Environment-friendly dust suppression material with strong curing property as well as preparation method and application of environment-friendly dust suppression material

Abstract

The invention discloses a preparation method of a high-curability environment-friendly dust suppression material, which is characterized by comprising the following steps: (1) weighing locust bean gum, putting the locust bean gum into a container, adding water, uniformly stirring, adjusting the pH value to 2-3 by using hydrochloric acid, adding sodium hypochlorite, heating to 50-60 DEG C, and reacting for 1-2 hours to obtain a mixed solution I; (2) adding waterborne polyurethane into the mixed solution I, heating to 60-80 DEG C, reacting for 1-1.5 hours to obtain a mixed solution II, adding erythritol, and sufficiently and uniformly mixing to obtain a mixed solution III; and (3) cooling the mixed solution III to room temperature, adjusting the pH value of the solution to be neutral, and adding a surfactant into the mixed solution III to obtain the dust suppressant solution. The mechanical property of the dust suppressant is improved, the evaporation rate of water can be reduced, a cured layer is prevented from cracking, the lasting time of the dust suppression effect is prolonged, and the need of repeatedly applying the dust suppressant is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of dust suppressants, and in particular to a highly curable, environment-friendly dust suppressant material and a preparation method and application thereof. Background Art

[0002] In order to prevent the safety hazards of coal dust and effectively reduce the concentration of coal dust, dust removal is often carried out by means such as spray dust suppression. However, the wetting efficiency of water on coal dust is low, especially for respirable dust with small particle size, which is more difficult to be effectively adsorbed and wetted by spray droplets, resulting in limited dust suppression effect.

[0003] Chemical dust suppression is a long-term and efficient means of dust suppression. Single-component chemical dust suppressants have the advantages of simple manufacturing process, but their effective dust suppression time is short, degradation rate is low, and dust suppression rate is not high. Composite dust suppressants have become a hot topic of current research due to their excellent dust suppression effect. Existing composite dust suppressants are difficult to degrade naturally after use, and may cause secondary pollution to the environment, which is contrary to the original intention of environmental protection. Patent application number 202410550509.7 discloses a double-network reinforced structure dust suppression material and a preparation method thereof. The dust suppressant includes the following raw materials: sesbania gum, polyacrylamide, carboxymethyl cellulose, a cross-linking agent, an oxidant, a water-retaining agent, and a wetting agent. The double-network reinforced structure dust suppressant provided by the invention can effectively improve the hydrophilicity and adhesion of dust, and can form a dense protective film on the surface of dust. The patent with application number 202011343202.8 discloses a solid railway coal dust suppressant and its preparation method. The raw materials of the dust suppressant are: crusting agent, film-forming agent, dispersant, corrosion inhibitor, surfactant. The solidified shell formed by the solid railway coal dust suppressant provided by the invention is a mesh structure, which has good permeability while fixing and locking the dust, and is convenient for the heat dissipation of coal powder during coal transportation. However, the functional scope of the above-mentioned dust suppressant is relatively limited, and the curing effect in actual application is not considered. For example, the dust suppression efficiency will be reduced in harsh environments such as high and low temperatures, which limits its application scope to a certain extent.

[0004] Therefore, there is an urgent need to develop a new type of dust suppression material that is both highly curable and environmentally friendly to address the shortcomings of existing dust suppression technologies. Summary of the invention

[0005] In view of the deficiencies in the prior art, the first purpose of the present invention is to provide a method for preparing a highly curable environmentally friendly dust suppression material, the second purpose is to provide a highly curable environmentally friendly dust suppression material prepared thereby, and the third purpose is to provide its application. The mechanical properties of the dust suppressant are increased, the evaporation rate of water can be reduced, the cracking of the cured layer is prevented, the duration of the dust suppression effect is extended, and the need for repeated application of the dust suppressant is reduced.

