What are the hidden dangers of mine safety?
High temperature and humidity
The temperature inside the mine is characterized by high temperature, high humidity, large temperature difference, and different airflow sizes in different locations. The temperature is related to the depth of the roadway, the deep ground temperature is increased, and the underground working environment is seriously damaged. At the same time, it is difficult to deal with the fresh wind source supply and the dirty air source in the deep mining area. Poor temperature conditions in mines are an important factor in the rise in the prevalence of upper respiratory infections and rheumatic diseases in workers. If these problems are not solved well, they will not only cause the risk of casualties and occupational hazards in these enterprises, but also make normal production impossible.
dust
Productive dust is the main harmful factor in underground mines. Many production processes and processes, such as drilling, shooting, falling mines, rock loading, transportation, etc., can generate a large amount of dust. Long-term inhalation of such dust by workers can cause silicosis, coal lungs or mixed pneumoconiosis. At present, 70% of pneumoconiosis patients in the world in China, the number of deaths from mine pneumoconiosis in China exceeds the number of deaths due to work. The concentration of dust in mines is high, the qualified rate of dust concentration in underground mines is only 40%-60%, and that in open pit mines is only 70%-80%. As the mining depth decreases, comprehensive hazards such as atmospheric pollution in deep open pit mines should be taken seriously.
Toxic and harmful gases
Biogas is often present in the mine air and its main component is methane. There are also harmful gases such as carbon monoxide, nitrogen oxides and hydrogen sulfide. Methane is a colorless and odorless flammable gas with a density of O.559kg/m3. Methane is mainly derived from coal seams, coal blocks and rock gangs. Methane can be mixed with air to form an explosive gas, which can explode in the event of an open flame. The concentration of methane explosion is 5%-16%. An important source of carbon monoxide and nitrogen oxides is the gunfire produced by shooting. The use of a nitrate fry can produce large amounts of carbon monoxide, while the use of ammonium nitrate explosives often produces large amounts of nitrogen oxides. In poorly ventilated mines, gunpowder poisoning may occur due to accumulation of gun smoke after firing.
Noise vibration
Noise is one of the hazards of polluting the mine environment, and the downhole workers are even more exposed. In recent years, the use of many large, high-efficiency, high-power equipment has reduced the labor intensity and increased production efficiency, and the noise pollution brought by it has become more and more serious. In particular, the downhole equipment has many sound sources, continuous noise, high sound level and high noise spectrum characteristics, and the medium frequency is combined. The downhole working face is narrow and the reflecting surface is large to form a mixed sound field, and the noise can only propagate along the roadway extension direction. It is more harmful to the workers. Noise and vibration in the mine are mainly generated during rock drilling, mining and transportation. In general, pneumatic tools are more serious than electric tools and vibrating conveyors than noise and vibration generated by belt conveyors. Miners have a high labor intensity, such as manual loading of rock is a heavy physical labor; rock drilling and carts are moderately manual labor. When working in a thin ore layer, workers have to take a bad position such as squatting and bending over the entire working day.
Blasting safety
Blasting safety plays an important role in mine production. The blasting safety problem can be summarized into the following three categories: safety accidents caused by mechanical effects of blasting (such as seismic waves generated by blasting, shock waves, noise and individual flying stones); physical and chemical reactions due to explosion of explosives, that is, when explosives are exploded A large number of toxic gases, electromagnetic effects and other safety accidents; sudden accidents caused by blasting, such as early explosion of explosives, refusal of explosions and safety accidents caused by operational errors.
Personal injury and equipment damage caused by mine blasting accounted for a large proportion of the entire mine accident. With the development of the mining industry, the open-pit mine blasting is very close to the industrial site of the mine itself, and there are also neighboring township residential areas; deep-hole blasting of underground mining mines and large-quantity engineering blasting are increasing, and the formation of high-temperature areas of mineral materials Explosives such as self-explosion, early explosion, and gunpowder poisoning often occur. The most typical is the 2002 June 22, Fanzhi County of Shanxi Province Yi Xing Village gold mine in the serious explosion, at least 37 miners were killed. Therefore, how to control the harmful effects of blasting and take protective measures is a common concern of mines.
Safety accidents are no small matter, especially in the mining industry. Only when you notice this small aspect, you can annihilate the accident in the bud!
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