Processing nickel-containing lateritic ores

Claim 1

A PROCESS FOR RECOVERING NICKEL, COBALT AND A CONTROLLED PROPORTION OF IRON FROM LATERITIC NICKEL- AND COBALT-BEARING ORES OF THE IRON OXIDE TYPE WHICH COMPRISES REDUCING THE ORE AT A TEMPERATURE WITHIN THE RANGE OF ABOUT 930*F. TO ABOUT 1500*F. IN A SELECTIVELY REDUCING ATMOSPHERE CONTAINING REDUCING GASES FROM THE GROUP CONSISTING OF CARBON MONOXIDE AND HYDROGEN AND OXIDIZING GASES FROM THE GROUP CONSISTING OF CARBON DIOXIDE AND WATER VAPOR WITH A REDUCING POTENTIAL EQUIVALENT TO A RATIO OF CARBON MONOXIDE TO CARBON DIOXIDE OF NOT MORE THAN ABOUT 3 TO 2 AND NOT LESS THAN ABOUT 1 TO 3 TO SELECTIVELY REDUCE NICKEL AND COBALT TO THE METALLIC STATE AND A SUBSTANTIAL BUT CONTROLLED PART OF THE IRON AMOUNTING TO NOT LESS THAN ABOUT 1% AND LESS THAN ABOUT 15% OF THE IRON IN THE ORE TO THE METALLIC STATE; COOLING THE SELECTIVELY REDUCED ORE IN A NON-OXIDIZING ATMOSPHERE WHILE MAINTAINING SAID ORE IN A DRY STATE; THEN TREATING THE SELECTIVELY-REDUCED, COOLED AND DRY ORE WITH CARBON MONOXIDE AT NOT LESS THAN ABOUT 100*F. AND NOT MORE THAN ABOUT 200*F. TO VOLATILIZE MOST OF THE NICKEL IN THE ORE AS NICKEL CARBONYL AND A SIGNIFICNT PROPORTION OF THE IRON IN THE ORE AS IRON CARBONYL TO PRODUCE AN IRON TO NICKEL RATIO IN THE TOTAL VOLATILIZED CARBONYLS OF NOT LESS THAN ABOUT 1 TO 7 AND NOT MORE THAN ABOUT 2 TO 1; SEPARATING THE MIXED CARBONYLS FROM EACH OTHER TO PERMIT PRODUCTION OF METALLIC NICKEL AND METALLIC IRON; CHLORINE THE CARBONYL-EXTRACTED, DRY MATERIAL WITH DRY CHLORINE GAS AT NOT LESS THAN ABOUT 100*F. AND NOT MORE THAN ABOUT 200*F. TO CONVERT COBALTT, RESIDUAL NICKEL AND A MINIMUM AMOUNT OF IRON TO CHLORIDES; HEATING THE DRY, CHLORINATED MATERIAL IN AIR AT ABOVE ABOUT 200*F. AND BELOW ABOUT 500*F. AFTER THE COMPLETION OF SAID TREATMENT WITH DRY CHLORINE GAS TO DECOMPOSE SUBSTANTIALLY ALL THE IRON CHLORIDES FORMED; AND WATER LEACHING TO EXTRACT SUBSTANTIALLY ALL OF THE COBALT AND RESIDUAL NICKEL.