Method for preventing coal self-ignition in mines

FIELD: mining.

SUBSTANCE: method involves supply of frozen fluid obtained by mixing with liquid gas to the worked-out space. In addition, distribution of coal dust supplied to the worked-out space is determined as to particle fractions. Distribution of the obtained frozen fluid particles as to fractions is equal to distribution of coal dust as to particle fractions.

EFFECT: improving the prevention efficiency of coal self-ignition in mines.

 

The invention relates to the mining industry and can be used to prevent fires from spontaneous combustion of coal in mined-out space mines.

The known method of preventing spontaneous combustion of coal in the mines, including the isolation of a goaf mines by building bridges in mines (A.A. Skochinsky, A.A., Ogielski V.M. Mine fires. - M.: Whiteheat, 1954. - 387 S.).

The disadvantage of this method is low efficiency due to the system of air through the jumpers and the impossibility of their facilities in the existing faces.

Also known way to prevent spontaneous combustion of coal, including the filing in a goaf inert gas (see A.S. 158837, CL 21F 5/00).

The disadvantage of this method is the resumption of the process of spontaneous combustion of coal in the event of termination of the supply of inert gas.

The closest technical solution is the way to prevent spontaneous combustion of coal in the mines, including the filing in a goaf frozen liquid obtained by mixing with liquid gas (A.S. 1718981 CL A62C 5/00; A.S. 1714159, CL 21F 5/00).

The disadvantage of this method is its low efficiency due to the unmanageable process settling in the developed space pulverized coal supplied structure.

Technical is the result of the invention is to improve the efficiency of the method of prevention of spontaneous combustion of coal in the mines.

This technical result is achieved that the way to prevent spontaneous combustion of coal in the mines, including the filing in a goaf frozen liquid obtained by mixing with liquid gas, according to the invention further define the distribution of the fractions of particles of coal dust, carried away in the mined-out area, and the distribution of the obtained particles of the frozen liquid fractions is equal to the distribution of the fractions of particles of coal dust.

The introduction of increasingly powerful coal mining machinery in the mines leads to an increase in the number of coal dust generated during coal mining. Moreover, a significant amount of this coal dust entrained in the mined-out area, settling in hollows and cracks. Due to the large specific surface coal dust has a high chemical activity and able to spontaneously upon contact with air, if its mass reaches a critical value.

When driving on the worked-out space of the process particles of coal dust depends on particle size and flow velocity of carrier gas. The velocity of the gas in the developed space is determined by the cross-sectional area of the channels, which moves the mixture of gas and coal dust. Since the cross-sectional area of the channels in the developed space is changing, and quantities of the coal dust deposited in different areas of the goaf will be different.

In a known way with not a controlled particle size of the frozen liquid settling of particles of coal dust and frozen liquid may not be the same, so some accumulations of coal dust will have the number of the settled frozen liquid in a quantity sufficient to prevent spontaneous combustion of coal.

Adjusting the particle size of the frozen liquid will distribute the particles in the channels goaf settling in proportion to the quantity of coal dust. To achieve this effect it is necessary to determine the distribution of particles of coal dust on fractions.

The same distribution on fractions create the formed particles of the frozen liquid. Therefore, moving the frozen particles of a liquid are deposited in the mined-out space in proportion to coal dust deposited uniformly processing the coal particles during the melting of the frozen liquid and reducing its reactivity and temperature.

An example of a specific application of the method

Coal mining was accompanied by the formation of large amounts of dust, carried away by the flow of air in the goaf. The high reactivity of coal dust has led to the development of spontaneous combustion deposited in mined-out space dust, ended the isolation of the site from loss ogledow is a growing technology.

To prevent spontaneous combustion of coal dust in the air flow coming into the goaf, it was decided to submit the particles of the frozen fluid from the joint dispersion liquid gas (liquid nitrogen) or liquid. In this case, the used liquid antipiren (aqueous urea solution). For uniform distribution of antipyrene settled in coal dust were initially carried out the measurements of the concentration of coal dust in the air and the distribution of dust particles in fractions. The measurements showed that the concentration of coal dust in the air coming into the goaf, is 0.8 g/m3. Dispersion analysis showed that the distribution of dust fractions following:

- less than 5 μm - 10%;

from 5 to 20 μm - 25%;

from 20 to 40 μm - 30%;

from 40 to 60 μm - 25%;

from 60 to 100 μm - 5%;

more than 100 μm is 5%.

