On the Possibility of Electrochemical Processing of Dump Industrial Iron-Antimony Matte

One of the most important and urgent problems facing the metallurgical industry is the problem of processing dump mattes (DM). These are alloys of sulfides of various metals, and in some locations have accumulated to such an extent that they fill entire landfills with environmentally hazardous substances. During prolonged storage in air, DM decomposes and produces toxic substances. Therefore it is important to find an environmentally safe way to store or processes DM. The available information on the technologies for processing sulfide-oxide metallurgical raw materials and sources of DM formation are analysed in this study. Chemical analysis of the DM indicates a high iron content, which a priori determines the high conductivity of dump materials. The aim of this research is to examibne the physicochemical properties of the DM melts of the Kadamjai antimony industrial complex, in which, according to the technological schedule, iron and antimony are accumulated in sulfide form, followed by pyroelectrochemical processing of them into commodity products in the case of optimal metal current yields and good extraction. The electrical conductivity (æ) of the industrial DM melt is characteristic of multifunctional conductors with a predominant semiconductor mechanism of conductivity. The addition of a heteropolar additive (Na2S) into the DM melt suppresses the electronic component of conductivity and decreaseds æ in the system to values that are typical for ionic melts. Current-voltage characteristics for the composition of the system with 60 and 70 mol. % Na2S indicate polarization in the melts. The electrolysis of DM-Na2S melts is accompanied by the release of sulfur on the anode. For a final assessment of the possibility of using electrochemical processing of DM melts into antimony metal, it is recommended that a preliminary economic calculation of the entire technological process be performed. Keywords: dump mattes, iron and antimony sulfides, physicochemical properties, ecology, utilization