Equilibrium content of cerium in pipe steel under CaO-SiO2-Ce2O3-Al2O3-MgO slag system

Abstract

Thermodynamic simulation of the reduction of cerium from slag system of the CaO-SiO₂-Ce₂O₃-Al₂O₃-MgO at temperatures of 1550 and 1650°C was performed using the HSC 6.1 Chemistry software package (Outokumpu) jointly by the method of planning a simplex lattice experiment. The results of mathematical modeling were presented graphically in the form of "composition–equilibrium content of cerium in the metal" diagrams. During the exposure of steel (0.17% carbon, 0.47% silicon and 0.05% aluminum) under cerium-containing slag, from 0.39 to 27.93 g/t of cerium passes into steel, depending on the temperature of the metal, the basicity of the slag and cerium oxide content. The process of cerium recovery is positively affected by increases in the process temperature, slag basicity and cerium oxide content. Experimental studies have shown direct microalloying of steel with cerium from slags containing cerium oxide due to the reduction of its reduction. It is shown that up to 20 ppm of cerium passes into steel, kept under slag with 7% Ce₂O₃, basicity 5, in 10 min.