自蔓延冶金法制备硼粉的基础研究

提出采用自蔓延冶金法制备硼粉的新工艺·计算知B2O3 Mg反应体系的绝热温度(Tad)为2604K,对B2O3 Mg反应体系的相关反应进行了热力学分析,确定了采用自蔓延模式的可行性·差热分析(DTA)表明反应体系850～930℃放热峰的表观活化能为903 75kJ·mol-1,反应级数为n=1·X射线衍射分析表明燃烧产物主要由MgO,Mg3B2O6和B2O3等相组成,确定了燃烧产物的浸出条件以及三步浸出方案·光谱分析及化学分析表明硼粉纯度可达92 43%,平均粒度为0 5～0 8μm·

Primary Research on Preparation of Boron Powder by Self-Propagating High-Temperature Synthesis with a Stage of Metallurgy

A new technique named self-propagating high-temperature synthesis with a stage of metallurgy was proposed to prepare boron powder. The adiabatic temperature (Tad) in B2O3-Mg reaction system was calculated to be 2604 K, through which the thermodynamic data of correlative reactions were analyzed to determine the feasibility of the self-propagating high-temperature synthesis reaction consequently. The DTA results indicate that the apparent active energy of the exothermic peak of B2O3-Mg reaction system is 903.75 kJ·mol^-1 with reaction order equal to 1, and the XRD results show that the combustion products are composed mainly of MgO, Mg3B2O6 and B2O3. Thus the three-step leaching conditions were confirmed. The purity of boron powder can be up to 92.43% as indicated by spectral and chemical analyses. Its mean grain size is 0.5-0.8 μm.