Difficulties in mine ventilation in the future

1. Thermal damage control in deep well mining

As the surface minerals are increasingly mined, the mining depth increases, as the ground temperature increases with the depth of the mine, coupled with the exothermic effects of other heat sources (air compression, oxidation process, mechanical equipment work), etc., causing high temperature threats. The number of mines is increasing. According to statistics from the national high temperature thermal damage survey, at present, the temperature of the mining face of 38 pairs of mines in China has exceeded 30 °C. During the "Ninth Five-Year Plan" period, more than 80 pairs of mines in China experienced heat damage. Working in a high temperature environment will not only reduce labor productivity, but also damage the health of miners. It will also seriously threaten the safe operation of underground mines and cause disasters and accidents. In order to ensure safe production, the Mine Safety Regulations issued by the State Council in 1982 stipulates that the air temperature at the underground operation site shall not exceed 28 °C, and the new regulations shall not exceed 26 C. There are similar regulations in foreign countries. Therefore, research on deep well cooling technology has become an important field in mining technology at home and abroad.

2. Pre-side and prevention of rock burst disaster in deep well hard rock mine

Deep gold mine or underground mining coal mine belongs, it may be simply referred to as hard rock in deep mines. The potential geological disasters in deep hard rock mines mainly include impact ground pressure or rockburst, mining earthquake, water inrush or water inrush, instability of surrounding rock in mining and roadway, and geothermal heat in high rock temperature. The causes of these geological hazards are mainly due to the increase of rock bearing pressure and the joint effect with the weak surface of geological structure. With the extension of mine mining in China, rockburst prevention has become a major issue facing mines in China. To this end, during the national "Nine Five" to Tongling Nonferrous Metals Company Dongguashan large-scale exploitation of mines as deep research base, we set the "theory and technology research deep mine strata control" issues, prevention and treatment research on rock burst in deep mining.

3. Deep well environmental control

Deep well environmental control is one of the problems in deep well mining. For conventional methods, the calculation and analysis is very complicated. It can not provide timely and accurate scientific basis for underground heat exhaust ventilation. Through the national “Ninth Five-Year” scientific and technological research, deep wells have been developed. The environmental management program simplifies the calculation of air volume, network calculation, climate prediction calculation and network prediction calculation of deep well exhaust ventilation working surface into simple computer operation. As the mine is deepened deeper, the underground heat damage becomes more and more serious. It is an important part of deep well mining technology, which directly affects the investment and operation effect of deep well mining. However, deep well environmental control is a very complicated and unsolvable problem.

4. Research on cold storage technology of deep mine formation

High-temperature mine productivity is low. According to years of research in South Africa, when the air wet bulb temperature at the mine site reaches 28.9 °C (equivalent to 30 °C dry bulb temperature), heatstroke death has begun. The use of large refrigeration units to cool down the working face of the well can achieve the purpose of cooling. However, due to its huge power consumption, its operating cost is too high, which makes it unable to be widely used in the Chinese coal industry. The formation cooling technology stores the natural cold energy in the winter air into the underground cold storage aquifer through a set of uphole energy conversion system. In the remaining seasons, this part of the cold is from the cold storage aquifer through another set of well supporting conversion system. It is extracted and passed through the downhole transduction system for cooling and cooling of the downhole working face.