Thermodynamics of trace elements As, Bi, Pb, and Sb in copper-iron and nickel-copper matte

Abstract

A transportation method was used to evaluate the activity coefficients of the minor elements, As, Bi, Pb, and Sb, in both Cu - Fe and Ni - Cu mattes, white metal, and molten Ni₃S₂ as a function of their concentration. Values for the activity coefficients are compared to values obtained by other investigators. With the Cu - Fe mattes and white metal, the analysis was conducted at Cu/Fe molar ratio between 1 to ∞, at sulfur deficiencies from -0.02 to +0.02, and at temperatures between 1493 and 1573 K. Activities of As and Sb in the melts are both concentration dependent at weight percents less than 0.3. No such dependency is observed for Bi or Pb. First and second order self interaction parameters are also reported for As and Sb in Cu - Fe matte. With the Ni-Cu mattes only the sulfur deficiency and the Ni/Cu molar ratio were varied. The experiments were conducted at 1473 K at Ni/Cu molar ratios of ∞, 2, and 1, and at SD values from 0 to -0.1. As and Sb are substantially more stable in Ni - Cu mattes than in Cu - Fe mattes, while for Pb and Bi the presence of Ni does not change the activity of Pb and Bi significantly. The Henrian activity coefficients of these minor elements in both Cu - Fe and Ni - Cu mattes are reported. (Abstract shortened by UMI.)