[0006] In order to achieve the above first purpose, the present invention adopts the following technical scheme: a method for preparing a highly curable environmentally friendly dust suppression material, characterized in that the material is prepared according to the following steps:

[0007] (1) Weigh locust bean gum and place it in a container, add water and stir evenly, adjust the pH to 2-3 with hydrochloric acid, add sodium hypochlorite, raise the temperature to 50-60° C. and react for 1-2 hours to obtain a mixed solution I;

[0008] (2) adding waterborne polyurethane to the mixed solution I, heating to 60-80° C. for reaction for 1-1.5 h to obtain a mixed solution II, adding erythritol, and mixing thoroughly to obtain a mixed solution III;

[0009] (3) After the mixed solution III is cooled to room temperature, the pH of the solution is adjusted to be neutral, and a surfactant is added to the mixed solution III to prepare a dust suppressant solution.

[0010] In the above scheme: the water is distilled water.

[0011] In the above scheme: for every 2000 mL of water, 2-6 parts of locust bean gum, 1.5-3.5 parts of sodium hypochlorite, 1-5 parts of water-based polyurethane, 1-3 parts of erythritol, 6-10 parts of wetting agent and 2-4 parts of water retaining agent are added according to weight proportions.

[0012] In the above scheme: the water retaining agent is glycerol.

[0013] In the above scheme: the wetting agent is dodecyl dimethyl amine oxide.

[0014] In the above scheme: the mass concentration of the hydrochloric acid solution is 4-10%. Erythritol is added, mixed thoroughly and then reacted at 60-80°C for 0.5-1h to obtain a mixed solution III.

[0015] The second object of the present invention is achieved as follows: a highly curable environmentally friendly dust suppression material prepared by the method for preparing the highly curable environmentally friendly dust suppression material.

[0016] The third object of the present invention is achieved by: applying the highly curable environmentally friendly dust suppression material to dust suppression in coal mines.

[0017] In the present invention:

[0018] Locust bean gum is a natural plant gum whose components are environmentally friendly and will not pollute the environment. Locust bean gum can synergize with other materials to improve the performance of dust suppressants and has good biodegradability.

[0019] The molecular structure of waterborne polyurethane contains amino, urea and ionic bonds, has high cohesive energy, strong adhesion, and low-temperature film-forming properties. No film-forming aids or plasticizers need to be added. Waterborne polyurethane has high physical and mechanical properties and weather resistance. It can meet the requirements of different application fields by adjusting the molecular structure and changing the synthesis conditions. It is non-toxic and pollution-free.

[0020] Sodium hypochlorite has strong oxidizing properties and can effectively oxidize organic matter. The byproduct after oxidation is non-toxic and harmless sodium chloride, so it is environmentally friendly and harmless.

[0021] Erythritol has many advantages such as low hygroscopicity, high stability, high heat of solution, good crystallinity and environmental friendliness.

[0022] Glycerin, as a water-retaining auxiliary material, can prevent the cured film from drying out and cracking.

[0023] Dodecyl dimethyl amine oxide (OA-12) is an amphoteric surfactant that behaves as a cationic in acidic media and as a nonionic in alkaline media, which enables it to maintain good performance at different pH values. OA-12 can significantly reduce the critical micelle concentration of the solution and improve wettability.

[0024] Reaction formula of the present invention is as follows:

[0025] (1) Oxidation reaction

[0026]

[0027] (2) Schiff base reaction

[0028]

[0029] (3) Three-dimensional hydrogen bond network structure

[0030]

[0031] Locust bean gum is represented by LBG-OH. Locust bean gum molecules contain multiple hydroxyl groups, so the product of step (3) still exists in the form of HO-LBG.

[0032] The strong oxidizing property of sodium hypochlorite breaks the CC and CH bonds of locust bean gum, oxidizes the hydroxyl groups to aldehyde groups, breaks the diol compounds and oxidizes them to dicarbonyl compounds.

[0033] Oxidized locust bean gum and waterborne polyurethane undergo a Schiff base reaction, and the aldehyde group and the amino group undergo nucleophilic addition and electron transfer to form an imine structure containing a carbon-nitrogen double bond, thereby building a bridge between locust bean gum and waterborne polyurethane. Oxidized locust bean gum-waterborne polyurethane-erythritol are connected by hydrogen bonds, and the molecular chains are entangled and crossed to form an interpenetrating network structure, and finally form a three-dimensional hydrogen bond network structure with water and surfactants.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] (1) The present invention adopts an oxidation method to modify locust bean gum. The aldehyde groups in the oxidized locust bean gum molecules react with the amino groups on the waterborne polyurethane molecules to produce a Schiff base reaction. The newly generated chemical bonds continuously replace the original hydrogen bonds on the original molecular chain, thereby increasing the mechanical properties of the dust suppressant.

