A method for preventing spontaneous combustion of a gangue pile

Abstract

The present application relates to coal gangue mountain treatment technical field, and disclose a kind of fire extinguishing method for preventing gangue mountain spontaneous combustion, for the spontaneous combustion treatment problem of gangue mountain, the present application uses nitrogen injection to cooperate with the treatment mode of conduction heat dissipation, heat conduction rod column is used to the heat conduction of inner layer of gangue mountain, realize cooling treatment and reduce the spontaneous combustion probability of gangue mountain, and nitrogen injection rod column is injected into nitrogen into inner layer of gangue mountain, oxygen supply space is reduced by nitrogen gas and oxygen content, both realize rapid fire extinguishing under the cooperation of continuing, compared with traditional rolling and grouting treatment mode has better treatment effect, heat conduction rod column and nitrogen injection rod column are all set with the structure of rod column, simple structure has lower installation and use cost, heat conduction rod column and nitrogen injection rod column are all installed with pile column buried insertion type, installation is not affected by topography, geographical position and can be completed by punching and inserting installation, installation construction is convenient.

Description

Technical Field

[0001] This invention relates to the field of coal gangue pile management technology, specifically to a fire extinguishing method for preventing spontaneous combustion of coal gangue piles. Background Technology

[0002] Coal gangue is a solid waste generated and discharged during coal mining and processing, accounting for approximately 10% to 15% of total coal production. In recent years, with the continuous improvement of coal mining mechanization and the rapid development of the coal sorting and processing industry, the amount of coal gangue discharged has increased year by year. The accumulation of large quantities of coal gangue has now formed thousands of gangue mountains of varying sizes, occupying land, wasting resources, and, more seriously, causing spontaneous combustion of gangue mountains under long-term oxidation in the air, polluting the atmospheric environment and endangering public health.

[0003] Conditions and process of spontaneous combustion of coal gangue piles:

[0004] ① Gangue has spontaneous combustion properties

[0005] ② There is enough oxygen

[0006] ③ It has good heat storage conditions

[0007] If a certain part of a coal gangue pile meets the above three conditions, it will generate a large amount of heat through physical adsorption and chemical adsorption. When the ignition point of the coal gangue is reached, it enters an oxygen-deficient combustion state. After entering the combustion state, the surrounding gangue material becomes the combustion material of this spontaneous combustion source, forming an uncontrollable spontaneous combustion fire.

[0008] Currently, the main remediation methods are based on oxygen isolation, with the most representative being the layered compaction method and the grouting method. Both of these methods achieve flame retardancy by isolating oxygen, which is not only difficult to implement but also has a limited effective time. Over time, due to wind and rain, the surface and slope soil becomes loose and cracked. In addition, the loose soil required for the growth of vegetation roots makes it difficult to prevent the intrusion of rainwater and oxygen. As a result, the previously treated coal gangue piles have successively experienced varying degrees of re-ignition. Therefore, a fire extinguishing method to prevent spontaneous combustion of coal gangue piles and its extinguishing method are proposed. Summary of the Invention

[0009] The purpose of this invention is to provide a fire extinguishing method for preventing spontaneous combustion of coal gangue piles, comprising the following steps:

[0010] S1. Hole location planning and opening: Transport the prepared heat-conducting rod column and nitrogen injection rod column to the gangue mountain area, select the installation location in the gangue mountain area, then plan the hole location by positioning measurement and mark it by sprinkling ash. After completion, use drilling equipment to drill and open the heat-conducting installation hole and nitrogen injection installation hole at the marked location.

[0011] S2. Heat-conducting rod installation: After the holes are opened, the heat-conducting rod is installed into the inside of the holes by alignment and insertion according to the installation requirements, and the surrounding area is sealed and filled with fine sand.

[0012] S3. Nitrogen injection rod installation: According to the installation requirements, the nitrogen injection rod is installed into the inside of the nitrogen injection installation hole by alignment and plugging, and the surrounding soil layer is sealed and compacted.