For uniform filling of sedimentary coal dust particles of frozen liquid, the liquid before freezing spray to particles, which are distributed on fractions correspond to fractions of coal dust. To this end, pick up the nozzle, in which the formation of liquid particles, and the ratio of fluid flow through the respective nozzles, which allows to obtain the desired distribution of the frozen particles of a liquid fractions. So, were selected 6 injectors. the first formed particles down to 5 microns, the second from 5 to 20 μm, the third from 20 to 40 μm, fourth from 40 to 60 μm, fifth from 60 to 100 μm, in the sixth over 100 microns. Then determined the costs of liquid through the nozzle, allowing to obtain percentage distribution of particles freezing liquid fractions, corresponding to the distribution of dust particles. For example, when the total consumption of liquid antipyrene 6 l/min, at first nozzle filed 0.6 l/min fluid, the second 1.5 l/min, the third is-1.8 l/min, fourth - 1.5 l/min, fifth and sixth - 0.3 l/min. Through preventive work, managed to avoid self-ignition in the developed space.

The application of the proposed method will reduce the economic damage caused by endogenous fires mines, by preventing the spontaneous combustion process and improve the safety of mining operations.

The way to prevent spontaneous combustion of coal in the mines, including the filing in a goaf frozen liquid obtained by mixing with liquid gas, characterized in that it further determine the distribution of the fractions of particles of coal dust, carried away in the mined-out area, and the distribution of the obtained particles of the frozen liquid fractions is equal to the distribution of the fractions of particles of coal dust.



 

Same patents:

FIELD: mining.

SUBSTANCE: previously laboratory analysis is carried out on coal from a bed and its packs to detect availability of elements and substances in them that may create compounds with water; natural cracking is detected, as well as cleat in the coal bed; wells are drilled from a bottomhole by coal, with length more than by 1 m of the mine skirting cycle; water is injected into the bed with continuous measurements of the methane, water pressure, injection time; the mine is tunnelled for the value of the hydrated bed with the speed that does not exceed methane release within permissible norms; in the area of bed hydration blast holes are drilled in the sides of the mine at each cycle to detect the hydration area. During arrangement of the mine, parameters are varied, which are related to injection of water into bed, maximum reduction of the released methane, optimising arrangement of the mine.

EFFECT: higher efficiency of development of gas-bearing coal beds.

4 dwg

FIELD: mining.

SUBSTANCE: method includes long-term treatment of a dust and gas cloud with water vapour during the blast and afterwards. Vapour is produced by a mobile steam generator by introduction of water in it that has been heated previously up to 65-70°C. The steam generator is installed in the place that is safe from the blast and is directed along with the wind. Besides, prior to blasting, atmosphere above the blasting area undergoes treatment.

EFFECT: higher efficiency of dust suppression, manoeuvrability of plants.

1 dwg

FIELD: mechanics.

SUBSTANCE: device of pressure water supply to irrigation systems arranged on sections of shield mechanised support for underground mines, includes at least one system of plough or combine working element route irrigation in longwall, and at least one system for irrigation of worked space, upper ceiling and/or side mine with central water line for supply of spray nozzles of irrigation systems and switching valves. At the same time all switching valves for irrigation systems are installed in a single irrigation valve box, which is equipped with connection for water line and is arranged on section of shield mechanised support in the form of unit separated from hydraulic valve box.

EFFECT: improved operational safety of device for water supply into irrigation system.

8 cl, 4 dwg

FIELD: mining.

