Research On The Ni-Mo-V Deposites In Lower Cambrian Black Rock Series In Western Hunan

Ni, Mo, V deposits in Lower Cambrian black rock series Xiangxi (Western Hunan) were to be of intermittent development and utilization in the mid-late-80s and to be achieved success in the late nineties. However, research is lagging behind, although there are many scholars, experts and professors who studied the thematic on several aspects and achieved a lot of research results, the study of Ni, Mo, V deposits is still need to be strengthened, especially for vanadium ore research in this area.Research topics of nickel-molybdenum-vanadium deposits in the Lower Cambrian of Xiangxi is based on the research results of the predecessors, fully utilized the deep mineral exploration results achieved by the exploration teams since September 1,2005. From the ore-forming geological background, the main rock types of black shales, rock (ore) geochemical features, deposit geological characteristics, combined with the enrichment of ore-forming elements of mineralization, ore genesis, as well as the prospects for development and utilization of deposit, etc. It makes my study work more in-depth and systematic.This research work is guided by the rock geochemistry and ore geochemical theory; based on the information of deep exploration and mining development in the area; relied on the research results of black shales of the predecessors in South China. Through the field inspection of the known exploration area and the mining zone, sampling inspection, indoor comprehensive research and other means, identified the regional geological background of Ni-Mo-V ore and the Lower Cambrian black rock series, diagenetic ore-forming geological conditions, deposit geological characteristics. Explored the ore-controlling factors, ore-forming law, ore-thermodynamic conditions, ore deposit origin pattern and so on. And studied simply the ore deposit mining engineering factor, dressing and smelting technology and prospects for development and utilization.Lower Cambrian black shales in Western Hunan are an important part of black shales in South China. In the late Sinian-Early Cambrian, Yangzi continental block converted from tensile to thermal subsidence, as well as evolved passive continental margin in the early Cambrian-Early Ordovician. Had the formation of a carbonate platform margin deposits and slope deposits of carbonate, clastic rocks. The appropriate deposit with the layered deposits of the Lower Cambrian black rock series in South China may be assimilated. Huayuan-Cili is an important regional deep fault, which controlled rock-ore structure, stratigraphic distribution, and has very close ties with the formation of ore-deposits.Ore-bearing rocks (black shales), is not in carbonaceous shale-based, but a set of carbonate, chert, phosphate rock, clastic rock combination. Vanadium-containing rocks are mainly carbonaceous cherts phosphorus, carbonaceous siliceous dolomite and siliceous phosphate rock, siliceous clay, rocks, etc. Ni.Mo-Containing rocks are mainly carbonaceous silicified rocks, carbonaceous phosphorus siltstone, carbonaceous silicified phosphorite, silicious carbonate-based phosphate rock, silicon phosphate rock, heavy goods, barite gravel dust phosphate rock, carbonaceous dolomite and so on.The studies of rock (ore) geochemical characteristics have shown that Ni-Mo-V deposit are quite different in the ore-environment and ore mineralization, including ore-material sources. According to the content changes of trace elements, rare earth elements, dispersed elements, noble metals, as well as portfolio characteristics and the characteristics of fluid inclusions in deposits, it could be that:V-seam formed in a normal shallow marginal sea basin setting, mineralized process is mainly biochemical mineralization, ore sources for multi-source; Nickel, molybdenum formed in the more specific marginal trough environment, mineralized process is mainly marine hydrothermal mineralization, and submarine volcanic effusion to provides a rich minerals.In Ni, Mo, V-Containing black rock series, the associated elements have obvious specific combination. V, P, C, Yb, Ba are the main anomalous elements with very high contents in the region. The associated element in Vanadium ore bed is very low, and do not have comprehensive value. The associated elements in Ni-Mo ore bed are of more complex combination: associated V, Cu, Zn, rich in Pt, Pd, Os, and dispersed elements Se, Cd with high content of a markedly anomalies. Major Elements in the ore-bearing black shales, are basically the same average concentration with Continental sedimentary shell components, exception to CaO with slightly higher.Changes in element content have the following law:Yb content in the formation and content of ore bodies is as hundreds of thousands of times as the crust elements abundance; Ba,V content in the ore body formation are the number of times higher than that in the Ni-Mo ore bodies; Vanadium ore body is lower Ni, Mo content, and without other associated elements (Ba, Yb, except); Ni-Mo ore bodies is rich in precious metal elements, Mo and precious metals (Pt, Pd, Os) with significant positive correlation, but Ni and precious metals with no correlation.Ni, Mo, V studies have shown that the occurrence condition:Vanadium mainly occurs in the clay minerals,as ions adsorbed, isomorphism, etc., In the carbon and organic matter, its content is extremely low. It is necessary for us to pay attention to that the pyrite and molybdenite contain vanadium. But in what form, need to be further studied. Of course, it is difficult to determine the independent vanadium minerals in the region. More independent nickel minerals are mainly arsenic sulfide and sulfur, Molybdenum independent minerals is mainly molybdenite. This study suggests that:a considerable part of Ni, Mo should not existed in the independent minerals. Is only a general explanation of the "sulfur-carbon molybdenum" more reluctantly. The only independent molybdenum mineral molybdenite, which is the typical secondary (epigenetic) minerals in the microscopic observation, formed after diagenesis; A large number of major nickel-bearing mineral-capillose, is also a typical secondary minerals, decomposed by nickel-bearing pyrite.In the study area, nickel-molybdenum-vanadium ore body are bedding integrated with formation. V-seam with the Ni-Mo ore bed can be compared in the profile, with the basic characteristics of sedimentary deposits. Mineralization are mainly biological deposition and ore sources with characteristics of multi-source model. Marine hydrothermal mineralization and submarine volcanic effusion provided a rich ore-materials for the formation of Ni-Mo deposits. That is why the Ni, Mo, V ore deposits display two sets of minerogenesis systems and many kinds of mineralization characteristic in the area.Whether it is in western Hunan, Guizhou and Zunyi, or western Zhejiang-kaihua-Zhuji, any Ni-Mo-bearing deposits (including the precious metals mineralized) zone in the Lower Cambrian black rock series of which underlying strata must be dolomite of the Upper Sinian Dengying group.Once the strata lithology along the strike changed into silicified rocks of the Upper Sinian(Liuchapou group) formed by hot-water sedimentation, Then became sedimentary vanadium ore bed, while the nickel-molybdenum enrichment horizon disappeared.The research results of Ni-Mo-V deposits in Xiangxi(Western Hunan) show that:This type of ore-deposite is easy to do exploration, simple to do dressing and smelting, effective to do mining and production. It is able to meet the requirements for "green mining" construction, and possesses good prospects for development and utilization.