Distribution of vanadium between liquid iron and MgO saturated slags of the system CaO-MgO-FeOx-SiO2.

Abstract

Experiments have been made to study the vanadium distribution between the CaO-MgO-FeOx-SiO2 slag and liquid iron equilibrated in a magnesia crucible in the temperature range from 1550°C to 1650°C. The vanadium distribution ratios (V)/[V] were about an order of magnitude higher and their dependence of slag compositions and temperature was found to be smaller compared with the phosphorus distribution ratios (P)/[P]. A linear relationship was observed between logarithm of (V)/ {[V][O]n} (n=2 or 2.5) and CaO/SiO2 ratio. The V5+/(V4++ V5+) ratio increases with increasing CaO/SiO2 ratio, while V3+, V4+ ions were observed in the slag compositions of CaO/SiO2<1. Phosphorus, silicon, and vanadium distribution ratios between slag and carbon saturated iron melt was obtained at 1350°C by use of the distribution ratios between slag and liquid iron at a high temperature and interaction parameters. The order of oxidation of silicon, phosphorus, vanadium, manganese and chromium in pig iron is discussed on the basis of the equilibrium partitions and capacity concept.