Prepared by: Dr.. Ashok Jaiswal Dr
SYLLABUS Introduction to Surface and Underground Mining Terms Terms (AJ + SKS) Definition of common mining terms. Overview of unit operations in surface and underground mines. Explosives (SKS) Types of explosives and blasting agents. Detonators, fuses, delays and other accessories. Stemming materials. Testing of explosives. Storage and transport of explosives. Causes of accidents and safety precautions. Substitute of explosives. Types of Support (AJ) Prop, bar, cog, friction and hydraulic prop, girder. Mine Entries (AJ) Choice, location and size of mine entries. Shafts, inclines and adits – merits and demerits, applicability applicabili ty.. Cross-measure drifts and laterals. Sinking (SKS) Conventional methods of shaft sinking. Drilling, blasting, loading and hoisting of muck. Lining, ventilation, ventilation, drainage drainage and lighting. lighting. Sinking through through loose, loose, fractured, fractured, flowing and and water water bearing bearing ground. Widening and deepening of shafts. Shaft boring. Primary and Secondary Development Drivages in Underground Mines (AJ) Drivage of drifts and main development headings. Conventional methods. Drilling, blasting, loading and transport of muck. Support, ventilation, drainage and lighting. Special methods through loose, fractured, flowing and water bearing ground. High speed drivages.
QUESTION PAPER STYLE FOR END SEM. Unit – 1 (Compulsory) Any short questions from from syllabus syllabus (5 Marks) Introduction to Surface and Underground Mining Terms (5 Marks) Unit -2 (Any one out of two) Explosives Unit – 3 (Any one out of two) Mine Entries Types of Support
Unit -4 (Any one out of two) two) Sinking Unit -5 (Any one out of two) Primary and Secondary Development Drivages in Underground Mines
MINE DEVELOPMENT
Lecture – 1
MINING TERMINOLOGIES Ore: The naturally occurring material from which a mineral or minerals of economic value can be extracted profitably or to satisfy social or political objectives. The term is generally but not always used to refer to metalliferous material, and is often modified by the names of the valuable constituent; e.g., iron ore.; ore mineral. Name of the Ore Iron Copper Aluminum Lead-zinc Uranium
Name of the Mine
location
MINING TERMINOLOGIES Mineral: A naturally occurring inorganic element or compound having an orderly internal structure and characteristic chemical composition, crystal form, and physical properties. Metal Iron Copper Aluminum Lead-zinc Uranium
Name of the Ore
Chemical composition
MINING TERMINOLOGIES Gangue: The valueless minerals in an ore; that part of an ore that is not economically desirable but cannot be avoided in mining. It is separated from the ore minerals during concentration.
MINING TERMINOLOGIES Metal: In most cases, an opaque, lustrous, elemental substance that is a good conductor of heat and electricity. It is also malleable and ductile, possesses high melting and boiling points, and tends to form positive ions in chemical compounds.
MINING TERMINOLOGIES Vein: An epigenetic mineral filling of a fault or other fracture in a host rock, in tabular or sheet-like form, often with associated replacement of the host rock; a mineral deposit of this form and origin.
MINING TERMINOLOGIES Orebody: A continuous, well-defined mass of material of sufficient ore content to make extraction economically feasible.
MINING TERMINOLOGIES Coal Seam: A stratum or bed of coal or other mineral; generally applied to large deposits of coal.
MINING TERMINOLOGIES Dip: The angle at which a bed, stratum, or vein is inclined from the horizontal, measured perpendicular to the strike and in the vertical plane.
Dip angle
MINING TERMINOLOGIES Strike: The course or bearing of the outcrop of an inclined bed, vein, or fault plane on a level surface; the direction of a horizontal line perpendicular to the direction of the dip.
MINING TERMINOLOGIES Footwall: The underlying side of a fault, orebody, or mine working; esp. the wall rock beneath an inclined vein or fault.; lower plate; foot.
Hanging wall: The overlying side of an orebody or mine working, esp. the wall rock above an inclined vein.
MINING TERMINOLOGIES Outcrop: The course or bearing of the outcrop of an inclined bed, vein, or fault plane on a level surface; the direction of a horizontal line perpendicular to the direction of the dip.
MINING TERMINOLOGIES Mining: Mining is the extraction of valuable minerals or other geological materials from the earth, from an orebody, lode, vein, (coal) seam or reef, which forms the mineralized horizon and package of economic interest to the miner. It can be classified into two vis. Underground mining and Surface mining.
