复合煤层综放工作面瓦斯涌出分析及精准瓦斯治理技术

Analysis of gas emission and accurate gas control technology in composite coal seam fully-mechanized caving face

综放工作面由于开采强度大、回采率低,导致在回采过程易出现回风隅角瓦斯异常,受顶板来压影响,其回风隅角瓦斯比较难控制。为了解决复合煤层综放工作面开采过程回风隅角异常问题,首先,对复合煤层综放工作面进行瓦斯涌出量预测,结合现场实际瓦斯涌出情况,分析工作面的瓦斯涌出规律和来源,分析了工作面回风和回风隅角瓦斯涌出的主要影响因素,最后结合工作面煤层、瓦斯赋存情况,制定了精准的瓦斯综合防治技术措施。研究表明,某低瓦斯矿井复合煤层综放工作面瓦斯涌出主要来源于本煤层,其采空区、邻近层瓦斯涌出及顶板周期来压是影响回风隅角瓦斯异常的主要因素。根据瓦斯涌出来源及影响因素分析,最终采取工作面合理配风、采空区进回风隅角封堵、采空区埋管+插管抽采、顶板走向钻孔抽采及局部高瓦斯赋存区域的本煤层顺层钻孔抽采等综合治理技术措施实施精准治理后,回风瓦斯浓度最大值控制在0.5%以下,回风隅角瓦斯浓度控制在0.4%以下,实现了复合煤层综放工作面安全回采。

The fully-mechanized caving face often has high mining intensity and low recovery rate,which leads to abnormal gas in the return air corner during the mining process,due to the influence of roof pressure,the gas in the return air corner is difficult to control,in order to solve the problem of abnormal return air corner during the mining process of composite coal seam fully-mechanized caving face,firstly,the gas emission amount of the composite coal seam fully-mechanized caving face was predicted.Based on the actual gas emission situation on site,the law and source of gas emission in the working face were analyzed,and the main influencing factors of gas emission in the return air and return air corner of the working face were analyzed.Finally,precise comprehensive gas prevention and control technical measures were formulated based on the coal seam and gas occurrence in the working face.Research showed that the gas emission from the composite coal seam fully-mechanized caving face in a low gas mine mainly came from the coal seam itself,and the gas emission from the goaf,adjacent layers,and roof periodic pressure were the main factors affecting the abnormal gas in the return air corner.Based on the analysis of the sources and influencing factors of gas emission,comprehensive control measures such as reasonable air distribution in the working face,sealing of the inlet and outlet air corners in the goaf,burying and inserting pipes in the goaf for drainage,drilling and drainage along the roof direction,and drilling and drainage along the coal seam in local high gas storage areas were taken.After precise control,the maximum concentration of return air gas was controlled below 0.5%,and the concentration of return air corner gas was controlled below 0.4%,realizing safe mining of composite coal seam fully-mechanized caving face.