Chemical processing of a low grade molybdenite concentrate to recover molybdenum

Abstract

The conventional oxidative roasting process, as applied to high grade molybdenite ores (containing ≥54% molybdenum), cannot be applied to low grade sulphide ores/concentrates for a variety of reasons. That is why these ores/concentrates require alternative processing schemes to extract molybdenum metal in a quantitative manner. The present investigation deals with two such processes, namely, soda ash roasting and lime enhanced carbothermic reduction that were successfully applied to extract molybdenum from an indigenous (and low grade) molybdenite concentrate (MoS₂).

These processes yielded molybdenum in the form of molybdenum trioxide (MoO₃) and molybdenum metal respectively. MoO₃ and molybdenum metal, so prepared, were further refined by carbon adsorption desorption and molten salt electrorefining techniques respectively. The final purity of MoO₃ and molybdenum metal were 99·9% and 99·8% respectively. These processes offered effective measures to contain environmental pollution and bypass tedious off gas treatment procedures, which, otherwise, are two major problem areas in the traditional processing of high grade MoS₂ ores/concentrates.

Keywords

MOLYBDENITE REDUCTION MOLYBDENUM TRIOXIDE ELUTRIATION MOLTEN SALT ELECTROREFINING RECOVERY CURRENT EFFICIENCY

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