[0036] (2) The modified locust bean gum is copolymerized with waterborne polyurethane and erythritol, and then compounded with dodecyl dimethyl amine oxide to finally obtain a dust suppression material with high adhesion and curing properties.

[0037] (3) After the dust suppressant prepared by the present invention is sprayed on the coal dust, it can wet and penetrate into the gaps of the coal dust particles. Dodecyl dimethylamine oxide connects the dust suppressant through hydrogen bonding, and adsorbs on the coal dust surface through van der Waals and hydrophobic effects. As an intermediate carrier between the dust suppressant and the coal surface, the dust suppressant increases the penetration of the dust suppressant in the pores of the coal dust particles, thereby better consolidating the coal dust. The dust suppressant molecules form polysaccharide molecular chains through Schiff base covalent bonding and hydrogen bonding, and are entangled around the adsorption film to form a three-dimensional network structure, which increases the thickness and mechanical strength of the film, improves the toughness and elasticity of the dust suppressant material, and has good crust strength. In addition, glycerol can make the solidified layer retain a certain amount of moisture, which can reduce the evaporation rate of water and prevent the solidified layer from cracking.

[0038] (4) The dust suppressant prepared by the present invention significantly improves the dust suppression efficiency, and the dust suppression rate exceeds 95%. While keeping the coal dust moist, the present invention also particularly strengthens its bonding and curing properties, and can form a solid protective film on the surface of the coal dust. The strength of the cured layer is as high as 85.7HA, which effectively prevents the flying and diffusion of dust. This strong curing property not only improves the dust suppression efficiency, but also prolongs the duration of the dust suppression effect, reducing the need for repeated application of the dust suppressant. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a comparison chart of the dust suppression efficiency of Examples 1-9 and Comparative Examples 1-2 tested in Experiment 2.

[0040] Figure 2 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0041] The present invention is further described in detail below through specific embodiments:

[0042] Example 1

[0043] (1) Weigh 0.2 g of locust bean gum into a three-necked flask, add 200 mL of distilled water and stir evenly, adjust the pH to 2-3 with 4% hydrochloric acid, slowly add 0.15 g of sodium hypochlorite, heat to 50°C and react for 1 h to obtain mixed solution I.

[0044] (2) Add 0.1 g of waterborne polyurethane to the mixed solution I, stir and heat to 60°C for 1.5 h to obtain a mixed solution II, then add 0.2 g of erythritol, mix thoroughly and heat in a water bath at 60°C for 1 h to obtain a mixed solution III.

[0045] (3) After the mixed solution III is cooled to room temperature, the pH of the solution is adjusted to neutral, and 0.2 g of glycerol and 1 g of dodecyl dimethyl amine oxide are added to the mixed solution III to prepare a dust suppressant solution.

[0046] Example 2

[0047] (1) Weigh 0.2 g of locust bean gum into a three-necked flask, add 200 mL of distilled water and stir evenly, adjust the pH to 2-3 with 10% hydrochloric acid, slowly add 0.25 g of sodium hypochlorite, raise the temperature to 50°C and react for 2 h to obtain a mixed solution I.

[0048] (2) Add 0.5 g of waterborne polyurethane to the mixed solution I, stir and heat to 70°C for 1 h to obtain a mixed solution II, continue to add 0.2 g of erythritol, mix thoroughly and heat in a water bath at 70°C for 0.5 h to obtain a mixed solution III.

[0049] (3) After the mixed solution III is cooled to room temperature, the pH of the solution is adjusted to neutral, and 0.2 g of glycerol and 1 g of dodecyl dimethyl amine oxide are added to the mixed solution III to prepare a dust suppressant solution.

