Research and application on key technologies and equipment for intelligent high-efficiency mining of extremely thin coal seams

Aiming at the challenges associated with 0.7–1.0 m extremely thin coal seam mining in China, including restricted working space, poor equipment adaptability, limited intelligent mining capability, and inadequate resource recovery, this study takes an extremely thin coal seam working face in the eastern Heilongjiang mining area as the engineering background and investigates the key technologies and equipment for intelligent high-efficiency mining. A dynamic updating method for the geological model was developed by integrating geological characteristics with multi-source coal–rock interface sensing information, integrating roadway sketching, borehole detection, in-seam seismic exploration and image recognition data, to realize dynamic updating and transparent display of geological information such as coal seam roof-floor fluctuation and fault structures. On this basis, a full closed-loop intelligent ventilation control system featuring “perception-decision-regulation” was constructed to realize dynamic and precise air volume regulation at the working face, forming a collaborative guarantee technology system integrating geology and ventilation. Targeting the narrow space constraints of extremely thin coal seams, a complete set of mining equipment suitable for extremely thin coal seam conditions was developed, including bridge-type low-profile shearer, hydraulic supports with split elastic connecting top beams, permanent-magnet variable-frequency-drive scraper conveyor and intelligent cable towing device with coal-ploughing float coal cleaning function. Key operating parameters such as drum helix angle and rotation speed were optimized, addressing challenges such as low coal loading efficiency and cable jamming during dragging in extremely thin coal seams. A shearer automatic control system based on a dual-DSP architecture and an electro-hydraulic control system based on CAN/Modbus TCP industrial Ethernet were established, implementing core functions such as shearer memory cutting, automatic hydraulic support following, and coordinated operation of the three machines. In addition, an integrated intelligent mining management and control platform incorporating a transparent geological model and intelligent ventilation control was constructed. An engineering demonstration was carried out at Shuangyang Coal Mine. The field application results show that the demonstration working face realized an intelligent mining mode featuring no personnel following the shearer, on-site patrol inspection, and remote centralized control. The monthly output remained above 30000 tons, the longwall extraction efficiency increased by 300%, the fully mechanized equipment operation rate increased to over 85%, the coal recovery rate exceeded 95%, and the direct production cost per tonne of coal decreased by 32.8%, the electricity consumption per tonne of coal decreased by 15.1%, and the number of underground workers per shift reduced by 67%. The developed replicable and scalable technology and equipment system provides an integrated technical approach for intelligent mining of extremely thin coal seams and offers an engineering reference for the safe and efficient extraction of coal resources under similar geological and mining conditions.