SUBSTANCE: invention is related to the field of mining, in particular, to safety issues in coal mines, namely to explosions of methane caused by friction spark created as a result of mine machines picks friction against hard rocks. Method is suggested to assess danger of rocks regarding friction inflammation of air-methane mixture, which consists in the fact that rock samples are taken, their strength and content of silicon dioxide are determined, and then tests are carried out at test bench danger of friction sparking. In order to perform test, explosive mixture is formed in test bench, and nominal cutting speed is increased 1.5 times. If at hardness of rocks f from 3 and content of silicon dioxide up to 30% no inflammations were observed and no friction sparks were produced, then rock is considered safe. If at hardness of rock from 3 to 5 and silicon dioxide content from 30 to 50% with availability of friction sparks with temperature of up to 300°C and absence of inflammations, rock is considered as spark-hazardous of the 1st extent, and if their temperature is more than 300°C - to spark-hazardous of the 2nd extent. If at least one inflammation occurred from friction sparks, rock is considered highly explosive. Use of suggested method makes it possible to increase safety of cleaning and preparatory works.

EFFECT: development of fundamentals for rock classification procedure by danger of friction inflammation in case of their damage with account of their physical-mechanical properties.

FIELD: mining, particularly to depress dust generated during rock milling in enterprises of mining and smelting, coal, construction industries.

SUBSTANCE: plant comprises control unit, high-pressure source, siphon-type vessels filled with ionized water having opposite polarities, spraying jets, which generate fine spray, electromagnetically driven pneumatic and hydraulic valves, pressurizing and purging air channels, water pipelines, coupling members for air and water pipelines and control circuits.

EFFECT: increased dust depression efficiency.

1 dwg

FIELD: mining industry, particularly to catch dust generated by machines and/or rigs in mines and tunnels.

SUBSTANCE: dust catcher comprises body with precipitation member formed as demister comprising moistening nozzles and drip catching means. Fan with drive is arranged near inlet/outlet side thereof. Moistening nozzles located in front of the demister in air flow direction are made as spaced multijet nozzles having separate sprayers, which form common sprayed curtain. The fan is installed in cleaned gas flow downstream the demister and drip catching means. The fan is arranged in case connected to dust catcher body. Demister is installed in contaminated air flow at inlet side and is arranged in inclined position. Upper edge thereof projects relatively lower edge. Air deflectors are arranged between the demister and drip catching means. Bottom sheet is inclined towards drip catching means. Multijet nozzles project towards contaminated air flow and are connected to load-bearing frame obliquely installed in accordance with demister inclination angle. Dust catcher is provided with separate vessels for additives, which pass through metering device into water-pipe. Mixer connected to water-pipe or built in water-pipe is installed downstream the metering device. Spraying device is arranged in front of moistening nozzles and demister with drip catching means. Spraying device comprises spraying heads, which create water mist and is connected with water source or with water-pipe and metering device with mixer. Dust-contaminated air flow is mixed with water mist and then the obtained sludge is gathered. Moist air is dried by water droplet separation and then the dried air is introduced in cleaned gas flow. Gases generated as a result of explosion are laden with water mist preliminarily mixed with additives, which create ecologically safe compositions with nitrose or similar gases formed during explosion.

EFFECT: increased operational efficiency and reduced dust catcher size.

20 cl, 8 dwg

FIELD: mining industry, particularly means or methods for preventing, binding, depositing, or removing dust and preventing explosions or fires.

SUBSTANCE: method involves treating dust-and-gas cloud with finely-dispersed ionized liquid, for instance with water, with the use of sprinkling plants alternately arranged so that ions of liquid spays generated by plants have opposite charges. The sprinkling plants are located outside zone of possible plant damage or are protected against explosion action. Sequence of plant alternation, ionicity, liquid quantity and liquid spraying pattern are determined from tests and calculations based on particular pit or underground mine blasting conditions.

EFFECT: reduced time of particle coagulation on liquid droplets and time of particle precipitation, possibility to reduce dust cloud propagation.

2 cl, 2 dwg

FIELD: mining, particularly methods and devices to prevent dust generation in tailing pit benches by moistening thereof with water or liquid binding agent.

SUBSTANCE: device comprises self-moving vehicle, for instance pontoon water craft, provided with pump, vessel for reagent, hydraulic monitor, unit with executive tool for channel forming in bank area and isolated power generating plant. Above mechanisms are installed on water craft deck. Hydraulic monitor may rotate in horizontal and vertical planes. Drives of all mechanisms are linked with the power generating plant. Executive tool is installed below water craft floating line. Vessel for reagent is provided with proportioning device. Dust control method involves initially installing the water craft on tailing pit water surface; directing the water craft towards bank to area to be sprayed, in which working tool forms channel for water craft movement; pumping water from tailing pit into hydraulic monitor; adding reagent from vessel to water with the use of proportioning device and spraying the obtained liquid over dust-forming area. Water from tailing pit is used for above spraying operation and for water craft movement.

