Coal seam group with high gas content pressure relief and co-mining method based on gob-side entry retaining of working face of first mining total rock pressure relief

• Main Authors: WANG LEI, QIAO SHUN, ZHANG NONG, YANG LIN, WU PENGQI, ZHAO YIMING
• Format: Patent
• Language: English
• Published: 17.06.2015
• Subjects: EARTH DRILLING; EARTH DRILLING, e.g. DEEP DRILLING; FIXED CONSTRUCTIONS; MINING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR ASLURRY OF MINERALS FROM WELLS; SAFETY DEVICES, TRANSPORT, FILLING-UP, RESCUE, VENTILATION, ORDRAINING IN OR OF MINES OR TUNNELS

The invention discloses a coal seam group with high gas content pressure relief and co-mining method based on gob-side entry retaining of a working face of first mining total rock pressure relief. When a first mining pressure relief coal seam can not be selected, the coal and rock seams are moved and broken through the working face of first mining total rock pressure relief, an upper covered coal seam with high gas and a lower covered coal seam which high gas are subjected to pressure relief and swollen, fractures of a surrounding rock mass are developed, the gas permeability is increased, the gas is subjected to desorption and transportation, and finally a top plate pressure relief annular fracture area and a bottom plate pressure relief annular fracture area are generated. To create a favorable stress environment of retained roadway surrounding rock, retained roadway mining empty side cantilever crest truncation is conducted to first advance mining drill site toward and backward the working face in a bi-directional mode, according to the top plate lithologic characters, the first advance is subjected to top plate deep hole pre-splitting and cover caving so that it is guaranteed that the top plate is sufficiently collapsed to fill a worked out section. By means of the method, the prominent problems of exhausting and mining of coal seam group pressure relief gas and safe mining when the first mining pressure relief coal seam of the coal seam group with high gas content is difficult to select are solved.