我国的铝土矿多为一水硬矾土，密度低，结晶水含量约为14%，硫含量在0.25%-3%之间。焙烧时烟气必须经过严格的除尘脱硫脱硝，否则污染严重。
    下图是一台中型空气清洗机为贵州某铝土矿焙烧点进行含水状态下除尘、脱硫脱硝：
    Chinese bauxite are mostly in Monohydrate, with about 14% of H2O, and S ranges from 0.25% to 3%. The following picture shows an air cleaner is working for dust eliminating, denitration and de-sulphure for calcine of raw bauxite in Guizhou province.