Distribution of Minor Elements among Liquid Copper, White Metal and Silica-Saturated Slag

Abstract

Distribution of nickel, cobalt, lead, antimony and arsenic among three liquid phases of copper, white metal and silicasaturated iron silicate slag was investigated. The melting experiments were carried out at 1300°C under varying oxygen partial pressure which was realized by controlled SO₂ pressure. In the lower oxygen pressure region, copper content in the matte was designated under flow of nitrogen gas. On the basis of the analytical results for the minor elements in the solidified samples, the distribution ratios for an element X, defined by equations 1 to 3, were derived, and are plotted against oxygen potential as illustrated in Figs. 1 to 3. As are thermodynamically expected by equations 8, 11and 12, considerable dependences on oxygen pressure are observed in the distribution ratios between copper and slag, and also matte and slag, but any appreciable dependence can not be recognized in the distribution ratio between copper and matte. Under reducing conditions, minor elements tend to be concentrated in the metal and matte phases, while are oxidized into the slag phase under higher oxygen potential. In the conventional smelting condition characterized by the coexistence of considerable SO₂ pressure, Co is highly concentrated in slag, Pb and Ni are distributed among all three melts in rather similar concentration, while As and Sb arehighly concentrated in copper metal.