沙曲矿4#煤层井下瓦斯抽采技术

4# seam gas drainage control techniques in Shaqu coal mine

沙曲矿为近距离煤层群开采矿，4#煤层为高瓦斯有突出危险煤层，为防止工作面回采时出现瓦斯超限或发生突出危险，并将瓦斯资源加以有效利用，通过在采前、采中及采后分别实施本煤层、邻近层及采空区瓦斯抽采措施，实现平均瓦斯抽采量分别达12．89m3／min、22m^3／min与10m3／min。采用沿空留巷Y型通风方式，平均配风量3300m3／min，实现风排瓦斯量15～20m3／min，占涌出量的44％。24207工作面回采时，回风瓦斯体积分数稳定在0．4％～0．6％，未发生上隅角瓦斯超限或煤与瓦斯突出现象，日产量由初期的800t／d提高至3600t／d。

This paper is aimed to solve the problem of coal and gas outburst threat from the coal and gas explosion in the process of coal mining in Shaqu coal mine. As is known, the coal seam condition in this coal mine is characterized by contiguous seams and the major mining seams abundant in high coal and gas outburst hazards. In or- der to prevent the mining head-face from gas overrun or outburst, we have taken a series of suitable and realistic measures before and after mining the coal resources, such as strengthening the gas drainage and improvement on the mining ventilation. In hoping to make the full use of the gas and coal resource most effectively. Through the implementatian of synergistic extraction technology, we have achieved signifi- cant results. For example, in order to use the gas extraction in cur- rent seam before mining, we have increased the average drainage quantity to 12.89 m3/min, a great lot more than that before. In order to use the extraction in the adjacent seam while mining, we have in- creased the average drainage quantity to 22 m3/min. Due to the adoption of the above methods by using the extraction in goaf after mining, we have pushed up the average drainage quantity to 10 m3/min. Combining the gob-side entry retaining with Y type ventila- tion with the enhanced average air ventilation in 3 300 m3/min in working face, the gas exhaust quantity reached 15 - 20 m3/min, ac- counting for 44% in the total gas emission. In doing so, we have managed to stabilize the gas concentration of the return air at about 0.4% - 0.6% while mining in No.24207 working face, making the daily coal production increase from 800 t/d from the initial stage up to 3 600 t/d after the implement of the above-said the measures. Successfully getting rid of coal and gas outburst hazards, we have re- alized safe and secure high-efficient exploitation of the coal and gas