A composite dust suppressant and its preparation method

Abstract

This invention discloses a composite dust suppressant and its preparation method, relating to the field of dust control technology. It comprises the following raw materials in parts by weight: 3-6 parts polyvinyl alcohol, 0.3-0.6 parts sodium carboxymethyl cellulose, 3-9 parts glycerol, 0.5-1.0 parts sodium dodecylbenzene sulfonate, citric acid, and deionized water. Based on the total mass of polyvinyl alcohol and sodium carboxymethyl cellulose, the amount of citric acid added is 10%-20% of their total mass. The deionized water is used to make up the total mass of the entire system to 300 parts. This invention exhibits excellent wind erosion resistance. At a spraying rate of 2.5 L / m², the composite dust suppressant achieves a wind erosion resistance rate of 99.96%, and no structural damage to the solidified layer is observed under a continuous wind speed of 15 m / s. Furthermore, the water erosion resistance rate reaches 98.54%, and the solidified layer morphology remains basically intact after 60 minutes of simulated heavy rain at 50 mm / h. Compared with water spraying treatment, the dust suppressant of this invention can significantly reduce particle loss under simulated heavy rain conditions, indicating that the cross-linked solidified layer it forms has strong water erosion resistance.

Description

Technical Field

[0001] This invention relates to the field of dust control technology, specifically to a composite dust suppressant and its preparation method. Background Technology

[0002] Coal is a core energy source for industrial production, with massive global production and consumption. However, due to limitations in current technology and industry conditions, such as immature large-scale high-value resource recovery technologies, high disposal costs, and limited large-scale consumption channels, open-pit surface storage has become the primary method for disposing of coal gangue, resulting in large-scale gangue piles. These large-scale open-pit gangue dumps not only occupy vast amounts of land resources but also continuously cause multiple ecological and environmental problems, becoming a critical environmental bottleneck that urgently needs to be addressed in the green and low-carbon development of mining areas.

[0003] In the existing technology, the mainstream technical method for dust control in the industry is to spray chemical dust suppressants to achieve solidification and dust suppression. Chemical dust suppressants can be divided into three categories according to their mechanism of action: hygroscopic and water-retaining type, polymer film-forming and bonding type, and surfactant wetting type. When single-function dust suppressants are applied to complex working conditions of open-pit coal gangue, they all have obvious technical defects. Among them, single hygroscopic dust suppressants rely solely on hygroscopic components to maintain the moisture of the material surface, resulting in limited water retention time. In harsh environments such as high temperatures, drought, and strong winds in mining areas, surface moisture evaporates rapidly, causing the dust suppression effect to be lost in a short time. Frequent repeated spraying and maintenance are required, leading to high overall operation and maintenance costs. Single polymer film-forming dust suppressants form a protective film layer with poor toughness and excessive rigidity after curing. Under multiple operating conditions such as continuous wind shearing, disturbance from mechanical operations in the stockpile, and seasonal rainfall, they are prone to cracking, peeling, powdering, and detachment, causing the protective layer to fail quickly and failing to achieve long-term dust suppression. Single surfactant-based dust suppressant products can only improve the surface wettability of gangue particles and enhance water penetration. They lack the ability to bond, solidify, and cross-link to form a film, and cannot form a stable and continuous protective solidified layer on the gangue surface. They can only achieve short-term dust reduction, and their long-term dust suppression performance is severely inadequate. Summary of the Invention

[0004] The purpose of this invention is to provide a composite dust suppressant and its preparation method, thereby solving the technical problems in related technologies. To achieve the above objective, this invention provides the following technical solution:

[0005] A composite dust suppressant is composed of the following raw materials in parts by weight: 3-6 parts polyvinyl alcohol, 0.3-0.6 parts sodium carboxymethyl cellulose, 3-9 parts glycerol, 0.5-1.0 parts sodium dodecylbenzene sulfonate, citric acid, and deionized water; based on the total mass of polyvinyl alcohol and sodium carboxymethyl cellulose, the amount of citric acid added is 10%-20% of the total mass of the two; the deionized water is added to make up the total mass of the entire system to 300 parts.