[0050] Example 3

[0051] (1) Weigh 0.2 g of locust bean gum into a three-necked flask, add 200 mL of distilled water and stir evenly, adjust the pH to 2-3 with 4% hydrochloric acid, slowly add 0.35 g of sodium hypochlorite, heat to 50°C and react for 1 h to obtain mixed solution I.

[0052] (2) Add 0.3 g of waterborne polyurethane to the mixed solution I, stir and heat to 80°C for 1 h to obtain a mixed solution II, then add 0.2 g of erythritol, mix thoroughly and continue to heat at 80°C in a water bath for 0.5 h to obtain a mixed solution III.

[0053] (3) After the mixed solution III is cooled to room temperature, the pH of the solution is adjusted to neutral, and 0.2 g of glycerol and 0.8 g of dodecyl dimethyl amine oxide are added to the mixed solution III to prepare a dust suppressant solution.

[0054] Example 4

[0055] (1) Weigh 0.4 g of locust bean gum into a three-necked flask, add 200 mL of distilled water and stir evenly, adjust the pH to 2-3 with 4% hydrochloric acid, slowly add 0.15 g of sodium hypochlorite, heat to 50°C and react for 1 h to obtain mixed solution I.

[0056] (2) Add 0.5 g of waterborne polyurethane to the mixed solution I, stir and heat to 80°C for 1 h to obtain a mixed solution II, then add 0.1 g of erythritol, mix thoroughly and heat in a water bath at 80°C for 0.5 h to obtain a mixed solution III.

[0057] (3) After the mixed solution III is cooled to room temperature, the pH of the solution is adjusted, and 0.2 g of glycerol and 0.8 g of dodecyl dimethyl amine oxide are added to the mixed solution III to prepare a dust suppressant solution.

[0058] Example 5

[0059] (1) Weigh 0.4 g of locust bean gum into a three-necked flask, add 200 mL of distilled water and stir evenly, adjust the pH to 2-3 with 4% hydrochloric acid, slowly add 0.25 g of sodium hypochlorite, heat to 60°C and react for 1 h to obtain mixed solution I.

[0060] (2) Add 0.3 g of aqueous polyurethane to the mixed solution I, stir and heat to 60°C for 1.5 h to obtain a mixed solution II, then add 0.2 g of erythritol, mix thoroughly and heat in a water bath at 60°C for 1 h to obtain a mixed solution III.

[0061] (3) After the mixed solution III is cooled to room temperature, the pH of the solution is adjusted to neutral, and 0.2 g of glycerol and 0.8 g of dodecyl dimethyl amine oxide are added to the mixed solution III to prepare a dust suppressant solution.

[0062] Example 6

[0063] (1) Weigh 0.4 g of locust bean gum into a three-necked flask, add 200 mL of distilled water and stir evenly, adjust the pH to 2-3 with 4% hydrochloric acid, slowly add 0.35 g of sodium hypochlorite, heat to 50°C and react for 2 h to obtain a mixed solution I.

[0064] (2) Add 0.1 g of waterborne polyurethane to the mixed solution I, stir and heat to 70°C for 1 h to obtain a mixed solution II, then add 0.3 g of erythritol, mix thoroughly and heat in a water bath at 70°C for 0.5 h to obtain a mixed solution III.

[0065] (3) After the mixed solution III is cooled to room temperature, the pH of the solution is adjusted to neutral, and 0.2 g of glycerol and 0.6 g of dodecyl dimethyl amine oxide are added to the mixed solution III to prepare a dust suppressant solution.

[0066] Example 7

[0067] (1) Weigh 0.6 g of locust bean gum into a three-necked flask, add 200 mL of distilled water and stir evenly, adjust the pH to 2-3 with 4% hydrochloric acid, slowly add 0.35 g of sodium hypochlorite, heat to 50°C and react for 2 h to obtain mixed solution I.

[0068] (2) Add 0.3 g of waterborne polyurethane to the mixed solution I, stir and heat to 70°C for reaction for 1 h to obtain a mixed solution II, then add 0.3 g of erythritol, mix thoroughly and heat in a water bath for 0.5 h to obtain a mixed solution III.

[0069] (3) After the mixed solution III is cooled to room temperature, the pH of the solution is adjusted to neutral, and 0.2 g of glycerol and 0.6 g of dodecyl dimethyl amine oxide are added to the mixed solution III to prepare a dust suppressant solution.

