冶金级硅酸洗提纯研究

冶金工艺被认为是非常有前途的一种有别于传统的西门子工艺而且能够满足市场对太阳能级硅需求的工艺.冶金级硅的预处理是冶金提纯工艺路径中非常重要的一个环节,因为酸洗可以有效地去除硅中的金属杂质例如铝、铁和钙等.通过系统性的对比试验对酸洗工艺去除硅中杂质的效果进行了详细的研究,分别探讨了酸的种类、酸的浓度、酸洗时间、酸洗温度以及硅粉颗粒粒径对杂质去除效率的影响.研究结果表明最佳的酸洗工艺参数为15%的盐酸,80℃,10h和100μm.在最佳酸洗工艺参数条件下金属杂质铝、铁和钙的去除率分别为70.90%、94.82%和82.69%.

Research on purification of metallurgical grade silicon (MG-Si) by acid leaching

Metallurgical route is recognized as a promising process to meet market demands for solar energy silicon material which is different from the traditional Siemens process.Pre-treatment of metallurgical grade silicon(MG-Si) is an important part in metallurgical purification process because it can remove the metallic impurities,such as aluminum,iron and calcium effectively in acid leaching process.A series of comparative experiments were designed to study the effects of acid leaching parameters on impurities removal efficiency in detail.The effects of acid agent,acid concentration,time,temperature and silicon particle size on impurities removal efficiency were investigated,respectively.The results show that the optimum processing parameters for acid leaching are as follows: 15% hydrochloric acid,80 ℃,10 h and 100 μm.The removal efficiencies of aluminum,iron and calcium are 70.90%,94.82% and 82.69% at the optimal process parameters,respectively.