INTRODUCTION

1. Chemical and physical properties coal dust

Dangerous impact of coal mining in the Kemerovo region

Physiological mechanisms that damage organs

Occupational diseases of coal miners

Sanitary standards for coal mining

Means and methods of protection against harmful factor in production

CONCLUSION

Bibliography

INTRODUCTION

Relevance. Rapid development of the coal industry in Donbass and other regions Russian Federation, the introduction of new equipment and technology in production requires workers, engineers and technicians to have clearer knowledge, careful adherence to occupational hygiene rules and healthy lifestyle standards.

Exposure to dust miners, metro builders, masons, workers in cement, brick, tile, flour mills, sugar factories, road workers, molders, foundry workers, textile workers are exposed confectionery production. When dust particles enter the respiratory tract, they cause inflammation of the tissue of the pulmonary vesicles, which leads to the development of connective tissue in them. Bronchopulmonary diseases of occupational etiology continue to remain the most important problem medicine in terms of the amount of social damage caused, which is primarily due to insufficient knowledge of the mechanisms of action of fibrogenic dust of mixed composition, as well as the action of combined factors of gases, aerosols, etc.

1. Chemical and physical properties of coal dust

Dust is characterized by a set of properties that determine its behavior in the air, its transformation in the body, and its effect on the body. Of the various properties of industrial dust, the chemical composition, solubility, dispersion, explosiveness, shape, electrical charge, and radioactivity are of greatest importance.

Most important properties dusts are determined directly by their dispersion, particle shape, good dissolution ability and unique chemical composition. To evaluate dust from a hygienic point of view, the most important characteristic is nothing more than dispersion.

Dust formation in different mines varies and depends on mining and geological conditions, the microstructure of coal, its strength, humidity, conditions of the seam, as well as the method of extracting coal, the mechanisms used, etc. It has been shown that on hard coals the formation of dust is approximately 25% greater than on soft ones. Wet coal produces less dust. More dust is formed on steep seams than on flat ones, which is associated with the descent of coal. Excavation of coal along the cleavage (bedding) produces less dust than excavation against the cleavage. The main operations associated with dust emission are coal mining with a combine, seam cutting with a shearer, manual and jackhammer breaking, conveyor loading, coal breaking on steep seams with jackhammers, loading coal from a conveyor into trolleys, roadheader operation, drilling and blasting operations, machine loading of rock, delivery to the shaft by trolleys, unloading of skips.

In terms of dust generation intensity, not all of these operations are equivalent. According to research, 95% of all dust is generated in mines. Of the total amount of dust generated, 60% comes from the operation of machinery, about 20% from blasting in the face, 10% from breaking and 10% from other work. .

The amount of dust suspended in the air also varies in different mines depending on the reasons mentioned above. The highest dust content in the air is usually observed during the operation of combine harvesters; in the absence of dust control means, its concentration can reach several grams per 1 m3 of air. Another most dusty operation is the operation of a shearing machine, a roadheader. Dust concentrations can reach hundreds of milligrams per 1 m3. Air dust content during dry drilling can reach up to 1000 mg/m3. High dust levels are observed during blasting operations. On steeply dipping seams, large dust formation (several thousand milligrams per 1 m3) is observed when coal is lowered to the loading hatch.

Coal dust is generated during the following production operations:

.Coal breaking with combines and blasting operations.

.Drilling holes.

.Loading coal with loading machines.

.Transportation of coal by conveyors.

.Loading at loading and unloading points.

Maximum permissible concentrations of coal dust:

The process of grinding dispersed materials is well described by Rittinger's law (the specific energy consumption for grinding is directly proportional to the size of the newly formed surface.

Coal dust is well transported by air flow or combustion products. The dust-air mixture forms a very mobile emulsion that has the properties of a liquid and is easily pumped through pipes. In individual dust preparation systems located directly at the steam generator, the dust concentration in the air mixture is relatively low and is usually |A1= = 0.5 h-1 kg of dust per 1 kg of air (or gases). If there is a central dust plant (CDP), dust is transported from the CPZ bins to the dust bunkers of steam generators at high concentrations (about 30-35 kg of dust/kg of air) through small-section pipelines using transfer pumps, in which the dust is mixed with compressed air having a pressure of 0. 5-1 MPa (5-10 kgf/cm2). Pumping of a highly concentrated dust-air mixture can be carried out over long distances, on the order of several hundred meters.

Factors affecting the explosiveness of coal dust:

1.The explosive concentration of suspended coal dust is from 16 - 96 g/m3 to 2000 g/m3.

2.The yield of volatile substances is 15% or more.

.The size of dust particles is up to 1 mm, the smaller it is, the more dangerous.

The ignition temperature of coal dust is 750 - 850 0 C. The speed of the blast wave is 1000 m/sec. The strongest explosion is at a concentration of 300 - 400 g/m3. When the combine is operating without irrigation, the dust content in the air is 50 g/m3, with blasting and blasting - 300 g/m3. The deposition of coal dust during the operation of a roadheader is 600 g/m3 per day at the face. When the shearer is operating - 900 g/m3 per day. At loading points (transfers) - 100 g/m3 per day. 4. Humidity and ash content - the higher the humidity and ash content of coal, the less explosive the dust is. The dispersion of dust suspended in the air is generally high: up to 40-80% of dust particles have sizes up to 1.3 microns, 15-35% - up to 2.6 microns, 5-20% - up to 4 microns and 3-10% - over 4 microns.

2. Dangerous impact of coal mining in the Kemerovo region

coal dust mining disease

The transition of the coal industry to market relations requires the profitable operation of its enterprises. The basis of such work is high-performance and reliable equipment that corresponds to the mining and geological conditions of the occurrence of coal seams. Many mines in Kuzbass are currently equipped with mechanized treatment complexes of domestic production, in particular, the Yurginsky Machine-Building Plant (KM-138, KM-142, KM-144). However, there is a steady trend towards the use of imported equipment. As a result of these processes, coal mining enterprises have already become dependent on foreign suppliers, whose services are becoming more and more expensive, which has a negative impact on the cost of coal. Approximately the same situation arises with underground transport equipment, especially with belt conveyors. A serious negative consequence of coal growth is a further deterioration of the environment in the Kemerovo region, which is already not the most prosperous region for life. In the Siberian regions (the cities of Omsk, Tomsk, Novosibirsk, Krasnoyarsk, Kemerovo) there are enough conversion engineering plants that can provide coal mining enterprises with highly productive and reliable equipment. It is necessary to reorient these enterprises to produce just such equipment, for example, by acquiring licenses for the production of the required equipment. Considering that domestic technology 3-4 times cheaper than imported ones, the transfer of the coal industry to domestic equipment will help increase its profitability. In addition, this will create thousands of new jobs in the regions of Siberia.

