Comprehensive treatment method for spontaneous combustion of coal gangue

Abstract

The invention discloses a coal gangue spontaneous combustion comprehensive treatment method, which belongs to the field of coal gangue treatment, and comprises the following steps: S1, regularly collecting temperature distribution of a coal gangue storage yard, and determining a potential spontaneous combustion area of the coal gangue storage yard in combination with a quantitative evaluation model of coal gangue spontaneous combustion harm; s2, an acrylamide monomer is inserted between montmorillonite layers through a solution intercalation polymerization method, and a composite nanometer inhibitor is obtained; s3, the spraying density of the composite nano inhibitor is determined according to the danger assessment result, determined in the step S1, of the potential spontaneous combustion area, and the spraying amount is determined according to the volume of the potential spontaneous combustion area; and S4, directionally injecting the composite nano inhibitor with the determined spraying density into the potential spontaneous combustion area. According to the comprehensive treatment method for spontaneous combustion of the coal gangue, temperature monitoring, a quantitative evaluation model and preparation and application of the composite nano inhibitor are combined, a complete closed loop from monitoring and early warning to targeted treatment is formed, and therefore effective prevention and treatment of spontaneous combustion of the coal gangue are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of coal gangue treatment, and in particular to a comprehensive treatment method for spontaneous combustion of coal gangue. Background Art

[0002] Coal gangue is solid waste discharged during the coal mining and coal washing process. It is a black-gray rock with low carbon content and harder than coal that is associated with coal seams during the coal formation process. It includes excavation gangue during tunnel excavation, gangue mined from the roof, floor and interlayer during mining, and washed gangue picked out during coal washing. Its main components are Al2O3 and SiO2, and it also contains varying amounts of Fe2O3, CaO, MgO, Na2O, K2O, P2O5, SO3 and trace rare elements (gallium, vanadium, titanium, cobalt).

[0003] Since gangue contains combustibles such as residual coal, carbonaceous mudstone and waste wood, C and S can constitute the material basis for spontaneous combustion of gangue. Therefore, when gangue is piled in the open air, the heat inside the gangue mountain gradually accumulates over time. When the temperature reaches the combustion point of combustibles, the residual coal in the gangue pile can spontaneously combust. After spontaneous combustion, the temperature inside the gangue mountain is 800℃-1000℃, which melts the gangue and releases a large amount of harmful gases such as CO, CO2, SO2, H2S, NOx, etc., among which SO2 is the main one. The spontaneous combustion of a gangue mountain can last for more than ten years to several decades. The emission of these harmful gases not only reduces the environmental air quality around the gangue mountain and affects the health of residents in the mining area, but also often affects the surrounding ecological environment, causing slow growth of trees, increased pests and diseases, reduced crop yields, and even death.

[0004] To solve the above problems, the existing technology mainly adopts the following measures to prevent and control the spontaneous combustion of coal gangue and the environmental pollution caused by it:

[0005] 1. Waste rock pile fire extinguishing technology: Water injection cooling method: By injecting water into the waste rock pile, the temperature is lowered to prevent the combustion point of combustibles from being reached. This method is simple and easy to implement, but it consumes a lot of water and has limited effect on extinguishing deep spontaneous combustion.

[0006] 2. Grouting fire extinguishing method: inject fire extinguishing materials such as mud and fly ash into the waste rock pile to form an isolation layer to prevent oxygen from entering, thereby extinguishing the flames. This method has a good fire extinguishing effect, but the construction difficulty and cost are relatively high.

[0007] 3. Covering with flame retardant: Cover the surface of the waste rock heap with a layer of flame retardant material, such as loess, gravel, etc., to isolate the air and prevent spontaneous combustion. This method is suitable for small-scale or initial spontaneous combustion waste rock heaps, and its scope of application is limited. Summary of the invention

[0008] The purpose of the present invention is to provide a comprehensive treatment method for spontaneous combustion of coal gangue to solve the above technical problems.

