| The Yangshan gold deposit of Wenxian country, gansu province is located in the south of Gansu province and in the central south area of Qinling mountain. And the anba ore block is locsted in Ann changhe-- Guanyin dam fault zone of east wing of Wenxian arc structure, the trend of this fault is NEE, fold development better in the fault zone, and there are a series of secondary interlayer shear zones or fractures development in fold wing, the main orebody of anba ore block is located in these secondary interlayer shear zones or fractures. So far, 45 veins have been discovered in anba ore block, the ore bearing strate are located in the Lower Devonian rock bridge(Dq) which is made of the organic metamorphic phyllite, calcareous phyllite and siliceous limestone. The anba ore block is composed of four main veins which are314、305 、360 and 311 from south to north, they are roughly NE--NEE parallel distribution, the average grade of Au is 5.55g/t, the average thickness of orebody is4.93 meters, the anba ore block is a mineralization of Yangshan ore zone, the anba ore block explore for resources in the amount of 349.559 kg, it accounts for 92.97% of the total amount of gold ore belt in Yangshan.Through systematically field geological survey、collecting mining rock samples and laboratory analysis, in this paper, from the research background and the regional geological background of anba ore block, focusing on relationship between geological conditions in anba ore block and mining test、beneficiation test as the key research contents, combining with theory 、methods and means of the structural geology 、modern petrology、mineralogy、petrography、mineral deposit geology、environmental geology to study the anba ore block of the Yangshan gold deposit. This paper mainly discusses the choices of anba ore block’s mining technical plans and beneficiation technology solutions, this paper on the selected scheme’s impact on the environment also makes a meticulous research. And provides reasonable and economic feasibility basis for the development and utilization of the anba ore block in the future.Based on collecting a vast amount of previous data, this paper makes a detail analysis of the study area’s mining geological、hydrogeology、engineering geology、environmental geology and ore geology and other geological factors related to mining,so wo know that(1) The exposed atrate in this area from old to new are Sinian-Cambrian、Devonian、Carbonniferous、Triassic and Quaternary, the outcropped lithology are mainly carbonate rocks、siliceous rocks、limestone、phy- llite、slate、sandstone and Ma Lan loess and eluvial material of quaternary; the formation are given priority to with Devonian and Quaternary, and the third lithologic section of san hekou group is the main strata for ore hosting;(2) The surface water in the mining area has a little influence on ore body water filling, the water yield property of the mining area’s aquifer is weak, the infiltration recharge is small, precipitation has little influence on ore bodies filled with water; although the orebody’s roof developed cracks, but the water yield property is bad, The groundwater is given priority to with storage. Thus hydrogeological conditions belongs to the simple deposit;(3) The terrain and topography in mining area is complex, eluvial of Quaternary develops well,the boundaries between ore and non-ore is unclear, ore bodies and surrounding rocks are broken, most of roadway is opened up maybe occur collapse、drop out rocks and other bad engineering geological phenomenon, the stability of surrounding rock is not good. With the mining depth is deep, underground stressfield change, some of the hidden crack expand and form permeable fracture which affect the stability of the surrounding rock, so the engineering geology condition belongs to medium;(4) The Quaternary develop well, some of the surface has appeared a small area of the collapse、landslide and other engineering geological problems, so the environmental geological condition belongs to medium;(5) According to the existence conditions of the ore bodies, the characteristics of mining area’s orebody are: most orebodies are inclined- steeply inclined, the orebodies are in lenticular to discontinuously distyibute,the thickness of ore body are 0.63-7.76 meters, the average taste is 5.55g/t. The studies have shown that the study area is roughly belong to complex problem(Ⅱ-4)type of deposit mining conditions are moderate(Ⅱ) deposit type.Study the ore properties that affect gold ore containing process, wo known that the ore types of the study area are mainly pyritization vein type and fractured altered phyllite type, the ore minerals are mainly pryrite、chalcopyrite、arseno- pyrite、stibnite etc, and arsenopyrite、pyrite、stibnite and clay minerals are the main gold bearing minerals of mining area; the gangue minerals are mainly quartz、feldspar; the ore contain carbonaceous matter、arsenic and antimony highly; there are three main types of gold occurrence----(1) In the form of inclusions in arsenopyrite、limo- nite and clay minerals;(2) Gold in the form of crack occurs in micro fractures of pyrite and limonite;(3) Gold in the form of intergranular occurs in clay minerals. They show thatthe ore belongs to refractory gold ore.In summary, for the mining of anba ore block, I make the following recommendations of program: suggestion for mining is underground mining, mining method is shallow hole ore mining; the beneficiation process is recommended flotation.Related literature、the results of previous studies of the study area and this thesis,we form the following understanding of the development and utilization of mineral and environmental benefits of anba ore block:(1) The environmental influences caused by Anba ore block in the development process have two main aspects : the influenc of mining impact on the environment and the beneficiation impact on the environment;(2) The impacts on the environment caused by mining are the geological disasters, such as debris flow, collapse, ground subsidence, landslide etc;(3) The impacts on the environment caused by beneficiation are environmental pollutions,lack of equipment and technology, the improper selection of flotation reagents, lack of supporting engineering and so on, they will lead to the destruction of vegetation, such as water pollution, soil pollution, noise pollution and air pollution and other environmental pollution problems;(4) Because of the mine production of anba ore block is the underground mining, compared to surface mining, the damage to the environment is less, if pay attention to the protection of vegetation in production, and ensure the timely restoration of vegetation, the impact on the environment will be smaller. But in the process of mine development and utilization, environmental pollution can not be avoided, so the follow-up in anba ore block of mining, the timing of the development process, I suggest that control of geological disasters in mining area and environmental pollution problems. |
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