[0013] S4. Heat dissipation: After the heat-conducting rods are installed, the heat-conducting rods that are in contact with the inner layer of the gangue pile conduct heat and quickly transfer the heat to the upper part of the heat-conducting rods through the heat exchange medium to achieve heat conduction and dissipation of the inner layer of the gangue pile, thus completing the heat dissipation and cooling of the inner layer of the gangue pile.

[0014] S5. Nitrogen injection operation: An external gas supply pipe is connected to the upper part of the nitrogen injection rod. Nitrogen gas from the gas tank is transported into the nitrogen injection rod through the pipeline, and then injected into the slag layer of the spontaneous combustion zone of the gangue hill through the nitrogen injection rod. The discharged nitrogen gas is evenly diffused into the slag layer of the spontaneous combustion zone of the gangue hill through the diffusion pores. By squeezing the oxygen supply space in the slag layer of the spontaneous combustion zone, the oxygen content is reduced. With the continuous cooperation of the heat-conducting rod, the purpose of rapid fire extinguishing is achieved.

[0015] Preferably, both the heat-conducting rod and the nitrogen-injecting rod in S1 are metal rods, with a total length of 5m for the heat-conducting rod and 6m for the nitrogen-injecting rod. The opening depth of the heat-conducting mounting hole is 3.4-3.8m, and the opening depth of the nitrogen-injecting mounting hole is 5.4-5.6m.

[0016] Preferably, the heat-conducting rods in S2 are arranged in a grid and installed with varying spacing according to the temperature zone distribution. For the high-temperature zone (spontaneous combustion zone) above 320℃, the horizontal spacing is 3m; for the medium-temperature zone (heat storage zone) between 80-320℃, the horizontal spacing is 4-5m; and for the low-temperature zone (control zone) below 80℃, the horizontal spacing is 5-6m.

[0017] Preferably, in the above-mentioned S2, the depth of the heat absorption zone of the heat-conducting rod embedded under the ground surface is 3.4-3.8m, and the height of the exposed heat dissipation zone of the heat-conducting rod located above the ground surface is 1.2-1.6m.

[0018] Preferably, in the above-mentioned S3, the nitrogen injection rods are arranged in a staggered pattern only in the spontaneous combustion zone, the horizontal installation spacing between adjacent nitrogen injection rods is 5m, the insertion depth of the nitrogen injection rods under the ground surface is 5.4-5.6m, and the height of the exposed area of ​​the nitrogen injection rods above the ground surface is 0.4-0.6m.

[0019] Preferably, the heat-conducting rod column in the above-mentioned S4 is provided with a heat exchange cavity for filling the heat exchange medium. The upper outer side of the heat-conducting rod column is provided with heat dissipation fins. When working, the heat exchange medium after being heated absorbs heat and turns into a gaseous state and moves upward, quickly conducting the heat to the heat dissipation fins on the upper part of the heat-conducting rod column, and then quickly dissipating the heat through the heat dissipation fins. The heat exchange medium after releasing heat turns into a liquid state again and flows into the lower part of the heat exchange cavity. The cycle is repeated to achieve heat dissipation and cooling of the inner layer of the gangue pile.

[0020] Preferably, the upper part of the nitrogen injection rod in the above-mentioned S5 is provided with a gas supply interface for connecting the gas supply pipeline, and the lower part of the nitrogen injection rod is provided with a diffusion port for supplying nitrogen gas.

