| 摘要 |
<p>The process is for mining a subterranean mineral seam, for complete removal of the mineral over a selected circular area, and for minimum distance of transport of supplies and product. A large dia. central vertical or slope shaft is drilled at a selected point on the surface of the earth, down to the selected seam of the mineral. The shaft is enlarged at its base in the seam to a selected radius to form a workroom. A small dia. central shaft is drilled parallel to the first shaft adjacent the workroom. A radial shaft is drilled in the seam from the workroom, to a selected radius by any conventional method. A second radial shaft is drilled by using a continuous mining method directed radially at a selected angle to the axis of the first radial shaft.</p> |
