关键词: 合成莫来石, 物相组成, 显微结构, 理化性能

Abstract: To analyze the performance characteristics of bauxite-based mullite from typical production areas in China,eight kinds of bauxite-based mullite raw materials were obtained from Shanxi,Henan and Hunan,among which Shanxi A,Henan A,Shanxi B and Shanxi C were fired in tunnel kilns,Henan B,Shanxi D and Hunan A were fired in rotary kilns,and Hunan B was fired in electric arc furnaces.The apparent porosity,bulk density,water absorption,microstructure and phase composition of the raw materials were studied.The results show that:(1)the water absorption of mullite calcined in tunnel kilns is 2.5%-3.5%,and the mullite grains are fully developed as columnar,with large length-diameter ratios;(2)the water absorption of mullite calcined in rotary kilns is ≤2.0%,and the grain size of mullite is small;(3)fused mullite is the densest,with the water absorption <1.0% as well as completely developed sturdy crystals;(4)the main phase of all the bauxite-based mullite raw materials is mullite,and some of them contain a small amount of corundum and rutile;among them,fused mullite has a low glass phase content,and sintered mullite contains 8 mass%-14 mass% glass phases.

Key words: synthetic mullite, phase composition, microstructure, physical properties and chemical composition