贵州织金下寒武统黑色页岩矿物岩石成分及资源利用特征

Mineral and rock composition and resource properties of Lower Cambrian black shale in Zhijin,Guizhou Province

通过野外采样、化学分析、电子探针(EPMA)和X射线衍射(XRD)分析等手段,研究了贵州织金地区黑色页岩矿物成分、化学组分、微量元素、稀土元素特征。研究区矿样化学成分以SiO_2和Al_2O_3为主,且具有高K低Na的特征。电子探针和X射线衍射分析表明,研究区黑色页岩主要矿物组成有石英、粘土矿物、白云石及黄铁矿等。织金黑色页岩中Pb、Ni、U、V、Cr等金属元素存在不同程度的富集,稀土元素总量为153.2×10^(-6)~224.89×10^(-6),属轻稀土元素富集型。同时从多金属层、页岩气、页岩提钾及近底部含磷铀矿资源等方面讨论了织金黑色页岩资源化利用。织金黑色页岩多金属层含有Mo、V、Ni、Ag及U等多金属元素,具综合利用价值;其中有机碳含量达到页岩气开发大于2%的条件,可进一步开展研究;页岩中伊利石含量较多,可提取黑色页岩中的钾制备含钾复合肥;黑色页岩底部与磷矿层接触带产出磷铀矿,主要为胶状磷铀矿,接触带可作为铀矿找矿的标志层。

Field sampling, chemical analysis, electron microprobe analysis （EPMA） and X-ray diffraction （XRD） analysis were conducted to study the chemical composition, material composition, trace elements and rare earth elements characteristics of black shale in Zhijin, Guizhou Province. The chemical composition of the ore sample was given priority to SiO2 and Al2O3, which also had the characteristics of high K and low Na. The results of electron microprobe and X-ray diffraction analysis show that quartz, clay mineral, dolomite and pyrite are the main mineral composition. Pb, Ni, U, V, Cr and other metallic elements exist in the black shale of Zhijin with different degrees of enrichment. The amount of rare earth elements in black shale is 153.2×10-6～224.89×10-6, suggesting a LREE enrichment type. The authors also systematically discussed some problems such as resource utilization of black shale from polymetallic layers, shale gas, extraction of potassium from potassium-rich shale, and the phosphorus uranium resources near the bottom of the black shale. Black shale polymetallic layers contain Mo, V, Ni, Ag, U and other metal elements with utilization value. The content of organic carbon in the black shale is more than 2%, reaching geological conditions for shale gas development. Potassium can be extracted from illite in black shale for the preparation of potassium fertilizer. Phosphorus uranium deposit, mainly colloidal phosphorus uranium, is produced on the bottom of black shale and the contact zone phosphate layer, and hence the contact zone can serve as the uranium prospecting marker bed.