黔北道真新民铝土矿含铝岩系中关键金属富集特征与资源潜力

Characteristics of the critical metal enrichment and the resource potential for bauxite-bearing rocks in the Xinmin bauxite deposit in Daozhen County, Guizhou Province, China

黔北务(川)—正(安)—道(真)铝土矿成矿带是贵州省重要的铝土矿资源地,其中道真新民铝土矿床是近年在该成矿带内探获的又一大型铝土矿床,伴生Li、Ga、Sc和稀土元素等关键金属资源。以该矿床含铝岩系为剖析对象,对其中Li、Ga、Sc和REE等关键金属进行研究,系统总结其富集特征并分析其资源潜力。结果表明,研究区含铝岩系各类岩(矿)石中均不同程度富集Li、Ga、Sc和REE等关键金属。在含铝岩系垂向剖面上,关键金属具有上部富Li、中部富Ga、下部富REE,而Sc含量变化较小的富集特征。在岩(矿)石类型上,Li、Ga和REE分别主要富集于铝土岩、铝土矿和绿泥石泥岩中,Li主要富集在致密状铝土矿中,Ga在土状铝土矿、碎屑状铝土矿、豆鲕状铝土矿中相对富集,REE在致密状铝土矿和土状铝土矿中的含量相对富集,而Sc在不同类型岩(矿)石中的含量变化不大。研究区含铝岩系不同岩(矿)石中,Li与SiO2正相关,Ga、Sc与Al_(2)O_(3)、TiO_(2)正相关,而REE与Fe2O3正相关系,Li、Ga、Sc、REE之间不存在相关关系,原岩风化程度可能是控制这些元素富集的关键因素之一。新民铝土矿床含铝岩系中,关键金属Li、Ga、Sc、REE的资源潜力和潜在经济价值巨大,预测Li、Ga、Sc和REE的远景资源储量分别达到大型矿床规模的3.2倍、3.8倍、669倍和2.1倍。

The Wuchuan-Zheng’an-Daozhen bauxite metallogenic belt in the northern Guizhou is an important bauxite resource area in Guizhou Province.The Xinmin bauxite deposit in Daozhen County is a newly discovered large bauxite deposit with resources of associated critical metals of Li,Ga,Sc,REE and other elements.The bauxite-bearing rocks of the Xinmin bauxite deposit have been chosen for analyzing contents of critical metals of Li,Ga,Sc and REE in order to systematically summarize enrichment characteristics of those critical metals and to evaluate their resource potentials in the deposit.The results show that critical metals of Li,Ga,Sc,REE and other elements are enriched,to varying degrees,in bauxite-bearing rocks in the Xinmin bauxite deposit.On the vertical profile of the bauxite-bearing rock series,Li is enriched in the upper part,Ga is enriched in the middle part,and REE are enriched in the lower part,but Sc contents are limitedly changed among all parts.In terms of rock (ore) types,Li,Ga,and REE are mainly concentrated in bauxite-bearing rocks,bauxite,and chlorite mudstone,respectively.In terms of bauxite types,Li is mainly concentrated in compact bauxite,Ga is relatively concentrated in earthy bauxite,bean and oolitic bauxite,and detrital bauxite,the REE is relatively enriched in compact bauxite and earthy bauxite.However,Sc contents in various types of rocks (ores) are not changed significantly.In the different types of rocks (ores) of the bauxite-bearing rock series in the study area,Li is positively correlated with SiO2,Ga and Sc are positively correlated with Al_(2)O_(3),TiO_(2),REE is positively correlated with Fe2O3.However,there is no correlation among Li,Ga,Sc,and REE.The degree of weathering of the original rocks could be one of the key factors controlling the enrichment of these elements.The bauxite-bearing rock series of the Xinmin bauxite deposit have huge resource potential of critical metals of Li,Ga,Sc and REE with great economic values.It is predicted the potential resources of Li,Ga,Sc and REE in the bauxite-bearing rocks of the Xinmin bauxite deposit are about 3.2,3.8,669,2.1 times of their theoretical values of the large scale deposits,respectively.