矾土基莫来石的性能分析

Performance analysis of bauxite-based mullite

为分析我国典型产区矾土基莫来石的性能特点,从山西、河南、湖南等典型产区获取8种矾土基莫来石原料,其中山西A、河南A、山西B、山西C为隧道窑烧制,河南B、山西D、湖南A为回转窑烧制,湖南B为电弧炉生产。研究8种矾土基莫来石原料的显气孔率、体积密度、吸水率、显微结构和物相组成。结果表明:(1)隧道窑煅烧的莫来石吸水率为2.5%~3.5%,莫来石晶粒发育完整,呈柱状,长径比大;(2)回转窑煅烧的莫来石吸水率≤2.0%,莫来石晶粒小;(3)电熔莫来石最致密,吸水率<1.0%,晶体发育粗壮且完整;(4)矾土基莫来石原料的主要物相皆为莫来石,部分原料含有少量刚玉和金红石相,其中,电熔莫来石玻璃相含量较少,烧结莫来石含8%~14%(w)的玻璃相。

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.