Mining is one of the most important components of modern society, as mined minerals are used in almost all consumer goods. What is underground mining? What are the types of coal mining machinery?
What is underground mining?
What are the types of coal mining machinery?
How to choose the right mining equipment for yourself?
In underground coal mining, the working environment is completely surrounded by geological medium, including coal seam and its overlying and underlying strata. The coal seams are accessed through appropriate openings in the earth's surface, and a network of roads driven through the coal seams facilitates the installation of service facilities for basic activities such as the movement of people and supplies, ventilation, water treatment and drainage, and electricity. This stage of underground mining operations is called "mine development". The extraction of coal from coal seam in the process of mine development is called "first mining". The mining of the remaining coal seams is called "secondary mining".
1. More than two-thirds of underground coal mining is done by "continuous miners", tractors fitted with cylindrical grinders that separate coal from seams. Continuous miners deliberately leave undisturbed rock and coal pillars in the mine area to create natural support for the ceiling. This is called "room and pillar" mining. When most of the coal seam was mined out, the columns were pulled out one by one, allowing the roof to collapse naturally.
2. Between 20 and 30 percent of underground mined coal comes from longwall mining. This is performed by a mechanical cutter, which cuts the coal from the seam panel. The panels being processed may be 800 feet wide and 7,000 feet long. The mined coal is placed on a conveyor belt that moves the coal to the collection area. A hydraulically driven shield above the machine provides ceiling support. Longwall mining is more efficient than room pillar mining, but the equipment is more expensive.
3. To extract coal near the surface, giant dragline shovels remove the topmost layers of soil and rock, exposing the coal, which is then removed by smaller machines. Surface mining may involve removing the top layer of hilly parts or areas of flat surface. The layers of rock and soil covering the coal seam are retained until the coal is removed, at which point the soil and rock are replaced, the mine is covered, and the environment is restored as much as possible to its original state.
1. Identify the cost and revenue of the purchase, and then calculate the static return cycle. The data is calculated with reference to the theoretical computing power and power consumption of the mining machine, mining difficulty at the time of data release, block reward, real-time coin price and a specific electricity price. According to the above data, the net profit of mining on the day is calculated first. Then divide the net profit by the cost of the mining machine to obtain a static recovery period.
2. In the market of central mine equipment, there are spot and futures. Spot refers to the direct arrangement of packing and taking away, while futures refers to waiting (there will be a specified time on the official website). The two have their own advantages, spot can get the mining machine earlier, the earnings of mining is a game with time, the earlier the mining, the earlier the earnings. Futures prices of mining machines will be much lower than spot prices. But the choice between the two, depends on the individual's judgment of the market currency price trend. In terms of price comparison, it is suggested to use the algorithm of static return to the current cycle to remove the price of mining machine and the current price of the market.
The most important points of choosing mining machine are high computing power and low power mining. Compared with the new mining machine and second-hand mining machine, the new machine has more advantages. If you are looking for good quality mining equipment at a reasonable price, HANGZHOU CANDID I/E Co., Ltd is a wise choice.
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