重庆大佛岩铝土矿床地质特征、矿床成因及伴生矿产综合利用

重庆大佛岩铝土矿床位于渝南黔北成矿带内.铝土矿含矿岩系分布在二叠系栖霞组灰岩或二叠系梁山组炭质页岩之下、志留系韩家店组粉砂质页岩或石炭系黄龙组灰岩之上,为一套含铝黏土岩组合,矿体一般在含矿岩系中部,平面上连续分布;矿石以土状和致密状铝土矿为主,含少量砾屑状和土豆状铝土矿;矿石矿物主要由硬水铝石组成,次为高岭石.通过对含矿岩系微量以及稀土元素的分析,认为重庆大佛岩铝土矿床主要是在弱酸性、氧化环境中形成的具陆相沉积特点的铝土矿床,铝土矿物源主要来自陆源;从含矿岩系中稀土元素与基底页岩中稀土元素相关系数、稀土元素配分模式曲线来看,成矿物质来源主要为下伏志留系韩家店组粉砂质页岩.大佛岩铝土矿床不仅具丰富的铝土矿资源,同时伴生有REO(rare earth oxides)、Ga、Sc、Li以及V等多种有益元素.铝土矿中伴生Ga、V等的综合利用可同主元素铝的利用结合起来,但REO、Sc、Li等因受到多方制约,目前尚无综合开发利用的可行性.因此在开发铝土矿的同时,开展伴生元素综合利用研究具有重要意义.

Geological Characteristics,Ore Genesis and Comprehensive Utilization of Coexisting of Dafoyan Bauxite Deposit in Chongqing

Dafoyan bauxite deposit in Chongqing is a large-scale accumulation type bauxite.As a part of south Chongqing to north Guizhou metallogenic belt,Dafoyan bauxite deposit is characterized by its continental sedimentary bauxite formed in an oxidizing environment.The source rock serie exist under Qixia Formation or Liangshan Formation of Permian and on Hanjiadian Formation of Silurian or Huanglong Formation of Carbonic,and it is a combination of aluminum containing clay rocks.The ore body is in the middle of the ore bearing rock series and distributes continuously.This study is not only based on the analysis to the original bauxite test data,but also the test of trace and rare earth elements content to make preliminary judgment of metallogenic environment and parent rock.The ore minerals are mainly composed of diaspore composition,and kaolinite secondarily.The average content are:Al2 O3 61.33%,SiO2 14.61%,A/S 4.20.Some trace elements are closed to or over the industrial tenor of comprehensive utilization,especially the contents of Ga and V.They can be used under the present technology.This suggestes that an attention should be paid to the associated elements so as to improve the latent economic value of bauxite.