[0021] As a preferred option, the working principle of the nitrogen injection rod column in S5 above is as follows: The oxygen transmission mechanism in coal gangue mainly includes the following:

[0022] ① Molecular diffusion caused by oxygen concentration gradient (F yk )

[0023] ② Natural convection (F zD )

[0024] ③ Thermal convection (F rD )

[0025] ④ Chimney effect (F ys )

[0026] The above four phenomena are the main sources of oxygen when coal gangue is self-heating;

[0027] Total nitrogen – F DQ The total amount of oxygen before nitrogen injection is Y1; the total amount of oxygen after nitrogen injection is Y2. Therefore, the total amount of oxygen available for spontaneous combustion, Y1, is calculated as follows:

[0028] Y1 = F yk +F zD +F rD +F ys

[0029] Y2 = Y1 - F DQ

[0030] At this point, Y2 < Y1

[0031] By continuously injecting nitrogen to occupy the oxygen supply space, F DQ ↑ Makes Y1 ↓;

[0032] Let Y2 << Y1

[0033] At this point, the combustion conditions are disrupted, and the combustion rate drops sharply or stops.

[0034] Compared with the prior art, the present invention, employing the above technical solution, has the following technical effects:

[0035] 1. This invention employs a nitrogen injection combined with conductive heat dissipation method. It utilizes heat-conducting rods to conduct and dissipate heat from the inner layer of the waste rock pile, thereby cooling the pile and reducing its heat storage conditions. Nitrogen is injected into the inner layer of the waste rock pile through nitrogen injection rods, which reduces the oxygen content by crowding out the oxygen supply space. The continuous combination of these two methods can effectively extinguish spontaneous combustion of the waste rock pile, achieving better treatment results compared to traditional compaction and grouting methods.

[0036] 2. Both the heat-conducting rod column and the nitrogen-injecting rod column adopt a rod column structure, which is simple in structure and has low installation and use costs. Both the heat-conducting rod column and the nitrogen-injecting rod column adopt a pile-column embedded installation method, which is not affected by terrain or geographical location and can be installed by drilling and plugging. The installation and construction are convenient. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is a schematic diagram of the steps in the fire extinguishing method for preventing spontaneous combustion of coal gangue piles according to the present invention; Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] It should be noted that the structures, proportions, sizes, etc., shown in the accompanying drawings of this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the conditions under which this application can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size should still fall within the scope of the technical content disclosed in this application, provided that they do not affect the effects and purposes that this application can produce.

[0041] Example

[0042] Please see Figure 1 This invention provides a technical solution: a fire extinguishing method to prevent spontaneous combustion of coal gangue piles, the specific steps of which are as follows:

[0043] S1. Hole Position Planning and Drilling: The prepared heat-conducting and nitrogen-injecting rods are transported to the waste rock pile area. Both the heat-conducting and nitrogen-injecting rods are metal rods, specifically seamless steel pipes. The total length of the heat-conducting rod is 5m, and the total length of the nitrogen-injecting rod is 6m. The structure is simple and has low installation and usage costs. Both the heat-conducting and nitrogen-injecting rods adopt a pile-type embedded installation method, which is not affected by terrain or geographical location and can be completed by drilling and plugging. The installation is convenient. First, the installation location is selected in the waste rock pile area. Then, the hole positions are planned by positioning and measurement and marked by spreading ash. After completion, drilling equipment is used to drill and open the heat-conducting installation holes and nitrogen-injecting installation holes at the marked locations. Specifically, the drilling depth of the heat-conducting installation holes is 3.5m, and the drilling depth of the nitrogen-injecting installation holes is 5.5m.

[0044] S2. Heat-conducting rod installation: After drilling the holes, install the heat-conducting rods into the drilled holes using alignment and insertion, and then seal and compact the surrounding soil with fine sand. Specifically, the heat-conducting rods are arranged in a grid pattern and installed with varying spacing according to the temperature zone distribution.

[0045] For high-temperature zones (spontaneous combustion zones) above 320℃, the horizontal installation spacing is 3m;

[0046] For the medium temperature zone (heat storage zone) of 80-320℃, the horizontal spacing for installation is 4-5m;

[0047] For low-temperature zones (control zones) below 80℃, the horizontal spacing for installation is 5-6m;

[0048] Regarding installation depth: the heat absorption zone of the heat-conducting rod column is 3.5m deep when it is embedded under the ground surface, and the exposed heat dissipation zone of the heat-conducting rod column is 1.5m high.

