Study On Safe And Effective Backfill Technology For Steeply Dipping Seam Mining

Surface of the Third mining District of Shandong Huatai Mining Co., Ltd. is villages and farmland, the north-south railway line and east-west Ma Lai highway cross here, it's a typical "three under" resource(under the building, under the railway/Highway, under the water body). To solve the problem of coal gangue accumulation and the backfill work face of steeply dipping seam difficult to block for the Huatai Mining Co., Ltd. this paper studied the key technologies to filling with coal gangue and optimization of the measures to block the backfill work face comprehensively, in which theoretical analysis, laboratory test, program design, analysis and numerical simulation of large software systems by means of comprehensive evaluation techniques were used. Proposed the process of gangue hollow wall technology.The main contents and conclusions of this paper are summarized as follows:(1) Fully understand the geology of mining engineering through field investigation and testing, proposed paste-like backfill approaches according to the scope needs to fill and filling mining methods.(2) Analysis of physical and chemical properties of filling material resulted to an best slurry filling ratio. The low bleeding rate(less than 4%) of mixed slurry of coal gangue and powder coal is conducive to shorten the initial setting time, and reduce water leakage. Strength of coarse coal gangue paste-like backfill is better than fine coal gangue paste-like backfill used in the original experiment; Slag and coarse coal gangue paste-like backfill is similar in composition, which may contain glassy active ingredients, as long as we can solve the problem of fragmentation cost, coal slag is a good alternative of coal gangue.(3) Analyzed the adaptability of the filling process by numerical simulation software. According to different wall width and work face there are totally 9 programs. The results show that arranged work face along the strike would leading to too much pressure, and can not guarantee safety.(4) Designed a layout along the tendency, and proposed coal mining process of filling, roof management and filling technology. Analyzed the stability of roof under three filling height by numerical analysis software(5) Based on Fuzzy Comprehensive Evaluation and Data Envelopment analysis, using FAHP-DEA model which combined by analytic hierarchy process (AHP), Fuzzy evaluation and Data Envelopment(DEA) to determine the best mining and filling relationships and the corresponding wall charge build process.