[0009] To achieve the above object, the present invention provides a comprehensive treatment method for spontaneous combustion of coal gangue, comprising the following steps:

[0010] S1. Regularly collect the temperature distribution of the gangue dump and determine the potential spontaneous combustion area of ​​the gangue dump in combination with the quantitative assessment model of the spontaneous combustion hazard of gangue;

[0011] S2, inserting acrylamide monomer into the interlayer of montmorillonite by solution intercalation polymerization to obtain a composite nano-inhibitor;

[0012] S3, determining the spraying density of the composite nano-inhibitor according to the hazard assessment result of the potential spontaneous combustion area determined in step S1, and determining the spraying amount according to the volume of the potential spontaneous combustion area;

[0013] S4. Directly inject the composite nano-inhibitor with a determined spraying density into the potential spontaneous combustion area.

[0014] Preferably, step S1 specifically includes the following steps:

[0015] S11. Scan the gangue yard using infrared thermal imaging equipment and GPS equipment to generate a temperature distribution map of the gangue yard;

[0016] S12, taking coal gangue samples from different locations of the coal gangue yard, and numbering and marking the location of each coal gangue sample;

[0017] S13. Determine the evaluation indicators: aliphatic CH component, pyrite sulfur content, physical oxygen absorption capacity, ash content, ignition point temperature and thermal decomposition activation energy;

[0018] S14. Use the entropy weight method combined with the hierarchical analysis method to calculate the weight of each evaluation index and establish a quantitative evaluation model for the hazard of spontaneous combustion of coal gangue;

[0019] S15. Using the quantitative assessment model of the spontaneous combustion hazard of coal gangue, conduct a hazard assessment on each coal gangue sample and output the assessment result;

[0020] S16. Combine the evaluation results of each gangue sample with the temperature distribution map to determine the potential spontaneous combustion area.

[0021] Preferably, step S14 specifically includes the following steps:

[0022] S141. Calculate the weight of each evaluation indicator using the entropy weight method;

[0023] S1411. Calculate the information entropy H of each evaluation indicator j :

[0024]

[0025]

[0026] Where n is the number of coal gangue samples; p ij is the probability value of the i-th coal gangue sample on the j-th evaluation index; x ij is the value of the i-th coal gangue sample on the j-th evaluation index, and j∈(1,m), m is the number of evaluation indicators, m=6;

[0027] S1412. Calculate the coefficient of difference d for each evaluation indicator j :

[0028] d j =1-H j (3);

[0029] S1413. Calculate the weight w of each evaluation indicator j :

[0030]

[0031] S142, using the analytic hierarchy process to calculate the weight of each evaluation indicator;

[0032] S1421, construct judgment matrix A:

[0033]

[0034] In the formula, a jh Indicates the importance of the jth evaluation indicator relative to the hth evaluation indicator;

[0035] S1422, calculate the maximum eigenvalue λ max :

[0036]

[0037] Where β is the normalized vector; j is the jth element in the judgment matrix A;

[0038] S1423, consistency check:

[0039]

[0040]

[0041] In the formula, CI is the consistency index; RI is the random consistency index; CR represents the consistency ratio;

[0042] S1424. Judgment: When CR < Q, the judgment matrix A is determined to be consistent, and the normalized vector β at this time is output as the weight. Otherwise, return to step S1421 to adjust the judgment matrix A.

[0043] S143. Combine the weight w obtained by the entropy weight method j and the weight obtained by the analytic hierarchy process to obtain the final comprehensive weight w'. j :

[0044]

[0045] In the formula, α is a constant, and α ∈ (0, 1);

[0046] S144. Establish a quantitative evaluation model for the spontaneous combustion hazard of coal gangue:

[0047]

[0048] In the formula, D i is the spontaneous combustion hazard score of the i-th coal gangue sample.

[0049] Preferably, step S16 specifically includes the following steps:

[0050] S161. Determine the position coordinates of each coal gangue sample in the coal gangue yard based on its number and position mark.

[0051] S162. Integrate the hazard assessment results of each coal gangue sample with the position coordinates to obtain labeled data.

[0052] S163. Import the temperature distribution map into the geographic information system GIS as the base map, and add the labeled data to the new layer after creating a new layer.

