Analysis and prevention of occupational hazards in

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Analysis and prevention of occupational hazards in coal enterprises

Abstract: occupational hazards in coal enterprises refer to the health damage caused by miners' long-term work under poor working conditions. Analyzing and studying the occupational hazard factors in coal enterprises, finding out the causes of occupational hazards and formulating corresponding countermeasures will help to improve working conditions, prevent the occurrence of occupational diseases, protect workers' health and improve labor efficiency, and promote the healthy and steady development of coal enterprises

key words: coal enterprises; Occupational hazards; Quantitative analysis

occupational hazard factors in coal enterprises refer to the health damage caused by miners' long-term work under poor working conditions. Poor working conditions can cause various hazards to human health. As they are mainly caused by the establishment of macro-control and market regulation mechanism in the production process, they are collectively referred to as occupational hazards. The industrial field of coal enterprises is extremely extensive. From geological exploration to coal mining, from coal washing processing to comprehensive utilization, any link or process may cause occupational hazards (this analysis mainly analyzes the hazards of underground production and operation environment)

most of the working environment of coal enterprises is underground. Due to poor conditions, there are many toxic and harmful gases and substances in underground operation. If the management is poor and effective protective measures are not taken, for example, the place where toxic and harmful gases are generated is not detected in time, and the waste roadway is not sealed in time, it may cause personnel poisoning and suffocation accidents. Therefore, it is very necessary to understand and master the harm of toxic and harmful substances in coal mines to human body, and to prevent the harm of toxic and harmful substances to human body and the occurrence of poisoning accidents. Some toxic and harmful gas substances in coal mines are generated in the process of coal formation and exist in coal fissures and pores; Some substances exist in coal seams, roof and floor rocks P) automatic shutdown: rocks or other substances after sample fracture. When the concentration of these toxic and harmful gases and substances exceeds the critical value, they will do harm to human body. Sometimes, explosions will occur, endangering mine safety production, causing casualties and damage to facilities and equipment

I. types of toxic and harmful gases and their hazards

1 Carbon dioxide (CO2)

carbon dioxide is a colorless gas with slight acid odor. Its relative density to air is 1.52. It is easily soluble in water and often accumulates at the bottom of the roadway and the heading down the hill. CO2 does not support combustion nor can it be used for human respiration. It is slightly toxic and can stimulate respiration. The increase of lung content will increase the acidity of blood and stimulate the respiratory center. When the concentration reaches 5%, people will have difficulty breathing and tinnitus; When it reaches 10%, it makes people dizzy and comatose; When it reaches 20% ~ 25%, people will die quickly. The maximum allowable concentration in the mine is 1.5%

the main sources of carbon dioxide are: oxidation of organic matter; Personnel breathing; The slow oxidation of coal and rock, and the decomposition of mine water and carbonated rocks; Blasting work; Mine fire; Spontaneous combustion of coal; Gas and coal dust explosion can produce a large amount of CO2. In addition, some coal seams or rock formations can continuously emit CO2 for a long time, and even eject a large amount of pulverized coal (rock) and CO2 in a very short time, causing serious destructive accidents

2. Carbon monoxide (CO)

co is a colorless, odorless, tasteless and non irritating gas. Its relative density to air is 0.967 and is almost insoluble in water. However, it is easily soluble in ammonia, does not react with acid and alkali, and can only be adsorbed by a small amount of activated carbon. It burns in the air as blue fire stuffing, and is explosive when it is mixed with air to 12.5% ~ 80%. CO is a poison harmful to blood and nerves. After CO is inhaled into the body with air, it enters the blood through the alveoli and combines with the hemoglobin in the blood. The affinity between CO and hemoglobin is 200 ~ 300 times greater than that of oxygen, and the dissociation rate is 3600 times slower than that of oxygen and hemoglobin. In general, the degree of CO poisoning depends on how many turns it takes to break the content of carboxyhemoglobin in the blood. The more the content, the more serious the body's hypoxia, and the more serious the degree of poisoning. Underground coal mines, with high labor intensity, high temperature, high humidity and other toxic and harmful substances, will aggravate the degree of poisoning. The maximum allowable downhole CO concentration is 0.0024%

CO in coal mine mostly exists in goaf, closed roadway, etc. Blasting operation, coal spontaneous combustion, fire or gas and coal dust explosion can generate Co, which often causes poisoning and death

3. Hydrogen sulfide (H2S)

h2s is a colorless gas with the smell of rotten eggs. Soluble in water, the relative density to air is 1.19. H2S entering the body is quickly absorbed by the blood in the alveoli and oxidized into non-toxic sulfur salt, but the non oxidized H2S has toxic effect. H2S is also easily dissolved in the water on the mucosal surface, and combines with sodium ions to form sodium sulfide, which has a strong stimulating effect on the mucosa, and can cause ophthalmia, respiratory inflammation, and even pulmonary edema. The toxic effect of H2S on the whole body of human body is that it combines with ferric oxide of oxidized cytokine enzyme to make the enzyme lose its function, affect cell oxidation, and cause hypoxia in human tissues. Too high concentration of H2S in the air (above 900mg/m) can directly inhibit the respiratory center, causing asphyxia and rapid death. The sequelae of acute poisoning is headache and mental decline. The symptoms of chronic poisoning are sore eyes, burning sensation, swelling, photophobia, and tracheitis and headache. The maximum allowable concentration in the mine is 0.00066%

H2S gas in underground coal mines is mainly produced by the hydrolysis of sulfide minerals and the decay of pit wood and other organic substances. Some coal bodies can also release H2S gas. Since H2S gas is easily soluble in water, there is a large amount of H2S gas in the accumulated water in the old air

4. Nitrogen dioxide (NO2)

nitrogen dioxide is a kind of brown red gas with irritating odor. Its relative density to air is 1.448 and is very soluble in water. Nitrogen dioxide has a strong stimulating effect on the mucosa of eyes, nasal cavity and respiratory organs, especially on the lung tissue. When the content is 0.0066%, it will cause cough and chest pain in a short time; When the content is 0.01%, it has severe cough, vomiting and numbness of nervous system; When the content is 0.025%, it will die in a short time. It is more harmful than SO2 and No. in severe cases, it can cause emphysema and even death. The maximum allowable concentration in the mine is 0, with an average annual increase of more than 18% 00025%。

blasting operation in the mine will produce a series of nitrogen oxides, such as no and NO2. No is oxidized to NO2 in the air

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