Slag heterogeneity of autogenous copper concentrates smelting

Due to the deterioration of the raw material base of copper production, it becomes necessary to optimise the autogenous smelting of copper sulfide concentrates, intensify the thermal regime and reduce the loss of copper with slags. There were carried out physico-chemical studies of the properties of slag produced during smelting of copper sulfide concentrates from the Balkhash copper smelter (BCS) in Vanyukov furnaces (VF), using X-ray fluorescence, mineralogical, X-ray diffraction, X-ray microanalysis, thermal analysis. Slag samples were taken at various distances from the furnace bottom (800-2400 mm) when the furnace was stopped. An intermediate layer of variable composition and considerable thickness (250-400 mm), was detected especially at lower smelting temperature, it is located at the bottom of the slag melt, directly on the border with the matte in the VF furnace. The novelty in the obtained data consists in finding the dependence of the formation of the intermediate layer between the slag and matte on the temperature and the content of magnetite in the slag. In addition, it was found that the necessary condition for more complete separation of slag and matte and prevention of intermediate layer formation, is the melting of slag phases, regardless of its composition.