浅埋双硬特厚煤层放煤规律分析及参数研究

Analysis of coal drawing law and parameter research in shallow buried double hard and extra-thick coal seam

  • 摘要: 新疆地区煤炭资源埋藏较浅、煤层较厚、煤层与顶板坚硬而导致顶煤冒放性较差,无法实现安全高效放顶煤开采,并且目前针对浅埋双硬特厚煤层综放工作面高效放煤的相关研究较少。针对上述问题,以榆树岭煤矿110501综放工作面为工程背景,对浅埋双硬特厚煤层放煤规律进行研究,从而确定合理的采放比及放煤工艺,提高采出率。采用FLAC3D软件分析了综放工作面回采过程中煤岩破坏规律,以设计合理采放比。结果如下:① 随着工作面采高不断增大,顶煤及煤帮的屈服破坏系数不断增大,且工作面煤帮超前支承应力峰值和影响区域逐渐增大。② 综合考虑顶煤、煤帮的稳定性和冒放性,设计采高为4.0 m,放顶煤高度为4.6 m,采放比为1∶1.15。利用PFC2D软件分析了综放工作面顶煤冒放规律,以设计合理放煤工艺(包括放煤步距和放煤方式)。结果如下:① "一采一放"含矸率比"两采一放""三采一放"高,但由于放煤步距较小,整体放出率高于"两采一放""三采一放",因此选用"一采一放"的放煤步距。② 单轮放煤相比于2轮放煤,放煤速度高,但含矸率较大,放出率较小;2轮间隔放煤与2轮顺序放煤相比,放出率较高,因此选择2轮间隔放煤方式。将设计的采放比和放煤工艺应用于110501综放工作面工程实践,结果表明:该工作面顶煤放出率为82%~87%,平均放出率大于82%,放煤效果较好。

     

    Abstract: The coal resources in Xinjiang are shallowly buried, the coal seam is thick, resulting in poor top coal caving and drawing. And the roof is overhanging in a large area, which makes it impossible to achieve safe and efficient top coal mining. And at present, there are few related researches on efficient coal drawing in fully mechanized working face of shallow buried double hard and extra thick coal seam. In order to solve the above problems, taking 110501 fully mechanized working face of Yushuling Coal Mine as engineering background, the paper studies the coal drawing law of shallow buried double hard and extra thick coal seam, so as to determine reasonable mining-drawing rate and coal drawing technology, and improve the recovery rate. FLAC3D software is used to analyze the coal and rock failure law in the mining process of fully mechanized working face, so as to design reasonable mining-drawing ratio. The results are listed as follows. ① With the increase of the mining height of the working face, the yield failure coefficient of the top coal and the coal wall continues to increase, and the maximum value of the advance support stress and the affected area of the coal wall on the working face gradually increase. ② Considering the stability and caving and drawing of top coal and coal wall, the designed mining height is 4.0 m, the top coal drawing height is 4.6 m, and the mining-drawing ratio is 1∶1.15. The top coal drawing law of fully mechanized working face is analyzed by using PFC2D software, so as to design reasonable coal drawing technology (including the design of coal drawing step distance and coal drawing mode). The results are listed as follows. ① The gangue content of ‘one coal mining and one top coal drawing’ is higher than that of ‘two coal mining and one top coal drawing’ and ‘three coal mining and one top coal drawing’, but the overall drawing rate is higher than that of ‘two coal mining and one top coal drawing’ and ‘three coal mining and one top coal drawing’ due to the small coal drawing step distance. Therefore, the coal drawing step distance of ‘one coal mining and one top drawing’ is selected. ② Compared with two rounds coal drawing, single round coal drawing has higher coal drawing speed, but gangue content is higher and coal drawing rate is lower. Compared with two rounds sequential coal drawing, the two rounds interval coal drawing has a higher drawing rate. Therefore, the tow rounds interval coal drawing method is selected. The designed mining drawing rate and coal drawing process are applied to the engineering practice of 110501 fully mechanized working face, the results show that the top coal drawing rate of this working face is 82%-87%, the average drawing rate is higher than 82%, and the coal drawing effect is good.

     

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