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A Abutment — In coal mining, 1 the weight of the rocks above a narrow roadway is transferred to the solid coal along the sides, which act as abutments of the arch of strata spanning the roadway; and 2 the weight of the rocks over a longwall face is transferred to the front abutment, that is, the solid coal ahead of the face and the back abutment, that is, the settled packs behind the face.
Acid deposition or acid rain — Refers loosely to a mixture of wet and dry "deposition" deposited material from the atmosphere containing higher than "normal" amount of nitric and sulfuric acids. The precursors or chemical forerunners of acid rain formation result from both natural sources, such as volcanoes and decaying vegetation, and man-made sources, primarily emissions of sulfur and nitrogen oxides resulting from fossil fuel combustion.
Acid mine The characteristics of belt conveyor — Mine water that contains free sulfuric acid, mainly due to the weathering of iron pyrites.
Active workings — Any place in a mine where miners are normally required to work or travel and which are ventilated and inspected regularly. Adit — A nearly horizontal passage from the surface by which a mine is entered and dewatered.
A blind horizontal opening into a mountain, with only one entrance. Advance — Mining in the same direction, or order of sequence; first mining as distinguished from retreat. Agglomeration — A family of processes which can be used to concentrate valuable minerals including coal based on their adhesive properties.
Air split — The division of a current of air into two or more parts. Airway — Any passage through which air is carried.
Also known as an air course. Anemometer — Instrument for measuring air velocity. Angle of dip — The angle at which strata or mineral deposits are inclined to the horizontal plane.
For dipping seams, the angle of break increases, being The main break occurs over the seam at an angle from the vertical equal to half the dip. Angle of repose — The maximum angle from horizontal at which a given material will rest on a given surface without sliding or rolling.
Anthracite coal — Of the four types of coal, anthracite is the hardest and contains the highest heat value.
It is almost pure carbon and is used mainly for home heating and cooking. In some developing countries, it is also used for industrial purposes. Anticline — An upward fold or arch of rock strata. Aquifer — A water-bearing bed of porous rock, often sandstone. Arching — Fracture processes around a mine opening, leading to stabilization by an arching effect.
Area of an airway — Average width multiplied by average height of airway, expressed in square feet. Auger — A rotary drill that uses a screw device to penetrate, break, and then transport the drilled material coal.
Auxiliary operations — All activities supportive of but not contributing directly to mining. Auxiliary ventilation — Portion of main ventilating current directed to face of dead end entry by means of an auxiliary fan and tubing.
Azimuth — A surveying term that references the angle measured clockwise from any meridian the established line of reference. The bearing is used to designate direction. The bearing of a line is the acute horizontal angle between the meridian and the line.
Back — The roof or upper part in any underground mining cavity. Backfill — Mine waste or rock used to support the roof after coal removal. Barren — Said of rock or vein material containing no minerals of value, and of strata without coal, or containing coal in seams too thin to be workable.
Barricading — Enclosing part of a mine to prevent inflow of noxious gasses from a mine fire or an explosion. Barrier — Something that bars or keeps out. Barrier pillars are solid blocks of coal left between two mines or sections of a mine to prevent accidents due to inrushes of water, gas, or from explosions or a mine fire.
Beam — A bar or straight girder used to support a span of roof between two support props or walls. Beam building — The creation of a strong, inflexible beam by bolting or otherwise fastening together several weaker layers.
In coal mining this is the intended basis for roof bolting. Bearing — A surveying term used to designate direction. The meridian is an established line of reference. Azimuths are angles measured clockwise from any meridian.MOTOR SELECTION for BELT-CONVEYOR DRIVES Abstract—Rated power is the motor parameter always This paper shows how the running and starting characteristics of a belt conveyor are influenced by slip.
It shows that high-slip motors improve load sharing between directly coupled motors, and it shows that high-slip motors reduce the . A conveyor belt system is designed according to specific material transport and is arranged based on customer needs. In a belt conveyor, the one-piece belt is both the transport and the drive mechanism as it is carried by support rollers or a sliding table.
Belt Press Rentals and Dewatering Equipment Rantals. Wide variety of equipment available. Fast, cost-effective sludge reduction solutions. Dewatering equipment for both municipal and industrial applications. The shaft of a conveyor belt drive pulley failed in service.
An investigation was performed in order to determine the failure root cause and contribution factors. A flat belt is wider than it is thick and has a rectangular section.
This provides a large contact surface. It is often very flexible, silent and able to transmit high speeds ( meters/second) under low torque. A belt conveyor system consists of two or more pulleys (sometimes referred to as drums), with an endless loop of carrying medium—the conveyor belt—that rotates about them.
One or both of the pulleys are powered, moving the belt and the material on the belt forward. The warp refers to longitudinal cords which characteristics of.