High-wettability and strong-adhesion cross-linking enhanced dust fall material as well as preparation method and application thereof

Abstract

The invention discloses a high-wettability and strong-adhesion cross-linking enhanced dust fall material. The dust fall material comprises the following raw materials in parts by mass: 2-5 parts of pullulan, 2-5 parts of agarose, 5-15 parts of sodium hydroxide, 5-15 parts of chloroacetic acid, 5-15 parts of ethylene glycol diglycidyl ether, 3-11 parts of malic acid, 5-10 parts of a water-retaining agent, 5-10 parts of diluted hydrochloric acid and 1000-2500 parts of distilled water. The dust falling material has high wettability and strong adhesion, and can effectively settle coal dust in air; meanwhile, a coal dust consolidation layer formed after the dust falling material is sprayed is high in strength, reentrainment of dust can be effectively prevented, and the technical problems that the dust falling material is poor in dust falling effect, single in function and the like are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of dust control, in particular to a cross-linking enhanced dust reduction material with high wettability and strong adhesion, and a preparation method and application thereof. BACKGROUND

[0003] Currently, common dust reduction methods include spray dust reduction, ventilation dust removal, coal seam water injection, chemical dust reduction, etc., among which the most common are spray dust reduction and ventilation dust removal. However, spray dust reduction generally has problems such as high water consumption, poor wettability of water mist on coal dust, and low dust reduction efficiency. Ventilation dust removal has problems such as high energy consumption, high installation and maintenance cost, and large occupied area. Coal seam water injection is a source dust reduction method, but it is significantly limited by coal seam geological conditions and is difficult to operate in practice. Chemical dust reduction improves wettability or adhesion to some extent, but often has the problem of single function. For example, wettability materials have poor adhesion effect on dust, the formed solidified layer has low strength, and cannot effectively inhibit secondary dust raising. Adhesion materials often have problems such as poor wettability, and difficulty in quickly penetrating and wrapping coal dust particles.

[0004] Therefore, it is urgent to develop a dust reduction material with good wettability, strong adhesion, and the ability to form a durable solidified layer, so as to realize the long-term and efficient control of coal dust. SUMMARY

[0005] To solve the technical problems of single function of dust reduction materials, poor wettability and adhesion to coal dust, and poor secondary dust inhibition effect caused by insufficient strength of dust reduction materials in the prior art, the present application discloses a cross-linking enhanced dust reduction material with high wettability and strong adhesion, and a preparation method and application thereof. The dust reduction material has high wettability and strong adhesion, and can effectively settle coal dust in the air. At the same time, the coal dust solidified layer formed after spraying the dust reduction material has high strength, which can effectively prevent secondary dust raising, and solves the problems of poor dust reduction effect and single function of dust reduction materials.

[0006] The first object of the present application is to provide a cross-linking enhanced dust reduction material with high wettability and strong adhesion. The dust reduction material comprises the following raw materials in mass fraction: 2-5 parts of pullulan, 2-5 parts of agarose, 5-15 parts of sodium hydroxide, 5-15 parts of chloroacetic acid, 5-15 parts of ethylene glycol diglycidyl ether, 3-11 parts of malic acid, 5-10 parts of a water-retaining agent, 5-10 parts of dilute hydrochloric acid, and 1000-2500 parts of distilled water.

[0007] Specifically, the water-retaining agent is one or more of glycerol, propylene glycol, butanediol, dipropylene glycol, and sorbitol.

[0008] Specifically, when the distilled water is 100 mL, the weights of other raw materials are preferably 0.3 g of pullulan, 0.3 g of agarose, 1 g of sodium hydroxide, 0.75 g of chloroacetic acid, 1 g of ethylene glycol diglycidyl ether, 0.6 g of malic acid and 0.5 g of water-retaining agent, respectively; and the concentration of the dilute hydrochloric acid is 3%.