[0006] The aforementioned composite dust suppressant comprises 6 parts polyvinyl alcohol, 0.6 parts sodium carboxymethyl cellulose, 9 parts glycerol, 0.62 parts sodium dodecylbenzene sulfonate, 0.99 parts citric acid, with the remainder being deionized water, and a total system mass of 300 parts.

[0007] The aforementioned composite dust suppressant has a finished product with a pH value of 6.8 to 7.2.

[0008] The aforementioned composite dust suppressant, when sprayed onto the surface of coal gangue particles, can form an integrated composite solidified dustproof layer on the surface of the coal gangue. The composite solidified dustproof layer simultaneously has the functions of water retention, bonding, and film-forming solidification.

[0009] The aforementioned composite dust suppressant has a composite solidified dustproof layer that also functions as a water-retaining and water-locking agent, a particle bonding agent, and a surface film-forming and solidifying agent.

[0010] A method for preparing a composite dust suppressant, applicable to the aforementioned composite dust suppressant, comprising the following steps:

[0011] S1. Heat part of the deionized water to 90°C, add polyvinyl alcohol under stirring, and stir at a constant temperature for 1 hour until dissolved.

[0012] S2. Cool to 60°C, add sodium carboxymethyl cellulose, and continue stirring at a constant temperature for 1 hour;

[0013] S3. Add citric acid and glycerol, and continue stirring at a constant temperature for 3 hours.

[0014] S4. Cool to room temperature, add sodium dodecylbenzenesulfonate and stir for 1 hour;

[0015] S5. Adjust the pH to 6.8-7.2 using a 30% sodium hydroxide solution, and add deionized water to a total mass of 300 parts to obtain the composite dust suppressant.

[0016] The above-mentioned method for preparing a composite dust suppressant includes the following steps: in step S1, constant temperature stirring for 1 hour; in step S2, constant temperature stirring for 1 hour; in step S3, constant temperature stirring for 3 hours; and in step S4, stirring at room temperature for 1 hour.

[0017] The above-mentioned method for preparing a composite dust suppressant involves allowing the dust to settle and form a film naturally after spraying. The composite solidified layer formed by the dust suppressant fixes the surface coal gangue particles, thus blocking the spread of dust.

[0018] The above-mentioned method for preparing a composite dust suppressant, wherein the composite consolidation layer has long-lasting water retention properties, which can delay the evaporation of surface moisture in the stockpile and extend the effective period of dust suppression.

[0019] The above-mentioned method for preparing a composite dust suppressant has a composite consolidation layer with high bonding strength, resistance to wind and slight rain erosion, and is suitable for dust control in open-air long-term coal gangue stockpiles.

[0020] In the aforementioned composite dust suppressant and its preparation method, the radial dimensions of both ends of the roller press cylinder are larger than the radial dimensions of the rest of the arrangement, and the two ends of the roller press cylinder correspond to the slit plow.

[0021] The beneficial effects of this invention are as follows:

[0022] 1. The present invention has excellent wind erosion resistance. When the composite dust suppressant is sprayed at a rate of 2.5 L / m², the wind erosion resistance rate reaches 99.96%, and no structural damage is observed in the solidified layer under a continuous wind speed of 15 m / s.

[0023] 2. The present invention has outstanding water erosion resistance: the water erosion resistance rate reaches 98.54%, and the morphology of the solidified layer remains basically intact after 60 minutes of simulated rainstorm scouring at 50 mm / h. Compared with spray water treatment, the dust suppressant of the present invention can significantly reduce particle loss under simulated rainstorm scouring conditions, indicating that the cross-linked solidified layer formed by it has strong water erosion resistance.

[0024] 3. The present invention has good freeze-thaw resistance: after 7 freeze-thaw cycles, the compressive strength drops from 1.35MPa to 1.14MPa, with a cumulative decrease of about 15%, and the decrease process is gradual, which can meet the use requirements of seasonal freeze-thaw regions.

