUT 2% TOTAL SULFUR AND LESS THAN ABOUT 1% SULFIDE SULFUR, SPECIALLY REDUCING SAID CALCINE AT A TEMPERATURE BELOW ABOUT 1600* F. AND NOT BELOW ABOUT 1300* F. IN A CONTROLLED ATMOSPHERE CONTAINING A RATIO OF CARBON MONOXIDE TO CARBON DIOXIDE OF LESS THAN ABOUT 2 TO 1 AND LESS THAN ABOUT 1 TO 2 TO OBTAIN A REDUCED CALCINE CONTAINING NICKEL, COBALT AND IRON IN AN ACTIVE METALLIC STATE IN SUCH A CONDITION THAT WHEN SUBJECTED TO PRESSURE TREATMENT BY CARBON MONOXIDE, THE RATIO OF IRON AS CARBONYL TO NICKEL AS CARBONYL IS LESS THAN ABOUT 2 TO 1 AND NOT LESS THAN ABOUT 1 TO 4, REACTING THE REDUCED CALCINE WITH CARBON MONOXIDE UNDER A PRESSURE OF MORE THAN ABOUT 300 POUNDS PER SQUARE INCH GAUGE AND LESS THAN ABOUT 1000 POUNDS PER SQUARE INCH GAUGE AN AT A TEMPERATURE AT ELAST ABOUT 200* F. AND NOT MORE THAN ABOUT 350* F. TO FORM AND VOLTALIZE METAL CARBONYLS LEAVING A SOLID RESIDUE, REMOVING THE RESULTING NICKEL, COBALT AND IRON CARBONYLS FROM THE SOLID RESIDUE, SEPARATING THE NICKEL, COBALT AND IRON CARBONYLS FROM ONE ANOTHER AND DECOMPOSING THE SEPARATED CARBONYLS TO YIELD METALS OF HIGH PURITY.