含硬煤分层硬煤厚度对顶煤放出率的影响

Hard Coal Thickness of Slice Seam Affected to Top Coal Caving Rate

为研究含硬煤分层顶煤在硬煤厚度不同的条件下的顶煤放出率,采用PFC2D软件建立数值模型的方法,模拟出不同硬煤厚度影响下顶煤的冒放规律,统计出了不同条件下上位顶煤、硬煤分层、下位顶煤的损失率。结果表明:硬煤分层的存在影响顶煤冒放性,随着硬煤分层厚度增加,上位顶煤和硬煤分层的损失率随之增加,对下位顶煤影响程度低;适当调整工作面开采参数和采取煤层注水强制弱化硬煤分层,降低硬煤分层的强度,使顶煤更加破碎,可提高顶煤的回收率。

In order to study the top coal caving rate of the top coal in the slice seam under the dlllerent hard coal thickness condition, a method with a PFC2D software applied to establish a numerical model was applied to simulate the top coal caving law under the different hard coal thickness and the lost rate of the upper top coal, hard slice and bottom top coal under the different conditions were calculated. The results showed that the hard coal slice existed affected to the caving of the top coal. With the thickness of the hard coal slice increased, the lost rate of the upper top coal and the hard coal slice would be increased and there was less influence to the bottom top coal. With a proper adjustment of the mining parameters for the coal mining face and with the water injection of the mining seam to weaken the hard coal slice, the hardness of the hard coal slice was reduced, the top coal could be fully broken and the recovery rate of the top coal could be improved.