[0049] Specific results: After the temperature control device was installed, it rapidly and continuously released clean heat energy. The temperature of the external heat dissipation area remained between 30℃ and 60℃, with a peak release temperature reaching nearly 100℃. A 3m deep temperature measuring tube was installed adjacent to the temperature control device. After 60 days of continuous monitoring, the average temperature drop was 106℃, showing a clear downward trend. The temperature stabilized around 100℃.

[0050] S3. Nitrogen injection rod installation: According to the installation requirements, the nitrogen injection rod is installed into the inside of the nitrogen injection installation hole by alignment and insertion, and the surrounding soil layer is sealed and compacted. The nitrogen injection rods are arranged in a staggered pattern, with a horizontal installation spacing of 5m between adjacent nitrogen injection rods. The insertion depth of the nitrogen injection rod under the ground surface is 5.5m, and the height of the exposed area of ​​the nitrogen injection rod above the ground surface is 0.5m.

[0051] S4. Heat dissipation: After the heat-conducting rod is installed, the heat-conducting rod in contact with the inner layer of the gangue pile conducts heat and quickly transfers the heat to the upper part of the heat-conducting rod through the heat exchange medium, thereby dissipating the heat in the inner layer of the gangue pile. The heat-conducting rod has an internal heat exchange cavity for filling the heat exchange medium, and heat dissipation fins are provided on the upper outer side of the heat-conducting rod. During operation, the heated heat exchange medium absorbs heat, turns into a gaseous state, and rises, quickly transferring the heat to the heat dissipation fins on the upper part of the heat-conducting rod, and then quickly dissipating the heat through the heat dissipation fins. After releasing heat, the heat exchange medium turns into a liquid state again and flows into the lower part of the heat exchange cavity. This cycle repeats to achieve heat dissipation and cooling of the inner layer of the gangue pile, thus completing the heat dissipation and cooling of the inner layer of the gangue pile.

[0052] S5. Nitrogen Injection Operation: The upper part of the nitrogen injection rod is equipped with a gas supply interface for connecting to the gas supply pipeline, and the lower part is equipped with a diffusion vent for nitrogen discharge. An external gas supply pipe is connected to the upper part of the heat-conducting rod, and nitrogen is transported into the heat-conducting rod through the pipeline. The nitrogen is then injected into the slag layer of the spontaneous combustion zone of the coal gangue pile through the heat-conducting rod. A certain amount of pressurized nitrogen is injected into the designated extinguishing area at a depth of 5-6m above the ground surface, with a spacing of 5m. The total number of injection points is determined according to the size of the site. The discharged nitrogen diffuses evenly into the slag layer of the spontaneous combustion zone of the coal gangue pile through the diffusion vent. By squeezing the oxygen supply space in the slag layer, the oxygen content is reduced. With the continuous cooperation of the heat-conducting rod, rapid fire extinguishing is achieved. The working principle of the nitrogen injection rod: The oxygen transmission mechanism in coal gangue piles mainly includes the following:

[0053] ① Molecular diffusion caused by oxygen concentration gradient (F yk )

[0054] ② Natural convection (F zD )

[0055] ③ Thermal convection (F rD )

[0056] ④ Chimney effect (F ys )

[0057] The above four phenomena are the main sources of oxygen when coal gangue is self-heating;

[0058] Total nitrogen – F DQ The total amount of oxygen before nitrogen injection is Y1; the total amount of oxygen after nitrogen injection is Y2. Therefore, the total amount of oxygen available for spontaneous combustion, Y1, is calculated as follows:

[0059] Y1 = F yk +F zD +F rD +F ys

[0060] Y2 = Y1 - F DQ

[0061] At this point, Y2 < Y1

[0062] By continuously injecting nitrogen to occupy the oxygen supply space, F DQ ↑ Makes Y1 ↓;

[0063] Let Y2 << Y1

[0064] At this point, the combustion conditions are disrupted, and the combustion rate drops sharply or stops.