The problem of the influence of coal mining on environment It is not just kept silent, it remains poorly studied. The territory of the Kuznetsk Basin, where the coal basin of the same name is located, is, according to environmentalists, the most neglected area. Meanwhile, the largest cities of the region are concentrated in it - Novokuznetsk, Kemerovo, Prokopyevsk, Belovo, Leninsk-Kuznetsky, Tashtagol, Kiselevsk. The current methods of coal mining and processing in the Kuznetsk coal basin, whose capacity is estimated at 500 billion tons, have led to a significant transformation of the environment. Transformation is associated with catastrophic disturbances when, as a result of anthropogenic impact, the natural landscape, soil cover, and along with it flora and fauna are completely destroyed (due to the formation of quarries and dumps). Plowing of land, felling of forests, fires, construction of access roads, roads, damages the structure of phytocenoses. As a result, not a single river within the Kuznetsk Basin is suitable for drinking, although the water flows from the mountains is environmentally friendly. The situation is aggravated by the fact that the Kuznetsk basin is surrounded by the Shorsky highlands in the south, the Kuznetsk Alatau in the east and the Salair ridge in the west. This leads to the fact that harmful substances do not travel further than the mountain slopes, concentrating exclusively on the territory of Kuzbass.

Scientists see a way out of this situation in carrying out large-scale measures to rehabilitate disturbed areas, which should begin after the completion of the development of a coal mine or mine. The complex of these measures includes restoring land fertility, cleaning rivers, creating forest parks, protective forest belts and recreation areas. Specially protected areas should appear to preserve environmental biodiversity. The goal is to embed mining enterprises into the cultivated landscape and thereby preserve biological diversity nature of the region.

3. Physiological mechanisms that damage organs

From professional factors coal production, the existence of which, their effect on the body and measures to prevent the health problems they cause should be known to every miner, first of all, dust should be called dust. Along with the impact of coal dust on the respiratory system, it also affects other organs and systems of the body. Thus, coal dust contributes to the occurrence of pustular diseases of the skin of the subcutaneous tissue (boils, felons, abscesses). When dust is swallowed, the digestive tract can also be affected. Dust, irritating the mucous membrane of the eyes, contributes to the development of conjunctivitis and trauma to the cornea.

However, it should be noted that the impact of mixed dusts on the respiratory system has not been sufficiently studied. There is no justification for the possibility of using cytochemical indicators for rapid assessment of the degree of cygotoxicity of dust in alveolar macrophages, as well as for assessing the health status of workers industrial enterprises and the risk of occupational disease. In this regard, the cytochemical characteristics of neutrophils and erythrocytes of peripheral blood are of particular interest. It is known that peripheral blood obtained from a finger is convenient for a wide and multidisciplinary study and its indicators provide sufficient information for judging metabolic changes in the respiratory organs.

Working underground is associated with significant physical activity, which, in combination with the elevated temperature of the working environment, causes a sharp increase in sweating (up to 4 l/day), leading to a deficiency water-soluble vitamins and minerals.

Energy costs for miners, depending on their professional background and the nature of the work performed, can fluctuate in a wide range of 14,640-20,900 kJ (3500-5000 kcal). The daily diet should contain proteins 110-190 g, fats 120-180 g, carbohydrates 480-620 g. With daily energy expenditure less than 16,700 kJ (4000 kcal), the ratio between proteins, fats and carbohydrates should correspond to the ratio 14:30:56, and with higher energy consumption - 14:35:51.

Probability of occurrence silicosis is reduced by methionine and cysteine. Therefore, the menu of those working under conditions of exposure to silicon compounds must include sources of milk proteins (cheeses), poultry, fish, legumes, etc.

The change in the nature of the clinical course of the disease is largely due to impaired immune reactivity and lipid metabolism.

Therefore, it seems advisable to monitor early immunological and metabolic changes during inhalation of AMR for timely diagnosis and preventive measures. Experimental models make this possible. In this regard, the purpose of the study was a clinical and experimental study of the characteristics of immune reactivity and lipid profile during inhalation of AMR.

The role played by coal dust in mine accidents is increasingly recognized as important, as noted in the paper, which noted that it was first recognized in the UK following a coal mine explosion in Northumberland (Wales) in 1803. However, understanding this role was still imperfect at that time. The subsequent 1844 disaster at Haswell's Durham mines killed 95 people; The famous scientist Michael Faraday was invited to conduct the investigation. And although the report on the accident noted that mine gas (methane) was not the cause, it was only more than 50 years later that Galloway, a professor of mining at Cardiff University, determined that the cause of both this and more serious explosions was mainly coal dust. .

The mechanism of the phenomenon is currently known. It lies in the fact that a relatively weak methane explosion can cause air flow turbulence sufficient to form a cloud of coal dust in the adit. The ignition of the dust, in turn, generates a shock wave that kicks up even more coal dust, eventually leading to a devastating explosion. The paper determined that the majority of 645 similar incidents of coal mine accidents that occurred in Great Britain alone from 1835 to 1850 were caused by dust explosions. Cybulski notes that the number of coal mine accidents worldwide with at least 50 casualties was 135 between 1900 and 1951, or an average of 151. for one accident. According to the same source, due to explosions in US mines, the average number of casualties for the period from 1931 to 1955 was 117 people. in year.

In order to prevent dust explosions in coal mines or ultimately reduce their consequences, the following is necessary: ​​a) prevent initiating explosions by removing methane and eliminating possible ignition sources; b) limit, if possible, the amount of dust in the adit; c) moisten coal dust; d) use inert powder. This inert powder is silicate-free dust, usually limestone. The powder is loaded into a chute suspended from the ceiling of the adit, which is preferable to simply mixing it with coal dust, as was done before. When an explosion occurs, the chute swings and inert powder is scattered, mixing in the air with coal dust. Lime absorbs the heat generated by combustion, and thus the speed of flame propagation is reduced. In addition, lime participates in an endothermic decomposition reaction, which cools the gas. In Fig. Figure 12.1 shows a diagram of the distribution by year of the number of victims from mine accidents that occurred in the UK (accidents with at least 20 victims were taken into account). It is easy to see that the largest accidents occurred in the distant past.

Analyzing the complaints of miners, it can be noted that a high frequency of colds among miners is observed in the initial period of working underground, when the worker’s body, having found itself in unfavorable conditions, has not yet adapted to them. Then, thanks to the compensatory and adaptive mechanisms of the body colds are observed less frequently, and only in persons with an experience of over 31 years is there again a slight increase in incidence, which is apparently associated with a decrease in the immunobiological properties of the body at the corresponding age. .

Dust and smoke, as harmful impurities in the air, have become objects of paramount importance in the struggle to maintain the frequency of the air environment, since their presence invariably created tangible inconveniences, and they themselves were most often a consequence of human activity. Dust is tiny solid particles that can remain suspended for some time. Dust is characterized by the chemical composition, size and shape of particles, their density, electrical, magnetic and other properties.