[0053] S164. Use the geographic information system GIS for spatial analysis, search for areas where the temperature is higher than the set temperature threshold or the hazard assessment result is higher than the set assessment threshold, and label them as potential spontaneous combustion areas.

[0054] Preferably, step S2 specifically includes the following steps:

[0055] S21. Disperse montmorillonite in a solvent to form a uniform suspension.

[0056] S22. Add a quantitative acrylamide monomer to the suspension under stirring conditions.

[0057] S23. Add an initiator to the solution formed in step S22 at the set reaction temperature, so that the acrylamide monomer enters between the montmorillonite lamellae to initiate the polymerization reaction. After the reaction for the set time, a composite nano-inhibitor is obtained.

[0058] Preferably, the solvent in step S21 is water, and the weight percentage of montmorillonite in the suspension is 0.5wt%-2wt%;

[0059] In step S22, the mass ratio of acrylamide monomer to montmorillonite is 3:1-5:1;

[0060] In step S23, the reaction temperature is set to a range of 60°C-80°C, the reaction time is set to a range of 2h-6h, the initiator is ammonium persulfate, and the mass of the ammonium persulfate is 0.1%-1% of the total mass.

[0061] Preferably, step S3 specifically includes the following steps:

[0062] S31. By comparing the assessment results of the potential spontaneous combustion area with the level classification threshold, the potential spontaneous combustion area is divided into a high spontaneous combustion area, a medium spontaneous combustion area and a low spontaneous combustion area;

[0063] S32, setting the corresponding composite nano-inhibitor spraying density ρ corresponding to the high spontaneous combustion zone, the medium spontaneous combustion zone and the low spontaneous combustion zone divided in step S31;

[0064] S33. Calculate the spraying amount Q based on the volume V of the potential spontaneous combustion area and the corresponding spraying density ρ:

[0065] Q=V×ρ (11).

[0066] Preferably, in step S32, the spraying density range of the low spontaneous combustion zone is 0.5 kg / m 3 -1kg / m 3 ; The spraying density range in the spontaneous combustion zone is 1kg / m 3 -2kg / m 3 ; The spraying density range in the high spontaneous combustion area is 2kg / m 3 -3kg / m 3 .

[0067] Preferably, step S4 specifically includes the following steps:

[0068] S41, setting parameters: setting the injection speed and injection time based on the spraying amount described in step S3, and setting the injection pressure;

[0069] S42, extending the capillary nozzle with the nozzle into the potential spontaneous combustion area, and turning on the high-pressure pump according to the set parameters, injecting the composite nano-inhibitor in the storage tank into the potential spontaneous combustion area by using the high-pressure pump, and turning off the high-pressure pump after the injection time is over, and pulling out the capillary nozzle and the nozzle.

[0070] Preferably, in step S41, the injection pressure range is set to 5MPa-10MPa;

[0071] And based on Q=t×v, the injection time t and injection speed v are determined.

[0072] Therefore, the present invention adopts the above-mentioned comprehensive treatment method for spontaneous combustion of coal gangue, which has the following beneficial effects:

[0073] 1. Use multi-dimensional indicators (such as aliphatic CH components, pyrite sulfur content, etc.) to ensure the comprehensiveness and scientificity of the evaluation results;

[0074] 2. Combining two weight calculation methods (entropy weight method and hierarchical analysis method) improves the reliability and accuracy of the model;

[0075] 3. The combination of acrylamide monomer and montmorillonite enhances the stability and durability of the inhibitor, and the composite nanostructure gives the inhibitor stronger adsorption capacity and covering effect.

[0076] In summary, the present invention achieves effective prevention and control of spontaneous combustion of coal gangue by identifying potential spontaneous combustion areas and accurately injecting composite nano-inhibitors into the potential spontaneous combustion areas, thereby reducing environmental pollution and safety hazards.

[0077] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0078] Figure 1 The present invention is a flow chart of a comprehensive method for controlling spontaneous combustion of coal gangue. DETAILED DESCRIPTION

[0079] In order to make the purpose, technical scheme and advantages disclosed in the embodiments of the present invention clearer, the embodiments of the present invention are further described in detail in combination with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the embodiments of the present invention and are not used to limit the embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions.

