Study On The Mineralogy Characteristics Of Metallic Sulphide In The Jinchuan Ni-Cu Sulfide Ore Deposit, GanSu Province

Jinchuan copper-nickel sulphide deposit is in Jinchang city, Gansu Province. It is the largest copper-nickel sulphide deposit in China. Jinchuan deposit is formed by the four mining areas, it richs in copper, nickel, also contains a lot of platinum group elements, gold, silver, cobalt. Native and foreign geologists or geological workers pay extensive attention to it.This paper collects and collates the information on the basis of predecessors. With the observation of the samples of rocks and minerals from the mining area, and study with the electronic probe, It researches rock, deposit and mineralogical characteristics of Jinchuan copper-nickel sulphide deposit by system, based on the analysis and observation of the ore body shape, ore types and structure, mineral composition of Jinchuan deposit, especially for the mineralogical characteristics and the association of various metal minerals. The main results are as follows:(1) Ore-forming process of Jinchuan nickel-copper deposit includs four periods: cumulate period, crystallization phase, hydrothermal alteration stage and alteration, and expounds various mineral association and characteristics in four mineralization periods of the metal sulfides.(2) Silicate mineral in Jinchuan deposit mainly are olivine, pyroxene, feldspar and a small number of hornblende, metal sulfides are pyrrhotite, pentlandite , chalcopyrite, pyrite, cubanite, a small amount of sphalerite, It also contains chromite, magnetite.(3) The formation of the Jinchuan deposit at least has two important periods, the first is diagenesis mineralization period of ultra-magmatic intrusion, the performance is the crystallization of magma and liquation ore-formation, and the other is the tectonic metamorphism and hydrothermal superimposition reformation period after the mineralization period.(4) After hydrothermal hydrothermal superimposition reformation period, the mineral composition has a certain change compared with the crystallization phase. Trace elements As, Se, Ag, Te, Cd enrich, Ni, Cu, Co changes differently.