Abstract: To enhance the comprehensive utilization of iron tailings,mullite materials were prepared by the solid state reaction sintering method using iron tailings as the silicon source and Al(OH)₃ as the aluminium source.The effects of heat treatment temperatures (1 250,1 300,1 350 and 1 400 ℃ for 3 h) on the microscopic morphology and sintering properties of the mullite materials were investigated.The results show that:(1)Fe³⁺ in the iron tailings can partially replace Al³⁺ in mullite to form an iron-containing mullite solid solution during the solid state reaction,which leads to an increase in the lattice constant and a shift of mullite diffraction peaks to small angles;(2)increasing the heat treatment temperature produces more liquid phases in the system,and mullite grows gradually from granular to columnar;(3)after the heat treatment at 1 350 ℃ for 3 h,a mullite material with excellent comprehensive properties can be obtained with the apparent porosity of 18.2%,bulk density of 2.53 g·cm^-3 and cold modulus of rupture of 58.8 MPa.

Key words: iron tailings, mullite, aluminum hydroxide, sintering properties

摘要： 为提升铁尾矿的综合利用率,以铁尾矿为硅源,Al(OH)₃为铝源,通过固相反应烧结法制备莫来石材料,研究了热处理温度(1 250、1 300、1 350和1 400 ℃保温3 h)对莫来石材料微观形貌及烧结性能的影响。结果表明:1)铁尾矿中的Fe³⁺在固相反应过程中可以部分取代莫来石中的Al³⁺形成含铁莫来石固溶体,导致晶格常数增大,使莫来石衍射峰向小角度偏移;2)热处理温度的升高使得体系中液相增多,莫来石形貌由颗粒状逐渐生长成柱状;3)经1 350 ℃热处理3 h可以制备出综合性能优异的莫来石材料,其显气孔率为18.2%,体积密度为2.53 g·cm^-3,常温抗折强度为58.8 MPa。

关键词: 铁尾矿, 莫来石, 氢氧化铝, 烧结性能