A Fully Mechanized Mining Method for Top Layer of Ultra-thick Coal Seam Without False Roof in Shallow Buried Depth

Based on the conditions of shallow buried depth, lower layer mining without false roof in composite zone of No.12 coal in Shendong Mining Area Huojitu Coal Mine, combined with the existing mining technology level, through theoretical calculation and analysis, it is feasible to adopt fully mechanized mining. Then the first working face recovery is used as an example to verify the practice. Through comprehensive analysis of caving, recovery rate and economic benefit of top coal, fully mechanized caving mining is suitable for lower layer mining in No.12 coal.