METHOD FOR MAKING CHROMIUM OXIDE IN DUST AND SLUDGE GENERATED AT THE TIME OF PRODUCING CHROMIUM-CONTAINING STEEL INSOLUBLE

摘要

PURPOSE: To make chromium oxide included in dust and sludge generated at the time of producing chromium-containing steel insoluble. ;CONSTITUTION: When molten slag is separated or removed from a surface of a molten steel bath by adding dried dust and sludge to form molten slag in a furnace executing melting or refining of chromium-containing steel desulfurization distribution ratio (S)/[S] between molten steel and slag is adjusted so as to satisfy a formula described hereunder: (S)/[S]≥10^1.06x-0.62, where X=(CaO)/(SiO₂). Further, in order to promote desulfurization, melt-refining time is made longer or a deoxidizer such as Si and Al is added thereto. Thereby elution of hexavalent chromium from discharged slag is eliminated, to make chromium oxide in dust and sludge insoluble is attained and dust and sludge can be utilized as resources.;COPYRIGHT: (C)1996,JPO