Damage to the mucous membrane of the respiratory tract by dust deposited on it gradually leads to chronic inflammation - “dust bronchitis”, in the development of which the microflora of the respiratory tract also plays an important role. Peribronchial sclerosis characteristic of silicosis, accompanied by deformation of the bronchi, as well as changes in the physical properties of mucus associated with the action of SiO2 on goblet cells, disrupt the normal transport of this mucus along with dust particles and pathogenic microorganisms, contributing to the further development of the endobronchitic process. Thus, dust bronchitis is a combined infectious and dust lesion with a predominant role of one or another component. In addition, the development of chronic bronchitis can occur without significant participation of exogenous irritants (due to repeated colds and infectious diseases of the respiratory system), and among the irritants that certainly contribute to this development, non-occupational (primarily smoking) plays an important role. However, the increased prevalence of chronic bronchitis among eggs exposed to various industrial dusts is beyond doubt, and therefore in Kazakhstan this disease is officially classified as an occupational disease (“chronic dust bronchitis”). Under the influence of dust, diseases such as pneumoconiosis, eczema, dermatitis, conjunctivitis, allergies, etc. can occur. The finer the dust, the more dangerous it is for humans. The most dangerous particles for humans are considered to be particles ranging in size from 0.2 to 0.7 microns, which, entering the lungs during breathing, are retained in them and, accumulating, can cause diseases.

Modern scientific and technological progress in the coal industry has significantly influenced the sociological, physiological, psychological, industrial and economic aspects miners' labor. Working conditions in coal mines are often characterized by unfavorable combinations of temperature and relative humidity of the working environment, the possibility of contamination with harmful gases, high dust formation in all technological processes, lack of daylight, difficulties in organizing hot meals, water supply and sewage disposal underground, and often forced positioning of the body under earth. The operation of mining machines and mechanisms in confined spaces is accompanied by noise and vibration.

4. Occupational diseases of coal miners

Occupational morbidity in the Kemerovo region. remains one of the highest in the Russian Federation, almost 7-8 times higher than the level for the country as a whole, in 2005 it amounted to 10.8 cases (Russian Federation - 1.6) per 10 thousand workers, 1102 newly identified cases were registered professional patients.

The highest occupational morbidity is recorded in Anzhero-Sudzhensk, Osinniki and Prokopyevsk.

The incidence of miners with temporary disability is at an average level compared with the incidence of workers in other industries. The underground group of workers, as a rule, has more high level morbidity than that of the above-ground group of workers in the same mines. When comparing the morbidity of miners in individual coal basins, one can note a significant difference both in the overall level of morbidity and in its nature; here, to a certain extent, the specificity of sanitary and hygienic working and living conditions is affected, which are determined by many factors (climatic and geographical zone of mine location, their depth and extent, the state of ventilation, water supply, method of extracting minerals, quality of medical care, etc.).

Miners, primarily working in the production and development faces, have a very high level of industrial injuries. Behind last years Miner injury rates are steadily declining due to the mechanization of coal mining and more careful compliance with safety regulations.

Of the nosological forms, the largest share (up to 25 - 30%) is occupied by influenza, catarrh of the upper respiratory tract, tonsillitis, etc., the so-called colds. Their appearance is promoted by cooling the body, getting wet clothes and shoes. One of the first places in the general morbidity of miners is occupied by pustular skin diseases, which is associated with skin contamination with dust, the use of dirty workwear, microtrauma to the skin, and the use of untreated mine water for washing.

The number of acute gastrointestinal diseases and helminth infections among miners is relatively high, which is due to the lack of properly organized underground sewage disposal and cleaning of mine workings in a number of mines, unsatisfactory drinking water supply, eating food directly at the place of work and improper diet.

Among the hydraulic mine workers there were high performance morbidity in such nosological forms as diseases of the peripheral nervous system and rheumatism. The level of other nosological forms in general structure morbidity among miners differs little from morbidity among workers in other industries. Working conditions in mines may cause occupational diseases miners.

Until 2005 in the structure of professional pathology first place was occupied by dust diseases of the respiratory system (31.5%), occupational hearing loss was 24.4%, vibration disease - 17.2%, diseases of joints and muscles - 20.9%. In 2005, changes occurred in the nosological structure of occupational pathology. The first place is occupied by diseases of the joints, tendons and muscles (27.9%), vibration disease accounts for 23%. Compared to 2001-2003, the proportion of respiratory diseases (21.2%) and occupational hearing loss (17.6%) decreased; occupational infectious diseases accounted for 1.5%.

The structure of morbidity with temporary disability is dominated by three nosological groups: diseases of the respiratory system, musculoskeletal system and injuries (up to 55% of all causes of temporary disability).

Analysis of the distribution of occupational diseases by industry in the Kemerovo region. showed that for 2003-2005. 77.8% of occupational patients are from the coal industry. Basically, these are people employed in underground mining. In non-ferrous and ferrous metallurgy - 5.7% of professional patients, in mechanical engineering, metalworking and electrical industry - 4.7%, in construction - 2%, the agricultural sector accounts for 1.9%, in healthcare - 1.4%. This structure has essentially remained unchanged over the past 5-6 years. Thus, it is confirmed that the coal industry of Kuzbass has the highest occupational morbidity rate

Of the factors in the working environment, the most significant for occupational risk are: noise, vibration, coal-rock aerosols, toxic substances (carbon monoxide, nitrogen dioxide) . The impact of noise and vibration on workers is due to the imperfection of mining equipment. So, according to the results of measurements on coal mines In Novokuznetsk, noise levels at the workplaces of excavator drivers exceed the maximum permissible level by 4 dB, general vibration - by 4 dB, local vibration levels are higher than the required values ​​- by 1-2 dB. At the workplaces of drilling rig operators, the levels of sound pressure and general vibration exceed the maximum permissible by 3 dB. In the driver's cabins of heavy-duty vehicles, noise levels are 2-4 dB above the maximum limit, and overall vibration exceeds the maximum limit by 6 dB.

When operating mining and transport equipment, in addition to noise and vibration, workers are adversely affected by the severity and intensity of the labor process, characterized by physical overstrain of the muscles of the arms, shoulder girdle, and body, as a result of which pathology of the musculoskeletal system develops. An aggravating factor in the development of occupational diseases is a 12-hour work shift. The risk group for the development of occupational pathology includes such professions as excavator and bulldozer operators, drilling rig operators, and heavy truck drivers. The working conditions of these professions are characterized as hazardous, class 3. Exposure to dust miners, metro builders, masons, workers in cement, brick, tile, flour mills, sugar factories, road workers, molders, foundry workers, textile workers, and confectionery workers are exposed. When dust particles enter the respiratory tract, they cause inflammation of the tissue of the pulmonary vesicles, which leads to the development of connective tissue in them. Bronchopulmonary diseases of occupational etiology continue to be the most important medical problem in terms of the amount of social damage caused, which is primarily due to insufficient knowledge of the mechanisms of action of fibrogenic dust of mixed composition, as well as the action of combined factors of gases, aerosols, etc.

