壁式连采连充保水采煤技术及实践

Technology and practice of continuous mining and backfilling with wall system for water conservation

针对极薄阻隔层条件下保水采煤难题,提出一种壁式布置、负压通风和全采充填的连采连充保水采煤技术。该技术将壁式体系采煤法和房式连续快速采煤法相融合,建立了“多支巷布置、采充并行”的开采模式,将充填材料密实充入始终受到保护的采场支巷约束空间内,在能满足保护浅表生态水资源或维持含水层稳定性的同时,高效采出极薄阻隔层条件下的煤炭资源。开采块段按正常壁式采煤工作面布置回采巷道,设置2个及以上安全出口,并形成负压通风系统。按照旺格维利式布置采场支巷,对采场支巷进行多阶段间隔开采,块段内始终保持一条或多条采场支巷采煤与充填同时作业的高效开采模式,直至开采并充填完毕所有采场支巷。为了提高采煤效率,研发了高强度、大排距和低成本的大断面采场支巷快速支护技术,研制了以工业固体废渣为基础的多元化高水膨胀充填材料,发明了内置排气管的受约束空间内充填材料主动密实接顶技术,并结合快速采煤与连续运输技术,形成了“采装运支充”一体化高效采煤工艺及作业线。建立了基于壁式连采连充的覆岩变形结构力学模型,得出了包括隔水层在内的采场上覆各岩层变形计算公式,确定了能够保证安全开采的采场支巷最大空巷数目、最大滞后充填距离等关键开采参数。研究成果在煤矿现场进行了工业性试验,实现了极薄阻隔层条件下水资源保护性采煤。

In view of difficult water conservation during mining with extremely thin barrier layer,a continuous mining and backfilling technology for water conservation with wall layout,negative pressure ventilation,and full mining filling was innovated.Wall system coal mining method and chamber continuous rapid coal mining method were integrated to establish the mining mode of“multi-branch roadway layout and backfilling while mining”.The filling material was densely filled into the restricted space of supporting roadways in the stope which was always protected.This method can not only protect the shallow ecological water resources or maintain the stability of the aquifer,but also efficiently extract the coal resources under the condition of extremely thin barrier layer.The mining blocks were arranged as normal wall-type workingface with two or more safety exits and negative pressure ventilation system.The mining roadway was arranged according to Wongawilli mining method,and mining was carried out in multi-interval way.In the stope,the efficient coal mining mode of simultaneous mining and backfilling in one or more mining roadways till the completion of mining and backfilling in the last roadway.In order to improve the coal mining efficiency,a fast support technology with high strength,large row spacing and low cost for large cross-section stope support roadway,a plurality of high-water expansion filling material based on industrial solid waste residue,and a constrained space filling material with built-in exhaust pipe were developed.Combined with rapid coal mining and continuous transportation technology,the integrated and efficient coal mining technology and operation line of“mining,loading,transporting,supporting,and backfilling”was formed.Based on continuous mining and backfilling with wall system,the structural mechanics of rock deformation model was established.The deformation characteristics of overlying strata,including aquicludes were analyzed.Such key mining parameters as the maximum number of not backfilled mining roadways and the maximum delay distance between mining and backfilling were determined.The results have been industrially tested in coal mines,and realized water conservation mining with extremely thin barrier layers.