[0070] Example 8

[0071] (1) Weigh 0.6 g of locust bean gum into a three-necked flask, add 200 mL of distilled water and stir evenly, adjust the pH to 2-3 with 4% hydrochloric acid, slowly add 0.25 g of sodium hypochlorite, heat to 50°C and react for 1 h to obtain mixed solution I.

[0072] (2) Add 0.1 g of waterborne polyurethane to the mixed solution I, stir and heat to 80°C for 1 h to obtain a mixed solution II, then add 0.3 g of erythritol, mix thoroughly and heat in a water bath at 80°C for 0.5 h to obtain a mixed solution III.

[0073] (3) After the mixed solution III is cooled to room temperature, the pH of the solution is adjusted to neutral, and 0.4 g of glycerol and 0.8 g of dodecyl dimethyl amine oxide are added to the mixed solution III to prepare a dust suppressant solution.

[0074] Example 9

[0075] (1) Weigh 0.6 g of locust bean gum into a three-necked flask, add 200 mL of distilled water and stir evenly, adjust the pH to 2-3 with 4% hydrochloric acid, slowly add 0.35 g of sodium hypochlorite, heat to 60°C and react for 1 h to obtain mixed solution I.

[0076] (2) Add 0.5 g of waterborne polyurethane to the mixed solution I, stir and heat to 60°C for reaction for 1 h to obtain a mixed solution II, then add 0.3 g of erythritol, mix thoroughly and heat in a water bath for 0.5 h to obtain a mixed solution III.

[0077] (3) After the mixed solution III is cooled to room temperature, the pH of the solution is adjusted to neutral, and 0.3 g of glycerol and 1 g of dodecyl dimethyl amine oxide are added to the mixed solution III to prepare a dust suppressant solution.

[0078] Comparative Example 1

[0079] Weigh 1 g of dodecyl dimethyl amine oxide and heat until it is uniformly dissolved.

[0080] Comparative Example 2

[0081] Add common commercial dust suppressant to the beaker and stir until evenly dissolved.

[0082] The effects of Examples 1-9 and Comparative Examples 1 and 2 were investigated by testing. The following tests were conducted in accordance with the TB / T3210.1-2020 standard for coal sample preparation, and the coal sample of 200 mesh was screened using a standard sieve. The coal was dried in a drying oven at (50±2)°C for 4 hours to remove moisture, and then taken out and placed at room temperature for 2 hours.

[0083] Test 1

[0084] The dust suppressants prepared in Examples 1-9 and Comparative Examples 1 and 2 were tested for water retention and curing effect.

[0085] The test method is: 5g of coal dust is placed in multiple culture dishes respectively, 10g of the solution of Examples 1-9 and Comparative Examples 1-2 is sprayed on the coal dust, and the samples treated with Comparative Examples 1 and 2 are used as the control group. All samples are placed in a 50°C vacuum drying oven for high temperature heating for 4 hours, and then placed in a refrigerator for 4 hours. Three cycles are performed, the initial value is compared with the residual mass, and the cumulative mass loss rate is calculated.

[0086] The hardness of the cured layer after drying was measured with a Shore hardness tester, and each sample was tested 3 times to obtain the average value.

[0087] Wheat seeds with full grains and uniform size were soaked in Examples 1-9 and Comparative Examples 1 and 2 for 6 hours, and then placed in seedling trays. According to the experimental design, 300 mL of dust suppressant solution was added to each group, and the same dose of solution was added every other day to observe the germination of the seeds. The test results are shown in Table 1 below.

[0088] Table 1 Freeze-thaw resistance, environmental protection and curing effect test

[0089]

[0090]

[0091] The results of analysis test 1 show that compared with comparative examples 1 and 2, the mass loss rates of embodiments 1-9 are all lower than 96%, among which the mass loss rate of embodiment 5 remains the lowest, at 93.97%. After 3 cycles, the mass loss rates of comparative examples 1 and 2 reach more than 98%. The results show that the dust suppressant of the present invention has a high water retention. The crust hardness of the sample sprayed with the embodiment can reach up to 85.7HA, which is much greater than the film hardness of comparative examples 1 and 2, and has excellent adhesion and curing effects. The germination rate of wheat seeds treated with the dust suppressant solution is all above 90%, indicating that the dust suppressant prepared by the present invention has no toxic effect on plants, conforms to the current concept of green environmental protection and clean production, and is an ideal dust suppression material.

