Antimony in the metallurgical industry: A review of its chemistry and environmental stabilization options

Antimony (Sb) is an impurity element that is increasingly encountered in the mineral processing/metallurgical industries of gold, copper and lead. Its occurrence in metallurgical feedstocks is in the form of various antimony minerals with stibnite, Sb2S3, being the most important one. During processing antimony is mobilized reporting to waste solid tailings or effluent streams. This becomes a matter of concern since antimony is similar to arsenic in many respects, both sharing similar chemical properties as well as toxicity and thus have negative environmental implications, especially in the context of industrial effluents and their treatment. This review summarizes the available literature on antimony in the environment and its removal with emphasis on effluent treatment. Antimony speciation as well as oxidation was presented at various conditions (pH, Eh, temperature, and concentration) to provide a basis of its aqueous behavior, an important foundation for industrial effluent treatment. For immobilizing antimony in the environment via precipitation from effluents several mineral candidates were identified of which schafarzikite, FeSb2O4, and tripuhyite, FeSbO4, were proposed as very attractive due to their very low antimony solubility (< 1 mg L− 1).