Copper Distribution between Na₂S Bearing Fluxes and Carbon Saturated Iron Melts

Abstract

Copper distribution between NaS_0.5 bearing fluxes and carbon saturated iron melts was measured at 1 200°C. Coefficients L_Cu and K_Cu which are defined below were used to discuss the decopperization behavior of different sulfide fluxes with different sulfur content in carbon saturated iron melts. L_Cu≡(%Cu)/[%Cu] K_Cu≡(%CuS_0.5)/[%Cu]·[%S]^1/2
The results are summarized as follows.
1) The distribution ratio L_Cu was between 11 and 21.5 for the NaS_0.5-FeS-CuS_0.5 system at 1 200°C. The maximum K_Cu was 213 for the 95%NaS_0.5-5%FeS system with L_Cu=17 and [%S]=0.01.
2) The temperature dependence of K_Cu, from 1 170°C to 1 325°C for the melts containing 79.9-88.5%NaS_0.5+10.7-19.4%FeS+0.55-0.76%CuS_0.5 can be expressed by the following equation.
lnK_Cu=1.25×10⁴/T-3.07
3) NaS_0.5 was found to be the best component for the decopperization among five sulfides FeS, NaS_0.5, KS_0.5, CaS, CuS_0.5 investigated in the present work.