太平矿区堆积铝土矿矿泥物质来源与成因地球化学分析

Analysis of material sources and genetic geochemistry of ore slime in the accumulative bauxite,Taiping Ore District

岩溶堆积型铝土矿中小于1mm的颗粒称作矿泥，随着粒级的降低，矿泥Al203含量及A／S明显降低，三水铝石含量明显增加，微量元素、稀土元素地球化学特征表明，矿泥的物质来源为原生铝土矿和堆积铝土矿。矿泥形成的地球化学机制为一水硬铝石的水化作用生成三水铝石，三水铝石与硅酸的结合形成高岭土以及析出表生水条件下的石英。结合经济效益及矿泥地质特征，可以先回收堆积铝土矿矿泥中0．1～1mm粒级颗粒，太平矿区可回收利用的0．1～1mm粒级干矿泥量约570万t。本研究成果对桂西北地区堆积铝土矿矿泥的综合利用具有重大的指导意义。

Ore slime is the grain that less than 1 millimeter in the karst accumulative bauxite. With the decrea- sing in grain size, Al2O3 content and A/S value of ore slime is significantly getting lower, while gihbsite content sig- nificantly increases. The characteristics of trace elements and rare earth elements show that the material sources of ore slime are primary bauxite and acecumulative bauxite. The geochemical mechanism of ore slime formation is the hydration of diaspore that generated gibbsite, the combination of gibbsite and silicic acid that generated kaolinite, and the precipitation of quartz from the hypergene water. Combined with economic and geological characteristics, we can firstly recycle the grains between 0.1~ 1 millimeter of ore slime in the acccumulative bauxite. The recyclable grains between 0.1~1 millimeter of dry ore slime is about 5.7 million tons in Taiping Ore District. This research has great significance on comprehensive utilization of ore slime in the acccumulative bauxite of northwestern Guangxi.