[0065] Specific results: After 60 days of monitoring, a 3-meter deep temperature measuring tube installed at a horizontal distance of 1.5m from the temperature control device showed an average temperature decrease of 16℃. After 60 days of monitoring, a 3-meter deep temperature measuring tube installed in an area without the device showed an average temperature increase of 23℃, showing a significant upward trend. The heat-conducting rod column was used to conduct and dissipate heat from the inner layer of the waste rock pile, achieving cooling treatment and reducing the probability of spontaneous combustion of the waste rock pile. Nitrogen was injected into the inner layer of the waste rock pile through a nitrogen injection rod column. The nitrogen squeezed the oxygen supply space, reducing the oxygen content. The continuous cooperation of the two achieved rapid fire extinguishing, which is faster and more thorough than the traditional compaction and grouting treatment methods.

[0066] In summary, this invention employs a nitrogen injection combined with conductive heat dissipation method. It utilizes heat-conducting rods to conduct and dissipate heat from the inner layer of the waste rock pile, achieving cooling and reducing the probability of spontaneous combustion. Nitrogen is injected into the inner layer of the waste rock pile through nitrogen injection rods, reducing oxygen content by crowding out oxygen supply space. The continuous combination of these two methods enables rapid fire extinguishing, which is faster and more thorough than traditional compaction and grouting methods. Both the heat-conducting and nitrogen injection rods use a rod-type structure, which is simple and has low installation and usage costs. Both rods are installed using a pile-pile embedding method, which is unaffected by terrain or geographical location and can be installed simply by drilling and plugging, making installation convenient.

[0067] Those skilled in the art will understand that the features described in the various embodiments and / or claims of the present invention can be combined or combined in various ways, even if such combinations or combinations are not explicitly described in the present invention. In particular, the features described in the various embodiments and / or claims of the present invention can be combined or combined in various ways without departing from the spirit and teachings of the present invention. All such combinations and / or combinations fall within the scope of the present invention.

Claims

1. A method for extinguishing fires to prevent spontaneous combustion of coal gangue piles, characterized in that, Includes the following steps: S1. Hole location planning and opening: Transport the prepared heat-conducting rod column and nitrogen injection rod column to the gangue mountain area, select the installation location in the gangue mountain area, then plan the hole location by positioning measurement and mark it by sprinkling ash. After completion, use drilling equipment to drill and open the heat-conducting installation hole and nitrogen injection installation hole at the marked location. S2. Heat-conducting rod installation: After the holes are opened, the heat-conducting rod is installed into the inside of the holes by alignment and insertion according to the installation requirements, and the surrounding area is sealed and filled with fine sand. S3. Nitrogen injection rod installation: According to the installation requirements, the nitrogen injection rod is installed into the inside of the nitrogen injection installation hole by alignment and plugging, and the surrounding soil layer is sealed and compacted. S4. Heat dissipation: After the heat-conducting rods are installed, the heat-conducting rods that are in contact with the inner layer of the gangue pile conduct heat and quickly transfer the heat to the upper part of the heat-conducting rods through the heat exchange medium to achieve heat conduction and dissipation of the inner layer of the gangue pile, thus completing the heat dissipation and cooling of the inner layer of the gangue pile. S5. Nitrogen injection operation: An external gas supply pipe is connected to the upper part of the nitrogen injection rod column. Nitrogen gas is transported into the nitrogen injection rod column through the pipeline and injected into the slag layer of the spontaneous combustion zone of the gangue mountain through the nitrogen injection rod column. The discharged nitrogen gas is evenly diffused into the slag layer of the spontaneous combustion zone of the gangue mountain through the diffusion pores. By squeezing the oxygen supply space in the slag layer of the spontaneous combustion zone, the oxygen content is reduced. With the continuous cooperation of the heat-conducting rod column, rapid fire extinguishing is achieved.