[0025] 4. This invention is environmentally friendly: After 30 days of burial in soil, the degradation rate of the solidified film is approximately 33.8%, demonstrating a certain degree of natural degradation capability. Testing showed that all heavy metal indicators were below the limits specified in GB5749-2022 "Standards for Drinking Water Quality," and no abnormalities were observed in acute skin irritation tests. In seed germination experiments, the germination rate and seedling height of pea seeds treated with the dust suppressant were superior to those in the deionized water control group, indicating that the dust suppressant has no inhibitory effect on early plant growth.

[0026] 5. The invention has good flexibility: The added GLY, as a small molecule plasticizer, can penetrate between polymer segments, soften and solidify the film by enhancing the activity of polymer segments, reduce the brittleness of the film, and effectively make up for the engineering defect that the film shell is prone to brittle disintegration.

[0027] 6. The invention is economically viable: the added CA is a bulk food-grade chemical raw material that is inexpensive, widely available, and can be degraded by microorganisms in the natural environment, making it a promising candidate for widespread application.

[0028] 7. The present invention exhibits strong structural stability: The added CA undergoes an esterification and cross-linking reaction with PVA and CMC-Na, forming a composite cross-linked structure with covalent ester bonds as nodes and hydrogen bonds as a supplement, giving the composite dust suppressant good thermal stability. After treatment, dust particles change from a free and dispersed state to a bridged and aggregated state, effectively improving the connection strength between particles and the surface consolidation ability. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0030] Figure 1 This is a schematic diagram of the preparation process of the dust-suppressing composite dust agent of the present invention;

[0031] Figure 2 This is a schematic diagram illustrating the mechanism of action of the dust suppressant of the present invention on the surface of coal gangue;

[0032] Figure 3 This is a schematic diagram of the wind erosion resistance test of the present invention;

[0033] Figure 4 These are before-and-after comparison images of coal gangue dust erosion treated differently according to the present invention.

[0034] Figure 5 This is a schematic diagram of the water erosion resistance test of the present invention;

[0035] Figure 6 These are before-and-after comparison images of coal gangue dust erosion treated differently according to the present invention.

[0036] Figure 7 This is the orthogonal experimental factor level table of the present invention;

[0037] Figure 8 This presents the orthogonal experimental design and performance test results of this invention.

[0038] Figure 9 This is a comprehensive evaluation of the normalized scores of each group of experiments in this invention;

[0039] Figure 10 This is the result of the comprehensive score range analysis of this invention;

[0040] Figure 11 These are the experimental results verifying the optimal formulation of this invention;

[0041] Figure 12 This is a performance comparison between the optimal formulation of the present invention and Example 7;

[0042] Figure 13This is a table showing the component dosages for Comparative Examples 1-5 of the present invention;

[0043] Figure 14 The results and overall scores of the dust suppressant under different component deficiency conditions of this invention are as follows;

[0044] Figure 15 These are the wind erosion resistance test results for different treatment groups of this invention;

[0045] Figure 16 The results of water erosion resistance tests for different treatment groups of this invention are shown. Detailed Implementation

[0046] To enable those skilled in the art to better understand the technical solution of the present invention, the following will be described in conjunction with the appendix. Figure 1 To be continued Figure 16 The present invention will now be described in further detail.

[0047] In this embodiment of the invention, a composite dust suppressant is provided, which is composed of the following raw materials in parts by weight: 3-6 parts of polyvinyl alcohol, 0.3-0.6 parts of sodium carboxymethyl cellulose, 3-9 parts of glycerol, 0.5-1.0 parts of sodium dodecylbenzene sulfonate, citric acid, and deionized water; based on the total mass of polyvinyl alcohol and sodium carboxymethyl cellulose, the amount of citric acid added is 10%-20% of the total mass of the two; the deionized water is added to make up the total mass of the entire system to 300 parts.

[0048] Specifically, the mixture comprises 6 parts polyvinyl alcohol, 0.6 parts sodium carboxymethyl cellulose, 9 parts glycerol, 0.62 parts sodium dodecylbenzene sulfonate, 0.99 parts citric acid, with the balance being deionized water, for a total mass of 300 parts. The finished dust suppressant has a pH value of 6.8–7.2. When the dust suppressant is sprayed onto the surface of coal gangue particles, it forms an integrated composite solidified dustproof layer on the coal gangue surface. This composite solidified dustproof layer simultaneously possesses water retention, bonding, and film-forming consolidation functions. The composite solidified dustproof layer also combines water retention and water locking, particle bonding, and surface film-forming consolidation functions.

