Distribution of Ni, Cr, Mn, Co and Cu between Fe-Ni alloy and FeOX-MgO-SiO2 base slags

The distribution of nickel and minor elements such as chromium, manganese, cobalt and copper between the Fe-Ni alloy and the FeOx-MgO-SiO2 base slag i n a magnesia crucible was studied at 1773 and 1873 K under controlled parti al pressure of oxygen in a range between 1.8 x 10(-5) and 3.2 x 10(-2) Pa u sing CO-CO2 gas mixtures. The effect of adding lime (CaO/SiO2 molar ratio o f about 1) and alumina AlO1.5/SiO2 molar ratio of about 0.25) to the plain FeOx-MgO-SiO2 slag was also investigated. The distribution ratios of chromi um and manganese, defined by (mass %X in slag)/[mass%X in alloy] where X is th e minor element, for the plain slag at 1773 K have large values greater than 100 and 1000, respectively. These are 4 and 5 orders of magnitude lar ger than that of nickel, while those of cobalt and copper a-re of a magnitu de similar to that of nickel. It was clarified that the addition of lime re duces the distribution of chromium and manganese into the slag while the ad dition of alumina increases the dissolution of chromium though it reduces t he dissolution of nickel, cobalt and copper.