What is a longwall shearer?
What is a longwall shearer?
Longwall. shearers cut away the face of a coal seam in longwall mining operations by mounting over an armored face conveyor (AFC). They are equipped with cutting drums positioned against the coal seam by ranging arms powered by hydraulic rams.
What is longwall method?
longwall mining Longwall mining is an underground method of excavating coal from tabular deposits, as well as soft mineral deposits such as potash. Large rectangular blocks of coal are defined during the development stage of the mine and are then extracted in a single continuous operation.
What is longwall equipment?
Longwall mining is an efficient mining method and using the right equipment can make it even more profitable. Joy longwall systems incorporate shearers, roof supports, face conveyors and more into one system that can be tightly orchestrated by advanced electronics — including cutting-edge automation.
What is coal shearer?
A shearer consists of a machine body containing electric motors, hydraulic equipment and controls which is mounted over the AFC. Horizontal cutting drums are mounted on the face side of the machine, laced with cutting picks and rotating in a plane parallel to the face.
How much does a longwall shearer cost?
A single longwall machine of this size costs $70 million, but at current coal prices, it pays for itself in about two months.
How does a longwall shearer work?
As the shearer removes the coal, the AFC is snaked over behind the shearer and the powered roof supports move forward into the newly created cavity. As mining progresses and the entire longwall progresses through the seam, the goaf increases. This goaf collapses under the weight of the overlying strata.
How much does a longwall cost?
How much does a continuous miner cost?
| EQUIPMENT OPERATING COST CALCULATIONS | ||
|---|---|---|
| PRODUCTION | # UNITS | TOTAL R&M |
| CONTINUOUS MINERS | 2 | $848.00 |
| SHUTTLE CARS | 4 | $416.00 |
| ROOF BOLTERS | 2 | $176.00 |
What is a GOAF?
The goaf is a mining term which refers to the part of the mine from which the mineral has been partially or completely removed.
How many tons of coal can the longwall shearer produced each minute?
“Moving at a rate of up to 130 feet per minute, the shearer removes or cuts about 1,300 tons of coal for each one meter of advance in the process,” Sollars said. The shearer — and the entire longwall operation — advances 60 to 80 feet into the panel each day.
Where is longwall mining used?
Most longwall mining occurs in the coal basins of New South Wales and Queensland. Mining depths are often between 200 and 600 metres below ground surface in New South Wales, and usually at a shallower depth in Queensland.
What is a joy miner?
[′jȯi ′mīn·ər] (mining engineering) A continuous miner weighing about 15 tons (13,600 kilograms) and made up of a turntable, a ripper bar, and a discharge boom conveyor; used mainly in coal headings and in extraction of coal pillars.
