Mining engineering, like all scientific disciplines, has its own specialized terminology. Underground mining, in particular, involves a wide range of technical terms that are essential for accurately describing its methods, structures, and processes. To enhance understanding of topics related to the mining industry, especially those concerning underground operations, some of the most commonly used terms are presented below.
Adit: a horizontal or nearly horizontal passage driven from the surface for the working or dewatering of a mine. If an adit is driven through the hill or mountain to the surface on the opposite side, it is called a tunnel.
Chute: opening, usually constructed of timber and equipped with a gate, through which ore is drawn from a stope into mine cars.
Drift: a horizontal underground opening that follows along the length of a vein or rock formation as opposed to a crosscut, which crosses the rock formation.
Incline: any entry to a mine that is not vertical (shaft) or horizontal (adit). Often incline is reserved for those entries that are too steep for a belt conveyor (+17 degrees to -18 degrees), in which case a hoist and guide rails are employed. A belt conveyor incline is termed a slope. Alt: Secondary inclined opening, driven upward to connect levels, sometimes on the dip of a deposit; also called “inclined shaft”.
Roof bolt: a long steel bolt driven into the roof of underground excavations to support the roof, preventing and limiting the extent of roof falls. The unit consists of the bolt (up to 4 feet long), steel plate, expansion shell, and pal nut. The use of roof bolts eliminates the need for timbering by fastening together, or “laminating,” several weaker layers of roof strata to build a “beam.”
Room and Pillar: a form of underground mining in which typically more than half of the ore is left in the mine as pillars to support the roof. Room and pillar mines are generally not expected to subside, except where retreat mining is practiced. The mining method is used for thick and/or flat-lying industrial, metal, and nonmetal mineral deposits, such as coal, limestone, trona, and salt.
Shaft: a vertical or inclined excavation in rock for the purpose of providing access to an orebody. Usually equipped with a hoist at the top, which lowers and raises a conveyance for handling workers and materials.
Slope: a belt conveyor incline. (Note: Defined under “Incline” as a specific type.)
Stope: an excavation in a mine from which ore is, or has been, extracted.
Vein: a fissure, fault, or crack in a rock filled by minerals that have travelled upwards from some deep source.
Vug: a small cavity in a rock, frequently lined with well-formed crystals. Amethyst commonly forms in these cavities.
