Short-wall interval gangue filling mining technology in Yuecheng Coal Mine

In order to tackle the challenges of coal resource mining beneath the industrial square and villages in Yuecheng Coal Mine, as well as gangue disposal, the mine plans to adopt a short-wall interval paste filling mining technology system. By constructing a phased mining model of "mining one and retaining two" and employing an interval filling process with skip mining, the working face is divided into composite units of 5m branch roadways and 10 m coal pillars, forming a three-phase alternating advancement system for simultaneous mining and filling. Research indicates that the paste mix (cementitious material 200 kg/m³, fly ash 350 kg/m³, gangue 1250 kg/m³) achieves a 28-day strength of ≥3.5 MPa and an active roof-contact expansion rate of 5%～10%. The collaborative filling process with dual discharge outlets ensures a roof-contact rate exceeding 95%, reducing the mining-filling cycle to 7 days per coal pillar. The predicted maximum surface subsidence is 135 mm, with horizontal deformation of 0.30 mm/m, both below the Grade I damage threshold for buildings (structures). Engineering applications demonstrate that this technology processes 900,000 tons of gangue annually, releases 593,000 tons of trapped coal, and generates comprehensive benefits of 153 million yuan.