Luo Tong, Xu Lei, Peng Jinhui, Zhang Libo, Xia Yi, Ju Shaohua, Liu Jianhua, Gang Ruiqi, Wang Zemin
Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, PR China.
State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming 650093, PR China.
ACS Omega. 2020 Mar 4;5(11):5834-5843. doi: 10.1021/acsomega.9b04027. eCollection 2020 Mar 24.
In this study, the waste silicon powder generated in the production of solar-grade polysilicon scrap was used as the raw material, and silicon nitride (SiN) was directly efficient prepared by the microwave heating nitridation. The temperature raising characteristics of silicon powder by microwave heating and the influencing factors of the nitridation reaction process were studied. The thermogravimetric analysis was performed, and the temperature raising dielectric properties of silicon powder were studied. The electromagnetic field and temperature distributions of the microwave heating-induced silicon powder nitridation process were simulated using COMSOL software. The nitridation reaction of silicon powder induced by microwave heating has better temperature raising characteristics: the average heating rate can reach 135 °C/min, and the reaction time is significantly shortened (only 10-20 min). Microwave heating decreases the nitridation reaction temperature by more than 100 °C and greatly shortens the reaction time. With the increase of nitrogen pressure and reaction time, the nitridation reaction is better. In addition, the conversion of the nitridation reaction is more than 97%, and the products are mainly β-SiN with the uniform and columnar morphology. Finally, it is proved that the efficient recovery and utilization of industrial waste silicon powder are realized, and there is lower energy consumption by microwave heating technology.
在本研究中，将太阳能级多晶硅废料生产过程中产生的废弃硅粉用作原料，通过微波加热氮化直接高效制备氮化硅（SiN）。研究了微波加热硅粉的升温特性以及氮化反应过程的影响因素。进行了热重分析，并研究了硅粉的升温介电性能。使用COMSOL软件模拟了微波加热诱导硅粉氮化过程的电磁场和温度分布。微波加热诱导硅粉的氮化反应具有较好的升温特性：平均升温速率可达135℃/min，反应时间显著缩短（仅10 - 20分钟）。微波加热使氮化反应温度降低100℃以上，大大缩短了反应时间。随着氮气压力和反应时间的增加，氮化反应效果更好。此外，氮化反应转化率超过97%，产物主要为β-SiN，形态均匀且呈柱状。最终证明实现了工业废弃硅粉的高效回收利用，且微波加热技术能耗较低。