[0080] It should be noted that the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or server that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units that are not explicitly listed or inherent to these processes, methods, products or devices.

[0081] The embodiments of the present invention are described in detail below in conjunction with the accompanying drawings.

[0082] like Figure 1 As shown, a comprehensive treatment method for spontaneous combustion of coal gangue includes the following steps:

[0083] S1. Regularly collect the temperature distribution of the gangue dump and determine the potential spontaneous combustion area of ​​the gangue dump in combination with the quantitative assessment model of the spontaneous combustion hazard of gangue;

[0084] Step S1 specifically includes the following steps:

[0085] S11. Scan the gangue yard using infrared thermal imaging equipment and GPS equipment to generate a temperature distribution map of the gangue yard;

[0086] S12, taking coal gangue samples from different locations of the coal gangue yard, and numbering and marking the location of each coal gangue sample;

[0087] S13. Determine the evaluation indicators: aliphatic CH component, pyrite sulfur content, physical oxygen absorption capacity, ash content, ignition point temperature and thermal decomposition activation energy; and the spontaneous combustion hazard of coal gangue is positively correlated with the aliphatic CH component, pyrite sulfur content and physical oxygen absorption capacity, and negatively correlated with the ash content, ignition point temperature and thermal decomposition activation energy.

[0088] S14. Use the entropy weight method combined with the hierarchical analysis method to calculate the weight of each evaluation index and establish a quantitative evaluation model for the hazard of spontaneous combustion of coal gangue;

[0089] Step S14 specifically includes the following steps:

[0090] S141. Calculate the weight of each evaluation indicator using the entropy weight method;

[0091] S1411. Calculate the information entropy H of each evaluation indicator j :

[0092]

[0093]

[0094] Where n is the number of coal gangue samples; p ij is the probability value of the i-th coal gangue sample on the j-th evaluation index; x ij is the value of the i-th coal gangue sample on the j-th evaluation index, and j∈(1,m), m is the number of evaluation indicators, m=6;

[0095] S1412. Calculate the coefficient of difference d for each evaluation indicator j :

[0096] d j =1-H j(3);

[0097] S1413. Calculate the weight w of each evaluation index j :

[0098]

[0099] S142. Calculate the weight of each evaluation index using the analytic hierarchy process;

[0100] S1421. Construct the judgment matrix A:

[0101]

[0102] In the formula, a jh represents the importance of the jth evaluation index relative to the hth evaluation index;

[0103] S1422. Calculate the maximum eigenvalue λ max :

[0104]

[0105] In the formula, β is the normalized vector; β j is the jth element in the judgment matrix A;

[0106] S1423. Consistency test:

[0107]

[0108]

[0109] In the formula, CI is the consistency index; RI is the random consistency index; CR represents the consistency ratio;

[0110] S1424. Judgment: When CR < Q, the judgment matrix A is considered consistent, and the normalized vector β at this time is output as the weight Otherwise, return to step S1421 to adjust the judgment matrix A;

[0111] S143. Combine the weight w obtained by the entropy weight method j and the weight obtained by the analytic hierarchy process to obtain the final comprehensive weight w'; j :

[0112]

[0113] In the formula, α is a constant, and α ∈ (0, 1);

[0114] S144. Establish a quantitative evaluation model for the spontaneous combustion hazard of coal gangue:

[0115]

[0116] Where D i is the spontaneous combustion hazard score of the i-th coal gangue sample.

[0117] S15. Using the quantitative assessment model of the spontaneous combustion hazard of coal gangue, conduct a hazard assessment on each coal gangue sample and output the assessment result;

[0118] S16. Combine the evaluation results of each gangue sample with the temperature distribution map to determine the potential spontaneous combustion area.

[0119] Step S16 specifically includes the following steps:

[0120] S161, determining the location coordinates of each gangue sample in the gangue yard based on the number and location mark of each gangue sample;

[0121] S162, integrating the hazard assessment result of each coal gangue sample with the location coordinates to obtain annotation data;

[0122] S163, importing the temperature distribution map into a geographic information system (GIS) as a base map, and adding the annotation data to the new layer after creating a new layer;

[0123] S164. Use the Geographic Information System (GIS) to perform spatial analysis, search for areas where the temperature is higher than the set temperature threshold or the hazard assessment result is higher than the set assessment threshold, and mark them as potential spontaneous combustion areas.

