镁热自蔓延高温合成碳化硼粉体及其成分调控研究  

Preparation and Composition Regulation of Boron Carbide Powder via Magnesiothermic-SHS

作　　者：石浩 豆志河[1,2] 孟扬 张廷安 SHI Hao;DOU Zhihe;MENG Yang;ZHANG Ting’an(Key Laboratory for Ecological Metallurgy of Multimetallic Mineral,Ministry of Education,Northeastern University,Shenyang 110819,China;School of Metallurgy,Northeastern University,Shenyang 110819,China)

机构地区：[1]东北大学多金属共生矿生态化冶金教育部重点实验室,沈阳110819 [2]东北大学冶金学院,沈阳110819

出　　处：《材料导报》2022年第16期128-133,共6页Materials Reports

基　　金：国家自然科学基金(U1908225,U1702253);中央高校基本科研业务费(N182515007,N170908001,N2025004)。

摘　　要：针对自蔓延高温合成制备碳化硼(B_(4)C)存在的纯度低、游离硼含量高等缺陷,本工作以热力学平衡计算为指导,研究了镁热自蔓延高温合成B_(4)C粉体过程中杂质相的形成规律与赋存状态,以及自蔓延产物中杂质相强化浸出去除规律。结果表明:自蔓延快速合成过程中配料比是影响自蔓延产物物相组成的根本因素。随着Mg配料量增加,自蔓延产物中B_(4)C相和MgO相含量逐渐增加,Mg_(3)B_(2)O_(6)相含量逐渐减少;当Mg配料量达到化学计量比后再增加时,自蔓延产物中相含量变化不再明显。酸浸可有效除去自蔓延产物中的MgO副产物相,Mg_(3)B_(2)O_(6)杂质相的强化去除需要采用密闭强化酸浸。密闭强化酸浸可强化酸浸提纯效果,酸浸产物中Mg残留量降至2.06%,游离硼含量降至3.61%。B_(4)C产物为团聚颗粒,平均粒径为5.30μm,比表面积达13.36 m^(2)·g^(-1)。To address the defects of low purity and high free boron content in the preparation of boron carbide(B_(4)C)via Magnesiothermic-SHS method,this work investigated the formation rule and fugacity state of the impurity phase in the process of Magnesiothermic-SHS and the impurity phase removal rule via enhanced leaching,guided by thermodynamic equilibrium calculations.The results show that the ingredient ratio in SHS process is a fundamental factor affecting the phase composition of the SHS products.The content of B_(4)C and MgO phases in the SHS products gradually increases with the increase of Mg content,while the content of Mg_(3)B_(2)O_(6) decreases.When the Mg content reaches the stoichiometric ratio and then increases,there is no obvious change in the phase content of the products.The MgO byproduct phase from the SHS products can be effectively removed by acid leaching,while the intensive removal of the Mg_(3)B_(2)O_(6) impurity phase requires the closed enhanced acid leaching,which can enhance the purification effect.The Mg residue in the leached product decreases to 2.06%and the free boron content decreases to 3.61%.The B_(4)C product is agglomerated particles with an average particle size of 5.30μm and a specific surface area of 13.36 m^(2)·g^(-1).

关 键 词：碳化硼 自蔓延高温合成 强化浸出 游离硼 

分 类 号：TB321[一般工业技术—材料科学与工程]