Coniotuberculosis occurs among coal workers much less frequently than among mining workers, and its course is much more favorable.

The prevalence of pneumoconiosis among coal industry workers is decreasing every year. In 1963-1964. in the Donetsk basin, during annual medical examinations, less than 1% of those examined were found to be ill. Pneumoconiosis in miners of the Donetsk basin is detected with an average dust exposure of 8-10 years.

Coal dust is assessed from two points of view: sanitary and hygienic and safety. The sanitary and hygienic significance of coal dust is determined by the changes that it causes in the respiratory system. The main place among them is pneumoconiosis. The most important role in protecting the body from the harmful effects of industrial environmental factors belongs to nonspecific protection, its basal main link, namely, phagocytosis carried out by alveolar macrophages of the lungs and blood neutrophils. In the development of protective and adaptive mechanisms that arise in the body at the early stages of the pathological process, an important role belongs to the earliest metabolic reactions occurring at the cellular and subcellular levels.

A dust explosion is an object of intensive study, to which numerous works and individual monographs are devoted. It can be considered in two distinct aspects: dust explosions in adits and dust explosions in equipment and inside buildings. The former are characterized by a shock wave propagating along the adit, the length of which can reach several kilometers. Although the description of dust explosions in coal mines does not correspond to the main topic of this work.

This reduces the respiratory capacity of the lungs and disrupts gas exchange; Along with this, keratinization of the epithelium of the airways occurs, which reduces its ability to retain dust particles. Consequently, with systematic exposure to dust, the supply of oxygen to the body through the lung tissue deteriorates and the barrier function of the respiratory tract decreases, and occupational diseases develop, such as silicosis, which occurs under the influence of quartz dust. It is known that prolonged exposure to any damaging factor leads to disruption of enzyme systems and metabolism occurring in cells, which are classified as nonspecific protective factors. In recent years, factual material has been accumulated that suggests that changes in the functional and metabolic activity of blood leukocytes can act as sensitive indicators of homeostasis disturbances in the respiratory organs during early protective and adaptive reactions. According to the opinion, quantitative and qualitative changes in blood elements, namely a decrease in the functional activity of leukocytes, an increase in the level of destruction, reflect the initial phenomena of decompensation. .

The leading forms of occupational diseases are silicosis, anthracosis and dust bronchitis, vibration disease, diseases of the musculoskeletal system, auditory neuritis and bursitis. As evidenced by data from the Research Institute of Occupational Hygiene and Occupational Diseases of the USSR Academy of Medical Sciences [Vorontsova E.I., 1984], as a result of the introduction of health-improving measures of a social, engineering, technical and therapeutic-prophylactic nature, the level of occupational respiratory diseases is steadily decreasing. Thus, during the period from 1975 to 1980, the incidence rate of pneumoconiosis in the coal industry decreased by more than half. The forms of pneumoconiosis depend on the nature of the coal, in particular on its strength and ash content, percentage silicon dioxide in coal and rocks, as well as on experience in mines and work in coal or rock and the degree of dust in the air. The predominant type of pneumoconiosis in miners is stage I anthracosilicosis. It is registered among workers with 15 - 20 years of underground work experience. Chronic dust bronchitis is becoming increasingly important in the professional pathology of miners. In addition to industrial dust, factors predisposing to the development of chronic dust bronchitis are a cooling microclimate, pollution of the mine atmosphere with irritating gases, frequent acute respiratory diseases, and smoking.

Vibration disease ranks second after pneumoconiosis among the occupational diseases of miners. It can occur in miners who are constantly working with jackhammers and drilling hammers. Points that aggravate the harmful effects of vibration are muscle strain, forced working posture, cooling of the hands and the whole body, which can be observed in water-rich mines, especially with low temperatures of the air and the soil being mined. Among miners who work for a long time in conditions of intense noise (100 dB and above), cases of auditory neuritis and other symptoms of noise pathology have been recorded.

Among the occupational diseases of the musculoskeletal system among miners, the leading place belongs to bursitis.

5. Sanitary and hygienic standards for coal mining

Microclimate parameters, levels of physical factors (noise, vibration, ultra- and infrasound, electromagnetic fields), dust content and harmful substances in the air of the working area must comply with hygienic standards. The leading harmful factors in the mining and processing of coal (oil shale), leading to the development of severe occupational diseases, are high dust levels, intense noise and vibration, high severity and intensity of labor, most pronounced in underground mining.

For all technological processes that require the use of water for dust suppression and for sanitary services for workers, water is used that meets bacteriological and sanitary-hygienic indicators, hygienic requirements for water quality centralized systems drinking water supply.

For dust suppression purposes, it is prohibited to use mine and other waters to supply water to sprinklers, foggers, drilling and loading machines if the concentration of radon or thoron in them exceeds curie/l. If there are no other sources of water supply, then to use waters containing emanations in large quantities, are taking measures to de-emanate them.

The use of surfactants (hereinafter referred to as surfactants) to bind settled dust is possible only by mechanized means. Workers who have direct contact with highly concentrated surfactant solutions polymer materials, reagents and antifreezes used for heat, hydro and gas insulation, prevention of sudden emissions and strengthening of mountain ranges, as well as means for treating coal against freezing and weathering, are provided with protective waterproof clothing and shoes, goggles, respirators, rubber gloves.

During development technological processes and design of equipment, maximum mechanization of repair, installation and dismantling is provided and measures are provided to reduce the levels of factors in the working environment and the labor process when performing these works.

Operation and repair of devices with sources of ionizing radiation, radiation monitoring and registration of its results are carried out in accordance with the requirements for ensuring radiation safety.

Requirements for the conduct of work and for the premises in which mercury-filled instruments, devices, apparatus are installed must comply with the provisions sanitary rules when working with mercury.

The use and maintenance of lasers is carried out in compliance with hygienic requirements for their design and operation.

The employer provides workers with special clothing, safety footwear and personal protective equipment (hereinafter referred to as PPE), flushing and disinfecting agents and organizes their proper storage, use, cleaning, washing, repair, disinfection and other types of preventive treatment.

In coal mining and processing organizations, production control in accordance with hygienic requirements for organizations engaged in mining and processing of coal (oil shale). The employer is obliged to provide information to the bodies authorized to carry out state sanitary and epidemiological supervision on the severity of factors in the working environment, the sanitary state of atmospheric air, water bodies, soil, solid industrial waste and the compliance of the technology used with the approved project.

In Russia, standards in the field of various harmful factors have been developed and put into effect long ago. In many countries, there are laws and federal programs for the reclamation of the area followed by mining, and technologies for filling mined-out space with household and construction waste have been developed. If mining regulations or safety requirements are not followed during mining operations, undesirable consequences such as underground fires, fires in dumps, pollution of watersheds with water containing acids, metals or suspended solids, and in addition landslides are possible unstable slopes. In many countries, including the United States, there is a series of laws that cover all aspects of the development of coal deposits and provide for the implementation of continuous monitoring during mining operations, eliminating the possibility of undesirable environmental consequences. .

