A secondary coal mining method with strip reverse paste filling

Abstract

The invention relates to a secondary coal-mining method for reversely filling paste in stripes. The secondary coal-mining method is suitable for the safe recovery of coal resources under buildings, railways and water bodies. The secondary coal-mining method comprises the following steps of: determining the range of mining coal under building groups according to regulations, and alternatively partitioning paste filling stripes and recovery stripes in the determined coal mining range; sequentially mining the partitioned paste filling stripes and filling mine-out areas of the partitioned paste filling stripes; and sequentially drilling without section pillar along the two paste filling strips and mining the recovery stripes by a caving method after a filler in the past filling stripes is completely solidified. Under usual conditions, the paste filling stripes are wider, and normal recovery stripes are narrow. By the method, the damage to the surface buildings caused by mining subsidence can be effectively reduced, the safety of coal mining can also be ensured without reserving narrow coal pillars, so that the coal resource is completely recovered; and simultaneously, coal resources utilization of solid wastes such as coal gangues and fly ash is realized.

Description

technical field [0001] The invention relates to a coal mining method, in particular to a coal mining method which is suitable for safe and fully recovered coal resources under buildings, railways and water bodies and is filled twice with strip reverse paste. Background technique [0002] my country is the largest coal producing country in the world. In 2009, coal output reached 2.97 billion tons. In 2010, my country’s coal output reached 3.24 billion tons. At the same time, coal consumption continues to grow. By 2015, the total national coal consumption will reach 4 billion tons or so. In the case of a large increase in coal demand in my country, especially in the east, there are not many recoverable coal resources. It is an important problem to accumulate a large amount of coal resources in the "three downs" (under buildings, under railways, and under water bodies). According to incomplete statistics of key state-owned coal mines, the amount of coal pressed in the country is...

AI Technical Summary

Problems solved by technology

Although the first two methods can control the coal resources extracted from the surface, the recovery rate of the strip mining method is only 30% to 50%, while the recovery rate of the room and pillar coal mining method is generally less than 40%, which is a serious waste of resources. However, the current general filling mining method can improve the recovery rate of coal to a certain extent and reduce the subsidence of the surface, but it still faces problems such as a considerable amount of coal that cannot be extracted and subsidence of the surface.

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