[0049] A method for preparing a composite dust suppressant, applicable to the aforementioned composite dust suppressant, comprising the following steps:

[0050] S1. Heat part of the deionized water to 90°C, add polyvinyl alcohol under stirring, and stir at a constant temperature for 1 hour until dissolved.

[0051] S2. Cool to 60°C, add sodium carboxymethyl cellulose, and continue stirring at a constant temperature for 1 hour;

[0052] S3. Add citric acid and glycerol, and continue stirring at a constant temperature for 3 hours.

[0053] S4. Cool to room temperature, add sodium dodecylbenzenesulfonate and stir for 1 hour;

[0054] S5. Adjust the pH to 6.8-7.2 using a 30% sodium hydroxide solution, and add deionized water to a total mass of 300 parts to obtain the composite dust suppressant.

[0055] In step S1, the constant temperature stirring time is 1 hour; in step S2, the constant temperature stirring time is 1 hour; in step S3, the constant temperature stirring time is 3 hours; in step S4, the room temperature stirring time is 1 hour.

[0056] After spraying, the mixture is left to stand and form a film naturally. The composite consolidation layer formed by the dust suppressant fixes the surface coal gangue particles and blocks the spread of dust.

[0057] The composite consolidation layer has long-term water retention properties, which can delay the evaporation of surface moisture in the stockpile and extend the effective period of dust suppression.

[0058] The composite consolidation layer has high bonding strength and is resistant to wind and light rain erosion, making it suitable for dust control in open-air long-term coal gangue stockpiles.

[0059] In this embodiment:

[0060] 1. Experimental Materials and Instruments

[0061] Experimental materials: polyvinyl alcohol (PVA), sodium carboxymethyl cellulose (CMC-Na), glycerol (GLY), citric acid (CA), sodium dodecylbenzene sulfonate (SDBS), and deionized water.

[0062] Main instruments: heated magnetic stirrer (LC-OB-2L type), digital viscometer (NDJ-1S type), Shore hardness tester (LX-A type), electric heating drying oven (PCD-D9000 type), electronic analytical balance (accuracy 0.001g).

[0063] 2. Performance Testing Methods

[0064] 2.1 Water retention test

[0065] Weigh 100g of dried dust and spread it evenly in a petri dish. Add 10g of the test solution evenly, then place the dish in a 50°C drying oven for 24 hours. Weigh the dust every 2 hours. The moisture content of the dust after 24 hours is calculated using the following formula:

[0066]

[0067] In the formula: The moisture content (%) is measured over 24 hours. The total mass of the sample at 24 hours ( ); The initial dry mass of the sample ( ); For the quality of the petri dish ( ).

[0068] 2.2 Viscosity Test

[0069] The viscosity was measured using an NDJ-1S digital viscometer at 25°C. A suitable rotor and speed were selected based on the estimated viscosity, and the viscosity value was read after the reading stabilized. Each group of samples was measured in triplicate, and the average value was taken.

[0070] 2.3 Hardness Test

[0071] The Shore hardness tester, LX-A type, was used. After the sample had formed a film and cured to constant weight, the indenter was pressed vertically onto the surface, and the reading was taken after the reading stabilized. Five test points were evenly selected for each sample (avoiding edges and cracks), and the average value was taken.

[0072] 2.4 Wind Erosion Resistance Test

[0073] The wind speed was set at 15 m / s, corresponding to a gale-force wind of level 7. Before the experiment, the coal gangue powder was dried at 105°C to constant weight and then evenly packed into a square pan using a funnel method (the mass of the square pan is recorded as ). The samples were kept in a natural stacking state. Three groups were set up for the experiment: an untreated group, a water-treated group, and a dust-suppressant-treated group. After spraying, all samples were dried in a 50°C oven to constant weight. A blower outlet was placed 1.5m from the center of the sample, and continuous erosion was carried out at a wind speed of 15m / s for 20 minutes. Wind erosion resistance rate... Calculate according to the following formula:

[0074]

[0075] In the formula, The wind erosion resistance rate (%) The total mass (g) of the sample and the square plate before wind erosion. The total mass (g) of the sample and the square plate after wind erosion. The mass of the disk is (g). Each experiment was repeated 3 times, and the average value was taken.