[0124] S2, inserting acrylamide monomer into the interlayer of montmorillonite by solution intercalation polymerization to obtain a composite nano-inhibitor;

[0125] Step S2 specifically includes the following steps:

[0126] S21, dispersing montmorillonite in a solvent to form a uniform suspension;

[0127] The solvent in step S21 is water, and the weight percentage of montmorillonite in the suspension is 0.5wt%-2wt%; montmorillonite is a layered silicate mineral with a large specific surface area and abundant interlayer space. In order to ensure the effective progress of the subsequent reaction, the montmorillonite needs to be evenly dispersed in the solvent to fully expose its interlayer structure.

[0128] S22, adding a quantitative amount of acrylamide monomer to the suspension under stirring;

[0129] In step S22, the mass ratio of acrylamide monomer to montmorillonite is 3:1-5:1;

[0130] Acrylamide (C3H5NO) is an organic compound with good polymerization properties. Under stirring, acrylamide monomer can be evenly distributed in the suspension and gradually approach the interlayer area of ​​montmorillonite. Due to the negative charge characteristics of the montmorillonite interlayer, the positively charged amino group (-NH2) of acrylamide monomer can be attracted to the montmorillonite interlayer.

[0131] S23, at a set reaction temperature, adding an initiator to the solution formed in step S22, so that the acrylamide monomer enters between the montmorillonite sheets to start the polymerization reaction, and after the reaction time is set, a composite nano-inhibitor is obtained.

[0132] In step S23, the reaction temperature is set to a range of 60°C-80°C, the reaction time is set to a range of 2h-6h, the initiator is ammonium persulfate, and the mass of the ammonium persulfate is 0.1%-1% of the total mass.

[0133] Ammonium persulfate ((NH4)2S2O8) is a strong oxidant that decomposes under heating conditions to produce free radicals (such as SO4 - and OH), under the initiation of free radicals, the double bonds of acrylamide monomers open and connect to each other to form linear or cross-linked polymer chains. Due to the restriction effect between montmorillonite layers, the polymer chains will preferentially grow along the layers to form an intercalated structure (that is, acrylamide monomers are inserted into the montmorillonite layers and form a stable composite nanostructure through polymerization). This composite material combines the high specific surface area of ​​montmorillonite and the efficient flame retardant properties of acrylamide polymers, thereby achieving efficient suppression of spontaneous combustion of coal gangue.

[0134] This composite nano-inhibitor has the following characteristics: (1) High adsorption capacity: Due to the high specific surface area of ​​montmorillonite, the composite material can effectively adsorb oxygen and other combustion-supporting substances, reducing the risk of spontaneous combustion of coal gangue. (2) Good covering effect: The long chain structure of acrylamide polymer can form a dense protective film on the surface of coal gangue, further enhancing the flame retardant effect. (3) Long-term stability: The layered structure of montmorillonite and the cross-linked network of the polymer make the composite material have high thermal stability and mechanical strength, and can maintain its inhibitory effect for a long time.

[0135] S3, determining the spraying density of the composite nano-inhibitor according to the hazard assessment result of the potential spontaneous combustion area determined in step S1, and determining the spraying amount according to the volume of the potential spontaneous combustion area;

[0136] Step S3 specifically includes the following steps:

[0137] S31. By comparing the assessment results of the potential spontaneous combustion area with the level classification threshold, the potential spontaneous combustion area is divided into a high spontaneous combustion area, a medium spontaneous combustion area and a low spontaneous combustion area;

[0138] S32, setting the corresponding composite nano-inhibitor spraying density ρ corresponding to the high spontaneous combustion zone, the medium spontaneous combustion zone and the low spontaneous combustion zone divided in step S31;

[0139] S33. Calculate the spraying amount Q based on the volume V of the potential spontaneous combustion area and the corresponding spraying density ρ:

[0140] Q=V×ρ (11).

