| 摘要 |
<p>An improved open-pit mining method provides one or more working faces for breaking out the minerals and rock, the face advancing either horizontally or along a helical spiral path. A turning point area is provided, usually at the center of the open pit where the faces extend radially from the turning point, enabling crushing equipment adjacent the benches to feed a belt conveyor system by which crushed mined mineral is conveyed directly to the turning point area. The turning point area communicates with a shaft down which the conveyed mined mineral materials are discharged. The turning point area is mined in any way that keeps the floor horizontal, and such floor is maintained deeper than the benches. A plurality of downwardly-directed shafts may be provided for receiving different grades or qualities of mined mineral.</p> |
