铜陵矿区废矿石次生氧化产物及其成因初探  

Secondary Minerals and Their Weathering Mechanisms of the Waste Sulfide-bearing Ores in Shizishan Mine,Tongling

作　　者：李娟[1] 陆建军[1] 陆现彩[1] 王汝成[1] 徐兆文[1] 屠博文[2] 

机构地区：[1]内生金属矿床成矿机制研究国家重点实验室南京大学地球科学与工程学院,江苏南京210093 [2]南京大学生命科学学院,江苏南京210093

出　　处：《矿物学报》2011年第4期676-682,共7页Acta Mineralogica Sinica

基　　金：国家重点基础研究发展计划(2007CB815603);国家自然科学基金(批准号:4093074210979018);南京大学博士生创新基金(2010CL10)

摘　　要：对铜陵矿区废矿石的矿物组成及其成因进行研究,利用X射线衍射仪(XRD)和扫描电子显微镜(SEM)分析原生矿物及其风化产物的组成,探讨次生矿物的形成机制。XRD及SEM/EDS分析表明,废矿石中残留的主要原生矿物为黄铁矿,次生矿物为针铁矿、赤铁矿、水铁矿及次生硫酸盐矿物。原生矿物风化为次生矿物的过程是从黄铁矿的裂隙带等有缺陷的部位开始,逐步氧化成最终产物针铁矿。中间过程出现了矿物相及形态的多样性,局部可能会先形成中间产物水铁矿,由于水铁矿很不稳定,在不同的温、湿度条件下会很快转化成针铁矿或赤铁矿。针铁矿在风化过程中呈现出多种形态,针状矿物最先形成,随后重结晶成球状集合体和菱方双锥单晶,最后在废矿石表面完全覆盖一层土状针铁矿。SEM观察到的黄铁矿表面的生物矿物与最外层风化层上的菌丝类物质说明,在废矿石的风化过程中生物亦起了一定的作用。An investigation on the waste sulfide-bearing ores in Shizishan Mine,Tongling,Anhui Province was carried out.By employment of XRD and SEM/EDS analyses,the mineral association of the weathered sample was disclosed and then the formation mechanism of secondary minerals was discussed.The major residual primal mineral identified is pyrite,and the secondary minerals are goethite,hematite,ferrihydrite and efflorescent sulfates.Pyrite firstly was oxidized from the flaw spot such as fissure,and then gradually oxidized until forming finally goethite.In the intermediate process,there are multiplicity of the secondary minerals and their morphology.Before goethite formed,the intermediary ferrihydrite might have been produced.Due to its unstable property,ferrihydrite would transform into goethite or hematite quickly under different conditions.There were various configurations of goethite.The acerose goethite was formed first and then recrystallized into globose and rhombic dipyramid goethite.In the end,the layer of dusty goethite formed on the waste ore＇s surface.SEM observation shows that there maybe biominerals in pyrite surface and hypha in the surface of the mostouter oxidized layer,which indicate that the organism might have been played a certain role in the weathering process of waste ores.

关 键 词：废矿石 次生矿物 生物矿物 

分 类 号：P571[天文地球—矿物学] P572[天文地球—地质学]