Abstract: The coarse Al-Si alloy was produced in a carbon tube furnace by using bauxite tailing and soft coal as raw materials. The phases of products obtained in different temperatures and carbon additions were analyzed by X-ray diffraction. The reaction process of producing coarse Al-Si alloy was studied and the acceptable product obtained. The results show that the carborundum was gained at the lower temperature (below 1600℃) when the raw materials were deoxidized in the vacuum carbon tube furnace. When the temperature rised to 1700~1800℃, alumina began to react with carbon to form aluminum oxycarbide. When the temperature was higher than 1800℃, the silicon carbide decomposed aluminum oxycarbide into aluminum and silicon, and the aluminum and silicon reacted to form coarse Al-Si alloy. The content of Al in the coarse Al-Si alloy was more than 40%.

Key words: carbothemal reduction, coarse Al-Si alloy, alumina tailing, silicon carbide, aluminum oxycarbide

摘要： 以Al2O3尾矿和烟煤为原料，在碳管炉内进行了一次铝硅合金熔炼，采用X射线衍射光谱对不同温度不同加碳量反应后的产物进行物相分析，探讨了由尾矿生产一次铝硅合金的反应过程并获得了合格的一次铝硅合金产品. 结果表明，尾矿加烟煤在碳管炉内还原时，在较低温度(<1600℃)下，尾矿中的SiO2与C反应生成SiC，当温度上升到1700~1800℃时，尾矿中的Al2O3开始与C反应生成铝氧碳化物，当温度继续升高到1800℃以上时，在较低温度生成的铝氧碳化物被SiC分解，生成铝和硅，成为一次铝硅合金，最终获得的一次铝硅合金含铝量达40%以上.

关键词: 碳电热还原, 一次铝硅合金, 氧化铝尾矿, 碳化硅, 铝氧碳化物