基于Al-Si合金熔体的冶金级硅纯化新工艺

New Purification Process of Molten Al-Si Alloy Based Metallurgical Grade Silicon

为了提高冶金级硅的纯度,本文研究了Al对去除冶金级硅中金属杂质的作用。结果表明,以工业Si和工业Al为原料,通过Al-Si合金化和酸浸除杂相结合制备Si材料,将Al-Si合金破碎成一定尺寸的颗粒,然后采用氢氧化钠溶液、氢氟酸和盐酸溶液顺序腐蚀去除Al和其他杂质,最终获得纯度为99.91%的Si颗粒。结合扫描电镜(SEM)、能谱仪(EDS)以及X射线荧光光谱(XRF)等分析手段,对腐蚀前后材料的微观结构和杂质含量的变化进行研究,初步探讨了冶金级Si经过Al-Si合金熔炼更有利于除杂的原理。

In order to improve purity of metallurgical grade silicon （MG--Si）, this paper has researched the effects of Al on the removal of metal impurities. The results indicated that the Al-Si alloy has been synthetized by Al-Si alloying and acid leaching using industrial--grade silicon and industrial aluminum as the raw materials, which then broke into particles. In order to removal AI and other impurities, the particles are corroded by sodium hydroxide solution, hydrofluoric acid and hydrochloric acid in turn. Finally, silicon particles with a purity of 99.91% were obtained. The changes of microstructure and content of impurities have been investigated by means of scanning electron microscope, energy dispersive spectroscopy and X --ray fluorescence spectrometry. The principle of the impurities removed more completely by Al-Si alloy was discussed.