煤矿井下CO来源辨识与浓度超限原因研究——以内蒙古串草圪旦煤矿为例

为准确辨识井下CO来源,查明CO异常涌出与浓度超限原因,更好指导煤矿安全生产工作。以内蒙古串草圪旦煤矿为研究实例,统计了该矿井下6103、6104和6106工作面1059个气样组分测试数据,分析了采煤工作面、密闭采空区CO浓度变化特征,确定了井下CO主、次要来源,探讨了地质因素、工程因素对CO浓度超限的影响。研究结果表明:所有统计气样中,CO与O₂浓度具有较好的负相关性,CO浓度超限主要在工作面上隅角、支架、密闭采空区等通风条件较差的位置;CO主要来源于煤炭开采氧化自燃,局部存在煤天然氧化次生CO;开采煤层埋藏浅、小型逆断层发育及煤变质程度低是CO浓度超限的地质原因;工作面长度过大,通风方式不合理是CO浓度超限的工程原因;地质与工程因素共同作用下,煤炭开采氧化自燃CO与天然次生CO叠加涌出,导致在风流速度低的位置CO积聚而引起井下CO浓度超限。

Study on identify sources of CO and reasons of concentration overrun in underground coal mine:a case study of Chuancaogedan Coal Mine in Inner Mongolia

Identifying the source of CO and finding out the reasons of abnormal CO emission and concentration overrun can guide coal mine safety production.Taking 6103,6104 and 6106 coal mining faces of Chuancaogedan Mine in Inner Mongolia as the research object,this paper analyzes the variation characteristics of CO concentration in working face and closed goaf,determines the main and secondary sources of underground CO,and discusses the influence of geological and engineering factors on CO concentration overrun.The results show that there is a good negative correlation between CO and O₂ concentration in statistical gas samples.CO concentration overrun mainly occurs in the upper corner of mining face,supports,closed goaf and other places with poor ventilation conditions.CO mainly comes from coal mining oxidation spontaneous combustion and there is secondary CO in coal seam naturally oxidized locally.The geological reasons of CO concentration overrun are shallow buried coal seam,development of reverse fault and low coal metamorphism degree;the engineering reasons of CO concentration overrun are too long working face length and unreasonable ventilation mode.Under the synergetic action of geological and engineering factors,the mining oxidized CO and natural oxidized CO emission superimposed,and accumulated in the position of low air flow velocity,resulting in underground CO concentration exceeding the limit.