(1. 中国矿业大学 化学与环境工程学院，北京 100083；
2. 中国科学院 过程工程研究所 湿法冶金清洁生产技术国家工程实验室，北京 100190；
3. 中国科学院研究生院，北京 100049)
摘 要: 以王水和氢氟酸为酸洗介质，研究酸洗对冶金硅中典型杂质元素的脱除效果。结果表明：王水和氢氟酸对金属类杂质均有明显的去除作用，但对非金属B和P去除效率差。Al杂质经王水和氢氟酸酸洗后去除率分别为80%和86.3%，Fe杂质的去除率分别为78.6%和89.4%。氢氟酸对总杂质去除率比王水提高12%，但其对Cu的去除率仅为4.8%。Cu的相态分析表明：Cu在冶金硅中主要是以Al-Si-Cu合金相存在，抗氢氟酸腐蚀性强。与氢氟酸不同，王水通过化学破碎作用使硅粉粒度变小，利于杂质相暴露。两种酸对硅粉的损失率均小于3.5%。
关键字: 冶金硅；酸洗；提纯；杂质相
metallurgical grade silicon by acid leaching
（1. School of Chemical and Environmental Engineering, China University of Mining and Technology,
Beijing 100083, China;
2. National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology,
Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China;
3. Graduate University of Chinese Academy of Sciences, Beijing 100049, China）
Abstract:The removals of representative impurities by acid-leaching were studied using aqua regia and HF as the leaching acids. The results show that the two acids have obvious removal efficiency to metal impurities, but have little removal effect to B and P. After leaching, the removal rates of Al are 80% and 86.3% by aqua regia and HF, meanwhile, the removal rates of Fe are 78.6% and 89.4%, respectively. The total impurities removal rates after HF increase by 12% than that after aqua regia, but the removal efficiency of Cu by HF is very poor, with the removal rate reaches 4.8%. The structural phase analysis results show that Al-Si-Cu is the main existence form of Cu in metallurgical grade silicon (MG-Si), which is strong acid-resistance to HF. Unlike HF，the chemical stripping-off effect of the particle size of silicon powder made by aqua regia decreases obviously and the impurity phases easily expose at the grain boundaries. The loss rates of Si powder after two acids are less than 3.5%
Key words: metallurgical silicon; acid leaching; purification process; impurity phases