MINING TERMINOLOGIES Surface Mining/opencast/open pit mining:
MINING TERMINOLOGIES Underground Mining:
MINE DEVELOPMENT
Lecture – 2
UNIT OPERATION Definition: The unit of mining are the basic steps employed to produce mineral/coal from the deposit, together with the auxiliary steps involved. Those steps contributing directly to mineral extraction are production operation, comprising the production cycle of operation. Those ancillary steps which support the production cycles are called auxiliary operation.
UNIT OPERATION The production cycle employs unit operations which are normally group in two functions: rock breakage and materials handling. Breakage includes a variety of mechanism but in rock is usually accomplished by drilling and blasting. Handling generally encompasses loading or excavation and haulage (horizontal transport), with optional hoisting ( vertical or inclined ). Thus the basic production cycle in mining consists of these unit operations: Production cycle = drilling + blasting + roof supporting + loading + hauling
DEVELOPMENT WORKS Basic development works for underground mines:
Mine Entries: A passageway or approach from surface to underground workings. Levels/ galleries: A main underground roadway or passage driven along a level course to afford access to stopes or workings and to provide ventilation and a haulageway for the removal of coal or ore. Levels are commonly spaced at regular depth intervals and are either numbered from the surface or designated by their elevation below the top of the shaft. Drift: An underground entry driven either horizontal or incline into a coal seam.
DEVELOPMENT WORKS Basic development works for underground mines:
Raise: A vertical or inclined opening in a mine driven upward from a level to connect with the level above, or to explore the ground for a limited distance above one level. After two levels are connected, the connection may be a winze or a raise, depending upon which level is taken as the point of reference. Vinze: A winze is an opening in an underground mine that is sunk downward (as opposed to a raise, which is mined upward) from inside to connect lower levels. The top of a winze is located underground, in contrast to a shaft where the top of the excavation is located on surface
MINE ENTRIES Types of Mine entries for underground mines:
Shaft Decline/incline Ramp Adit
MINE ENTRIES Shaft: A primary vertical or non vertical opening through mine strata used for ventilation or drainage and/or for hoisting of personnel or materials; connects the surface with underground workings.
MINE ENTRIES Shaft:
MINE ENTRIES Decline/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 -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".
MINE ENTRIES Ramp: A secondary or tertiary inclined opening, driven to connect levels, usually driven in a downward direction, and used for haulage.
MINE ENTRIES Adit: A nearly horizontal passage from the surface by which a mine is entered. A blind horizontal opening into a mountain, with only one entrance.
Underground Drilling Pattern Blasting off-the solid (Solid Blasting) For Galleries
Wedge or V cut Pyramid or diamond cut Drag cut Fan cut Burn cut
Underground Drilling Pattern Blasting off-the solid (Solid Blasting)
Wedge or V cut: Blasthole are drilled at an angle to the face in a uniform wedge formation so that the axis of symmetry is at the centre line of the face. The cut displaces a wedge of rock out of the face in the initial blast and this wedge is widened to the full width of the drift in subsequent blasts, each blast being fired with detonators of suitable delay time. The apex angle is as near as possible to 60 0 (Figure) This type of cut is particularly suited to large size drifts, which have well laminated or fissured rocks. Hole placement should be carefully preplanned and the alignment of each hole should be accurately drilled.
Underground Drilling Pattern Blasting off-the solid (Solid Blasting)
Wedge or V cut:
Underground Drilling Pattern Blasting off-the solid (Solid Blasting)
Pyramid or diamond cut The pyramid or diamond cut is a variation of the wedge cut where the blastholes for the initial cavity may have a line of symmetry along horizontal axis as well as the vertical axis (Figure).
Underground Drilling Pattern Blasting off-the solid (Solid Blasting)
Pyramid or diamond cut
Underground Drilling Pattern Blasting off-the solid (Solid Blasting)
Drag cut The drag cut is particularly suitable in small sectional drifts where a pull of up to 1.0 m is very useful (Figure).
Underground Drilling Pattern Blasting off-the solid (Solid Blasting)
Drag cut
Underground Drilling Pattern Blasting off-the solid (Solid Blasting)
Fan cut The fan cut is one-half of a wedge cut and is applicable mainly where only one machine is employed in a narrow drive. Generally the depth of pull obtainable is limited to 1.5 m (Figure).
Underground Drilling Pattern Blasting off-the solid (Solid Blasting)
Fan cut
Underground Drilling Pattern Blasting off-the solid (Solid Blasting)
Burn cut A series of parallel holes are drilled closely spaced at right angles to the face. One hole or more at the centre of the face are uncharged. This is called the burn cut (Figure). The uncharged holes are often of larger diameter than the charged holes and form zones of weakness that assist the adjacent charged holes in breaking out the ground. Since all holes are at right angles to the face, hole placement and alignment are easier than in other types of cuts. The burn cut is particularly suitable for use in massive rock such as granite, basalt etc.