[0076] 2.5 Water erosion resistance test

[0077] The rainfall intensity was set at 50 mm / h, which, according to GB / T28592-2012 "Rainfall Grades", falls under the category of heavy rain. Before the test, the square tray, which had been sprayed and cured to constant weight, was fixed on a test frame at a 30° inclination angle. An artificial rainfall control system was used to continuously spray at 50 mm / h for 60 minutes. After spraying, the tray, along with any residual particles inside, was placed in a 105°C drying oven and dried to constant weight. Water erosion resistance rate... Calculate according to the following formula:

[0078]

[0079] In the formula, Water erosion resistance rate (%) The total mass (g) of the sample and the square plate before rain erosion. The total mass (g) of the sample and the square plate after rain erosion. The mass of the disk is (g). Each experiment was repeated 3 times, and the average value was taken.

[0080] 3. Orthogonal experimental design and results

[0081] 3.1 Orthogonal Experimental Design

[0082] Using L9 ( An orthogonal array was used for the experiment. The levels of each factor are shown in Table 1. The amount of CA added was calculated as a percentage of the total mass of PVA and CMC-Na. SDBS was fixed at 0.62 parts, deionized water at 200 parts, and finally replenished to a total mass of 300 parts. Figure 7 As shown.

[0083] 3.2 Test Plan and Performance Testing

[0084] Nine dust suppressant samples (Examples 1-9) were prepared according to the above factor levels. The preparation method was uniform: 200g of deionized water was heated to 90°C, PVA was added with stirring, and the mixture was stirred at a constant temperature for 1 hour; the temperature was cooled to 60°C, CMC-Na was added, and the mixture was stirred for 1 hour; CA and GLY were added, and the mixture was stirred for 3 hours; the temperature was cooled to room temperature, 0.62g of SDBS was added, and the mixture was stirred for 1 hour; the pH was adjusted to 7.0 with 30% NaOH, and water was added to a final volume of 300g. The performance test results of each sample group are as follows: Figure 8 As shown.

[0085] 3.3 Comprehensive weighted scoring and range analysis

[0086] The weighting is as follows: water retention 50%, hardness 30%, viscosity 20%. After normalization, the overall score is calculated, and the results are as follows. Figure 9 As shown. A range analysis was performed using the overall score as the evaluation index, and the results are as follows. Figure 10 As shown.

[0087] Range analysis shows that the order of influence of each factor on the overall score is: film-forming agent (A) > binder (B) > crosslinking agent (D) > water-retaining agent (C). The optimal combination is A3B3C3D2, namely: PVA 6g, CMC-Na 0.6g, GLY 9g, and CA added at 15% of the total mass of PVA and CMC-Na (i.e., CA = (6 + 0.6) × 15% = 0.99g).

[0088] 3.4 Theoretical Prediction and Verification Experiment

[0089] An index prediction model was used to theoretically predict the performance of the optimal combination A3B3C3D2. Taking water retention rate as an example, the overall mean of the nine experimental groups was 9.76%, and the average values ​​of the optimal levels for each single factor were: A3 water average 11.38%, B3 water average 10.17%, C3 water average 10.72%, and D2 water average 10.10%. Substituting these values ​​into the model, the predicted water retention rate was 12.15%. Similarly, the predicted hardness was 65.33 HA, and the viscosity was 30.53. .

[0090] Three batches of samples were prepared according to the A3B3C3D2 formula for verification experiments, and the results are as follows: Figure 11 As shown.

[0091] The experimental results were close to the model predictions, and the standard deviation of the three parallel experiments was small, indicating that the repeatability was relatively stable.