The presence of substances with toxic properties in dust increases its danger. The dust concentration in real production conditions can range from several mg/m3 to hundreds of mg/m3. GOST 12.1.005-88 “General sanitary and hygienic requirements for the air of the working area” establishes maximum permissible concentrations (MAC) of dust in the air of the working area.

6. Means and methods of protection against harmful factors at work

Prevention and prevention measures: dust control measures are determined by the nature of production. In order to reduce the harmful effects of dust on workers, if the maximum permissible concentration is exceeded, work time is limited, personal protective equipment is used, local and general ventilation is used, and constant wet cleaning of premises is used.

Measures to combat the formation of coal dust:

1.Moistening of coal seams (preliminary injection of water into the seam).

2.Irrigation, pneumatic hydroirrigation.

.Water curtains.

.Water-air ejectors.

.Hydrojet sprayers.

.Dust collection (dust extractors, construction of casings on embankments, fabric partitions)

.Dust-removing ventilation

.Sharp cutting tool.

Measures to prevent coal dust explosion:

1.Rinse, moisturize.

2.Serging.

.Whitewashing: lime-cement mortar; 1 part cement, 2 parts lime, 30 parts water.

.Water curtains, foggers.

.Oslanization.

.Shale or water barriers.

.Drinking water, or from treatment facilities.

Health activities. Reduced dust levels; heating the air supplied to the mine during the cold season; eliminating seepage and accumulation of water in places where workers stay and move; installation of heated chambers in the courtyards near the shaft for miners waiting to rise; installation of rational welfare facilities with dressing rooms, showers, installations for storage, dust removal, drying, washing and repair of work clothes, daily sanitation of microtraumas, washing of safety shoes, ultraviolet irradiation of workers. In coal mines - the installation of mobile heated rooms to warm workers in the cold season, insulation of the cabins of excavators, bulldozers and dump trucks, timely delivery of the necessary protective clothing and footwear.

In order to prevent occupational diseases in the coal industry, mandatory preliminary examinations have been introduced upon entry into work and periodic medical examinations. Those working in tunneling and clearing operations are subject to a medical examination once every 12 months, other mine workers - once every 24 months. There is a wide network of dispensaries equipped with the necessary equipment for physiotherapeutic procedures, therapeutic exercises, and diet. Recently, the so-called comprehensive mechanization of coal mining has been widely introduced, based on the use of powerful coal miners, metal shields and powered roof supports, which will make it possible to switch to remote control units.

Protection of miners from the harmful effects of dust includes:

air dust removal;

organization of ventilation of mine workings;

measures to combat dust in the air entering the mine from the surface;

providing miners with personal protective equipment against dust (filtering respirators). A healthy lifestyle and avoidance of bad habits, adequate sleep, balanced nutrition, exercise, breathing exercises. .

CONCLUSION

Coal industry is a branch of industry for the extraction of hard coal from its deposits in the earth's crust. There are two methods of coal mining: closed (in mines) and open (in open pits, quarries).

The main work in mines is: cutting the seam using cutters, breaking coal using explosives, pneumatic jackhammers, combines, “mechanized” complexes or hydraulically. Coal is transported from the longwalls by conveyors to the haulage drift and delivered to the shaft by electric locomotives for delivery to the surface.

In open-pit mines, the coal seam is loosened using the drilling and blasting method, the coal is loaded onto dump trucks and transported to the surface.

Leading professions in underground work: tunnelers, drillers, blasters, bulk breakers, riggers, combine and cutter operators. In most mines they are organized into complex teams with wide interchangeability. The leading professions in the quarries are drillers, blasters, excavator and electric locomotive drivers, bulldozer and dump truck drivers.

Occupational hazards in the coal industry: unfavorable meteorological conditions, emission of dust (see) and harmful gases, noise (see), vibration (see), forced body position on gently sloping thin seams, in hydraulic mines there is a danger of eye injuries (for hydraulic monitor workers).

Almost all coal mines contain methane, carbon dioxide, carbon monoxide, sulfur dioxide and nitrogen oxides.

Dust in the air of mines and open pit mines consists of coal and rock particles. The mineral content in it ranges from 15 to 40%, free silicon dioxide - from 1 to 10%. According to Sanitary Standards SN 245-71, the maximum permissible concentration of coal dust in the air of workings should not exceed 10 mg/m3 - when the free silicon dioxide content in coal is up to 2% and 4 mg/m3 - when its content is more than 2%. However, dust content in the air often exceeds this value many times, especially when harvesters are operating. To reduce dust formation during coal mining, the following are used: 1) injecting water into the coal seam before extracting coal from it; 2) spray irrigation with water in places of greatest dust formation; 3) dry dust collection from coal mining sites using special devices of a combine or “mechanized complex”.

Occupational injuries are always higher among workers in the face group. The most common reasons are violations of safety regulations during mining and coal transportation.

Occupational diseases: silicosis, silicic anthracosis, anthracosilicosis; observed among workers in rock and coal faces with an average of 15-20 years of work experience. Bursitis (see) occurs in those working on gently sloping seams, vibration disease - in combine operators working in mines with steep seams and in drillers.

Pustular skin diseases and colds, myositis, neuritis, radiculitis are more common among workers in cold, damp coalfaces, when working in an uncomfortable position and under great physical stress.

Bibliography

1. T.A. Hwang, P.A. Hwang. Fundamentals of ecology. Series "Textbooks and teaching aids". - Rostov n/d: "Phoenix", 2001. - 256 p.

Belov S.V. Life safety - 1999 - 449 p.

O.E. Falova. Physiology of the respiratory system - 2006 - 124 p.

Life safety: Tutorial. Part 2 / E.A. Rezchikov, V.B. Nosov, E.P. Pyshkina, E.G. Shcherbak, N.S. Chvertkin / Edited by E.A. Rezchikova. - M.: MGIU, - 1998.

5. Golubev E.I.. Cleaning works. - M: Medicine, 1998.

6. Ecology and life safety: textbook. manual for universities / D.A. Krivoshein, L.A. Ant, N.N. Roeva and others; Ed. L.A. Ant. - M.: UNITY-DANA, 2000. - 447 p.

Similar works to - Coal dust. Physiological mechanisms of damaging effects on the body

One of the main mistakes made when operating a standard coal boiler is the use of low-quality fuel. There is one single rule that must be strictly used when choosing fuel for the boiler - this is the choice of coal with exactly the characteristics specified in technical documentation. Otherwise, the operation of the device may be not only unproductive, but also unsafe.

Fuel selection

Often, owners of heating boilers are faced with the question of using coal dust. You need to know that not every device is designed for this type of operation. First, you should study the parameters of the device, and only after that, with special responsibility, approach the choice of combustible material according to its composition, fraction, and brand.