[0009] The second object of the present application is to provide a preparation method of a cross-linked enhanced dust fall material with high wetting and strong adhesion, comprising the following steps:

[0010] S1 adding distilled water and pullulan into a beaker in sequence, placing the beaker in a water bath for first heating and stirring treatment, so that the pullulan is completely dissolved in the distilled water to obtain a pullulan aqueous solution;

[0011] S2 adding distilled water and agarose into another beaker in sequence, placing the beaker in a water bath for second heating and stirring treatment, so that the agarose is completely dissolved in the distilled water to obtain an agarose aqueous solution;

[0012] S3 mixing the pullulan aqueous solution and the agarose aqueous solution and stirring uniformly to obtain a composite polysaccharide aqueous solution; adding sodium hydroxide into the composite polysaccharide aqueous solution and stirring uniformly, then adding chloroacetic acid, and performing a carboxymethylation reaction in a water bath to obtain a carboxymethyl composite polysaccharide aqueous solution;

[0013] S4 adjusting the pH value of the carboxymethyl composite polysaccharide aqueous solution to 10, then adding ethylene glycol diglycidyl ether into the solution, and performing a cross-linking reaction in a water bath under heating and stirring to obtain a cross-linking product I aqueous solution;

[0014] S5 adjusting the pH value of the cross-linking product I aqueous solution to 5 by using dilute hydrochloric acid, then adding malic acid into the solution, and performing a grafting reaction in a water bath under heating and stirring to obtain a grafting product II aqueous solution;

[0015] S6 adjusting the pH value of the grafting product II aqueous solution to neutral, then adding a water-retaining agent into the solution, and stirring to dissolve at room temperature to obtain a cross-linked enhanced dust fall material with high wetting and strong adhesion.

[0016] Specifically, the temperature of the first heating and stirring treatment in step S1 is 60-70℃, and the time is 1-2h.

[0017] Specifically, the temperature of the second heating and stirring treatment in step S2 is 80-90℃, and the time is 1-2h.

[0018] Specifically, the temperature of the carboxymethylation reaction in step S3 is 70-80℃, and the time is 3-4h.

[0019] Specifically, the temperature of the cross-linking reaction in step S4 is 50-60℃, and the time is 6-8h.

[0020] Specifically, the grafting reaction in step S5 is carried out at a temperature of 80-90°C for 1-2 hours.

[0021] The third objective of this invention is to provide an application of the aforementioned highly wettable and strongly adhesive cross-linked reinforced dust-suppressing material in dust suppression during coal mining.

[0022] The reaction equations for the carboxymethylation reaction involved in this invention are as follows:

[0023]

[0024] The reaction equations for the crosslinking reaction involved in this invention are as follows:

[0025]

[0026] The reaction equations for the grafting reaction involved in this invention are as follows:

[0027]

[0028] (1) Carboxylation reaction mechanism: The sodium hydroxide added in this invention acts on the abundant hydroxyl groups (-OH) on the pullulan and agarose molecular chains, causing them to deprotonate and generate highly reactive alkoxide anions (-O). - This allows them to possess the ability to launch nucleophilic attacks. Pullulan and agarose alkoxide anions (-O... - As a strong nucleophile, it attacks the partially positively charged carbon atoms in the chloroacetic acid molecule to undergo nucleophilic substitution reactions, producing alkoxy anions (-O... - ) Replace chlorine atom (Cl - ), and forms a new ether bond with the methylene group (-CH2), thereby converting the carboxymethyl group (-CH2COO) into a methyl group. - The groups are respectively attached to the backbones of pullulan and agarose to form carboxymethyl pullulan aqueous solution and carboxymethyl agarose aqueous solution, which together form a carboxymethyl complex polysaccharide aqueous solution.

[0029] (2) Crosslinking reaction mechanism: In an alkaline environment, the remaining hydroxyl groups (-OH) in carboxymethyl pullulan and carboxymethyl agarose are deprotonated to form more nucleophilic alkoxy anions (-O). - Activated alkoxy anion (-O) -Nucleophilic attack occurs on the electron-deficient carbon atoms in the epoxy groups at both ends of the ethylene glycol diglycidyl ether molecule, leading to ring-opening of the epoxy groups. After ring-opening, the oxygen atoms on the carboxymethyl pullulan and carboxymethyl agarose chains are linked to the methylene (-CH2) group of the glycidyl group in the ethylene glycol diglycidyl ether molecule via ether bonds, simultaneously exposing new hydroxyl groups (-OH). Since an ethylene glycol diglycidyl ether molecule contains two such epoxy groups, it acts as a cross-linking agent, covalently linking the originally independent carboxymethyl pullulan and carboxymethyl agarose, thereby forming a three-dimensional entangled cross-linked network of carboxymethyl polysaccharides.