[0092] Test 2

[0093] The dust suppression properties of the dust suppressants prepared in Examples 1-9 and Comparative Examples 1 and 2 were tested below.

[0094] The test method is as follows: a dust suppression test is carried out on a wind erosion simulation platform, 10g of coal powder is placed in a culture dish respectively, the wind speed is set to 11m / s, and the concentrations of PM2.5 and PM10 at this time are detected by a handheld laser particle counter and recorded as α0, 15g of Examples 1-9 and Comparative Examples 1 and 2 are respectively evenly sprayed into the culture dish, and the concentrations of PM2.5 and PM10 after spraying are detected by a handheld laser particle counter and recorded as α1, and the dust suppression rate is calculated according to the following formula.

[0095]

[0096] η is the dust suppression rate (%), α0 is the initial concentration of PM2.5 and PM10 (μg / m 3 ), α1 is the concentration of PM2.5 and PM10 after spraying dust suppressant (μg / m 3 ).

[0097] The test results are as follows Figure 1 shown.

[0098] A comparative analysis of the dust suppression effect of Test 2 shows that the samples of the spraying embodiments have a coal dust suppression rate of more than 95%, among which Example 5 has the best dust suppression effect, with PM2.5 and PM10 suppression rates of 97.89% and 98.16%, respectively, which are about 1.8 and 1.7 times that of Example 2. Therefore, the dust suppressant does have good dust suppression performance.

[0099] In summary, the dust suppression prepared by the present invention can suppress dust efficiently, effectively solve the general technical problems of the bonding and curing effects of dust suppression materials in mining areas, and has good social benefits and considerable economic benefits.

[0100] 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 the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A method for preparing a highly curable environmentally friendly dust suppression material, characterized in that: Prepare according to the following steps: (1) Weigh locust bean gum and place it in a container, add water and stir evenly, adjust the pH to 2-3 with hydrochloric acid, add sodium hypochlorite, raise the temperature to 50-60° C. and react for 1-2 hours to obtain a mixed solution I; (2) adding waterborne polyurethane to the mixed solution I, heating to 60-80° C. for reaction for 1-1.5 h to obtain a mixed solution II, adding erythritol, and mixing thoroughly to obtain a mixed solution III; (3) After the mixed solution III is cooled to room temperature, the pH of the solution is adjusted to neutral, and a surfactant is added to the mixed solution III to prepare a dust suppressant solution.

2. The method for preparing the highly curable environmentally friendly dust suppression material according to claim 1, characterized in that: The water is distilled water.

3. The method for preparing the highly curable environmentally friendly dust suppression material according to any one of claims 1 to 2, characterized in that: For every 2000 mL of water, add 2-6 parts of locust bean gum, 1.5-3.5 parts of sodium hypochlorite, 1-5 parts of water-based polyurethane, 1-3 parts of erythritol, 6-10 parts of wetting agent and 2-4 parts of water retaining agent according to weight proportions.

4. The method for preparing the highly curable environmentally friendly dust suppression material according to claim 3, characterized in that: The water retaining agent is glycerol.

5. The method for preparing the highly curable environmentally friendly dust suppression material according to claim 4, characterized in that: The wetting agent is dodecyl dimethyl amine oxide, and the mass concentration of the hydrochloric acid solution is 4-10%.

6. The method for preparing the highly curable environmentally friendly dust suppression material according to claim 4, characterized in that: Add erythritol, mix thoroughly and continue to react at 60-80°C for 0.5-1h to obtain mixed solution III.

7. A highly curable and environment-friendly dust suppression material prepared by the method for preparing a highly curable and environment-friendly dust suppression material according to any one of claims 1 to 6.

8. Use of the highly curable environmentally friendly dust suppression material according to claim 7 in dust suppression of coal mines.

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