摘要
以硼含量为16.6×10^(-6)(质量比)的冶金级硅为原料,在高温电阻炉中,利用SiO_2-CaO-CaCl_2、SiO_2-CaCl_2和CaO-CaCl_2造渣剂进行渣硅比、精炼时间、精炼温度和CaCl_2不同配比的除硼精炼实验。研究发现,在熔渣精炼除硼过程中,随着温度的升高和精炼时间的增长,硅中硼含量越来越低,而渣中硼含量越来越高。当渣硅比为2∶1、精炼温度为1550℃、精炼时间为120 min时,硼的分配系数LB由0.93增大到2.85,杂质硼的去除效果最好。在SiO_2-CaO-CaCl_2三元体系中加入质量比为16.67%CaCl_2时,硼的分配系数最高达到3.71,精炼效果最好。本研究为进一步获得低硼含量的高纯硅产品提供了依据。
Here,we experimentally addressed the removal of boron（ 16. 6 × 10^（-6）（ wt）） from metallurgical grade silicon（ 98. 5% Si） by adding CaCl_2 to the slag-forming agents,such as SiO_2-CaO-CaCl_2,SiO_2-CaCl_2 and CaO-CaCl_2,in high temperature resistance furnace. The influence of the refining conditions,including the slag / silicon ratio,CaCl_2-proportion,refining-time and temperature,on the B-removal was investigated. The results show that the refining-temperature and time,and adding CaCl_2 to SiO_2-CaO-CaCl_2 all strongly affect the B-removal. For example,as the refining-temperature and time increased,B-content in the refined silicon decreased,but B-content in the slag increased; refined at 1550℃ for 120 min with slag / silicon ratio of 2 ∶ 1,the distribution coefficient of boron（ LB） increased from 0. 93 to 2. 85,indicating fairly high B-removal efficiency. An increase of CaCl_2 to 16. 67% in SiO_2-CaO-CaCl_2 slag forming-agent,the highest LBwas found to be 3. 71. We suggest that the results be of some technological interest in Si-refining.
出处
《真空科学与技术学报》
EI
CAS
CSCD
北大核心
2016年第7期731-736,共6页
Chinese Journal of Vacuum Science and Technology
基金
国家自然科学基金项目(51574133
51334002)
云南省自然科学基金项目(2014FB124)
关键词
冶金级硅
除硼
造渣
分配系数
精炼
Metallurgical grade silicon
Boron removal
Slagging
Distribution coefficient
Refining
