Current situation and development of intelligent mining technology for thin coal seams

Thin coal seams account for 20% of China’s total coal reserves.Due to restricting by special conditions,such as narrow mining space,thin coal seam has poor mining efficiency and low intelligent level, thin coal seams output accounts for only 10% of total coal production. Based on the diverse conditions of thin coal seams and the different mining needs to increase the unit production, pressure relief effect and production rate of the working face, the technical requirements for thin seam mining are divided into three categories: longwall intelligent comprehensive mining of thin seams, and protection of thin seams intelligent mining and thin coal seam high recovery rate mining technology. The status quo of research on mining design of thin coal seam mines, longwall comprehensive mining equipment, intelligent mining technology, semi-coal rock roadway mining and ultra-thin coal seam mining technology is systematically analyzed, and the research progress of three types of thin coal seam mining technology is introduced in detail,specifically includes: ①In terms of intelligent long-wall fully-mechanized mining face, a three-dimensional design method for enlarging the size of the mining area (face) and reducing the mining height is proposed, and the auxiliary decision-making expert system such as the thin coal seam mining method and equipment supporting was developed,a high-power, short-body semi-coal rock rapid heading machine and its supporting equipment , short-type ultra-long fully-mechanized mining face complete equipment and “accurate detection of preset coal cutting trajectories based on coal seam conditions + three-machine cooperative control + video monitoring” intelligent mining technology were developed;② In the intelligent mining of high gas and thin coal seam protective layers, the stress-damage-seepage coupling mechanism of pressure relief mining was revealed,and the method to determine the reasonable parameters of the ultimate pressure relief thickness of the longwall and the pressure relief and permeability enhancement of the drilling and production surface is put forward.A method for determining reasonable parameters of pressure relief and permeability enhancement in coal mining face and intelligent coal cutting technology based on gas concentration regulation were researched;③ In terms of improving thin coal seam recovery rate, longwall fully-mechanized mining technology for ultra-thin coal seams and five-bit automatic drill-changing auger coal mining machine and the technology to keep lanes along thin seams in different conditions have been developed. The research direction of thin coal seam intelligent mining technology is improving the adaptability and its control accuracy of thin coal seam mining equipment, and building the theory and technology of the integration of intelligent mining and disaster prevention and control.