Maximizing the use of valuable components in coal gasification slag is of great significance for resource recovery and the environment due to the huge annual emission of coal gasification slag. This study successfully produced Si–Fe–Al–Ca alloy with a composition of 63.83 wt% Si, 19.73 wt% Fe, 7.09 wt% Al, 6.32 wt% Ca, 1.70 wt% Ti, 0.03 wt% P, 0.66 wt% Mn, 0.05 wt% Cr, 0.53 wt% C, and 0.06 wt% others through electric arc furnace smelting from mixed coal gasification fine slag. The alloy composition is close to the standard 65% ferrosilicon, which can be used in the deoxidation of the molten steel industry. Moreover, the alloy yield was increased from 20.53% to 67.78% by using the residual carbon of the coal gasification slag as the reductant directly instead of adding petroleum coke. The transformation of coal gasification fine slag during the smelting process and the formation mechanism of the alloy were studied and the carbothermal reduction mechanism of Al₂O₃ and CaO can be explained by the reduction and decomposition theory of carbides. The complex liquid phase of the reactant system and product system in the smelting process made the carbothermal reaction of Al₂O₃ and CaO easier to occur, but it also brought the problem that the reactions were not fully completed.

煤气化渣每年排放量巨大，最大限度地利用煤气化渣中有价成分，对资源回收和环境具有重要意义。本研究成功制备了 Si-Fe-Al-Ca 合金，其成分为 63.83 wt% Si、19.73 wt% Fe、7.09 wt% Al、6.32 wt% Ca、1.70 wt% Ti、0.03 wt% P、0.66 wt% Mn , 0.05 wt% Cr, 0.53 wt% C, 0.06 wt% 其他通过电弧炉从混合煤气化细渣中冶炼。合金成分接近标准的65%硅铁，可用于钢水工业脱氧。此外，直接以煤气化渣的残碳为还原剂代替石油焦，合金收率由20.53%提高到67.78%。₂ O ₃和CaO可以用碳化物的还原分解理论来解释。冶炼过程中反应物体系和产物体系复杂的液相使得Al ₂ O ₃与CaO的碳热反应更容易发生，但也带来了反应不完全的问题。