REFINING METHOD WITH ELECTRIC FURNACE SLAG

摘要

PROBLEM TO BE SOLVED: To reduce the adding quantity of slag forming material as little as possible so that the produced quantity of the slag is decreased while keeping the refining performance of the slag effective to reduction, desulfurization, etc., of chromium oxide in an electric arc furnace. SOLUTION: At the time of melting molten iron for stainless steel while forming molten slag by adding raw material to be molten and the slag forming material into the electric arc furnace for stainless steel, B2 O3 -containing material is added as an alternative material of a part of CaF2 . Further, the adding quantity of CaF2 needed from the predicted quantity of the slag is reduced based on the equation 0.5×WC×WB<=CaF2 decreasing quantity <=WC×WB. Wherein, WC is CaF2 quantity ratio (wt.%) to the slag at the time of adding no B2 O3 - containing material and WB is B2 O3 quantity ratio (wt.%) to the slag. As for the B2 O3 -containing material, colemanite, ulexite, kernite, borax, B2 O3 -containing slag, etc., are used.