[0141] Preferably, in step S32, the spraying density range of the low spontaneous combustion zone is 0.5 kg / m 3 -1 kg / m 3 ; The spraying density range in the spontaneous combustion zone is 1kg / m 3 -2kg / m 3 ; The spraying density range in the high spontaneous combustion area is 2kg / m 3 -3kg / m 3 .

[0142] S4. Directly inject the composite nano-inhibitor with a determined spraying density into the potential spontaneous combustion area.

[0143] Step S4 specifically includes the following steps:

[0144] S41, setting parameters: setting the injection speed and injection time based on the spraying amount described in step S3, and setting the injection pressure;

[0145] S42, extending the capillary nozzle with the nozzle into the potential spontaneous combustion area, and turning on the high-pressure pump according to the set parameters, injecting the composite nano-inhibitor in the storage tank into the potential spontaneous combustion area by using the high-pressure pump, and turning off the high-pressure pump after the injection time is over, and pulling out the capillary nozzle and the nozzle.

[0146] Preferably, in step S41, the injection pressure range is set to 5MPa-10MPa;

[0147] And based on Q=t×v, the injection time t and injection speed v are determined.

[0148] Embodiment 1

[0149] 1. Determination of potential spontaneous combustion areas

[0150] (1) Using infrared thermal imaging equipment and GPS equipment, a coal gangue dump was comprehensively scanned to generate a detailed temperature distribution map.

[0151] (2) Randomly sample from different locations of the coal gangue dump, number and mark the locations, and obtain a total of 50 samples.

[0152] (3) Determine the evaluation indicators, including aliphatic CH components, pyrite sulfur content, etc., and use the entropy weight method combined with the hierarchical analysis method to calculate the weight of each indicator.

[0153] (4) Establish a quantitative assessment model for the hazard of spontaneous combustion of coal gangue and conduct a hazard assessment on each sample.

[0154] (5) The assessment results are combined with the temperature distribution map and, through GIS spatial analysis, areas with temperatures above 300°C or hazard assessment results above 0.8 are determined to be potential spontaneous combustion areas.

[0155] 2. Preparation of composite nano-inhibitor

[0156] (1) Montmorillonite was dispersed in water to form a 1 wt% uniform suspension.

[0157] (2) Under stirring conditions, acrylamide monomer is added to the suspension, and the mass ratio of the monomer to montmorillonite is 4:1.

[0158] (3) adding ammonium persulfate initiator at 70°C and reacting for 4 hours to obtain a composite nano-inhibitor.

[0159] 3. Spraying of inhibitors

[0160] (1) Based on the hazard assessment results of the potential spontaneous combustion area, the area is divided into high, medium and low spontaneous combustion zones.

[0161] (2) The spraying density is set at 2000 grams per cubic meter for the high spontaneous combustion zone, 1000 grams per cubic meter for the medium spontaneous combustion zone, and 500 grams per cubic meter for the low spontaneous combustion zone.

[0162] 4. Calculate the spraying amount according to the volume of each area and carry out spraying operations.

[0163] Embodiment 2

[0164] 1. Determination of potential spontaneous combustion areas

[0165] In this step, different from Example 1, in Example 2, infrared thermal imaging and GPS scanning are performed on another gangue dump to generate a temperature distribution map. 60 samples are taken, numbered and marked. Areas with temperatures above 280°C or hazard assessment results above 0.75 are determined as potential spontaneous combustion areas.

[0166] 2. Preparation of composite nano-inhibitor

[0167] In this step, different from Example 1, in Example 2, the concentration of montmorillonite suspension was adjusted to 0.5wt%. The mass ratio of acrylamide monomer to montmorillonite was adjusted to 3:1. The reaction temperature was set to 60°C and the reaction time was 6 hours to obtain a composite nano inhibitor.

[0168] 3. Spraying of inhibitors

[0169] In this step, different from Example 1, in Example 2, the spontaneous combustion area is divided into levels, and the spraying density is adjusted to 2500 grams per cubic meter in the high spontaneous combustion area, 1500 grams in the medium spontaneous combustion area, and 800 grams in the low spontaneous combustion area.

