Tin mine, mine, pillar, mining, mining, column

The mine is a gently inclined (10-20°) deposit. The riverbed pillar test mining area is in stages 6-9. The ore bodies are found in the strontium limestone, mainly the II and III deposits. The 8th to 9th stage ore body has a thickness of 4 to 25 m and an average thickness of 12 m. The direct roof is 4 to 8 m of limestone and shale interbedded and stable. There is a temporary tailings pond with an area of ​​18,000 ^m2 on the riverbed. In order to mine the pillars and other security pillars under the riverbed, the ground surface should be evenly sunk to prevent large cracks in the covered rock layers and the surface water to be poured into the pits. The mine pillars are all recovered by the house column method. Concrete cement filling and tailings filling, Figure 1.

Figure 1 Xi mining mine room column method mining column

1—transportation lane; 2—funnel; 3—cutting lane; 4—electric chamber; 5—cutting up the mountain;

6—reservation of the return airway; 7—disintegration of the ore; 8—filling the mine; 9—the column

The mine is 6~8m wide, and the pillar is 8~12m wide and 50~70m long. 3 to 5 ore blocks are a panel and leave the pillars in the panel. The mining method of the mine pillar is the same. The ratio of cement, tailings and crushed stone packed with cement is 1:3:6, and the actual strength of the packed body on site is 2.0-4.0 MPa. The technical and economic indicators of the pillar mining are close to the mine. Years of practice have proved that the surface subsidence value meets the requirements of safety protection.