Geological Characteristics And Resource Evaluation Of Shichang Graphite Deposit In Zixi County,Jiangxi Province

On the basis of previous geological data collection,through detailed field geological exploration work,indoor rock and mineral identification and chemical analysis test in Shichang graphite mining area of Zixi County,the distribution characteristics of strata,magmatic rocks and structures,as well as orebody shape,occurrence and ore quality in the mining area.The types and components of ore assemblages are analyzed,and the sedimentary metamorphic environment and genesis of the graphite deposit are discussed.The reserves estimation and economic evaluation are carried out,which has a certain guiding role for the development and utilization of the graphite deposit.Through this study the following understanding:(1)Shichang graphite deposit in Zixi County is a scale crystalline graphite deposit formed by regional metamorphism.The metamorphic rocks developed in the area are gneiss,mixed rocks,schist and lenticular quartzite,belonging to the green schist facies of albite-dolomite-biotite subfacies or albite-cordite-biotite subfacies.(2)The magmatic rock activity in the mining area is strong,but the rock type is mainly Chekanshan plagioclase granite body.Many dikes invade along the strata level,and local compression failure occurs to the ore body.The wall rock alteration of the deposit is developed,which is closely related to the mineralization of graphite by the potassiumization in magmatic period and the dolomitization generated by post-stage hydrothermal process.The ore body is hosted in the graphite schist and graphite quartz schist sections of the lower strata of the third member of the Nanhua-Sinian Hongshan Formation(Nh₂-Z₁h³),which are layered and stratoid,with stratabound characteristics.(3)Studies have shown that the ore in the mining area belongs to industrial scale crystalline graphite,and the average grade of the ore is 7.68%.Through the beneficiation test,the fixed carbon grade of the concentrate was 83.77–89.50%,which met or even exceeded the GB/T 3518-2008 flake graphite product brand LZ(-)45-90?LZ(-)45-86standard.(4)Field geological exploration found that in Zixi County,Jinxi County,Nancheng County and Yihuang County in the eastern Jiangxi Province,the third member of the Nanhua-Sinian Hongshan Formation(Nh₂-Z₁h³)lower strata are widely exposed,regional metamorphism is strong,with good geological conditions of graphite resource mineralization,in the scope of the mining area,where the third member of the Nanhua-Sinian Hongshan Formation(Nh₂-Z₁h³)lower strata exposed,there are different scales of graphite minerals.The study shows that the study area has good metallogenic conditions of high quality and high purity graphite ore,and there is a good prospect for geological prospecting work.