碳热还原氧化法制备氧化镁粉体研究

Research on preparation of magnesium oxide powder by carbothermal reduction oxidation method

为提高镁质含碳耐火材料中氧化镁的利用率,对该材料中的氧化镁进行提纯。以废弃镁质含碳耐火材料为原料,设计感应加热装置模型,利用感应炉加热系统对含碳原料加热,用碳热还原氧化法将废弃镁质含碳耐火材料中的氧化物在高温还原气氛下,还原成气相并在空气中氧化形成氧化镁粉体。经化学分析、XRD、SEM等测试发现,氧化镁粉体材料中氧化镁含量大于98%(质量分数),氧化镁粉体晶粒粒径为2～3μm,尺寸均匀。通过热力学分析,采用碳热还原氧化法还原生成的SiO气相在氧化过程中受到了Mg(g)、Ca(g)钙气相氧化的抑制作用。

To improve utilization efficiency of magnesium oxide（MgO）in carbon-containing magnesian refractory materials,magnesium oxide in the materials was purified.Induction heating model had been designed with waste carbon-containing magnesian refractories as raw materials.Using the mechanism that induction furnace heating the carbonic raw materials,the oxides in the waste magnesian carbon refractories were reduced to gas by the carbothermal reduction oxidation method under high temperature reducing atmosphere,and then oxidized to MgO powder in the air.Results of chemical analysis,XRD and SEM showed that magnesium oxide powder contains more than 98%（mass fraction） MgO,and the powders were uniform with the size of 2～3μm.Thermodynamic analysis indicated the generated SiO gas by carbothermal reduction oxidation was inhibited by the Mg（g） and Ca（g） gas oxides.