[0170] 4. Spray.

[0171] Embodiment 3

[0172] 1. Determination of potential spontaneous combustion areas

[0173] In this step, different from the first embodiment, in the third embodiment, the temperature distribution of the third gangue dump was scanned and sampled (70 samples), and the area with a temperature higher than 320°C or a hazard assessment result higher than 0.9 was determined as a potential spontaneous combustion area.

[0174] 2. Preparation of composite nano-inhibitor

[0175] In this step, different from Example 1, in Example 3, the concentration of the montmorillonite suspension was set to 2 wt %. The mass ratio of acrylamide monomer to montmorillonite was adjusted to 5:1. The reaction temperature was set to 80° C. and the reaction time was 2 hours to obtain a composite nano-inhibitor.

[0176] 3. Spraying of inhibitors

[0177] In this step, different from Example 1, in Example 3, according to the level of the spontaneous combustion area, the spraying density is set to 3000 grams per cubic meter in the high spontaneous combustion area, 2000 grams in the medium spontaneous combustion area, and 1000 grams in the low spontaneous combustion area.

[0178] 4. Calculate and spray the inhibitor.

[0179] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A comprehensive treatment method for spontaneous combustion of coal gangue, characterized in that: The following steps are involved: S1. Regularly collect the temperature distribution of the gangue dump and determine the potential spontaneous combustion area of ​​the gangue dump in combination with the quantitative assessment model of the spontaneous combustion hazard of gangue; S2, inserting acrylamide monomer into the interlayer of montmorillonite by solution intercalation polymerization to obtain a composite nano-inhibitor; S3, determining the spraying density of the composite nano-inhibitor according to the hazard assessment result of the potential spontaneous combustion area determined in step S1, and determining the spraying amount according to the volume of the potential spontaneous combustion area; S4. Directly inject the composite nano-inhibitor with a determined spraying density into the potential spontaneous combustion area.

2. A comprehensive treatment method for spontaneous combustion of coal gangue according to claim 1, characterized in that: Step S1 specifically includes the following steps: S11. Scan the gangue yard using infrared thermal imaging equipment and GPS equipment to generate a temperature distribution map of the gangue yard; S12, taking coal gangue samples from different locations of the coal gangue yard, and numbering and marking the location of each coal gangue sample; S13. Determine the evaluation indicators: aliphatic CH component, pyrite sulfur content, physical oxygen absorption capacity, ash content, ignition point temperature and thermal decomposition activation energy; S14. Use the entropy weight method combined with the hierarchical analysis method to calculate the weight of each evaluation index and establish a quantitative evaluation model for the hazard of spontaneous combustion of coal gangue; S15. Using the quantitative assessment model of the spontaneous combustion hazard of coal gangue, conduct a hazard assessment on each coal gangue sample and output the assessment result; S16. Combine the evaluation results of each gangue sample with the temperature distribution map to determine the potential spontaneous combustion area.

3. A comprehensive treatment method for spontaneous combustion of coal gangue according to claim 2, characterized in that: Step S14 specifically includes the following steps: S141. Calculate the weight of each evaluation indicator using the entropy weight method; S1411. Calculate the information entropy H of each evaluation indicator j : Where n is the number of coal gangue samples; p ij is the probability value of the i-th coal gangue sample on the j-th evaluation index; x ij is the value of the i-th coal gangue sample on the j-th evaluation index, and j∈(1,m), m is the number of evaluation indicators, m=6; S1412. Calculate the coefficient of difference d for each evaluation indicator j : d j =1-H j (3); S1413. Calculate the weight w of each evaluation indicator j : S142, using the analytic hierarchy process to calculate the weight of each evaluation indicator; S1421, construct judgment matrix A: In the formula, a jh Indicates the importance of the jth evaluation indicator relative to the hth evaluation indicator; S1422, calculate the maximum eigenvalue λ max : Where β is the normalized vector; j is the jth element in the judgment matrix A; S1423, consistency check: In the formula, CI is the consistency index; RI is the random consistency index; CR represents the consistency ratio; S1424. Judgment: When CR < Q, the judgment matrix A is determined to be consistent, and the normalized vector β at this time is output as the weight. Otherwise, return to step S1421 to adjust the judgment matrix A. S143, combined with the weight w obtained by the entropy weight method j and the weights obtained by AHP Get the final comprehensive weight w′ j : Where α is a constant, and α∈(0,1); S144. Establish a quantitative assessment model for the hazard of spontaneous combustion of coal gangue: Where D i is the spontaneous combustion hazard score of the i-th coal gangue sample.

