Slag–Copper Equilibria of Selected Trace Elements in Black Copper Smelting. Part I. Properties of the Slag and Chromium Solubility

The solubility of chromium in alumina- and lime-containing (≈5 wt% Al2O3 and 0- ≈ 10 wt% CaO) iron silicate slags has been measured at 1,300°C. In order to avoid contamination and the effects of further elements in the slag, the measurements were carried out at silica saturation. The solubility of chromium was a function of oxygen partial pressure. At high oxygen partial pressures PO2 ≈ 10−5 atm, the solubility was about 0.15 wt% (Cr) and it increased to about 0.3 wt% (Cr) in reducing conditions of pO2 ≈ 10−10 atm. Alumina and lime seemed to increase the solubility slightly.