Underground Mining Flashcards
These methods are used to extract mineral deposits that are roughly tabular (could also be flat or steeply dipping) and are associated with strong ore and surrounding rock.
Unsupported Methods
It is used primarily for flat-lying seams or bedded deposits where the support of the roof is provided by natural pillars of the mineral where it is left standing in a systematic (checkerboard) pattern.
Room-and-Pillar Mining
It is similar to room-and-pillar but used in non-coal deposits that are thicker and ore irregular. The pillars are spaced randomly and located in low-grade ore so that the high grade can be extracted.
Stope-and-Pillar Mining
It is where mining progresses upward with horizontal slices of ore are being blasted along the length of the slope.
Shrinkage Stoping
This provides sublevels from which vertical slices are blasted. The stope is mined horizontally from one end to the other.
Sublevel Stoping
This group of methods is used used in weak wall rock structure.
Supported Methods
It is used in steeply dipping deposits which is performed both overhand and underhand directions. As each horizontal slice is taken, the voids are filled with a variety of fill types to support the walls.
Cut-and-Fill Stoping
It involves backfilling mine voids but rely on timber sets as support. The usage of this method is in decline due to its high relative cost and labor.
Square-set Stoping
It is one of the methods that can be applied to steeply dipping ore bodies and uses artificial pillars of waste with timber or rock bolts to support the roof.
Stull Stoping
These methods allows the caving of the ore and/or overlying rock where subsidence normally occurs afterward.
Caving Methods
It is well adapted to horizontal seams such as coal. In this method, a face of considerable length is maintained and as mining progresses, the overlying strata are caved thus promoting breakage of coal itself.
Longwall Mining
It is employed in dipping tabular or massive deposit. As mining progresses downward, each new level is caved into the mine openings with the ore being recovered while the rock remains behind.
Sublevel Caving
A large-scale, highly productive, and low in cost which is used in massive deposits that are weak-moderately strong ore that readily break up when caved.
Block Caving
Unlike surface mining methods, underground methods are far more concerned on:
(1) Ore Deposit Strength
(2) Wall Rock Qualities
(3) Groundwater
(4) Mine Ventilation as an addition to challenges in the development stage.
The roof, top, or overlying surface of an underground excavation
Roof/ Back
The floor or underlying surface of an underground excavation
Bottom/ Floor
It refers to the waste material overlying the mineral deposit.
Capping
The broken, caved, and mined-out portion of the deposit
Gob
The unmined portions of the deposit to provide support to the roof/ hanging wall.
Pillar
A type of pillar designed to withstand major loads
Barrier Pillar
A portion of the deposit overlying an excavation and left in place as a pillar
Crown Pillar
The side wall of an excavation
Rib/ Rib Pillar
A portion of the deposit underlying an excavation and left in place as a pillar
Sill Pillar
It is designed to wield but not fail under loads.
Yield Pillar
A main horizontal or near-horizontal underground opening with single access to the surface.
Adit
A primary or secondary horizontal or near-horizontal opening; oriented parallel to the strike of a pitching deposit.
Drift
An opening or connection to the surface from an underground excavation.
Portal
A primary vertical or near-vertical opening, connecting the surface with underground workings.
(Vertical) Shaft
A primary inclined opening usually a shaft connecting the surface with underground workings
Slope
A main horizontal or near-horizontal opening, with access to the surface at both ends.
Tunnel
A secondary inclined opening driven upward to connect levels, sometimes on the dip of the deposit.
Incline/ Inclined Shaft
A secondary inclined opening, driven downward to connect levels, sometimes on the dip of a deposit.
Decline
A secondary horizontal or near-horizontal opening usually driven in multiples.
Entry
A secondary or tertiary horizontal opening, often parallel or at an angle to a haulageway, usually to provide ventilation or some auxiliary service
Lateral
A system of horizontal openings connected to a shaft; constitutes an operating horizon of a mine.
Level
A secondary or tertiary vertical or near-vertical opening driven upward from one level to another.
Raise
A vertical or near-vertical opening used to transfer bulk material from a stope to a drawpoint; often an interconnected set of raises.
Finger Raise
A compartment of a raise or a vertical or near-vertical opening intended for personnel travel between two levels.
Manway
A secondary or tertiary inclined opening, driven to connected levels, usually in a downward direction and used for haulage.
Ramp
A secondary or tertiary vertical or near-vertical opening driven downward from one level to another.
Winze
A tertiary horizontal opening, often connecting drifts, entries, or rooms, oriented perpendicularly to the strike of a pitching deposit.
Crosscut
A horizontal opening used for materials handling.
Haulageway
A funnel-shaped excavation formed at the top of the raise to move bulk material by gravity from a stope to a drawpoint.
Bell
A lateral intended for exhaust ventilation
Bleeder (Shaft)
A loading point beneath a stope, utilizing gravity to move bulk material downward and into a conveyance, by a chute or loading machine.
Drawpoint/ Boxhole
An opening from a drawpoint, utilizing gravity flow to direct bulk material from a bell or orepass to hold a conveyance.
Chute
A coarse screening or scalping device that prevents oversized bulk material from entering a materials transfer system; constructed of rails, bars, beams, etc.
Grizzly
The transfer point at a shaft where bulk material is loaded by bin, hopper, and chute into a skip.
Loading Pocket
A horizontal exploitation opening several hundred meters in length usually in a tabular deposit.
Longwall
A vertical or near-vertical opening through which bulk material flows by gravity.
Orepass
A horizontal exploitation opening for bedded deposits.
Room
A large exploitation opening, usually inclined, vertical, or horizontal where mucking takes place.
Stope
A narrow vertical or inclined opening excavated in a deposit at the end of a stope to provide a bench face.
Slot
A secondary or intermediate level between main levels or horizons, usually close to the exploitation area.
Sublevel
A location in the materials-handling system, either haulage or hoisting where bulk material is transferred between conveyances.
Transfer Point
A low horizontal opening excavated under a portion of a deposit usually a stope to induce breakage and caving of the deposit.
Undercut
The advancing in a near-horizontal direction; also the working face of an opening.
Breast
Advancing in an upward direction
Overhand
Advancing in a downward direction.
Underhand
The direction toward the working face, away from the mine entrance
Inby
The direction away from the working face, toward the entrance.
Outby
The country rock boundary adjacent to a deposit.
Wall Rock