4. A comprehensive treatment method for spontaneous combustion of coal gangue according to claim 3, characterized in that: Step S16 specifically includes the following steps: S161, determining the location coordinates of each gangue sample in the gangue yard based on the number and location mark of each gangue sample; S162, integrating the hazard assessment result of each coal gangue sample with the position coordinates to obtain annotation data; S163, importing the temperature distribution map into a geographic information system (GIS) as a base map, and adding the annotation data to the new layer after creating a new layer; S164. Use geographic information system (GIS) to conduct spatial analysis, search for areas where the temperature is higher than the set temperature threshold or the hazard assessment result is higher than the set assessment threshold, and mark them as potential spontaneous combustion areas.

5. A comprehensive treatment method for spontaneous combustion of coal gangue according to claim 4, characterized in that: Step S2 specifically includes the following steps: S21, dispersing montmorillonite in a solvent to form a uniform suspension; S22, adding a quantitative amount of acrylamide monomer to the suspension under stirring; S23, at a set reaction temperature, adding an initiator to the solution formed in step S22, so that the acrylamide monomer enters between the montmorillonite sheets to start the polymerization reaction, and after the reaction time is set, a composite nano-inhibitor is obtained.

6. A comprehensive treatment method for spontaneous combustion of coal gangue according to claim 5, characterized in that: The solvent in step S21 is water, and the weight percentage of montmorillonite in the suspension is 0.5wt%-2wt%; In step S22, the mass ratio of acrylamide monomer to montmorillonite is 3:1-5:1; In step S23, the reaction temperature is set to a range of 60°C-80°C, the reaction time is set to a range of 2h-6h, the initiator is ammonium persulfate, and the mass of the ammonium persulfate is 0.1%-1% of the total mass.

7. A comprehensive treatment method for spontaneous combustion of coal gangue according to claim 6, characterized in that: Step S3 specifically includes the following steps: S31. By comparing the assessment results of the potential spontaneous combustion area with the level classification threshold, the potential spontaneous combustion area is divided into a high spontaneous combustion area, a medium spontaneous combustion area and a low spontaneous combustion area; S32, setting the corresponding composite nano-inhibitor spraying density ρ corresponding to the high spontaneous combustion zone, the medium spontaneous combustion zone and the low spontaneous combustion zone divided in step S31; S33. Calculate the spraying amount Q based on the volume V of the potential spontaneous combustion area and the corresponding spraying density ρ: Q=V×ρ (11).

8. A comprehensive treatment method for spontaneous combustion of coal gangue according to claim 7, characterized in that: In step S32, the spraying density range of the low spontaneous combustion zone is 0.5 kg / m 3 -1kg / m 3 ; The spraying density range in the spontaneous combustion zone is 1kg / m 3 -2kg / m 3 ; The spraying density range in the high spontaneous combustion area is 2kg / m 3 -3kg / m 3 .

9. A comprehensive treatment method for spontaneous combustion of coal gangue according to claim 8, characterized in that: Step S4 The specific steps include: S41, setting parameters: setting the injection speed and injection time based on the spraying amount described in step S3, and setting the injection pressure; S42, extending the capillary nozzle with the nozzle into the potential spontaneous combustion area, and turning on the high-pressure pump according to the set parameters, injecting the composite nano-inhibitor in the storage tank into the potential spontaneous combustion area by using the high-pressure pump, and turning off the high-pressure pump after the injection time is over, and pulling out the capillary nozzle and the nozzle.

10. A comprehensive treatment method for spontaneous combustion of coal gangue according to claim 9, characterized in that: In step S41, the injection pressure range is set to 5MPa-10MPa; And based on Q=t×v, the injection time t and injection speed v are determined.

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