[0030] (3) Grafting reaction mechanism: Under acidic conditions, the carboxyl group (-COOH) in malic acid molecules undergoes esterification with the hydroxyl group (-OH) in cross-linked product I, removing one molecule of water and forming an ester bond, thereby grafting malic acid onto the backbone of cross-linked product I in the form of ester bonds.

[0031] Compared with the prior art, the present invention has the following beneficial technical effects:

[0032] (1) Pullulan in this invention is an extracellular polysaccharide produced by fungal fermentation. It is degradable, non-toxic, and contains a small number of α-1,6-glycosidic bonds on its molecular chain, giving it a multi-branched structure. It has good adhesion properties and can effectively adhere to dust in the air and cause it to agglomerate into large dust particles, thus causing the dust to settle. Agarose is a linear polysaccharide composed of D-galactose and 3,6-L-galactose. It is non-toxic and harmless, meets environmental protection requirements, and has good biocompatibility, high water retention and viscoelasticity. It can efficiently encapsulate and bind dust particles and form a dense and flexible covering film on the surface, effectively suppressing dust. Pullulan and agarose are modified by carboxylation with chloroacetic acid under alkaline conditions. The carboxylmethyl group (-CH2COO) with good hydrophilic properties is modified by carboxylation. - Grafted onto pullulan and agarose backbones, the carboxymethylated complex polysaccharide aqueous solution exhibits superior wettability and can better wet coal dust.

[0033] (2) The ethylene glycol diglycidyl ether in this invention belongs to the bifunctional epoxy crosslinking agent. Its molecular structure contains two highly reactive epoxy groups, and its molecular skeleton is composed of two glycidyl ether units bridged by ethylene glycol, which endows it with hydrophilicity, low viscosity and excellent water solubility. Using ethylene glycol diglycidyl ether as a crosslinking agent, through the ring-opening reaction of epoxy groups, it forms covalent ether bonds with hydroxyl groups, connecting the molecular chains of carboxymethyl pullulan polysaccharide and carboxymethyl agarose through covalent bonds, so as to form an entangled three-dimensional crosslinking network, and obtain crosslinking product I, which enhances the mechanical properties of dust-suppressing materials, improves the strength of coal dust solidification layer, and effectively prevents secondary dust;

[0034] (3) Malic acid in this invention is an organic acid that is naturally found in fruits and vegetables. Its molecule contains two carboxyl groups (-COOH) and one hydroxyl group (-OH). It has good degradability and hydrophilicity. By grafting it into crosslinking product I through esterification reaction, the wetting performance of the dust-suppressing material is further improved, while the viscosity of the dust-suppressing agent solution is also effectively reduced, which is more conducive to spraying.

[0035] (4) The highly wettable and strongly adhesive cross-linked reinforced dust-suppressing material prepared in this invention uses pullulan, agarose, sodium hydroxide, chloroacetic acid, ethylene glycol diglycidyl ether, malic acid, water-retaining agent, dilute hydrochloric acid, and distilled water as raw materials. The raw materials are readily available, environmentally friendly, and highly biodegradable. By covalently linking the molecular chains of carboxymethyl pullulan and carboxymethyl agarose, an entangled three-dimensional cross-linked network is formed. Malic acid is grafted into the three-dimensional cross-linked network through an esterification reaction to obtain the dust-suppressing material. This dust-suppressing material has superior adhesion. The material exhibits superior performance, effectively binding dust particles and effectively settling coal dust in the air, achieving a total dust reduction efficiency of up to 80%. The formed cross-linked structure enhances the mechanical properties of the dust-suppressing material and the strength of the coal dust solidification layer, effectively preventing secondary dust generation. Furthermore, the grafting of malic acid onto the cross-linked structure introduces a large number of carboxyl groups, further improving the wettability of the dust-suppressing material. After 2 seconds, the contact angle is as low as 12.27°, effectively wetting the dust. The dust-suppressing material prepared by this invention combines efficient dust reduction with secondary dust suppression, meeting the need for efficient and long-term treatment of coal mine dust. Attached Figure Description

