Abstract |
The Albany Metallurgical Research Center of the U.S. Bureau of Mines has developed a conceptual process for the extraction and recovery of nickel and cobalt from Western laterites. The process steps, in sequence, include drying, calcination and controlled reduction of the ore, selective oxidation and leaching of the reduced ore in ammoniacal ammonium sulfate solutions, separation of leach residues from pregnant liquor, selective solvent extraction of metals from leach solutions onto organic solvents and selective stripping of metals from the solvents into recycled electrolytes, and electrowinning the metal products from the stripping solution. The process steps have been demonstrated on a semicontinuous bench scale in the laboratory, and guide lines are provided for selection of criteria on which the design of a commercial size plant can be based and plant costs estimated. |