[0092] 3.5 Final Formula Determination

[0093] Based on the results of orthogonal experiments, weighted scoring analysis, theoretical predictions, and verification experiments, the basic formula for the composite dust suppressant was finally determined as follows:

[0094] PVA: 6 units

[0095] CMC-Na: 0.6 parts

[0096] GLY: 9 servings

[0097] CA: 15% (based on the total mass percentage of PVA and CMC-Na)

[0098] SDBS: 0.62 copies

[0099] Deionized water: 200 parts (add to a total of 300 parts by weight)

[0100] Under this formulation, the dust suppressant has a 24-hour water retention rate of 12.04%, a hardness of 65.0 HA, and a viscosity of 30.3 mPa·s.

[0101] 4. Comparative Analysis of Examples

[0102] To visually demonstrate the advantages of the optimal formulation (A3B3C3D2), it was compared with Example 7 (A3B1C3D2) from the original orthogonal experiment. The results are as follows: Figure 12 As shown.

[0103] 5. Comparative Example

[0104] To verify the necessity of each component in the dust suppressant, five comparative examples were set up based on the optimal formulation (A3B3C3D2), with PVA, CMC-Na, GLY, CA, and SDBS omitted respectively. In each comparative example, the missing component was replaced with an equal mass of deionized water to maintain a consistent total mass across all groups. The component dosages in each comparative example are as follows: Figure 13 As shown.

[0105] Note: The preparation methods for each comparative example are the same as the optimal formula. The initial amount of deionized water is 200g, and the final amount is added to a total mass of 300g; the pH is adjusted to 7.0.

[0106] The performance was tested according to the above testing method, and the results are as follows: Figure 14 As shown.

[0107] 5.1 Comparative Analysis

[0108] like Figure 14 It can be known that:

[0109] Comparative Example 1 (lacking PVA): Water retention decreased by 73.9%, hardness dropped significantly to 12.04HA, and the overall score was only 0.000, making film formation almost impossible. This indicates that PVA is the core component for film formation and water retention.

[0110] Comparative Example 2 (lacking CMC-Na): Water retention decreased by 42.5%, and viscosity significantly decreased to 8.1. The overall score of 0.368 indicates that CMC-Na is crucial for thickening and bonding.

[0111] Comparative Example 3 (lacking GLY): Water retention decreased by 55.1%, with a comprehensive score of 0.442, indicating that GLY is a key component for maintaining moisture.

[0112] Comparative Example 4 (lacking CA): Water retention decreased by 34.9%, hardness decreased to 41.8 HA, and the overall score was 0.513, indicating that the cross-linking effect of CA has a significant contribution to film strength and water retention performance.

[0113] Comparative Example 5 (lacking SDBS): The overall score was 0.785, a decrease of 21.5% compared to the optimal formulation, indicating that SDBS has a promoting effect on wetting penetration and uniform dispersion.

[0114] The above comparison results prove that the components of the dust suppressant of the present invention (film-forming agent, binder, water-retaining agent, crosslinking agent, and wetting agent) work together and are indispensable, and have a synergistic effect.

[0115] 6. Evaluation of wind erosion and water erosion resistance

[0116] The wind erosion and water erosion resistance of the composite dust suppressant prepared with the optimal formulation (A3B3C3D2) was evaluated according to the test methods described in Sections 2.4 and 2.5. An untreated group and a water-sprayed group were set up as controls. Each test was repeated three times, and the average value was taken.

[0117] 6.1 Resistance to wind erosion

[0118] After continuous erosion at a wind speed of 15 m / s for 20 minutes, the wind erosion resistance rates of each treatment group were as follows: Figure 15 As shown.

[0119] Under the experimental conditions, the wind erosion resistance rate of the dust suppressant group treated with the present invention reached 99.96%, and no obvious structural damage was observed in the consolidation layer after wind erosion, indicating that it has good wind erosion resistance stability.

[0120] 6.2 Water erosion resistance

[0121] After 60 minutes of continuous scouring by a simulated rainstorm at a speed of 50 mm / h, the water erosion resistance rates of each treatment group were as follows: Figure 16 As shown.

