关键词: 铁尾矿, 莫来石, 氢氧化铝, 烧结性能

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