[0036] Figure 1 This is a process flow diagram of the preparation of cross-linked reinforced dust-suppressing materials with high wettability and strong adhesion in Examples 1-9 of the present invention;

[0037] Figure 2 This is a comparison chart of the dust reduction efficiency of the dust reduction materials prepared in Examples 1-9 and Comparative Examples 1-2 of the present invention;

[0038] Figure 3 This is a comparison chart showing the secondary dust suppression efficiency of the dust-suppressing materials prepared in Examples 1-9 and Comparative Examples 1-2 of the present invention. Detailed Implementation Plan

[0039] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing specific embodiments only and is not intended to limit the present invention.

[0040] Please see Figure 1 , Figure 1 The process flow diagrams for preparing the highly wettable and strongly adhesive cross-linked reinforced dust-suppressing materials in Examples 1-9 of this invention are shown below. The specific steps of Examples 1-9 are as follows:

[0041] Example 1

[0042] S1. Add 50 mL of distilled water and 0.2 g of pullulan to a beaker. Place the beaker in a water bath and set the temperature to 70 °C. Perform a first heating and stirring treatment for 1 h to completely dissolve the pullulan in the distilled water, and obtain pullulan aqueous solution a.

[0043] S2. Add 50 mL of distilled water and 0.2 g of agarose to another beaker in sequence. Place the beaker in a water bath and set the temperature to 90 °C. Perform a second heating and stirring treatment for 1 h to completely dissolve the agarose in the distilled water and obtain agarose aqueous solution a.

[0044] S3 mix pullulan polysaccharide aqueous solution a and agarose aqueous solution a and stir evenly to obtain complex polysaccharide aqueous solution a; add 1g sodium hydroxide to complex polysaccharide aqueous solution a and stir evenly, then add 0.45g chloroacetic acid, and carry out carboxymethylation reaction in a water bath at 70℃ for 3h to obtain carboxymethyl complex polysaccharide aqueous solution a.

[0045] After adjusting the pH of the carboxymethyl complex polysaccharide aqueous solution a to 10, 0.5g of ethylene glycol diglycidyl ether was added to it, and the cross-linking reaction was carried out by heating and stirring in a water bath at 50℃ for 6h to obtain the cross-linking product I aqueous solution a.

[0046] S5 adjusted the pH of the crosslinking product I aqueous solution a to 5 with dilute hydrochloric acid, then added 0.4g of malic acid, and heated and stirred in an 80℃ water bath for 1h to carry out the grafting reaction, thus obtaining the grafting product II aqueous solution a.

[0047] After adjusting the pH of the graft product II aqueous solution a to neutral, S6 added 0.5 g of glycerol and stirred at room temperature until dissolved to obtain a cross-linked reinforced dust-suppressing material a with high wettability and strong adhesion.

[0048] Example 2

[0049] S1. Add 50 mL of distilled water and 0.2 g of pullulan to a beaker. Place the beaker in a water bath and set the temperature to 65 °C. Perform a first heating and stirring treatment for 1.5 h to completely dissolve the pullulan in the distilled water, and obtain pullulan aqueous solution b.

[0050] S2 adds 50 mL of distilled water and 0.2 g of agarose to another beaker, places the beaker in a water bath, sets the temperature to 85 °C, and performs a second heating and stirring treatment for 1.5 h to completely dissolve the agarose in the distilled water, thus obtaining agarose aqueous solution b;

[0051] S3 mix pullulan polysaccharide aqueous solution b and agarose aqueous solution b and stir evenly to obtain complex polysaccharide aqueous solution b; add 1g sodium hydroxide to complex polysaccharide aqueous solution b and stir evenly, then add 0.5g chloroacetic acid, and carry out carboxymethylation reaction in a water bath at 75℃ for 3.5h to obtain carboxymethyl complex polysaccharide aqueous solution b.

