铜硅合金-冰晶石低温复合精炼去除硅中硼杂质机理研究  

Removal mechanism of born from silicon by Si-Cu-Na3AlF6 composite refining at low temperature

作　　者：庾文庆 查鸿凯 史剑 李京伟 林银河 李军成 汤文明[1] YU Wenqing;ZHA Hongkai;SHI Jian;LI Jingwei;LIN Yinhe;LI Juncheng;TANG Wenming(Engineering Research Center of High Performance Copper Alloy Materials and Forming Processing(Ministry of Education),School of Materials Science and Engineering,Hefei University of Technology,Hefei 230009,China;College of Chemistry and Chemical Engineering,Fuyang Normal University,Fuyang 236037,China;College of Chemistry and Chemical Engineering,Yangtze Normal University,Fuling 408100,China;School of Energy and Environment Science,Yunnan Normal University,Kunming 650500,China)

机构地区：[1]合肥工业大学材料科学与工程学院高性能铜合金材料及成形加工教育部工程研究中心,安徽合肥230009 [2]阜阳师范大学化学化工学院,安徽阜阳236037 [3]长江师范学院化学化工学院,重庆涪陵408100 [4]云南师范大学能源与环境科学学院,云南昆明650500

出　　处：《中国有色冶金》2024年第6期120-128,共9页China Nonferrous Metallurgy

基　　金：国家自然科学基金项目(51874272);凉山州重点研发计划(23ZDYF0173,23ZDYF0156);西昌市科技项目(JSYJ-2023-16)。

摘　　要：太阳级硅制备过程中B杂质难以去除,合金-造渣复合精炼具有较好除B效果,但因渣系中均含有氧化物,精炼温度需要控制在1500℃以上,能耗较高。本研究采用冰晶石(氟铝酸钠)作为渣系材料,利用氟铝酸钠低熔点与良好的流动性,将冶金级硅与铜结合,通过合金造渣法实现低温下高效复合精炼除B,并考察了不同冷却速率、水淬温度和渣金比条件下铜硅合金-冰晶石熔盐体系中杂质B的含量变化及赋存状态。试验结果表明,在3~0.05℃/min范围内,冷却速率越低,B平衡分配系数越大,硼由合金相偏析到冰晶石相中的能力越强,越有利于硼杂质的去除;在共晶点(810℃)到液相点(910℃)范围内,水淬温度越低,B平衡分配系数越大,B去除效果越好;在渣金比1:2到10:1范围内,渣金比越高,B平衡分配系数越大;样品渣相中含有B化合物,说明B杂质由合金偏析至渣相中,低温下复合精炼可以有效去除B杂质。B impurity is difficult to remove during the preparation of solar grade silicon,and alloy-slag composite refining has a good effect on B removal.However,because the slag system contains oxides,the refining temperature needs to be controlled above 1500℃,and the energy consumption is high.In this study,sodium fluoroaluminate was used as a slag material.Using the low melting point and good fluidity of sodium fluoroaluminate,metallurgical grade silicon and copper were combined to achieve high-efficiency composite refining and B removal at low temperature by alloy slagging method.The content change and occurrence state of impurity B in copper-silicon alloy-cryolite molten salt system under different cooling rates,water quenching temperatures and slag-to-metal ratios were investigated.The experimental results show that in the range of 3~0.05℃/min,the lower the cooling rate is,the larger the equilibrium distribution coefficient of B is,and the stronger the ability of boron to segregate from the alloy phase to the cryolite phase is,which is more conducive to the removal of boron impurities.In the range of eutectic point(810℃)to liquid point(910℃),the lower the water quenching temperature,the greater the B equilibrium distribution coefficient,and the better the B removal effect.In the range of slag-to-metal ratio from 1:2 to 10:1,the higher the slag-to-metal ratio,the greater the equilibrium distribution coefficient of B.The slag phase of samples contains B compound,indicating that B impurity is segregated from alloy to slag phase,and B impurity can be effectively removed by compound refining at low temperature.

关 键 词：铜硅合金造渣 冰晶石渣剂 硼杂质 平衡分配系数 硅提纯 

分 类 号：TF803.11[冶金工程—有色金属冶金] TF304.12