Coal dust may differ not only in composition, but also technical characteristics– combustion temperature, efficiency, heat transfer. Of course, all of the above data directly depends on the type of product itself. Today, the most common fuel options are the following: lignite, stone, charcoal, brown coal, anthracite. Each of them has its own parameters of humidity, ash residue, carbon content, density, and calorific value. Combustion of combustible material of different manufacturers and composition can give completely different heating results.

Kindling methods

Considering in detail the question of how to burn with coal dust, it is necessary first of all to note that a high content of its particles in the air is explosive.

There are three options for using this type of fuel.

The first and most common is the use of a special device - a burner, into which coal is supplied under pressure. In this case, combustion occurs with a continuous air flow.

The second way is to ignite the boiler more traditional way– wood and coarse coal, only after this the dust is added. In this case, high concentrations of fuel elements should be avoided.

The third way to light a boiler is to produce briquettes yourself. To do this, fuel is mixed with sawdust, keeping the proportions 1/1. Add water and then mix thoroughly; the solution should resemble a plaster mixture. Small briquettes are formed from the resulting mass and dried in the open air.

Of course, the least dangerous way to burn coal dust in a boiler is to use a special device.

Not the best the best option. High humidity - they will burn poorly

Advantages of this type of fuel

Residential heating using coal various shapes has a number of advantages.

Firstly, these are excellent characteristics: high heat transfer properties, long burnout time. On average, one bookmark is enough for 10-12 hours of heating.

Secondly, big choice different brands, differing in composition and density. When choosing a mixture, you should pay special attention to the moisture coefficient: the lower it is, the easier it is to use the material during operation.

As a rule, manufacturers indicate on the packaging the characteristics, as well as instructions on how to burn coal dust in various conditions - a home heating boiler, an industrial furnace, etc.

You can buy coal dust from us at a competitive price. We guarantee excellent quality and individual service to each client.

INTRODUCTION

Relevance. The rapid development of the coal industry in the Donbass and other regions of the Russian Federation, the introduction of new equipment and technology in production require workers, engineers and technicians to have clearer knowledge, careful adherence to occupational hygiene rules and healthy lifestyle standards.

Miners, metro construction workers, masons, workers in cement, brick, tile, flour, and sugar factories, road workers, molders, foundry workers, textile workers, and confectionery workers are exposed to dust. When dust particles enter the respiratory tract, they cause inflammation of the tissue of the pulmonary vesicles, which leads to the development of connective tissue in them. Bronchopulmonary diseases of occupational etiology continue to be the most important medical problem in terms of the amount of social damage caused, which is primarily due to insufficient knowledge of the mechanisms of action of fibrogenic dust of mixed composition, as well as the action of combined factors of gases, aerosols, etc.

Coal dust is assessed from two points of view: sanitary and hygienic and safety. The sanitary and hygienic significance of coal dust is determined by the changes that it causes in the respiratory system. The main place among them is pneumoconiosis. The most important role in protecting the body from the harmful effects of industrial environmental factors belongs to nonspecific protection, its basal main link, namely, phagocytosis carried out by alveolar macrophages of the lungs and blood neutrophils. In the development of protective and adaptive mechanisms that arise in the body at the early stages of the pathological process, an important role belongs to the earliest metabolic reactions occurring at the cellular and subcellular levels.

Chemical and physical properties of coal dust

Dust is characterized by a set of properties that determine its behavior in the air, its transformation in the body, and its effect on the body. Of the various properties of industrial dust, the chemical composition, solubility, dispersion, explosiveness, shape, electrical charge, and radioactivity are of greatest importance.

The most important properties of dust are directly determined by their dispersion, particle shape, good dissolution ability and unique chemical composition. To evaluate dust from a hygienic point of view, the most important characteristic is nothing more than dispersion.

Dust formation in different mines is not the same and depends on the mining and geological conditions, the microstructure of the coal, its strength, humidity, the conditions of the seam, as well as the method of extracting coal, the mechanisms used, etc. It has been shown that on hard coals the formation of dust is approximately 25% greater, than on soft ones. Wet coal produces less dust. More dust is formed on steep seams than on flat ones, which is associated with the descent of coal. Excavation of coal along the cleavage (bedding) produces less dust than excavation against the cleavage. The main operations associated with dust emission are coal mining with a combine, seam cutting with a shearer, manual and jackhammer breaking, conveyor loading, coal breaking on steep seams with jackhammers, loading coal from a conveyor into trolleys, roadheader operation, drilling and blasting operations, machine loading of rock, delivery to the shaft by trolleys, unloading of skips.

In terms of dust generation intensity, not all of these operations are equivalent. According to research, 95% of all dust is generated in mines. Of the total amount of dust generated, 60% comes from the operation of machinery, about 20% from blasting in the face, 10% from breaking and 10% from other work. .

The amount of dust suspended in the air also varies in different mines depending on the reasons mentioned above. The highest dust content in the air is usually observed during the operation of combine harvesters; in the absence of dust control means, its concentration can reach several grams per 1 m3 of air. Another most dusty operation is the operation of a shearing machine, a roadheader. Dust concentrations can reach hundreds of milligrams per 1 m3. Air dust content during dry drilling can reach up to 1000 mg/m3. High dust levels are observed during blasting operations. On steeply dipping seams, large dust formation (several thousand milligrams per 1 m3) is observed when coal is lowered to the loading hatch.

Coal dust is generated during the following production operations:

1. Coal breaking with combines and blasting operations.

2. Drilling holes.

3. Loading coal with loading machines.

4. Transportation of coal by conveyors.

5. Loading at loading and unloading points.

Maximum permissible concentrations of coal dust:

The process of grinding dispersed materials is well described by Rittinger's law (the specific energy consumption for grinding is directly proportional to the size of the newly formed surface.

Coal dust is well transported by air flow or combustion products. The dust-air mixture forms a very mobile emulsion that has the properties of a liquid and is easily pumped through pipes. In individual dust preparation systems located directly at the steam generator, the dust concentration in the air mixture is relatively low and is usually |A1= = 0.5 h-1 kg of dust per 1 kg of air (or gases). If there is a central dust plant (CDP), dust is transported from the CPZ bins to the dust bunkers of steam generators at high concentrations (about 30-35 kg of dust/kg of air) through small-section pipelines using transfer pumps, in which the dust is mixed with compressed air having a pressure of 0. 5-1 MPa (5-10 kgf/cm2). Pumping of a highly concentrated dust-air mixture can be carried out over long distances, on the order of several hundred meters.

Factors affecting the explosiveness of coal dust:

1. Explosive concentration of suspended coal dust from 16 - 96 g/m3 to 2000 g/m3.

2. The yield of volatile substances is 15% or more.

3. The size of dust particles is up to 1 mm, the smaller it is, the more dangerous.

The ignition temperature of coal dust is 750 - 850 0 C. The speed of the blast wave is 1000 m/sec. The strongest explosion is at a concentration of 300 - 400 g/m3. When the combine is operating without irrigation, the dust content in the air is 50 g/m3, with blasting and blasting - 300 g/m3. The deposition of coal dust during the operation of a roadheader is 600 g/m3 per day at the face. When the shearer is operating - 900 g/m3 per day. At loading points (transfers) - 100 g/m3 per day. 4. Humidity and ash content - the higher the humidity and ash content of coal, the less explosive the dust is. The dispersion of dust suspended in the air is generally high: up to 40-80% of dust particles have sizes up to 1.3 microns, 15-35% - up to 2.6 microns, 5-20% - up to 4 microns and 3-10% - over 4 microns.

