Treatment of nickel-containing laterite ores

Claim 1

IN A PROCESS FOR RECOVERING NICKEL AND A CONTROLLED PROPORTION OF IRON FROM LATERITIC NICKEL-BEARING ORES, THE IMPROVEMENT WHICH COMPRISES SELECTIVELY REDUCING THE ORE WITHIN THE TEMPERATURE RANGE OF ABOUT 500*C. TO 850*C. IN AN ATMOSPHERE CONTAINING CARBON MONOXIDE AND CARBON DIOXIDE IN A RATIO OF CARBON MONOXIDE TO CARBON DIOXIDE OF NOT MORE THAN ABOUT 3 TO 2 AND NOT LESS THAN ABOUT 1 TO 3 OR THE EQUIVALENT THEREOF IN RATIO OF HYDROGEN TO WATER VAPOR, REGULATING THESE REDUCING CONDITIONS SO AS TO CONVERT A MAXIMUM PROPORTION OF THE NICKEL AND A SUBSTANTIAL BUT LIMITED PROPORTION OF THE IRON TO AN ACTIVE, ELEMENTAL STATE WHEREBY THE NICKEL IS AMENDABLE TO HIGH EXTRACTIOIN AND THE IRON IS AMENABLE TO PARTIAL EXTRACTION BY CARBONYL PROCEDURES, THEN TREATING THE SELECTIVELY REDUCED, COOLED, SUBSTANTIALLY DRY ORE WITH CARBON MONOXIDE TO VOLATILIZE MOST OF THE NICKEL IN THE ORE AS NICKEL CARBONYL TOGETHER WITH A CONTROLLED PROPORTION OF THE IRON IN THE ORE AS IRON CARBONYL WHEREBY THE IRON TO NICKEL RATIO IN THE VOLATILIZED CARBONYLS IS NOT LESS THAN ABOUT 1 TO 7 AND NOT MORE THAN ABOUT 2 TO 1 AND SEPARATING THE MIXED CRBONYLS FROM EACH OTHER SO AS TO PERMIT PRODUCTION OF HIGH PURITY METALLIC NICKEL AND HIGH PURITY METALLIC IRON.