Recovery and separation of nickel and cobalt from reduced laterite nickel ore

Abstract

Abstract THE PROCESS OF THIS INVENTION INVOLVES THE UTILIZATION OF AN AQUEOUS AMMONIACAL SOLUTION OF AMMONIUM CARBONATE AND AMMONIUM SULPHATE TO LEACH NICKEL AND COBALT FROM LATERITIC OR GARNIERITIC ORE WHICH HAS BEEN ROASTED UNDER CONTROLLED CONDITIONS TO SELECTIVELY REDUCE CONTAINED NICKEL AND COBALT TO CRUDE METALLIC FORM. UNDISSOLVED RESIDUE IS SEPARATED FROM THE LEACH SOLUTION AND IS REACTED WITH FREE OXYGEN BEARING GAS TO OXIDIZE DISSOLVED COBALT VALUES TO THE COBALTIC STATE AND TO CONVERT UNSATURATED SULPHUR VALUES TO T HE SULPHATE FORM. THE SOLUTION IS THEN HEATED TO A TEMPERATURE ABOVE ITS BOILING POINT TO DRIVE OFF FREE AMMONIA AND SUBSTANTIALLY ALL C ARBON DIOXIDE. THE EXPELLED AMMONIA AND CARBON DIOXIDE GASES ARE RECYCLED TO THE LEACHING OPERATION AND THE RESULTING SUBSTANTIALLY AMMONIUM CARBONATE-FREE NICKEL AND C OBALT BEARING AMMONIACAL AMMONIUM SULPHATE SOLUTION IS PASSED TO NICKEL AND COBALT RECOVERY OPERATIONS WHEREIN THESE METALS ARE RECOVERED WITH CONCURRENT PRODUCTION OF A METALS-DEPLETED SOLUTION CONTAINING AMMONIUM SULPHATE. THIS END SOLUTION IS RECYCLED TO THE LEACHING/OPERATION IN AMOUNT SUFFICIENT TO PROVIDE T HE AMMONIUM SULPHATE REQUIREMENTS OF THAT OPERATION.

Inventors

• 👤 W Kunda

Bibliographic Details