PANG Jihong, ZHANG Jinhua, WANG Jingran, YU Anyi

(State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology, Wuhan 430081, China)

Abstract: The method for the preparation of amorphous boron was developed by introducing alkali metal silicates into the reaction system and converting the by-product SiO₂ of the conventional silicothermic reduction reaction into water-soluble alkali metal silicate.Spherical amorphous boron was prepared from Si, Na₂B₄O₇ and Na₄SiO₄.The spherical amorphous boron sample was washed to remove water-soluble sodium silicate impurities，and then freeze-dried to obtain amorphous boron.The effect of reactant temperature as well as the amount of sodium salt added on the reaction process was also explored, and the structure and morphology of the amorphous boron powder was characterized by using X-ray diffractometer, FTIR spectrometer, field emission scanning electronmicroscope and transmission electron microscope.The results show that when the moles ratio of the raw materials n(Si)∶n(Na₂B₄O₇)∶n(Na₄SiO₄)is 3∶1∶2, the reactant temperature is 900 ℃, and the reaction time is 3 h, the amorphous boron with a particle size of 200～400 nm is obtained.The filtrate containing sodium silicate impurities can be recycled for the environmentally friendly preparation of spherical amorphous boron.

Keywords: amorphous boron; silicothermic reduction method; alkali metal silicate

中图分类号：TQ128.1                            文献标志码：A

文章编号：1008-5548(2022)03-0016-07

DOI:10.13732/j.issn.1008-5548.2022.03.003

收稿日期： 2022-01-17， 修回日期：2022-02-06，在线出版时间：2022-04-25。

基金项目：国家自然科学基金项目，编号：51802235。

第一作者简介：庞吉宏(1998—)，女，硕士研究生，研究方向为纳米粉体的制备。E-mail：1349536424@qq.com。

通信作者简介：张锦化(1981—)，男，副教授，博士，硕士生导师，研究方向为刚玉-尖晶石微纳米粉体、硼化物陶瓷纳米粉体的制备。E-mail：zhangjinhua@wust.edu.cn。