河南省禹州方山矿区高钾铝土矿的地质特征

Geological characteristics of high-potassium bauxite in Fangshan mining area,Yuzhou county,Henan province

禹州方山铝土矿是河南省已知铝土矿勘查区中含钾量最高的一个矿区。方山高钾铝土矿赋存于石炭系上统本溪组中,硬质黏土是构成高钾铝土矿的主体,高钾铝土矿层最厚79.47m,最薄1.98m,平均18.78m;主要含铝矿物为一水硬铝石,高钾铝土矿的化学成分与铝土矿基本相同,全矿区w(K2O)的平均值为3.75%,最高10.16%,最低0.04%。矿区很少有云母等含钾矿物的存在,高钾铝土矿中的K2O不完全来源于含钾矿物,也非矿区内仅存交换吸附阳离子能力最低的高岭石所致,况且方山铝土矿周边的寒武系张夏组水泥灰岩中w(K2O)<2%,在方山地段含铝岩系中能形成w(K2O)超过10%的地层实属罕见,方山铝土矿中K2O的来源尚需进一步研究。

Fangshan bauxite ore deposit is the highest in potassium content in the known bauxite ore prospecting areas in Henan province. The high potassium bauxite ore occurs in Benxi formation of Upper Series of Carboniferous System and is dominated by hard clay. The ore layer is maximum 79.47 m thick, minimum 1.98 m and averagely 18.78 m. Diaspore is the main ore mineral, composition of the high potas sium bauxite ore is similar to the normal bauxite ore w（Kz（）） 3.75% average, 10. if%maximum,0.04%. In the area high potassium minerals, such as mica are rare so KzO of the high potassium bauxite ore is not absolutely from the K bearing mineral nor from kaolinite that is lowest in exchange of absorbed cation in the area. And w（K2 O） of Cambrian cement-making limestone of Zhangxia formation is 〈2 %. Therefore further study should be carried out on the source of K20 of the high postasium bauxite ore.