“孤岛”工作面采空区漏风规律及煤自燃防控研究

Study on Air Leakage Law of Goaf and Prevention and Control of Coal Spontaneous Combustion in"Isolated Island"Working Face

“孤岛”工作面沿空侧煤柱破碎严重,漏风复杂,煤自燃危险性大。本文以某煤矿2202“孤岛”工作面为例,通过SF6示踪气体漏风测定法,测定采空区漏风通道,结合数值模拟的方法分析采空区周边氧气漏风流场,确定煤自燃危险区域,提出有针对性的煤自燃隐患防控方法。结果表明:该工作面主要漏风汇为回风隅角和沿空侧破碎煤柱区域;采空区漏风是由回风侧向后部采空区渗流并通过破碎煤柱向沿空侧采空区扩散,采空区后30~60m与沿空侧采空区煤柱内侧30m范围为煤自燃危险区域;针对该区域,提出了堵漏降氧、惰化降温及监测预报的综合防控方法,制定了回风顺槽端头喷浆、注水玻璃凝胶、注二氧化碳相结合的防控技术。现场实测表明,在工作面回采过程中,该方法降低了工作面回风隅角等区域CO体积分数,有效防控采空区煤自燃隐患,保障了工作面的安全回采。

The"isolated island"working face has serious coal pillar breakage,complex air leakage and high risk of coal spontaneous combustion.In this paper,taking 2202"isolated island"working face of a coal mine as an example,through the SF6 tracer gas leakage measurement method,the air leakage channel in the goaf is measured,and the oxygen leakage flow field around the goaf is analyzed by combining with the numerical simulation method,so as to determine the coal spontaneous combustion risk area,and put forward the targeted prevention and control methods of coal spontaneous combustion.The results show that the main air leakage sink of the working face is the return air corner and the broken coal pillar area along the goaf side.The air leakage in the goaf is from the return air side to the rear goaf and diffuses through the broken coal pillar to the goaf along the goaf side.The range of 30m~60m behind the goaf and 30m inside the goaf pillar along the goaf side is the risk area of coal spontaneous combustion;In view of this area,the comprehensive prevention and control methods of plugging and oxygen reduction,inerting and cooling,monitoring and prediction were put forward,and the prevention and control technology of spraying slurry at the end of return air chute,injecting glass gel and injecting carbon dioxide was developed.The field measurement shows that during the mining process of the working face,this method reduces the volume fraction of CO in the area such as the return air corner of the working face,effectively prevents and controls the hidden danger of coal spontaneous combustion in the goaf,and ensures the safe mining of the working face.