铝热还原法制备硼粉

Preparation of boron powder by aluminothermic reduction reaction

以B2O3为原料,Al粉为还原剂,用KClO3做助燃剂,通过自蔓延铝热还原制备硼粉,研究KClO3添加量(质量分数)及反应物料B2O3与Al粉的配比对产物纯度的影响,利用X射线衍射(XRD)、扫描电镜(SEM)和能谱仪(EDS)对产物进行物相、形貌和元素分析。结果表明:还原产物主要由α-B及少量Al、B2O3和α-Al2O3组成;随着助燃剂KClO3添加量增加,产物中B含量w(B)逐渐增多,Al含量w(Al)逐渐减少。当KClO3添加量(质量分数)为25%时,w(B)最高为94.38%,w(Al)为5.62%;随着反应体系中Al含量减少,产物纯度呈下降趋势,在Al欠量2%、4%和6%时,产物的纯度w(B)分别为95.08%、94.58%及94.15%。

Boron powder was prepared by self-propagating aluminothermic reduction reaction using B2O3 and Al powders as raw materials and reductant, respectively. The effects of KClO3 addition content and the mass ratio of starting materials on the purity of products were systematically studied. The phases, morphology and elementary analysis of pure boron were characterized by XRD, SEM and EDS. The results show that the reductive products consist of ct-B and a small quantity of Al, B2O3, α-Al2O3 phases. The content of Boron in the products increases with the increasing of additive KClO3 content, whereas the content of A1 decreases. When the addition amount of KC103 is w（KCLO3）=25%, the content of Boron comes to maximum value of about w（B）=94.38% and the content of Al is w（A1）=5.62%. The purity of products decreases with the content of Al decreasing. When the contents （mass fraction, %） of Al are respectively deficiency of 2%, 4% and 6%, the purities of products are 95.08%, 94.58% and 94.15%, respectively.