From the perspective of China's geological conditions, the total amount of green coal resources is relatively small, and the development pattern needs further improvement. Therefore, China's coal industry should be based on green coal resources, supported by technology, scientifically improve the level of coal resource recovery, and achieve coordinated development between resource extraction and the environment. The evaluation of efficient coal resource recovery can help achieve this goal. Below, we will evaluate some indicators of efficient coal resource recovery. Adopting advanced coal mining methods and equipment to ensure production safety to the greatest extent, and improving resource recovery rate and production efficiency are important aspects of efficient coal resource recovery. The efficient recovery of coal resources can be evaluated using safety indicators (mortality rate per million tons), efficiency indicators (mechanization of coal mining and annual production of mines, etc.), recovery indicators (resource recovery rate), and environmental indicators (treatment of surface subsidence areas, land reclamation, etc.).
After years of development, the updating and research and development of China's coal mining machinery and equipment have initially met market needs, and have reached international leading levels in some aspects. However, there are still some prominent issues, mainly manifested as low personnel efficiency, severe overcapacity, frequent safety issues, and insufficient investment in environmental protection. There is a big gap between China's coal mining industry and some western developed countries in terms of industrial concentration ratio, mechanization, raw coal efficiency and environmental protection, as shown in Table 1 [4].
Measures for Efficient Recovery of Coal Resources
2.1 Realizing Supply and Demand Balance and Closing Low Recovery Mines
Due to the outdated production technology in some mines, it is difficult to further improve the recovery rate of coal resources. According to relevant national regulations, these mines with outdated production technology can be closed to improve resource recovery rates. In practical work, an important measure to improve resource recovery rate is to close and exit some coal mines that are about to run out, and transform outdated production capacity (mainly low mechanization level mines and coal mines in the loss stage). For some difficult to mine coal mines, such as those in Sichuan, Yunnan, and Hunan, the focus is on developing some coal mines in Shanxi and Inner Mongolia regions, which is very helpful in ensuring supply and demand balance and improving the recovery rate of coal resources.
2.2 Using advanced technology and equipment to improve resource recovery rate
Advanced technology and equipment are very helpful for the development of coal. Shenhua Mining Area has adopted large mining height technology and equipment to achieve one-time mining of thick coal seams, with a resource recovery rate of 85%, reaching a world leading level. Of course, the mining technology, equipment and experience in the Shenhua area are not applicable to other mining areas, mainly due to two reasons: a) the dip angle of coal seams in the Shenhua area is relatively small and the occurrence of coal seams is relatively stable; b) The tectonics is relatively simple. Therefore, it is necessary to adopt advanced technical equipment in real-time based on the geological conditions of the coal mine, in order to effectively improve the recovery rate of coal mine resources. The key is to develop high mining technology, optimize the production deployment of mines, simplify production systems, achieve one mine, one side, and effectively improve the production level of mines.
2.3 Promote coal mine integration and improve production concentration ratio
In some mining areas, there are many small mines with limited production capacity, and the government should integrate these small mines. After the integration of small coal mines, not only can the overall equipment level of the coal mine be improved, but also more policy support from the country can be obtained and capital investment can be increased. In specific work, each coal mine adheres to the principle of being guided by the state and market-oriented, achieving the flow of assets to high-quality resources. Obtaining more financial support from coal mining enterprises can help achieve industrial integration, increase the concentration of the coal mining industry, and achieve diversified development in areas such as coal mines, power plants, and coal chemical industry. This not only contributes to the healthy development of coal mining enterprises, but also enhances their risk resistance ability.
3. Energy saving measures for coal mining
The article briefly elaborates on some measures for efficient recycling in coal mining, but now higher requirements are put forward for coal mines, that is, to achieve efficient recycling while also meeting some energy-saving indicators. The following focuses on analyzing some energy-saving measures for coal mining.
3.1 Develop policies for precise coal mining
Energy conservation in mining is a goal for the development of coal mining enterprises, which helps to achieve national energy conservation and emission reduction. In order to achieve this goal, the country should formulate and introduce corresponding policies to guide coal mining enterprises towards energy conservation, safety, and economic development. Although the country has formulated relevant policies and regulations, there are certain difficulties in implementing them. Therefore, it is necessary for the country to introduce specific rules and formulate a series of economic penalty measures to ensure the achievement of energy-saving goals. At the same time, coal mining related universities should focus on the research and development of coal production technology, providing corresponding technical support for achieving energy-saving development in coal mines. In coal mine production, mechanical and electrical equipment plays a decisive role in energy conservation. Modifying the design specifications of some mechanical and electrical equipment can help achieve the goal of energy conservation from the source.
3.2 Realizing Resource Recycling
At the enterprise level, the restructuring and merger of coal enterprises can help eliminate some outdated production capacity and equipment, and accelerate the pace of achieving energy conservation and emission reduction; At the government level, some reward and punishment measures and energy conservation and emission reduction funds should be established, such as some tax incentives, specialized financial subsidies, etc. In order to achieve the goal of energy conservation, the economic interests of many enterprises have been greatly affected, so there is a strong resistance when implementing some decisions. Therefore, the government should stand from the perspective of enterprises and provide certain energy-saving and emission reduction policies to help them deeply understand the advantages of energy conservation.
3.3 Formulating energy-saving standards for coal mine production
At present, the energy consumption of coal production in some mining areas in China is very low, which can serve as a certain reference standard. In Shanxi, Inner Mongolia and other places, precision coal mining has been achieved, with a energy consumption of 2.5 kg standard coal per ton, reaching a world leading level; In some deep mines in Shandong, the energy consumption per ton of coal production reaches 5 kg of standard coal; In Hebei and Northeast China, the production energy consumption of some coal mines is far higher than these standards and is tending to be phased out. Therefore, it is necessary to develop specific production equipment based on the actual situation of coal mine production.
4 Conclusion
After years of development, China's coal industry has made significant breakthroughs in technology and theory, further promoting the safe and efficient mining of coal mines in China. However, there are still problems with high energy consumption and low recovery rates. Due to the widespread distribution of coal resources and significant differences in geological conditions in China, the mining conditions of coal resources in some regions are extremely poor. The unreasonable exploitation of such coal resources not only leads to overcapacity issues, but also threatens the development of the entire coal industry. In practical work, adopting advanced coal mining methods and equipment can maximize production safety, thereby improving the recovery rate and production efficiency of coal resources.