[0052] After adjusting the pH of the carboxymethyl complex polysaccharide aqueous solution b to 10, 0.5g of ethylene glycol diglycidyl ether was added to it, and the cross-linking reaction was carried out by heating and stirring in a water bath at 55℃ for 7h to obtain the cross-linking product I aqueous solution b.

[0053] S5 adjusted the pH of the crosslinking product I aqueous solution b to 5 with dilute hydrochloric acid, then added 0.5g of malic acid, and heated and stirred in an 85℃ water bath for 1.5h to carry out the grafting reaction, thus obtaining the grafting product II aqueous solution b.

[0054] After adjusting the pH of the graft product II aqueous solution b to neutral, S6 added 0.5g of propylene glycol and stirred at room temperature until dissolved to obtain a highly wettable and strongly adhesive cross-linked reinforced dust-suppressing material b.

[0055] Example 3

[0056] S1. Add 50 mL of distilled water and 0.2 g of pullulan to a beaker. Place the beaker in a water bath and set the temperature to 60 °C. Perform a first heating and stirring treatment for 2 hours to completely dissolve the pullulan in the distilled water, and obtain pullulan aqueous solution c.

[0057] S2. Add 50 mL of distilled water and 0.2 g of agarose to another beaker in sequence. Place the beaker in a water bath and set the temperature to 80 °C. Perform a second heating and stirring treatment for 2 hours to completely dissolve the agarose in the distilled water, and obtain an agarose aqueous solution c.

[0058] S3 mix pullulan polysaccharide aqueous solution c and agarose aqueous solution c and stir evenly to obtain complex polysaccharide aqueous solution c; add 1g sodium hydroxide to complex polysaccharide aqueous solution c and stir evenly, then add 0.75g chloroacetic acid, and carry out carboxymethylation reaction in a water bath at 80℃ for 4h to obtain carboxymethyl complex polysaccharide aqueous solution c.

[0059] After adjusting the pH of the carboxymethyl complex polysaccharide aqueous solution c to 10, 1.5g of ethylene glycol diglycidyl ether was added to it, and the cross-linking reaction was carried out by heating and stirring in a water bath at 60℃ for 8h to obtain the cross-linking product I aqueous solution c.

[0060] S5 adjusted the pH of the crosslinking product I aqueous solution c to 5 with dilute hydrochloric acid, then added 0.6g of malic acid, and heated and stirred in a 90℃ water bath for 2h to carry out the grafting reaction, thus obtaining the grafting product II aqueous solution c.

[0061] After adjusting the pH of the graft product II aqueous solution c to neutral, 0.5g of butanediol was added and stirred at room temperature until dissolved to obtain a cross-linked reinforced dust-suppressing material c with high wettability and strong adhesion.

[0062] Example 4

[0063] S1. Add 50 mL of distilled water and 0.3 g of pullulan to a beaker. Place the beaker in a water bath and set the temperature to 70 °C. Perform a first heating and stirring treatment for 1 h to completely dissolve the pullulan in the distilled water, and obtain pullulan aqueous solution d.

[0064] S2. Add 50 mL of distilled water and 0.3 g of agarose to another beaker in sequence. Place the beaker in a water bath and set the temperature to 90 °C. Perform a second heating and stirring treatment for 1 h to completely dissolve the agarose in the distilled water and obtain an agarose aqueous solution d.

[0065] S3 mix pullulan polysaccharide aqueous solution d and agarose aqueous solution d and stir evenly to obtain complex polysaccharide aqueous solution d; add 1g sodium hydroxide to complex polysaccharide aqueous solution d and stir evenly, then add 0.45g chloroacetic acid, and carry out carboxymethylation reaction in a water bath at 70℃ for 3h to obtain carboxymethyl complex polysaccharide aqueous solution d.

