特厚煤层综放面采空区综合瓦斯治理技术研究

Study on Comprehensive Gas Control Technology for the Gob Area of Fully Mechanized Caving Face with Extremely Thick Coal Seam

针对特厚煤层综放面回采时瓦斯涌出量大、上隅角瓦斯超限严重影响安全生产的难题,提出地面立孔、L型钻孔和高抽巷三种瓦斯治理技术。借助数值模拟软件得到采动覆岩演化规律及三种治理方法的合理布置参数。现场实测结果表明:L型钻孔瓦斯抽采浓度是高抽巷的0.5倍,地面立孔瓦斯抽采浓度仅为2.4%。高抽巷的抽采瓦斯纯量是地面立孔的1.5倍,是L型钻孔的5倍,高抽巷抽采瓦斯纯量高达32m^3/min,瓦斯抽采浓度高达36%,治理效果良好。对比分析工程造价、抽采效果及经济效益等因素,决定实施高抽巷和地面立孔来治理采空区瓦斯。

To solve the issue of large gas emission and the over limit of gas content in the upper corner during the mining process in fully mechanized caving face with extremely thick coal seam,which would seriously influence the work safety,the paper proposes three gas control technology,including constructing surface vertical borehole,L-type drilling and high level drainage roadway. By using numerical simulation software,the evolution law of overburden rock under mining and the reasonable distribution parameters could be obtained. The field test results show that,the concentration of drained gas by L-type drilling is 0. 5 times as that of high level drainage roadway,and the concentration of drained gas by surface vertical borehole is 2. 4%. The amount of pure gas drained by high level drainage roadway is 1. 5 times as that of surface vertical borehole and 5 times as that of L-type drilling,reaching 32 m^3/min with the gas concentration up to 30%,which could achieve a good result for gas control. After comparing the factors including the cost of engineering construction,drainage effect,economic benefits,etc.,it is decided to construct high level drainage roadway and surface vertical borehole to control gas in gob area.