UG-Mining-Terms.pdf

Underground Mining Terms  Underground Mining - When surface mining is uneconomic due to ↑ stripping ratio - deep and/or steep ore deposit - high enough grades to exceed costs in extraction Categories: Soft Rock vs Hard Rock Mining Methods Selective vs Unselective Mining Methods Unsupport...

Underground Mining Terms  Underground Mining - When surface mining is uneconomic due to ↑ stripping ratio - deep and/or steep ore deposit - high enough grades to exceed costs in extraction Categories: Soft Rock vs Hard Rock Mining Methods Selective vs Unselective Mining Methods Unsupported, Supported and Caving Methods Excavation terms: overhand (downward) and underhand (upward) Underground Mining Openings Primary Secondary Tertiary (main openings) (level/zone openings) (lateral/panel openings) Adit Lateral Portal Decline Raise Shaft Drift Entry Ramp Crosscut Slope Incline Sublevel Tunnel Level Winze Underground Mining: Openings Underground Mining Openings UNDERGOUND MINE ANATOMY OREBODY ACCESS SHAFT Vertical or nearly vertical opening driven from the surface to the deposit. The shaft may be used solely to hoist ore to the surface, provide ventilation, or to transport people and supplies. UNDERGOUND MINE ANATOMY OREBODY ACCESS DECLINE Can take the form of a SLOPE, which is a straight opening driven at an angle, or a RAMP, which is similar to a slope except that it is generally helical in shape. Used primarily for access, to move people, supplies, and ore between levels or to the surface, and it will be sized to accommodate the largest piece of equipment in use. UNDERGOUND MINE ANATOMY OREBODY ACCESS ADIT A horizontal or nearly horizontal passage driven from the surface for the working or dewatering of a mine. If driven through the hill or mountain to the surface on the opposite side, it would be a tunnel. UNDERGOUND MINE ANATOMY OREBODY ACCESS DRIFT Drift is a more general mining term, meaning a near-horizontal passageway in a mine, following the bed (of coal, for instance) or vein of ore. A drift may or may not intersect the ground surface. A drift follows the vein, as distinguished from a crosscut that intersects it, or a level or gallery, which may do either. UNDERGOUND MINE ANATOMY DEPOSIT and SPATIAL TOP Overlying surface of an underground excavation. BOTTOM Floor or underlying surface of an underground excavation. UNDERGOUND MINE ANATOMY DEPOSIT and SPATIAL ROOF Top or overlying surface of an underground excavation. FLOOR Bottom or underlying surface of an underground excavation. BACK Roof, top, or overlying surface of an underground excavation. UNDERGOUND MINE ANATOMY DEPOSIT and SPATIAL COUNTRY ROCK Waste rock adjacent to a mineral deposit; HOST ROCK. WALL ROCK Country rock boundary adjacent to a deposit. FOOTWALL Wall rock under the deposit. HANGING WALL Wall rock above a deposit. UNDERGOUND MINE ANATOMY DEPOSIT and SPATIAL DIP Angle of inclination of a deposit, measured from the horizontal; also pitch or attitude. STRIKE Horizontal bearing of a tabular deposit at its surface intersection. UNDERGOUND MINE ANATOMY DEPOSIT and SPATIAL PILLAR Unmined portion of the deposit, providing support to the roof or hanging wall. CROWN PILLAR Portion of the deposit overlying an excavation and left in place as a pillar. SILL PILLAR Portion of the deposit underlying an excavation and left in place as a pillar. UNDERGOUND MINE ANATOMY DEPOSIT and SPATIAL BARRIER PILLAR pillar designed to withstand major loads. YIELD PILLAR pillar designed to yield, but not fail under heavy loads. UNDERGOUND MINE ANATOMY DEPOSIT and SPATIAL CAPPING Waste rock overlying the mineral deposit. RIB Side wall of an excavation. GOB Broken, caved, and mined- out portion of the deposit; or in some parts of the world, the GOAF. UNDERGOUND MINE ANATOMY DIRECTIONAL BREAST Advancing in a near-horizontal direction, also the working face of an opening. INBY Toward the working face, away from the mine entrance. OUTBY Away from the working face, toward the entrance. OVERHAND Advancing in an upward direction. UNDERHAND Advancing in a downward direction. UNDERGOUND