利用大载荷热重分析仪、质谱仪、碳分析仪、SEM和XRD测定不同还原条件下钛铁矿(FeTiO3)气基还原产物的质量损失率、钛和镁元素分布、微观结构及物相组成,研究富氢气体还原钛铁矿过程中各气体组分间的耦合作用机制。结果表明:在氢气还原过程中金属铁在颗粒外层聚集,并伴随着钛和镁两种元素的聚集形成致密层;富氢气体还原则不形成相应的致密层,金属铁以细小颗粒状较均匀地分布在颗粒内部,钛和镁也较为均匀地分散在整个颗粒内部。此外,富氢气体中的CO能在金属铁的表面形成一定量的表面碳,并能将H2O分子重新还原为氢气,从而提高了氢气在还原过程中的利用率。
Thermogravimetric analyzer,mass spectrometer,carbon analyzer,SEM and XRD were utilized to study the reduction product of ilmenite(FeTiO3). The mass loss,distribution of titanium and magnesium,micromorphology and phase transitions were investigated. The coupling reaction between different components of hydrogen-rich gas was also discussed. The results show that a dense layer forms inside ilmenite particle with the beneficiation of metal iron,titanium,and magnesium in the hydrogen reduction process. Unlike the hydrogen direct reduction,the dense layer can not form in the hydrogen-rich gaseous reduction. The metal iron in the form of granule type distributes evenly in the body of the particle,and titanium and magnesium also distribute in all particles. In addition,the CO in hydrogen-rich gas can be dissociated on the surface of metal iron which plays the role of catalyst. The surface carbon which is formed by the dissociation of CO can reduce H2O molecule again,so that the utilization of hydrogen can be elevated.