贵州瓮安牛蹄塘组多金属矿层镍钼钒赋存状态研究

STUDY ON THE OCCURRENCE STATE OF Ni-Mo-V FROM THE POLYMETALLIC LAYERS IN NIUTITANG FORMATION,WENG′AN COUNTY,GUIZHOU

贵州福泉地区瓮安大信北斗山矿区早寒武世地层富含多种金属元素。应用矿物学、岩石学常规研究方法,结合地球化学分析、X射线衍射分析、电镜能谱分析、电子探针分析等方法,对其寒武系牛蹄塘组黑色页岩段底部多金属富集层中镍-钼-钒等金属元素赋存状态开展研究。结果显示矿石中Ni(平均值2.83%)、Mo(平均值3.79%)含量相对较高,V含量相对较低;Ni主要赋存于(57.64%)硫化物相中,部分(29.86%)赋存于硫酸盐相中,少量(12.5%)赋存于硅酸盐相中;Mo主要赋存于硫化物矿物(占52.71%)和氧化物矿物(占47.29%)中;V主要赋存于云母类矿物(占64.92%)中。Ni主要以硫镍矿、辉砷镍矿等硫化物形式赋存于矿石中;其次赋存于硫酸盐矿物如镍矾中,少量的Ni可能呈分散状态存在于黄铁矿、胶黄铁矿及云母、粘土矿物中;Mo可能主要以胶状硫化物如胶硫钼矿的形式赋存于矿石中,与黔北遵义、湘西和浙西相似,在黄铁矿类、黄铜矿等硫化物中普遍存在可以回收利用的Mo;未见V的独立矿物存在,V可能主要赋存于云母或粘土矿物中,或以分散状态分布于矿石中,与黔北和湘西北的赋存形式一致。以上研究结果对研究上扬子地区寒武系黑色岩系多金属元素的赋存状态及形成机制有重要的科学价值。

In the area of Beidou Mountain mining area,Weng′an County,Fu Quan City,Guizhou Province,there are abundant metallic elements In the Cambrian strata.On the basis of conventional methods of mineralogy and petrology,the occurrence status of nickel-molybdenum-vanadium and other metal elements in the polymetallic rich layers at the bottom of the black shale section of the Cambrian Niutitang Formation in this area has been studied by geochemical analysis,X-ray diffraction analysis,electron microscope energy spectrum analysis,electron probe analysis and other methods.Analyses show that the contents of Ni(mean value=2.83%)and Mo(mean value=3.79%)in the ore are relatively high,while the contents of V are comparatively low.Ni mainly occurs in the sulfide phase(57.64%),some(29.86%)in the sulfate phase and a small amount(12.5%)in the silicate phase.Mo is mainly found in sulfide minerals(accounting for 52.71%)and oxide minerals(accounting for 47.29%).V mainly occurs in mica minerals(accounting for 64.92%),with a small amount in iron oxide+kaolin and tourmaline+garnet.Microscope,X-ray powder diffraction and electron probe analyses reveal that Ni in ores is mainly found in the form of sulfide,such as nickel sulfide and arsenopyrite,while the rest occurs in sulfate minerals such as nickel alum,and a small amount of Ni is dispersed in pyrite,collopyrite,mica and clay minerals.It is likely that Mo mainly occurs in ores in the form of colloidal sulfide,such as colloidal sulfur molybdenum,similar to that in Zunyi of northern Guizhou,western Hunan and western Zhejiang.Recyclable Mo is commonly found in pyrite,chalcopyrite and there is no independent minerals of V in the deposit,which probably occurs in mica or clay minerals,or distributes in ore in a dispersed state,consistent with the occurrence form of northern Guizhou and northwestern Hunan.This study has provided reference for the further research of the occurrence status and formation mechanism of polymetallic elements in the Cambrian black rock series in upper Yangtze Region.