Types and prevention measures of mine geological disasters

1.5 Mine engineering disaster

Irrational mining means and off-hand mining methods often lead to underground engineering disasters, such as cave-in, roof fall, sideway, bottom heave, rock burst and so on. These disasters are due to the crustal stress changes in the rock and soil layers in the mine and mine, resulting in the sudden release of rock and soil stress, resulting in a large number of rocks and debris, and bursting into the pit, which brings harm to the mine mining, critical miners' safety and property losses. For example, the rock burst in the pit is due to the surrounding and top and bottom wall rocks, under the condition of huge rock ring stress, once the mining surface can not maintain balance, it is possible to produce a sudden release of rock ring stress, resulting in rock rupture and burst, and a large number of jets into the pit, explosion, thus bringing devastating disasters to the mine.

2. Variable disaster of groundwater level

In the process of mining, deep mining sometimes destroys the structural stability of groundwater free shallow water layer or laminated aquifer, and then causes the change of groundwater level and mine geological environment, resulting in disastrous consequences.

2.1 Water inrush in mine

Water inrush and water gushing are one of the most common mine disasters. Due to the rapid change of the water table in a short time, the mine suddenly flooded. This kind of mine geological disaster is sudden and large scale, resulting in very serious consequences. In the process of mining, due to the insufficient estimation of the discharge rate of the inflow of water in the mine, the mining process often penetrates the water barrier fault, or suddenly encounters the water storage cave and underground river, resulting in a large number of groundwater gushing, resulting in the flood of pits and Wells, resulting in casualties or other serious catastrophic consequences. This kind of disaster occurs frequently in mines with serious illegal mining, mostly due to low mining technology and illegal mining. Sand gushing in the pit is the associated disaster of water inrush in the mine. When the aquifer or karst cave rich in sediment is encountered in the mining process, after the water-barrier layer is broken, sediment and rock debris rush into the mine together with the water, resulting in slurry gushing disaster. Other permeable faults and diving layers often leak into the pit because of fault dislocation and inclusion of sediment, which results in the mine being blocked by mud, equipment and mining personnel being buried by sand, resulting in disastrous consequences for the mine.

2.2 Groundwater leakage

Due to mining, the condition of groundwater burial is destroyed, and the water supply of groundwater cannot keep up with the speed of consumption. For example, mining caused by the diversion of underground rivers, excessive mining damage to the diving layer, these changes in the geological environment, resulting in an extraordinary decline in the groundwater level, from the underground water source depletion disaster, and then lead to the loss of river water, spring dry up, resulting in local arid areas.

3. Disaster caused by ore body

This kind of mine geological disaster is often caused by some accidental factors after the change of mine geological environment.

3.1 Gas Explosion

Gas explosion disasters are most common in large and small coal mines. Due to poor ventilation conditions in the mine, gas accumulates in the closed space to a certain extent, and accidental factors cause explosions. This kind of disaster often results in the death of mining personnel and injuries, and the mine is damaged by violent explosions, resulting in huge personnel and property losses.

3.2 Spontaneous combustion of coal seam

Due to the coal seam mining, part of the mining surface is exposed to the air, and some coal mines gradually increase the temperature due to oxidation and exothermic heat. After the heat accumulation, the temperature rises rapidly, and when the temperature rises to the ignition point of coal, it will cause combustion. Spontaneous combustion of coal seam has occurred in ancient and modern times. The coal resources destroyed by spontaneous combustion of coal seam in China are up to 200 million tons every year, and the economic loss is huge.

3.3 Mine Fire

Pit fires are common in coal mine gangue and sulfide deposits, because coal gangue and sulfide can also oxidize and generate heat, which can cause fires. Mine fire to the surrounding environment of the atmosphere is also very serious harm, some perennial burning mines, the local air pollution is serious, the regional microclimate has changed, a large number of seedlings around the mining area died, the field is barren, the environmental situation is worrying.

3.4 Geothermal

In the process of mining, all the mineral resources, including coal, metal and non-metal ores, need to be mined through deep rock and soil layers, when reaching a certain depth, they will encounter the harm of rising mine temperature. Usually after the mining depth reaches 800 meters, the mine due to high sulfur content, large mining depth, and very high ground temperature will also lead to poor working environment for miners, seriously affecting normal production.