MINE ANATOMY EXCAVATION BELL Funnel-shaped excavation formed at the top of a raise to move bulk material by gravity from a stope to a drawpoint. BLEEDER Exhaust ventilation lateral. CHUTE Opening from a drawpoint, utilizing gravity flow to direct bulk material from a bell or orepass to load a conveyance. UNDERGOUND MINE ANATOMY EXCAVATION CROSSCUT Tertiary horizontal opening, often connecting drifts, entries, or rooms; oriented perpendicularly to the strike of a pitching deposit; also BREAKTHROUGH. DRAWPOINT Loading point beneath a stope, utilizing gravity to move bulk material downward and into a conveyance, by a chute or loading machine; also BOXHOLE. DRIFT Primary or secondary horizontal or near-horizontal opening; oriented parallel to the strike of a pitching deposit. UNDERGOUND MINE ANATOMY EXCAVATION ENTRY Secondary horizontal or near- horizontal opening; usually driven in multiples. FINGER RAISE Vertical or near-vertical opening used to transfer bulk material from a stope to a drawpoint; often an interconnected set of raises. HAULAGEWAY Horizontal opening used primarily for materials handling. UNDERGOUND MINE ANATOMY EXCAVATION LATERAL Secondary or tertiary horizontal opening, often parallel or at an angle to a haulageway, usually to provide ventilation or some auxiliary service. LEVEL System of horizontal openings connected to a shaft; constitutes an operating horizon of a mine. LOADING POCKET Transfer point at a shaft where bulk material is loaded by bin, hopper, and chute into a skip. UNDERGOUND MINE ANATOMY EXCAVATION MANWAY Compartment of a raise or a vertical or near- vertical opening intended for personnel travel between two levels. OREPASS Vertical or near-vertical opening through which bulk material flows by gravity. PORTAL Opening or connection to the surface from an underground excavation. UNDERGOUND MINE ANATOMY EXCAVATION RAISE Secondary or tertiary vertical or near-vertical opening, driven upward from one level to another. RAMP Secondary or tertiary inclined opening, driven to connect levels, usually in a downward direction, and used for haulage. ROOM Horizontal exploitation opening, usually in a bedded deposit. UNDERGOUND MINE ANATOMY EXCAVATION SLOT Narrow vertical or inclined opening excavated in a deposit at the end of a stope to provide a bench face. STOPE Large exploitation opening, usually inclined or vertical, but may also be horizontal. SUBLEVEL Secondary or intermediate level between main levels or horizons, usually close to the exploitation area. UNDERGOUND MINE ANATOMY EXCAVATION TRANSFER POINT Location in the materials- handling system, either haulage or hoisting, where bulk material is transferred between conveyances. TUNNEL Main horizontal or near- horizontal opening, with access to the surface at both ends. UNDERGOUND MINE ANATOMY EXCAVATION UNDERCUT Low horizontal opening excavated under a portion of a deposit, usually a stope, to induce breakage and caving of the deposit; also a narrow kerf cut in the face of a mineral deposit to facilitate breakage. WINZE Secondary or tertiary vertical or near-vertical opening, driven downward from one level to another.  A steeply dipping sub-bituminous coal seam 1.8 meters thick was followed by a drift at level 900 to a strike length of 200 meters until it was lost by an intrusive formation. The same coal seam was intercepted by a crosscut at level 700 meters and followed it to a length of 200 meters until the same intrusive was reached. Assuming a consistent thickness of coal seam, how much coal reserve is there if the material specific gravity is 1.6? a) 157,632 MT b) 162,940 MT c) 207,455 MT d) 101,894 MT e) 314,675 MT  A steeply dipping sub-bituminous coal seam 1.8 meters thick was followed by a drift at level 900 to a strike length of 200 meters until it was lost by an intrusive formation. The same coal seam was intercepted by a crosscut at level 700 meters and followed it to a length of 200 meters until the same intrusive was reached. Assuming a consistent thickness of coal seam, how much coal reserve is there if the material specific gravity is 1.6?