Fully mechanized coal mining technology for thin coal seam under complicated geological conditions

In view of the present situations and existing problems of thin coal seam mining under complex geological conditions, low-profile mining equipment for fully mechanized coal mining was developed. This paper presents the study on the development of the equipment. The low-profile mining machinery includes the shearer, the scraper conveyer, the hydraulic powered supports and others. A highly efficient cutting system with a high-power mechanical drive was utilized to improve the rock breaking capacity. The ultrahigh-temperature laser cladding technology was applied in the cutting equipment for wear-resisting sparkless coal and rocks excavating, suitable for highly gassy mines. The lead-angle friction theory and the side-pushing principle of angled panel forward movement were applied in the development of the moldboard coal-loading equipment. This development successfully achieved a coal-loading rate of over 98% and ensured smooth movement of the scrapper. Automation was implemented with electro-hydraulic technology and shearer remote control technology in main coal mining operations such as the movement of hydraulic support and conveyor. The automation enabled fast mining operations following the rapid movement of the cutting machinery. Furthermore, advanced computer simulations and optimizations were conducted to achieve optimal structural designs of the hydraulic powered supports. With the above development of low-profile mining equipment, fully mechanized mining of thin coal seams under the complex geological conditions was achieved. The development equipment has great potential to be widely applied in coal mines with similar conditions.