How can you get rid of coal dust?

We are not considering the answer - only by ceasing to mine coal. The experience of the Siberian Anthracite company in the Novosibirsk region shows that the problem of dust suppression can be solved by using bischofite, a magnesium-based brine. This solution is used to water the road along which dump trucks loaded with coal drive.

Coal dust became a political topic, primarily due to riots and public rallies in port cities Far East. However, there is also local protest against suspensions in the air, which clearly do not enrich breathing. For example, last year a wave of negative publications hit the Siberian Anthracite company. The leading producer and exporter of anthracite coal in Russia and the world (UltraHighGrade) mines in the Iskitim region of the Novosibirsk region.

The Novosibirsk region is not Kuzbass, although it borders on it; and it is difficult to imagine that just 60 km from the metropolis of Novosibirsk, such valuable raw materials for metallurgists are mined. Residents of the village of Urgun, through which a section of the technological road passes from the open pit to the processing plant, where anthracite is enriched and then loaded into wagons and sent for export, knew about mining, as they say, firsthand. The village itself is located outside the sanitary protection zone, but what meets the standards on paper does not look so beautiful in real life.

However, the technological road, along which there is a constant flow of dump trucks (up to 120 vehicles per day), has been running along the mine and the village for several decades. The coal woke up, was crushed by wheels - and hung in the air. It is worth noting that the amount of suspended solids was always below the MPC level. But a couple of years ago, the current residents of Urgun got tired of this. Siberian Anthracite did not turn a blind eye to the requests of several hundred local residents and found a solution. And last year we tested it in practice.

The company modestly emphasizes that there is no special innovation in the use of magnesium chloride brine, or bischofite. This product has long been used in other regions, including the coal-mining Kuzbass. But for the Novosibirsk region, bischofite, of course, became a curiosity. Chief Editor "Oxygen.LIFE" Alexander Popov went to the enterprise and Urgun to see everything not only with his own eyes, but also to breathe with his own lungs. It turned out that an overall simple innovation - a binding solution for dust suppression - works quite effectively, and everyone seems to be happy.

Ineffective "phlegm"

All mining enterprises are forced to deal with dust suppression in one way or another. It’s just that coal miners always get more – due to the fact that coal dust is the most noticeable and unpleasant substance. Of course, this problem is most acute in ports. But even at the Siberian Anthracite open-pit mines (Kolyvansky and Gorlovsky), dust accounts for about half of the total emissions of pollutants into the atmosphere. The problem worsens during the hot period - from May to October.

For many years, yes, in fact, the entire history that the open-pit mines were functioning, they fought with dust in the old fashioned way - every two hours a water truck drove along the technological road and simply poured water on it. Scientifically, this is called the “wet” method of dust suppression. As noted in a publication in the journal “Ecology of Production” (No. 5 for 2015), such methods “are used to prevent dust generated during destruction, loading and transportation from rising into the air.” rock; for air dust removal or suppression of suspended dust with water; to prevent the re-introduction of settled dust particles into the air. Water moisturizes and binds dust particles.”

Everything would be fine, but “wet” methods of dealing with dust are not highly effective. The main disadvantage is obvious even to a person far from coal mining: the effect of watering the road, especially in summer period, will be short, like the heat in Siberia. And all this turns into huge costs for the company - after all, you need to constantly drive cars with water, which means that you have to get not only water from somewhere, but also gasoline, drivers’ salaries, and incur costs for depreciation of the equipment. To live through “Groundhog Day” several times a day.

“Wet” methods of dealing with dust are similar to the labor of Sisyphus: the effect of watering the road, especially in summer, will be short

What is bischofite?

It was necessary to find a way in which the dust settling on the road simply could not rise into the air. There are such solutions; Siberian Anthracite chose bischofite. This is granular or liquid magnesium chloride with a main substance content (MgCl2) of 47%. In bischofite, which was named after its discoverer - a German geologist and scientist Gustav Bischof– contained a large number of microelements (about 65), due to which its composition is superior to sea salt and Dead Sea salt. Extraction occurs by dissolving the mineral layer artesian water and obtaining a concentrated salt brine.

A trial purchase from a manufacturer in Volgograd and test tests of this substance took place in the Iskitim region at the end of last summer. But then autumn came, followed by winter, and the problem “resolved” itself thanks to the weather. “In spring and autumn we do not use bischofite due to precipitation. There is no point in winter either, winter period We do snow removal to keep cars from getting stuck and slipping. And we use bischofite from the end of April-May and, as last year’s experience showed, somewhere until mid-October. Everything dries out and minerals, as well as gravel and sand, thaw on the roads. We clean it up with graders, but it all starts to gather dust, and we have to do dust suppression,” says the head of the Siberian Anthracite Motor Transport Department. Alexey Fedorov.

Since this year, bischofite has been introduced into dust suppression practice in full. It looks like this. Concentrated particles, similar in appearance to coarse snow-white salt, are diluted in water in about five minutes at a rate of one to four. The brine is poured into a regular watering machine and sent along the technological route to the open-pit mine closest to the enterprise. First, an ordinary water truck clears the road, followed by the one with the solution. Only this small, a couple of kilometers, section that passes by Urgun has to be splashed. Along the entire further length of the road, right up to the Kolyvan cut (which is more than 40 km), there is no life so close to it.

For a square meter of gravel, the quality of which would be the envy of asphalt roads in many settlements, 100 grams of crystalline magnesium chloride is sufficient. Then you need to wait about 15 minutes, during which a kind of film forms on the surface of the route. The coating has a truly unique property: it absorbs moisture from the air and retains it for a long time, from five to 10 days. The road looks as if it has just been sprinkled with rain; but coal dust does not rise and hang in the air, and, accordingly, does not scatter around. “Bishofite also has the property that it does not dry out, but remains in a viscous state. And if a section of the road is covered with bischofite, then the cars roll it further with their wheels,” adds the head of the environmental protection department of Siberian Anthracite. Artem Burtsev.

Head of the Siberian Anthracite Motor Transport Department Alexey Fedorov: “In spring and autumn we do not use bischofitis due to precipitation. In winter there is no point either; in winter we engage in snow fighting. And we use bischofite from the end of April-May and, as shown

Are there any disadvantages?

Price. Siberian Anthracite does not disclose the volume of costs for the purchase of bischofite. But it is obvious that any amount goes to expenses one way or another - after all, the water that was used to water the road was and remains free (it is formed when the layers are ruptured at the cut itself). However, the company emphasizes that in the end they still win. First of all, no matter how much water you waste, the “wet” method of dust suppression is a priori ineffective. And after treating with bischofite, you don’t have to go near the road for a week.

