倾斜特厚煤层工作面初次放顶方案设计

Design of initial caving scheme for inclined extra-thick coal seam working face

针对新疆宽沟煤矿B2煤层I010203工作面顶板坚硬、放煤率低的问题,以I010203工作面实际(煤)岩层特征为基础,分别从煤层强度、赋存深度、煤层完整性、煤层结构、B2煤层直接顶的岩性与厚度、开采工艺参数方面对顶煤冒放性进行了分析。基于岩层垮落充填高度计算公式,确定了顶板处理的有效高度;同时揭示了I010203工作面切巷处拉槽弱化顶板后,关键层结构由“固支梁”转为“悬臂梁”的力学机制;在优化顶板爆破参数与初次切顶炮孔参数的基础上,通过在I010203工作面初放步距的35 m区域内,实施切巷处超前预裂方式处理顶板,并给出了施工工序和爆破工序,最终在宽沟煤矿实现了良好的放煤效果。该方案设计可为类似矿井提高煤炭资源回收率、为实现矿井安全、高效生产提供一定的参考。

Aiming at the problems of hard roof and low recovery rate of top coal in No.I010203 working face of B2 coal seam in Kuangou coal mine of Xinjiang,based on the actual coal-strata characteristics of No.I010203 working face,the top-coal caving characteristics are analyzed from the aspects of coal seam strength,buried depth,coal seam integrity,coal seam structure,lithology and thickness of coal seam direct roof,and mining process parameters.Based on the calculation formula of filling height of caving strata,the effective height of roof treatment is determined,and the mechanism of key layer structure changing from“fixed beam”to“cantilever beam”is revealed after the roof is weakened by slotting in No.I010203 working face.On the basis of optimizing the parameters of roof blasting and blast hole layout,construction process and blasting process,by using advanced presplitting method to deal with the roof within 35 m of the initial caving distance of No.I010203 working face,good top-coal caving effect is achieved in Kuangou coal mine,which can provide certain reference for similar mines to improve the recovery rate of coal resources and realize mine safety and efficient production.