| 摘要 |
PURPOSE:To suppress the wear of refractories on a furnace wall and to decrease the cost of refining by adding the source of MgO and/or source of Al2O2 to the titled molten iron under specific conditions in the last stage of refining said chrome-contg. molten iron. CONSTITUTION:One or more kinds among chromium ores, unreduced chromium pellets, semireduced chromium pellets chromium sintered ores are melted and reduced by the source of carbon such as coal, coke, etc., to produce the chromium-contg. molten iron for a stainless steel having <=39% Cr content. In this operation, The source of MgO and/or source of Al2O3 are added to the molten slag in the last stage of the refining when the concn. of chromium which is present as the oxide in said slag becomes <=5%, and the ratio of (MgO +Al2O3)/(CaO+SiO2+Al2O3+MgO) in the slag is regulated to >=0.45. By this method, the unit of refractories in a melt reducing treatment of chromium ores, etc., is drastically reduced.
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