本文论述了广西贵港三水型铝土矿针铁矿中铝的类质同象置换现象和规律,并测定了置换率。研究表明,矿石的针铁矿中含铝17mol%左右。这对阐明矿床的形成环境,准确计算矿物量和氧化铝溶出率以及合理选择矿石加工工艺流程有重要意义。 In this paper, the phenomenon and rule of the isomorphous substitution of aluminum in the gypsum trihydrate bauxite from Guigang, Guangxi were discussed. The displacement rate was also determined. Research shows that the ore goethite contains about 17 mol% of aluminum. This is of great significance for elucidating the formation environment of the deposit, accurately calculating the amount of minerals and the dissolution rate of alumina, and selecting the ore processing technological process rationally.