Distribution Equilibria of As and Sb between Na₂CO₃-Na₂ 0-SiO₂ Melt and Metallic Copper

Equilibrium study between sodium-base slag and metallic copper (3rd Report)

Abstract

Distribution ratios of As and Sb between the melts of Na₂CO₃-Na₂O-SiO₂ and metallic copper were measured at 1250°C. The results are as follows:
1) Distributions of As and Sb between sodium carbonate salt or Cu₂O-base slag and metallic copper were determined under coexistence of these three melts.
2) Distributions of As and Sb between sodium silicate slag or Cu₂O-base slagand metallic copper were determined under coexistence of these three melts.
3) Dependence of distribution ratios on soda-ratio and oxygen partial pressure was determined. The pentavalent oxide of As is predominant species in basic slags at high oxygen partial pressure. It is easy to eliminate As rather than Sb from crude copper by use of basic slag.
4) Distribution ratios of As, Sb and Cu at po₂=10^-8 atm increasewith Na₂X and reach the maximum values at 0.7 sodaradio. Above 0.7 soda-ratiothe distribution ratios decrease with increase in Na₂X (X=O, CO₃) dueto the existence of carbonate.