Bischofite also extends the life of the road surface by providing soil stabilization. And all this, as a result, has a positive effect on the service life of trucks, including engines, which suffer from coal dust no less than the lungs of Urgun residents and enterprise workers.

Other advantages include significant savings in time and costs. As already mentioned, water trucks drove along the road almost every two hours; It is enough to drive a car with bischofite solution once a week. The number of watering machine trips is reduced by 264 times per month, and total consumption water over the same period - almost 100%. Finally, according to measurements from the specialized and accredited laboratory of Rosprirodnadzor LLC Center for Hygienic Expertise, the use of bischofite reduces the presence of suspended substances in the air by 57-85%.

The main disadvantage is the rain. “He washes everything away,” Alexey Fedorov announces the verdict. So with what nature doesn't have bad weather, the company disagrees. But at the same time, nothing remains of the bischofite, no waste at all - if it is not washed away by rain, it rolls down and goes into the soil. It turns out that the land along the road in Urgun is abundantly fertilized with salts almost from the Dead Sea. By the way, bischofite in Siberian Anthracite is also used in winter. But not for irrigation, but against freezing of coal in cars.

How do other companies solve the problem of coal dust?

"Oxygen.LIFE" I addressed this question to the coal miners of Kuzbass. At the open-pit mines of the Southern Kuzbass company in summer time“hydraulic dust removal of technological roads” is being carried out - in other words, banal watering, and around the clock. At the company's sorting complexes, processing plants and transfer points, coal mass irrigation systems are installed, which moisten the coal during crushing.

In closed mining, in mines, dust becomes a factor increased danger. But there is no escape from it: it is formed during the separation of coal and rock from the massif during the operation of combines, excavation and loading machines, during blasting operations, as well as during loading, reloading and transportation of rock mass. The danger of coal dust, recalls the Raspadskaya Management Company (part of the Evraz Group), lies in its ability to explode. “Explosivity depends on volatile matter content, ash content, moisture content, fineness and concentration. Coal dust can explode if it contains more than 10% volatile substances with an ash content and moisture content of less than 40%, with a particle size of less than 0.1 mm and at a concentration of more than 1000 mg/cubic meter. The immediate causes of a coal dust explosion can be: an open flame, a flash or explosion of gas, blasting operations, a malfunction in electrical networks or devices and any exposure to high temperatures,” the company described the dangers. In addition, high dust levels in the air significantly reduce visibility, which is also dangerous for working in the mine.

To reduce dust concentrations, modern machines are used in mines, coal seams are pre-moistened, dust-forming areas are watered, and the workings are constantly ventilated. “Wetting (irrigation) of coal and rock occurs during all processes associated with the release of dust into the atmosphere: during the operation of shearers and tunneling machines, drilling rigs and reloading of coal along a chain of conveyors. Irrigation when the combine is operating at the face is carried out with a special foaming agent. To eliminate local accumulations of coal dust, regular washing of mine workings and mining equipment is carried out,” said the Southern Kuzbass. They water not only water, but also apply wetting and binding substances to the mine workings, and also install water or fog-forming curtains.

In addition to “hydropust explosion protection”, another method is used in mines – “shaling of mine workings”. “Essentially, this is an artificial increase in the ash content of coal dust, which is deposited on the surface of workings, by adding inert dust made from finely ground non-combustible material, most often dolomite, limestone or shale. High-quality inert dust should easily disperse and form a dust cloud that reduces the temperature of the flame of an explosion or flash,” said Raspadskaya. This method is used as dust is deposited or “based on the forecast of dust content in the mine air in the mine workings.” According to the company, more than 200 million rubles are spent annually on dust suppression measures. Of this amount, about 40 million rubles are for the purchase of inert dust in the amount of 12 thousand tons.

The costs of fighting dust in Southern Kuzbass were not disclosed. But they noted that this constant work “allows us to prevent the development of occupational pulmonary pathology among workers, reduce injuries and accidents during the operation of vehicles, as well as the burden on the environment. At the same time, labor productivity increases, losses during mining are reduced and wear and tear on mining transport equipment is reduced.”

Coal dust is generated during the following production operations:

1. Coal breaking with combines and blasting operations.
2. Drilling holes.
3. Loading coal with loading machines.
4. Transportation of coal by conveyors.
5. Loading at loading and unloading points.

Maximum permissible concentrations coal dust:

Factors affecting the explosiveness of coal dust:

1. Explosive concentration of suspended coal dust
   from 16 - 96g/m3 to 2000 g/m3.
2. The yield of volatile substances is 15% or more.
3. The size of dust particles is up to 1 mm, the smaller it is, the more dangerous.

The ignition temperature of coal dust is 750 - 850 0 C.
Blast wave speed 1000 m/sec.
The strongest explosion at a concentration of 300 - 400 g/m3,
When the combine is operating without irrigation, the air dust content is
50 g/m3, with blast-blasting - 300 g/m3.
The deposition of coal dust during the operation of a roadheader is 600 g/m3 per day at the face.
When the shearer is operating - 900 g/m3 per day.
At loading points (transfers) - 100 g/m3 per day.
4. Humidity and ash content - the higher the humidity and ash content of coal, the less explosive the dust is.

Measures against education coal dust:

1. Moistening of coal seams (preliminary injection of water into the seam).
2. Irrigation, pneumatic hydroirrigation.
3. Water curtains.
4. Water-air ejectors.
5. Hydrojet sprayers.
6. Dust collection (dust extractors, construction of casings on embankments, fabric partitions)
7. Dust-removing ventilation
8. Sharp cutting tool.

Explosion Prevention Measures coal dust

1. Rinse, moisturize.
2. Serging.
3. Whitewashing: lime-cement mortar; 1 part cement, 2 parts lime, 30 parts water.
4. Water curtains, foggers.
5. Oslanization.
6. Shale or water barriers.
7. Drinking water, or from treatment facilities.

Localization of explosions methane gas and coal dust

Screens.

Designed to localize (prevent the spread of) methane explosions
and coal dust.

SHALE– shelves - trapezoidal support. Width 250-500 mm.
The distance between the shelves is equal to the width of the shelf.
There are small sides - 5 cm. Inert dust is filled in -
(from slate, dolomite, shell rock)
The shelves are filled at the rate of 400 kg per 1 m2 of cross section
workings, the length of the barrier is at least 20 m.
The first barrier is installed no closer than 60m from the face,
subsequent ones - no further than 300m.

WATER– vessels with a capacity of more than 80 liters, trapezoidal cross-section 150 x 300 x 250
The amount of water and vessels at the rate of 400 liters per 1 m2 of cross-sectional area of ​​the excavation, length 30 m installation - no closer than 75 m,
Subsequent ones no further - 250m.

Automatic system explosion suppression - explosion localization (ASVP-LV)

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