EFFECT: increased dust control efficiency.

2 cl, 2 dwg

The invention relates to a ventilation flow in underground mine workings, mining companies

The invention relates to the mining industry, namely to underground coal mining

FIELD: mining, particularly methods and devices to prevent dust generation in tailing pit benches by moistening thereof with water or liquid binding agent.

SUBSTANCE: device comprises self-moving vehicle, for instance pontoon water craft, provided with pump, vessel for reagent, hydraulic monitor, unit with executive tool for channel forming in bank area and isolated power generating plant. Above mechanisms are installed on water craft deck. Hydraulic monitor may rotate in horizontal and vertical planes. Drives of all mechanisms are linked with the power generating plant. Executive tool is installed below water craft floating line. Vessel for reagent is provided with proportioning device. Dust control method involves initially installing the water craft on tailing pit water surface; directing the water craft towards bank to area to be sprayed, in which working tool forms channel for water craft movement; pumping water from tailing pit into hydraulic monitor; adding reagent from vessel to water with the use of proportioning device and spraying the obtained liquid over dust-forming area. Water from tailing pit is used for above spraying operation and for water craft movement.

EFFECT: increased dust control efficiency.

2 cl, 2 dwg

FIELD: mining industry, particularly means or methods for preventing, binding, depositing, or removing dust and preventing explosions or fires.

SUBSTANCE: method involves treating dust-and-gas cloud with finely-dispersed ionized liquid, for instance with water, with the use of sprinkling plants alternately arranged so that ions of liquid spays generated by plants have opposite charges. The sprinkling plants are located outside zone of possible plant damage or are protected against explosion action. Sequence of plant alternation, ionicity, liquid quantity and liquid spraying pattern are determined from tests and calculations based on particular pit or underground mine blasting conditions.

EFFECT: reduced time of particle coagulation on liquid droplets and time of particle precipitation, possibility to reduce dust cloud propagation.

2 cl, 2 dwg

FIELD: mining industry, particularly to catch dust generated by machines and/or rigs in mines and tunnels.

SUBSTANCE: dust catcher comprises body with precipitation member formed as demister comprising moistening nozzles and drip catching means. Fan with drive is arranged near inlet/outlet side thereof. Moistening nozzles located in front of the demister in air flow direction are made as spaced multijet nozzles having separate sprayers, which form common sprayed curtain. The fan is installed in cleaned gas flow downstream the demister and drip catching means. The fan is arranged in case connected to dust catcher body. Demister is installed in contaminated air flow at inlet side and is arranged in inclined position. Upper edge thereof projects relatively lower edge. Air deflectors are arranged between the demister and drip catching means. Bottom sheet is inclined towards drip catching means. Multijet nozzles project towards contaminated air flow and are connected to load-bearing frame obliquely installed in accordance with demister inclination angle. Dust catcher is provided with separate vessels for additives, which pass through metering device into water-pipe. Mixer connected to water-pipe or built in water-pipe is installed downstream the metering device. Spraying device is arranged in front of moistening nozzles and demister with drip catching means. Spraying device comprises spraying heads, which create water mist and is connected with water source or with water-pipe and metering device with mixer. Dust-contaminated air flow is mixed with water mist and then the obtained sludge is gathered. Moist air is dried by water droplet separation and then the dried air is introduced in cleaned gas flow. Gases generated as a result of explosion are laden with water mist preliminarily mixed with additives, which create ecologically safe compositions with nitrose or similar gases formed during explosion.

EFFECT: increased operational efficiency and reduced dust catcher size.

20 cl, 8 dwg

FIELD: mining, particularly to depress dust generated during rock milling in enterprises of mining and smelting, coal, construction industries.