[0122] Compared with water spraying, the dust suppressant of this invention can significantly reduce particle loss under simulated rainstorm conditions, with a water erosion resistance rate of 98.54%. During the 60-minute scouring process, the runoff remained clear and the morphology of the consolidation layer remained basically intact, indicating that the cross-linked consolidation layer it forms has a strong water erosion resistance, which is an important technical effect that distinguishes it from ordinary water spraying dust suppression methods.

[0123] The above results show that the dust-suppressing composite dust agent of the present invention can form a high-strength, tough, and erosion-resistant solidified layer, exhibiting excellent anti-erosion ability under strong winds of 15 m / s and heavy rain of 50 mm / h, meeting the stringent environmental requirements for dust control in open-air coal gangue stockpiles.

[0124] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of the claims of the present invention.

Claims

1. A composite dust suppressant, characterized in that, It is composed of the following raw materials in parts by weight: 3-6 parts polyvinyl alcohol, 0.3-0.6 parts sodium carboxymethyl cellulose, 3-9 parts glycerol, 0.5-1.0 parts sodium dodecylbenzene sulfonate, citric acid, and deionized water; Based on the total mass of polyvinyl alcohol and sodium carboxymethyl cellulose, the amount of citric acid added is 10% to 20% of the total mass of the two; the deionized water is added to make up the total mass of the entire system to 300 parts.

2. The dust-suppressing composite dust suppressant according to claim 1, characterized in that, The mixture consists of 6 parts polyvinyl alcohol, 0.6 parts sodium carboxymethyl cellulose, 9 parts glycerol, 0.62 parts sodium dodecylbenzene sulfonate, 0.99 parts citric acid, and the remainder is deionized water. The total mass of the system is 300 parts.

3. The dust-suppressing composite dust suppressant according to claim 2, characterized in that, The finished dust suppressant has a pH value of 6.8 to 7.

2.

4. The dust-suppressing composite dust suppressant according to claim 3, characterized in that, After the dust suppressant is sprayed onto the surface of coal gangue particles, an integrated composite consolidation dustproof layer can be formed on the surface of the coal gangue. The composite consolidation dustproof layer has the functions of water retention, bonding, and film-forming consolidation.

5. The dust-suppressing composite dust suppressant according to claim 4, characterized in that, The composite consolidation dustproof layer also has the functions of water retention and water locking, particle bonding, and surface film formation and consolidation.

6. A method for preparing a composite dust suppressant, applied to the composite dust suppressant of claim 5, characterized in that, The preparation method of the aforementioned composite dust suppressant includes the following steps: S1. Heat part of the deionized water to 90°C, add polyvinyl alcohol under stirring, and stir at a constant temperature for 1 hour until dissolved. S2. Cool to 60°C, add sodium carboxymethyl cellulose, and continue stirring at a constant temperature for 1 hour; S3. Add citric acid and glycerol, and continue stirring at a constant temperature for 3 hours. S4. Cool to room temperature, add sodium dodecylbenzenesulfonate and stir for 1 hour; S5. Adjust the pH to 6.8-7.2 using a 30% sodium hydroxide solution, and add deionized water to a total mass of 300 parts to obtain the composite dust suppressant.

7. The preparation method of the dust-suppressing composite dust suppressant according to claim 6, characterized in that, In step S1, the constant temperature stirring time is 1 hour; in step S2, the constant temperature stirring time is 1 hour; in step S3, the constant temperature stirring time is 3 hours; in step S4, the room temperature stirring time is 1 hour.

8. The method for preparing the composite dust suppressant according to claim 7, characterized in that, After spraying, the mixture is left to stand and form a film naturally. The composite consolidation layer formed by the dust suppressant fixes the surface coal gangue particles and blocks the spread of dust.

9. The preparation method of the dust-suppressing composite dust suppressant according to claim 8, characterized in that, The composite consolidation layer has long-term water retention properties, which can delay the evaporation of surface moisture in the stockpile and extend the effective period of dust suppression.

10. The preparation method of the dust-suppressing composite dust suppressant according to claim 9, characterized in that, The composite consolidation layer has high bonding strength and is resistant to wind and light rain erosion, making it suitable for dust control in open-air long-term coal gangue stockpiles.

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