| 摘要 |
A method of mining a large underground seam of mineral such as coal is described in which a first cylindrical shaft is drilled from the surface of the earth down to the mineral seam. A portion is enlarged at the base of the first shaft as a work room. A first radial shaft out to a selected radius R is drilled by conventional methods with the roofs supported by means such as hydraulic chocks which can be extended and moved selectively as the line of drilling progresses. When the first shaft is drilled a continuous miner working on a short face method of mining is directed radially from the work room and is advanced outwardly until the width of the first radial shaft is such that the original wall of the first shaft has been cut away. The direction of the miner is then turned to be parallel to the first horizontal shaft and a short wall cutting advance is made to cut away the first wall of the first shaft and in effect drill a second shaft having a first wall spaced by the width of the cutter. A continuous flexible curtain is provided between the floor and roof on the back side of the chocks so that fresh air can be brought down through the vertical shaft and radially outward toward the working face and back on the outside of the flexible curtain toward the working room and up to the surface in a second vertical slope shaft. |
