Mine name Mine production capacity (t/d) Ore production capacity (t/d) Mining ratio (m/kt) Pit wood consumption (m 3 /kt) Ore loss rate (%) Ore depletion rate Mining labor productivity Dongxiang copper mine Wushan Copper Mine ( North Belt ) Suzhou Kaolin Mine Malargue tin mine Yunxi old factory tin mine victory pit Seven hundred and five mines Pinghe Copper Mine 200,000 tons / year 800 200,000 tons / year 1900 60 36 58.2 50 50 28 30~40 19 19.1 35 35 18 17 8 twenty three 17 39 45 14 4.0 22~24.4 5 5.8 8.8 9 7 12.88 12 4.0 17.5 3~5 4.2 4.88 2.41~3.08 3.5 3.5~3.8 1.7 1.6~2.0 Amorphous Oil-immersed Transformer Amorphous Oil-Immersed Transformer,Alloy Power Transformer,Oil-Immersed Transforme,Amorphous Alloy Power Transformer Jiangsu Huayu Transformer Co., Ltd , https://www.huayutransformer.com
4-layered roadway; 5-back mining approach; 6-bamboo false top; 7-top pillar; 8--column; [next]
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( ton / work class )
Suzhou Kaolin Mine has three mining areas, of which Yangdong and Yangxi are being mined, and the Guanshan mining area will be mined in the near future. The deposit is a typical soft and thick ore body, f=1～3, with high cohesiveness, swelling and disintegration in water. The surrounding rock alteration is strong, the rocks on the upper and lower plates are not stable, and the mining conditions are complicated.
The ore body of the Yangxi mining area is located in the reverse fault zone and limestone cave, with a strike of 1.5km, which is layered, veined or lenticular. The variation of the occurrence is large, the thickness is generally 6-20m, the thickest is 62m, the inclination angle is 27°~60°, the rock on the upper plate is broken quartz sandstone , the rock in the lower plate is limestone, and the shallow cave is developed with confined water.
The ore body of the Yangdong mining area is located in the limestone cave. There are five isolated nested ore bodies, 100-200 m wide and 100-350 m long, of which the Bailingling ore body is the largest and is produced in the Gufeng Formation sand shale . Below, the Qixia Formation is above the erosion surface of the marble , and the longitudinal direction is inverted saddle shape.
The Yangxi and Yangdong mines currently produced are developed by the lower shaft and the flat-blind inclined shaft, respectively, with stage heights of 33m and 40m respectively.
The mine has been using a narrow approach to recovery for many years. The ore blocks are arranged along the ore body, generally 30 to 40 m long, and the width is equal to the thickness of the ore body. When the ore body is thick and the pressure is large, the length of the nugget is appropriately shortened. In principle, the area of ​​the nuggets is controlled within 800 to 1000 m 2 . The mining time of each layer is preferably 3 to 4 months.
The stratification height is 3~3.5m, the height of the layered roadway and the mining roadway is 2m, and the top column of 1~1.5m thick is left in the upper part. The center distance of the access road is 3.5~4.0m. The tunneling section is trapezoidal and the upper width is wide. 1.7m, 2.4m wide, leaving a 1.2-1.4m wide pillar between the roads.
The mining block layout is shown in Figure 1.
Figure 1 Alignment cutting arrangement
1-The lower plate transports the roadway along the vein; 2-passes the roadway for transportation; 3-Patio;
The ore is manually loaded with a type 03-11 or G-10 wind.
The layered roadway and the access road are supported by wooden sheds. The net section of the bracket is 1.8m high, the upper width is 1.4m, the lower width is 2m, and the shed distance is 0.6~0.7m.
The mining road tunnels to the boundary of the ore body, paving the bamboo raft on the floor, and then starting to retreat back. The pillars on the side of the goaf are first recovered, and the racks are manually recovered. The top column naturally falls off and is mined from the scaffold. The maximum mining step is 2.1m.
After the entire stratification is completed, it usually takes 1 to 2 months to mine the next layer to facilitate the formation of the regenerated roof.
The main technical and economic indicators are shown in Table 1.
Table 1 Â Â Technical and economic indicators of mines using stratified caving method in China
Note: The coal production capacity of the kaolin mine in Suzhou and the labor productivity of the miners are actual values ​​in 1985.