摘要
热力学分析了铝还原剂从MgO、2MgO·B2O3和3MgO·B2O3中提取金属镁的化学反应。实验研究了制团压力、CaF2添加、还原温度、还原剂用量等对氧化镁还原率的影响。结果表明,适当地提高反应物料的制团压力有利于改善氧化镁还原率,但较大的制团压力会导致球团孔隙率降低,从而阻碍了产物Mg蒸气的释放以及氧化镁还原过程。对还原渣的X射线衍射分析表明,铝热还原生成的Al2O3会先与CaO结合。添加少量的Ca F2有利于氧化镁的还原,CaF2与还原渣结合成11CaO·7Al2O3·Ca F2。添加3%的CaF2,制团压力为90 MPa,在1200℃下还原120 min,氧化镁的还原率为85%,铝利用率为74%。
Extraction of Mg from MgO,2MgO·B2O3and 3MgO·B2O3 by aluminothermic reduction in vacuum was thermodynamically analyzed and experimentally evaluated. The influence of the experimental conditions,including the reduction temperature,pellet compression pressure,Al-content and addition of Ca F2,on the MgO reduction rate was investigated. The slag was characterized with X-ray diffraction. The results show that the compression pressure and Ca F2 additive have a major impact on the MgO reduction rate. For example,as the compression pressure increased,the MgO reduction rate changed in an increase-decrease mode. Stronger compression lowered the Mg extraction rate because the decreased pellet-porosity inversely affected Mg vapor release and MgO reduction. CaO reacted with Al2O3 and Ca F2 significantly enhanced MgO reduction,forming 11 CaO·7Al2O3·CaF2. Reduced at 1200℃ for120 min of the pellet doped with 3% Ca F2 and compressed at 90 MPa,the MgO reduction and Al utilization rates were found to be 85% and 74%,respectively.
出处
《真空科学与技术学报》
EI
CAS
CSCD
北大核心
2014年第11期1246-1251,共6页
Chinese Journal of Vacuum Science and Technology
基金
中央高校基本科研业务专项资金资助(N100302009)
辽宁省镁质材料行业高新技术研发项目(MYF2011-34)
关键词
真空冶金
金属镁
铝热还原
硼镁石
Vacuum metallurgy
Magnesium
Aluminothermic reduction
Szaibelyite-suanite
