Effect of Slag Properties on Reduction Rate of Chromium Oxide in Cr_2O_3 Containing Slag by Carbon in Steel

摘要

The experiments were performed using a small-scale furnace in order to improve the reduction rate of chromium oxide in Cr_2O_3 containing slag by carbon in steel. As a result of the investigation of the experiments by SOLGASMIX, the following points were clarified: 1) The reduction rate of chromium oxide in slag was improved by lowering the basicity of the slag or by adding Al_2O_3 or CaF_2. This improvement was caused by the increase of liquid phase fraction of the slag. 2) The liquid fraction of the slag was related to the increase of the mass transfer coefficient and/or the effective reaction area of reaction. 3) The dissolution of MgO was accelerated greatly by lowering the basicity or by adding CaF_2. This phenomenon was caused by the increase of MgO solubility in the slag. 4) The optimum composition of slag is (Al_2O_3)= 15 percent and CaO/SiO_2 = 2.5 from the viewpoint of the compatibility of the improvement of reduction rate of chromium oxide and the prevention of the dissolution of the refractories.