EXTRACTION OF NICKEL, COBALT AND IRON FROM LATERITE ORES BY MIXED CHLORIDE LEACH PROCESS

摘要

Primary nickel is produced from both lateritic and sulfidic ores. Lateritic ores are formed by prolonged weathering of ultramafic rocks. The laterite deposits exhibit graded layers of ore, with high iron, low nickel ore on top and low iron, high nickel ore below. The low iron (＜ 15 % Fe) ores containing 1.7- 2.3% Ni are treated by pyrometallurgical processes to produce ferronickel or matte. High iron (＞ 35 % Fe) limonitic ores can be treated by high pressure leach using sulfuric acid. An alternative process for the production of base metals (Ni, Co and Fe) from both high and low iron laterite ores is being developed by Process Research ORTECH Inc. (PRO), a world leader in the development of chloride metallurgy. The process flowsheet developed by PRO is efficient and environmentally friendly. Novel leaching and solvent extraction separation steps have been developed to make this alternative more economically attractive in the current market conditions.