摘要
研究了氧压浸出提纯冶金级硅过程中添加剂(硫酸铵)及原料粒度对去除金属杂质Fe、Al、Ca、Ti的影响.研究结果表明,添加剂硫酸铵的加入能够有效提高冶金硅中主要金属杂质的去除率,低压(无氧)条件下浸出,金属杂质Fe、Al、Ca、Ti的去除率比常压浸出分别高出4.6%、17.3%、16.6%及0.5%;氧压浸出又比低压(无氧)浸出的去除率分别高出22.2%、34.9%、19.5%及0.6%,且随着氧分压的升高,除Ti外Fe、Al、Ca的去除率明显提高;氧压条件下加入添加剂硫酸铵后,金属杂质Fe、Al、Ca、Ti的去除效果更为显著,分别达到85.1%、80.6%、95.4%和16.3%.硅粉粒径<75μm后对金属杂质的去除率的影响不明显.此外,对比浸出前后的SEM-EDS结果发现,常压浸出时硅中的Si-Fe-Ti杂质相难以去除,在氧压浸出并加入添加剂时,可部分去除.
The effect of additives viz. ammonium sulfate and particle size on the purification of metallurgical grade silicon ( MG - Si) by pressure leaching is investigated. It is found that the addition of ammonium sulfate can promote the removal efficiency of major impurities obviously; low pressure leaching is a little more effective than atmospheric leaching. The removal efficiency of Fe, AI, Ca and Ti are increased by 4. 6%, 17. 3% , 16.6% and 0. 5% respectively. Compared with low pressure leaching, the oxygen pressure leaching can increase the removal efficiency by 22. 2% , 34.9% , 19.5% and 0. 6% respectively. Moreover, with the increase of oxy- gen pressure, the extraction of Fe, A1 and Ca are improved except for Ti. In the presence ammonium sulfate, the removal efficiency increases obviously which reaches to 85.1% , 80. 6% , 95.4% and 16.3% respectively. The particle size has no effect on the extraction of Fe, A1, Ca and Ti when it is less than 75 μm. Furthermore, it is found by comparing the SEM - EDS results before and after acid leaching that the Si - Fe - Ti phase in MG - Si cannot be removed by hydrochloric acid under atmospheric pressure. With the addition of additive, Si - Fe - Ti phase may be removed to a certain extent under oxygen leaching.
出处
《昆明理工大学学报(自然科学版)》
CAS
北大核心
2013年第1期1-5,共5页
Journal of Kunming University of Science and Technology(Natural Science)
基金
Supported by the National Natural Science Foundation of China(No.51064014)
the province Natural Science Foundation of Yunnan(No.2010CD025)
关键词
冶金级硅
提纯
氧压浸出
添加剂
metallurgical grade silicon
purification
oxygen pressure leaching
additive