SUBSTANCE: plant comprises control unit, high-pressure source, siphon-type vessels filled with ionized water having opposite polarities, spraying jets, which generate fine spray, electromagnetically driven pneumatic and hydraulic valves, pressurizing and purging air channels, water pipelines, coupling members for air and water pipelines and control circuits.

EFFECT: increased dust depression efficiency.

1 dwg

FIELD: mining.

SUBSTANCE: invention is related to the field of mining, in particular, to safety issues in coal mines, namely to explosions of methane caused by friction spark created as a result of mine machines picks friction against hard rocks. Method is suggested to assess danger of rocks regarding friction inflammation of air-methane mixture, which consists in the fact that rock samples are taken, their strength and content of silicon dioxide are determined, and then tests are carried out at test bench danger of friction sparking. In order to perform test, explosive mixture is formed in test bench, and nominal cutting speed is increased 1.5 times. If at hardness of rocks f from 3 and content of silicon dioxide up to 30% no inflammations were observed and no friction sparks were produced, then rock is considered safe. If at hardness of rock from 3 to 5 and silicon dioxide content from 30 to 50% with availability of friction sparks with temperature of up to 300°C and absence of inflammations, rock is considered as spark-hazardous of the 1st extent, and if their temperature is more than 300°C - to spark-hazardous of the 2nd extent. If at least one inflammation occurred from friction sparks, rock is considered highly explosive. Use of suggested method makes it possible to increase safety of cleaning and preparatory works.

EFFECT: development of fundamentals for rock classification procedure by danger of friction inflammation in case of their damage with account of their physical-mechanical properties.

FIELD: mechanics.

SUBSTANCE: device of pressure water supply to irrigation systems arranged on sections of shield mechanised support for underground mines, includes at least one system of plough or combine working element route irrigation in longwall, and at least one system for irrigation of worked space, upper ceiling and/or side mine with central water line for supply of spray nozzles of irrigation systems and switching valves. At the same time all switching valves for irrigation systems are installed in a single irrigation valve box, which is equipped with connection for water line and is arranged on section of shield mechanised support in the form of unit separated from hydraulic valve box.

EFFECT: improved operational safety of device for water supply into irrigation system.

8 cl, 4 dwg

FIELD: mining.

SUBSTANCE: method includes long-term treatment of a dust and gas cloud with water vapour during the blast and afterwards. Vapour is produced by a mobile steam generator by introduction of water in it that has been heated previously up to 65-70°C. The steam generator is installed in the place that is safe from the blast and is directed along with the wind. Besides, prior to blasting, atmosphere above the blasting area undergoes treatment.

EFFECT: higher efficiency of dust suppression, manoeuvrability of plants.

1 dwg

FIELD: mining.

SUBSTANCE: previously laboratory analysis is carried out on coal from a bed and its packs to detect availability of elements and substances in them that may create compounds with water; natural cracking is detected, as well as cleat in the coal bed; wells are drilled from a bottomhole by coal, with length more than by 1 m of the mine skirting cycle; water is injected into the bed with continuous measurements of the methane, water pressure, injection time; the mine is tunnelled for the value of the hydrated bed with the speed that does not exceed methane release within permissible norms; in the area of bed hydration blast holes are drilled in the sides of the mine at each cycle to detect the hydration area. During arrangement of the mine, parameters are varied, which are related to injection of water into bed, maximum reduction of the released methane, optimising arrangement of the mine.

EFFECT: higher efficiency of development of gas-bearing coal beds.

4 dwg

FIELD: mining.

SUBSTANCE: method involves supply of frozen fluid obtained by mixing with liquid gas to the worked-out space. In addition, distribution of coal dust supplied to the worked-out space is determined as to particle fractions. Distribution of the obtained frozen fluid particles as to fractions is equal to distribution of coal dust as to particle fractions.

EFFECT: improving the prevention efficiency of coal self-ignition in mines.

FIELD: mining.

SUBSTANCE: method includes spraying a liquid in a flow of air arriving to a mined space. At the same time liquid spraying is alternated with supply of dry gas into coal deposits. Moisture content in gas discharged from the coal deposit is measured. Gas supply is replaced with liquid spraying in case moisture content stops dropping in gas discharged from coal deposit.

EFFECT: improved safety of mining works.

Up!