The solubility of Cu, Pb, As, Sb of copper-lead matte in the slag

Abstract

An installation was developed and studies were carried out to determine the oxide solubility of copper, lead, arsenic, and antimony from copper-lead matte to slag under conditions of controlled values ​​of РО2=2,74*10-4 Pa and PS2=1,45*102 Pa, applicable to smelting reduction processes of copper-, lead-containing raw materials. It was found that the oxide solubility of copper from matte to slag increases monotonously with an increase of copper content in the matte. The presence of lead in the matte does not significantly affect the final solubility of copper in the slag. In a reducing atmosphere, the solubility of copper in slag is 0.28-0.35%, at the range of copper content of 30-45% in the matte, which is typical for industrial practice. The solubility of lead from copper-lead matte to slag has higher values ​​and increases to 1%. According to the results of mineralogical studies, there is no metallic form of arsenic in slags. Arsenic in slags was found in the form of oxide (As2O5) bound to silicate. Antimony in slag was found in oxide and metallic form. Moreover, the proportion of the last form in the slag prevails. It is shown that under reduction conditions the sublimation of arsenic and antimony from copper-lead matte is difficult. Equilibrium concentrations of As, Sb in the slag (0.17%) are achieved with their optimum content in the matte which is about 0.63%. Obtained results can be used to predict the loss of oxide solubility of copper and to develop optimal solutions to reduce the total loss of copper with slag during the reduction processes of separate processing of copper-, lead containing raw materials.