Some considerations in underground mining systems for extra thick coal seams

Some of the important considerations depending on geological and geotechnical conditions that need to be taken in underground mining systems in Thailand for extra thick coal seams are discussed. The LTCC method, which is never tried for extra thick seams, should be used now, allowing for up to an 80% recovery of additional coal that is usually unable to be mined using conventional longwall extraction. The multi-slicing longwall mining method using wire meshes is used as the artificial roof and is placed on the coal floor of the top slice. Hydraulic stowing systems can be used to increase coal recovery and protect surface environment. A more detailed investigation must be done for establishing appropriate mining and stowing systems and the developed system must be cost effective and cost competitive along with keeping the employment in the mine.