厚煤层巷内预置充填带无煤柱开采技术

 为减少厚煤层开采的区段煤柱损失，提出巷内预置充填带无煤柱开采技术，即在上区段回采工作面前方的运输平巷内，紧靠下一区段的巷帮煤壁，预置一条矸石混凝土巷内充填带，下区段回风平巷掘进时，沿预置的充填带进行掘进，实现厚煤层工作面无煤柱开采，用预置充填带把上下2个区段间应留设的区段煤柱置换出来。若上区段运输平巷为普通断面，如要实施此项新技术，首先，对上区段运输平巷靠近下区段工作面侧的煤壁，实施扩帮和支护；然后，在工作面前方扩帮位置处紧靠煤壁实施充填，预置巷内充填带。此项技术的关键是巷内充填材料的选择与配比，在保证充填体和巷道围岩稳定性的前提下，要尽可能减小充填体的宽度。充填材料选用的是以矸石渣为主辅以少量水泥、河沙加水混合而成的胶结体，水泥、河沙、矸石渣按1∶1∶4.7质量比例进行配比。现场工业性试验表明，该项技术的应用是成功而有效的，可实现厚煤层无煤柱开采，提高煤炭资源采出率，该成果已取得明显的经济效益。

MINING TECHNIQUE WITH PRESET PACKING BODY IN ROADWAY FOR THICK COAL SEAM WITHOUT COAL PILLARS

To decrease the loss of coal pillar for thick coal seam,a new technique with preset packing body for thick coal seam without coal pillars is put forward based on the analysis of reasonable model of surrounding rock structure. The actual steps for mining are:(1) the entry-in packing should be preset ahead of the coalface,which is nearby the coal wall of the next coalface;and (2) the gob-side entry of the next coalface is driven along the packing body without coal pillars. If the new technique is applied for an old entry,which is excavated with normal cross-sections,the coal wall of the next coalface should be enlarged and supported also by cablet ahead of the coalface. The key technique is the materials chosen and their mixture ratios of the packing body to guarantee the stability of packing body,and also the entry surrounding rock under the premise of minimizing the width of packing body. The selected filling material is mainly supported by a small amount of waste rock slag cement,sand cement mixture of water body,cement,sand,slag waste rock according to the weight in proportion to the ratio 1:1:4.7. The results of industrial test and field measurement show that the technique is successful;and it can be applied to thick coal seam with similar conditions. Meantime,it can enhance the recovery rate of coal resources and the economic efficiency.