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Three-dimensional Geological Model And Reserve Estimation Of Tongchang Copper Deposit In Yimen County, Yunnan

Posted on:2016-05-25Degree:MasterType:Thesis
Country:ChinaCandidate:C YuFull Text:PDF
GTID:2180330482468565Subject:Mineral prospecting and exploration
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Though the 3D visualization modeling technology starts relatively late in China and developed rapidly in theoretical research. With the development and perfection of the 3D mining software and statistical software, the 3D geological modeling technology has been widely used in the mining industry. It has become a important content of building digital mine, which can provide new directions to make a further study for the mineralization enrichment regularity. This paper take the Tongchang copper deposit as the object of research, and collected the geological data of Tongchang mining area and the investigation about the deposit geology. Based on the metallogenic geological conditions, meneralization type and the spatial distribution law, we constructed geological database,3D geological model and variation function model of copper grade by using DIMINE three-dimensional software and three-dimensional modeling technology. According to the block model and grade model, the estimation reserve of the Tongchang cooper deposit has been calculated by using the ordinary Kriging and Distance Power Inverse Ratio Method. The main results are as follows:(1) This research screened and classified the spatial data and 2D digitized diagrams of mining area, finally supplement 55 exploration lines where 15716 samples in 91 effective drills and 50 tunnel engineering, then complicated with these checked data and constructed the mine geological database. On this basis, the terrain model, fault solid model, stratum solid model and ore body solid model have established by boolean operation. This resaerch realized the three-dimensional of geological data in Tongchang mining area.(2) Based on the sample length combination and the statistical analysis of the 15716 original copper grade samples, we can concluded that, the copper grade of composite samples are focused on 0-0.3%, average value is 0.173%, crest value is 2.78%, variation coefficient is 104.04%. These results showed the low grade and uniform variation characteristic of Tongchang copper deposit. Then, we selected the Ordinary Kriging into grade value estimation because of the copper grade obey logarithm normal distribution.(3) The variation function model of copper grade for Tongchang cooper is established based on the geological statistical theory. In addition, we concluded that the anisotropy value of copper grade in ore body is 9:8:10(tendency:inclination:thickness). The copper grade in strike direction has the worst structure than the tilt direction and thickness direction but has better variability of tendency. This research showed the ore bodies are controlled by strata, and the mineralization is controlled by strata which occurs lean ore and the rich ore alternately.(4) Through a comprehensive analysis of formation thickness digital terrain model, fault solid model and the distribution of mineralization, we consider that the mineralization intensity has a close relation with the "two segs mingle with one uplift" structural framework for ore-bearing strata of Luoxue Formation. The sedimentary-diagenetic mineralization (Tongchang style copper) is located in the south section of mining area, which has the stratabound feature and well stability. It has a positive correlation between the ore-bearing strata thickness and the orebody thickness, copper grade. The hydrothermal vein type copper mineralization (Xinhzuang-Da Jianshan Ore Section) is mainly hosted by Fi fracture zone, which shows the strata-dissecting characteristic and poor stability. The significantly superimposed combination area between sedimentary-diagenetic mineralization and hydrothermal vein mineralization are corresponding to the distributing regions of high grade orebody, which mainly controlled by strata and tectonism.(5) According to the block model which constrained by the orebody solid model, the copper grade model is established. This model showed that, the mineralization is characterized by well continuity when taking Cu=0.2%as cut-off grade but reflected poor continuity when taking Cu≥0.4% as constraint condition. In general, the constrained grade model not only showed the change trend of face shape distributionâ†'banding distributionâ†' point-zonal distribution, but it also reflected the stratabound feature and orecontroling fault feature, which coincident with strike of the ore-bearing stratum and main fault in Tongchang mining area. Various of phenomenon express that the Tongchang copper deposit is characterized by lean ore has well continuity but rich ore has poor continuity.(6) Based on the DIMINE software, this paper take 0.2%,0.2-0.4%,0.4-3.0% as cut-off grade respectively, and calculated the resource reserves between the 31 exploration line and 34 exploration line by using the Ordinary Kriging Method and Distance Power Inverse Ratio Method. The copper ore quantity (332+333+334) of Tongchang copper deposit is 8936 million tons and the copper metal quantity is 25 million tons by the cut-off grade of 0.2%. The ore quantity represent 93.91% of the total ore reserves and the metal quantity represent 88.97%of the total ore reserves by the copper grade of 0.2-0.4%. In addition, the ore quantity represent 6.09% of the total ore reserves and the metal quantity represent 11.32% of the total ore reserves by the copper grade of more than 0.4%. These results showed that Tongchang deposit is a medium-sized type deposit which has low grade.Generally, this research lay a basin on the dynamic management of three-dimensional visualized for Tongchang copper deposit.
Keywords/Search Tags:3D geological modeling, DIMINE software, grade distribution, reserve estimation, copper deposit, Yimen Tongchang area
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