Longwall Mining Equipments
Longwall mining is a form of mining where coal is extracted by a machine which cuts the mine and the coal is extracted. In this form of mining a long block of coal is cut from the mine. The area which is being cut from the mine is approximately 250-400 m wide and 3 to 4 km long. Longwall mining is a very efficient way of mining coal from the coal mines and it accounts for more than 50% of the coals mined every day.
The basic idea of longwall mining actually started in 17th century when peoples in England extracted coal in the same way from the coal mines. In past miners used wooden props to make sure that the face of the coal does not fall. With changing time technology has also changed but the basic idea of longwall mining still remains the same. New machinery replaced the use of wooden props.
The equipments which are used in longwall mining are described below:
Hydraulic jacks - hydraulic jacks also known as powered roofs, shields or chocks are used to support the coal face and in general the dimensions of hydraulic jacks are 1.75 m wide and 400 m in length and they are placed side by side to make sure that the coal face roof is supported carefully. A single jack can weigh 400 - 500 tonnes and they can extend to a height of 6m. They can support a pressure of 1200 tones.
Shearer - this is a machine used for cutting the coal face. This machine consists of electric and housing functions, main body, and electrical units to move the shearer inside the mine. Cutting drums are attached to the ranging arms which move according to the hydraulic arms. These cutting drums move with speed of 25 - 30 km/h and they are very efficient in cutting the coal face.
Crusher - at the main gate the coal which is being cut by the shearer is reduced in size by the help of crusher. Crusher is a very important machine as uncrushed coal is very difficult to transport from one place to another.
Some of the advantages of longwall mining are:
1. Recovery of coal is efficient
2. Consumables required for roof support is less in the case of longwall mining.
3. Coal clearing system is highly increased.
4. Manual handling is minimized.
Longwall mining is a very efficient process in mining sector and till now it is the only process which can increase the efficiency.
This job title might make you think of what an electrician does. But you need to be aware that this is a very different role in many ways, and it does not have the same level of responsibility or involve as many tasks as an electrician would take on. The...