煤炭工程 ›› 2024, Vol. 56 ›› Issue (4): 67-72.doi: 10.11799/ce202404010

• 生产技术 • 上一篇    下一篇

近距离煤层上部工作面煤柱破坏及氧化特性研究

付文刚,关洪峰,石勇,杨佳龙   

  1. 1.朔州茂华白芦煤业有限公司,山西 朔州 036000 2.山东科技大学 安全与环境工程学院,山东 青岛 266590
  • 收稿日期:2023-09-22 修回日期:2024-02-24 出版日期:2023-04-20 发布日期:2024-12-09
  • 通讯作者: 付文刚 E-mail:1832410853@qq.com

Damage and oxidation characteristics of coal pillar in upper working face of contiguous coal seams

  • Received:2023-09-22 Revised:2024-02-24 Online:2023-04-20 Published:2024-12-09

摘要:

为研究近距离煤层开采对上部工作面煤柱破坏及氧化特性的影响,以白芦煤矿74201工作面为研究背景,基于数值模拟、实验研究等手段分析近距离煤层下部工作面开采对上部煤层煤柱塑性区域分布及氧化特性的影响。FLAC3D模拟结果表明,随4-2煤层推进,上部煤层煤柱破坏变形特征近似分为三个阶段:煤柱完整;煤柱变形破损,但保持基本连续性;煤柱大范围剪切破坏,煤柱破碎。程序升温实验表明,已发生一定破碎的煤柱,其二次氧化过程中COC2H4临界温度点均提前10~20℃,耗氧速率最高增2573.1×10-11mol/cm-3·s);完好煤柱未检测到C2H24-1碎裂煤柱及4-1破碎煤柱分别在250℃240℃检测到C2H2气体,分析得出煤柱破碎过程对煤二次氧化进程具有一定的促进作用,破碎煤柱相对于完好煤柱更易发生自燃反应。本研究得出了上部煤层破碎失稳煤柱自然发火危险性随着下部煤层回采进行不断增大的结论。

关键词: 煤自燃 , 近距离煤层 , 煤柱破碎 , 二次氧化

Abstract:

In order to study the influence of short-distance coal seam mining on the damage and oxidation characteristics of coal pillars in the upper working face, taking the 74201 working face in Bailu Coal Mine as the research background, based on numerical simulation and experimental research, the influence of short-distance coal seam mining on the plastic regional distribution and oxidation characteristics of coal pillars in the upper working face was analyzed. FLAD3D simulation results show that with the advance of 4-2 coal seam, the failure and deformation characteristics of coal pillars in the upper coal seam are approximately divided into three stages: the coal pillars are complete; The coal pillar is deformed and damaged, but it maintains basic continuity; The coal pillar is sheared and broken in a large range. The temperature programmed experiment shows that the critical temperature points of CO and C2H4 are advanced by 10~20℃ in the secondary oxidation process of coal pillars that have been oxidized to a certain extent, and the oxygen consumption rate increases by 2573.1×10-11 mol/(cm-3 s) at the highest. C2H2 was not detected in the intact coal pillar, C2H2 gas was detected in the 4-1 fractured coal pillar and 4-1 fractured coal pillar at 250℃ and 240℃ respectively, which proved that it entered the stage of violent oxidation. It was concluded that the coal pillar crushing process promoted the secondary oxidation process of coal to some extent, and the fractured coal pillar was more prone to spontaneous combustion than the intact coal pillar. This study draws the conclusion that the spontaneous combustion risk of broken and unstable coal pillars in upper coal seam increases with the mining in lower coal seam.

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