Mine water discharge: In the process of coal mine construction and production, various types of water source water will enter the roadway and working face through different ways. In order to ensure mine safety and prevent water damage, it is necessary to discharge the mine water. According to incomplete statistics, in the coal mining process, the mine water discharge of coal mines in China was about 3 billion m3 in 2004, and the average water inflow of coal was about 2 m3. Resource utilization rate only accounts for about 22%.
Gas drainage and mine ventilation: Gas drainage before and during coal mining is an important measure to ensure coal mine safety. However, the discharge of the discharged gas into the atmosphere will have a strong greenhouse effect, and the greenhouse effect of methane contained in gas is 20 times larger than that of carbon dioxide. In addition, in the production process of the coal mine, the underground roadway needs hundreds of thousands or even millions of cubic meters of air per second. They are mainly done through mine ventilation. The mine ventilation also contains gas and a large amount of dust. According to relevant evaluations in recent years, the national coal seam gas resource is 3×106 Mm3. In 2002, China's key coal mine gas production was 9773.37Mm3, of which the gas utilization was 517.49 Mm3, and the utilization rate was about 5%.
Traditional coal mining ignores the mining, processing and utilization of other symbiotic and associated minerals, resulting in waste of resources. China's coal-based symbiosis, associated with more than 20 kinds of minerals, the vast majority of the current use is not used, and the random storage and disposal of minerals will also cause environmental pollution and damage the ecological environment.
Ecological destruction: Coal mining destroys the original mechanical equilibrium state inside the earth's crust. Caused the surface collapse and the original ecosystem was destroyed. Such damage reduces or loses the original land revenue, and also causes damage to the surface water conservancy facilities and deterioration of the ecological environment. The surface subsidence area caused by mining has reached 400,000 hm2 per year, and the average annual increase rate is 15,000 hm2.
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