A three-dimensional roof control method for full-mechanized caving in steeply inclined and extra-thick coal seams

Abstract

The invention discloses a three-dimensional roof control method for fully-mechanized opening of steeply inclined and extra-thick coal seams. The steeply inclined and extra-thick coal seam is mined in a plurality of mining sections from the back to the front along the coal seam trend, and each mining section starts from the top. It is divided into multiple layers from bottom to bottom, and the uppermost layer is the top layer; when any mining section is mined, the multiple layers of the mining section are mined from top to bottom. As follows: 1. Top layer mining: including steps: roadway construction, extraction of toxic and harmful gases in the pre-explosion roadway, advance pre-blasting of the top coal, dewatering of the top coal, coal seam mining, nitrogen injection behind the working face and ground backfilling of the subsidence area; 1. Mining the next layer; 3. Repeat step 2 one or more times until the mining process of all layers in the mining segment is completed. The method of the invention has the advantages of simple steps, reasonable design, convenient realization and good use effect, and multiple protective measures are used in combination to effectively eliminate potential safety hazards such as roof fall and gob fire.

Description

technical field [0001] The invention belongs to the technical field of coal seam mining, and in particular relates to a three-dimensional roof control method for fully mechanized caving of steeply inclined extra-thick coal seams. Background technique [0002] The horizontal layered coal mining method refers to dividing the steeply inclined thick coal seam into several 2-3m thick layers along the horizontal direction, and mining them sequentially from top to bottom. The mining face and layered roadway are arranged in each layer, and the roadway in the mining area can be arranged according to double wings or single wings. Section height is generally 15m ~ 30m. The length of the mining face is the horizontal thickness of the coal seam, and the working face advances along the strike. When the horizontal thickness of the coal seam is less than 8m, only one layered roadway needs to be dug on the layered floor; when the horizontal thickness of the coal seam is greater than 8m, an...

AI Technical Summary

Problems solved by technology

In actual use, the above-mentioned protective measures have the following defects and deficiencies: first, due to the particularity of the steeply inclined and extra-thick coal seam, the goaf is prone to fire and has many safety hazards; Third, the degree of coal fragmentation is low, and the resource recovery rate is low; fourth, the roof migration is highly uncertain, which is likely to cause large-scale roof fall and gas impact; fourth, the protection method is relatively simple, and it cannot be comprehensive, three-dimensional defense and timely Dealing with Security Risks

Images