Chloride leaching of a complex matte: comparison of oxidants

Minerals & Metallurgical Processing , 2009, Vol. 26, No. 1, pp. 49-54

Kim, H.I.; Park, K.H.; Mohapatra, D.

ABSTRACT:

 The leaching of a complex matte in chlorine and chloride media was studied. The matte was prepared from manganese nodules by the reduction smelting-sulfidation route. From XRD analysis, the major phases of the matte were identified as CuFeS₂, CuS₂, (FeNi)₉S₈, (FeNi)S₂, Ni₉S₈, Ni₃S₂, (CoFeNi)₉S₈ and Co metal. Investigated were the chlorine, hydrochloric acid, hydrochloric acid-oxygen, ferric chloride, ferric chloride-oxygen, cupric chloride and cupric chloride-oxygen systems. The results are discussed in terms of reagent concentration, retention time, leach temperature and gas sparging rate. The chlorination process resulted >99% metal extraction efficiency within a short retention time and at atmospheric temperature. However, there were no preferential extractions of Cu, Ni and Co with respect to Fe. The cupric chloride-oxygen system produced leach liquors with the lowest Fe content and with a high base-metal extraction. Sulfide sulfur was converted to mixtures of elemental sulfur and sulfate in all the studied systems.