METHOD OF BOREHOLE MINING OF COAL Russian patent published in 2001 - IPC

FIELD: mining industry. SUBSTANCE: method includes drilling of at least two boreholes, creation of underground gas generator by formation of connecting channel between boreholes, ignition of coal in channel and gasification of coal mass with supply of blast to underground gas generator through one of boreholes and withdrawal of formed gas through other borehole. Formed round bottom part of boreholes by means of hydraulic giant unit are cavities. The process is continued up to beginning of self-caving of coal mass separating one cavity from other one. Then hydraulic extraction of coal is discontinued, water is pumped out and thermal preparation of coal mass accommodating gasification boreholes is begun. Supplied to cavity is gas with temperature of 350-400 C and after heating of coal mass to this temperature, supply of gas to one of boreholes is discontinued and at the same time, gas pressure in other borehole is raised up to breaking through of gases from one cavity to the other. Then supply of oxygen blast is begun, and gases - products of gasification are withdrawn from the other borehole. EFFECT: simplified operations for connection of formed cavities, and withdrawal of coal reserves with design sizes of cavity of underground generator at moment of begging of gasification process. 6 cl, 3 dwg