2. The fire extinguishing method for preventing spontaneous combustion of coal gangue piles according to claim 1, characterized in that: Both the heat-conducting rod and the nitrogen-injecting rod in S1 are metal rods. The total length of the heat-conducting rod is 5m, and the total length of the nitrogen-injecting rod is 6m. The opening depth of the heat-conducting mounting hole is 3.4-3.8m, and the opening depth of the nitrogen-injecting mounting hole is 5.4-5.6m.

3. The fire extinguishing method for preventing spontaneous combustion of coal gangue piles according to claim 1, characterized in that: In S2, the heat-conducting rods are arranged in a grid and installed with varying spacing according to the temperature zone distribution. For the high-temperature zone (spontaneous combustion zone) above 320℃, the horizontal spacing is 3m; for the medium-temperature zone (heat storage zone) between 80-320℃, the horizontal spacing is 4-5m; and for the low-temperature zone (control zone) below 80℃, the horizontal spacing is 5-6m.

4. A fire extinguishing method for preventing spontaneous combustion of coal gangue piles according to claim 1, characterized in that: In S2, the depth of the heat absorption zone where the heat-conducting rod is implanted under the ground surface is 3.4-3.6m, and the height of the exposed heat dissipation zone of the heat-conducting rod above the ground surface is 1.2-1.6m.

5. A fire extinguishing method for preventing spontaneous combustion of coal gangue piles according to claim 1, characterized in that: In S3, nitrogen injection poles are arranged in a staggered pattern, with a horizontal installation spacing of 5m between adjacent nitrogen injection poles. The insertion depth of the nitrogen injection poles below the ground surface is 5.4-5.6m, and the height of the exposed area of ​​the nitrogen injection poles above the ground surface is 0.4-0.6m.

6. A fire extinguishing method for preventing spontaneous combustion of coal gangue piles according to claim 1, characterized in that: The S4 heat-conducting rod column has an internal heat exchange cavity for filling the heat exchange medium. The upper outer side of the heat-conducting rod column is equipped with heat dissipation fins. During operation, the heated heat exchange medium absorbs heat, turns into a gaseous state, and rises, quickly conducting the heat to the heat dissipation fins on the upper part of the heat-conducting rod column. The heat is then quickly dissipated through the heat dissipation fins. After releasing heat, the heat exchange medium turns into a liquid state again and flows into the lower part of the heat exchange cavity. This cycle repeats to achieve heat dissipation and cooling of the inner layer of the gangue pile.

7. A fire extinguishing method for preventing spontaneous combustion of coal gangue piles according to claim 1, characterized in that: The upper part of the nitrogen injection rod in the S5 is equipped with a gas supply interface for connecting the gas supply pipeline, and the lower part of the nitrogen injection rod is equipped with a diffusion port for nitrogen gas discharge.

8. A fire extinguishing method for preventing spontaneous combustion of coal gangue piles according to claim 7, characterized in that: The working principle of nitrogen injection rods in S5: The oxygen transport mechanism in coal gangue mainly includes the following: ① Molecular diffusion caused by oxygen concentration gradient (F yk ) ② Natural convection (F zD ) ③ Thermal convection (F rD ) ④ Chimney effect (F ys ) The above four phenomena are the main sources of oxygen when coal gangue is self-heating; Total nitrogen – F DQ The total amount of oxygen before nitrogen injection is Y1; the total amount of oxygen after nitrogen injection is Y2. Therefore, the total amount of oxygen available for spontaneous combustion, Y1, is calculated as follows: Y1=F yk +F zD +F rD +F ys Y2=Y1-F DQ At this point, Y2 < Y1 By continuously injecting nitrogen to occupy the oxygen supply space, F DQ ↑ Makes Y1 ↓; Let Y2 << Y1 At this point, the combustion conditions are disrupted, and the combustion rate drops sharply or stops.

Images