(1. 武汉理工大学 资源与环境工程学院，武汉 430070；
2. 武汉理工大学 矿物资源加工与环境湖北省重点实验室，武汉 430070)
摘 要: 采用XRD、XPS、FTIR以及SEM-EDS分析手段对高岭石和氧化铁还原焙烧的反应过程进行研究，并借助碱浸实验明确还原焙烧产物中二氧化硅固溶体的溶解性，在此基础上探讨二氧化硅固溶体的形成机理。结果表明：高岭石在1000~1150 ℃还原气氛中单独焙烧时会转变为无定型态，氧化铁的添加可将高岭石在1050~1150 ℃完全转变为铁铝尖晶石和二氧化硅固溶体-石英固溶体和方石英固溶体。此外，石英固溶体和方石英固溶体与天然的石英和方石英具有相似的结构，但在氢氧化钠溶液中溶出性能有很大的区别。还原焙烧过程为固相反应，氧化铝会选择性与氧化亚铁反应并生成铁铝尖晶石，受氧化铝迁移的影响，少量的Fe2+进入硅氧四面体中并最终形成二氧化硅固溶体。
关键字: 高岭石；还原焙烧；铝酸亚铁；石英固溶体；方石英固溶体
（1. School of Resources and Environmental Engineering, Wuhan University of Technology, Wuhan 430070, China;
2. Hubei Key Laboratory of Mineral Resources Processing and Environment, Wuhan University of Technology, Wuhan 430070, China）
Abstract:The reaction behavior of kaolinite and ferric oxide during reduction roasting was systematically studied through the analysis methods of XRD, XPS, FTIR and SEM-EDS, meanwhile, the solubility of free silica in the reduction product was tested by leaching in NaOH solution. Based on the above studies, the formation mechanism of silica solid solution was discussed. The results show that kaolinite is converted into amorphous state during roasting alone at 1000-1150 ℃, while converted into hercynite and free silica, in the forms of quartz solid solution and cristobalite solid solution, during reductively roasting with hematite at 1050-1150 ℃. In addition, quartz solid solution and cristobalite solid solution have the similarity of structure with natural quartz and cristobalite, but have the dissimilarity of solubility in NaOH solution. Due to the solid-state reaction in reduction roasting, the alumina can selectively react with ferrous oxide to form hercynite, meanwhile, small amount of Fe2+ enters into silica tetrahedra, resulting in the formation of silica solid solution.
Key words: kaolinite; reduction roasting; hercynite; quartz solid solution; cristobalite solid solution
