The methods to deep underground mining There is also a form of underground mining known as long hole stopping. There is also the long hole stopping method, in which miners dig their own vertical tunnel into the ground basically. Otherwise the built tunnel is likely to end up falling apart or even caving in. If there is not enough surrounding rock that is at least reasonably strong, long hole stopping is not likely to work because the attempted tunnel will probably just end up caving in on itself. The cut and fill method is used when the rock is not considered as being safe enough for long hole stopping. For this, miners create their own platform far into the ground and then as they work their way up and retrieve the ore in slices, they add in back-fill.
As they go down and use machinery to retrieve the ore, back-fill will be laid and a new platform made so they are basically making their way up the shaft as though they were going up an elevator. These are the most often used methods and those which tend to be most successful in removing mining ore. If the coal seams are too deep underground, then deep underground mining is necessary. Deep underground mining methods include Continuous, Longwall, Blast, Retreat Mining and Shortwall Mining. Continuous Mining: A machine that has a large rotating steel drum with tungsten carbide teeth scrapes coal from the seam. Conveyors are used to transport the coal removed. About 5 tons of coal can be mined per minute. Accounts for about 45% of underground coal production.
Longwall Mining: A sophisticated machine that has a rotating drum that mechanically moves back and forth along the seam. Loosened coal falls on the bread line which takes the coal to the conveyor belt. Accounts for about 50% of coal production. Blast: An older mining method that uses dynamite and explosives to break away the coal seam. Accounts for less than 5% of coal production. Retreat Mining: One of the most dangerous coal mining methods. Pillars are used to hold up the mine roof as coal is extracted. The pillars collapse as miners retreat. Shortwall Mining: Similar to longwall mining. You use a continuous mining machine with moveable roof supports. The machine shears coal panels about 200 feet wide and half a mile long. We provide Professional technology, excellent product quality and intimate after-sales service when you purchase Rock cone crusher, Rotary kiln, from our company.As a professional mining machinery exporter, we will win your trust with our delivery speed, Enterprises Credit and product quality.