中国铝土岩系中伴生钪资源富集规律及富集机制初探

Enrichment mechanism and regularity of associated scandium resources in bauxite series of China

钪(Sc)作为新世纪的重要资源,广泛分布于自然界中,但其分布极为稀散,钪的独立矿物稀少,独立矿床几乎没有。铝土岩系中的钪资源储量巨大,本文统计了中国各铝土矿成矿带Sc数据,在对比山西(断隆)成铝区、华北陆块南缘成铝区、渝南—黔北成铝带、黔中成铝区和滇东南—桂西成铝区的数据基础上,发现滇东南—桂西成铝区的Sc含量最高,含钪铝土岩系形成时代主要为石炭纪和二叠纪。通过对比分析A/S与钪的关系,在A/S小于2.5,钪的含量总体较高,且与A/S正相关,大于2.5后,与A/S负相关。从而得出在铝土岩系中,Sc分布在顶层的黏土岩、中部的铁质铝土矿以及底部的铁质黏土岩、铁质岩,尤其是在含铁铝土岩系中高度富集。通过对比分析铝土岩系各元素含量,发现钪与铁、铌、钒、铬元素成正相关,综合铝土岩系中其他元素的矿物表现形式,推测钪在铝土岩系中的赋存形式可能为:类质同象、离子吸附、和超显微非结构混入物。本文初步探讨总结钪在铝土岩系中可能的赋存形式、时空分布规律及钪的迁移转化机制,为铝土矿中伴生钪资源的综合利用开发提供理论支撑。

Objectives:Scandium(Sc),as an important strategic reserve resource in the new century,is widely distributed in nature,but its distribution is very sparse,the independent minerals of Sc are rare,and there are almost no independent deposits.There are huge reserves of Sc resources in bauxite series.Based on the statistics of Sc data of bauxite metallogenic belts in China,we find that Sc content is the highest in bauxite metallogenic belt of Southeast Yunnan and West Guangxi,and the formation age of Sc bearing bauxite series is mainly Carboniferous And Permian.Through the comparative analysis of the relationship between A/S and scandium,when A/S is less than 2.5,scandium content is generally higher,and has a positive correlation with A/S and has a negative correlation with A/S when A/S is greater than 2.5.Thus,in bauxite series,Sc is distributed in top clay rock,middle iron bauxite and bottom iron clay rock and iron rock,especially in iron bearing bauxite series.Through the comparative analysis of the contents of various elements in bauxite series,it is found that scandium is positively correlated with iron,niobium,vanadium and chromium.Based on the mineral manifestations of other elements in bauxite series,it is speculated that the occurrence forms of scandium in bauxite series may be isomorphism,ion adsorption and ultra microstructure non structure mixture.In this paper,the possible occurrence forms,temporal and spatial distribution of scandium in bauxite series and the migration and transformation mechanism of scandium are preliminarily discussed and summarized,so as to provide theoretical support for the comprehensive utilization and development of associated scandium resources in bauxite.