[0066] After adjusting the pH of the carboxymethyl polysaccharide aqueous solution d to 10, 1g of ethylene glycol diglycidyl ether was added to it, and the cross-linking reaction was carried out by heating and stirring in a water bath at 50℃ for 6h to obtain the cross-linking product I aqueous solution d.

[0067] S5 adjusted the pH of the crosslinking product I aqueous solution d to 5 with dilute hydrochloric acid, then added 0.6g of malic acid, and heated and stirred in an 80℃ water bath for 1h to carry out the grafting reaction, thus obtaining the grafting product II aqueous solution d.

[0068] After adjusting the pH of the graft product II aqueous solution d to neutral, S6 added 0.5 g of dipropylene glycol and stirred at room temperature until dissolved to obtain a highly wettable and strongly adhesive cross-linked reinforced dust-suppressing material d.

[0069] Example 5

[0070] S1. Add 50 mL of distilled water and 0.3 g of pullulan to a beaker. Place the beaker in a water bath and set the temperature to 70 °C. Perform a first heating and stirring treatment for 1 h to completely dissolve the pullulan in the distilled water, and obtain pullulan aqueous solution e.

[0071] S2. Add 50 mL of distilled water and 0.3 g of agarose to another beaker in sequence. Place the beaker in a water bath and set the temperature to 90 °C. Perform a second heating and stirring treatment for 1 h to completely dissolve the agarose in the distilled water and obtain an agarose aqueous solution e.

[0072] S3 mix pullulan polysaccharide aqueous solution e and agarose aqueous solution e and stir evenly to obtain complex polysaccharide aqueous solution e; add 1g sodium hydroxide to complex polysaccharide aqueous solution e and stir evenly, then add 0.5g chloroacetic acid, and carry out carboxymethylation reaction in a water bath at 70℃ for 3h to obtain carboxymethyl complex polysaccharide aqueous solution e.

[0073] After adjusting the pH of the carboxymethyl complex polysaccharide aqueous solution e to 10, 0.5g of ethylene glycol diglycidyl ether was added to it, and the cross-linking reaction was carried out by heating and stirring in a water bath at 50℃ for 6h to obtain the cross-linking product I aqueous solution e.

[0074] S5 adjusted the pH of the crosslinking product I aqueous solution e to 5 with dilute hydrochloric acid, then added 0.4g of malic acid, and heated and stirred in an 80℃ water bath for 1h to carry out the grafting reaction, thus obtaining the grafting product II aqueous solution e.

[0075] After adjusting the pH of the graft product II aqueous solution e to neutral, 0.5g of sorbitol was added and stirred at room temperature until dissolved to obtain a cross-linked reinforced dust-suppressing material e with high wettability and strong adhesion.

[0076] Example 6

[0077] S1. Add 50 mL of distilled water and 0.3 g of pullulan to a beaker. Place the beaker in a water bath and set the temperature to 70 °C. Perform a first heating and stirring treatment for 1 h to completely dissolve the pullulan in the distilled water, and obtain a pullulan aqueous solution f.

[0078] S2. Add 50 mL of distilled water and 0.3 g of agarose to another beaker in sequence. Place the beaker in a water bath and set the temperature to 90 °C. Perform a second heating and stirring treatment for 1 h to completely dissolve the agarose in the distilled water and obtain an agarose aqueous solution f.

[0079] S3 mix pullulan polysaccharide aqueous solution f and agarose aqueous solution f and stir evenly to obtain complex polysaccharide aqueous solution f; add 1g sodium hydroxide to complex polysaccharide aqueous solution f and stir evenly, then add 0.75g chloroacetic acid, and carry out carboxymethylation reaction in a water bath at 70℃ for 3h to obtain carboxymethyl complex polysaccharide aqueous solution f.

[0080] After adjusting the pH of the carboxymethyl complex polysaccharide aqueous solution f to 10, 1g of ethylene glycol diglycidyl ether was added to it, and the cross-linking reaction was carried out by heating and stirring in a water bath at 50℃ for 6h to obtain the cross-linking product I aqueous solution f.

[0081] S5 adjusted the pH of the crosslinking product I aqueous solution f to 5 with dilute hydrochloric acid, then added 0.6g of malic acid, and heated and stirred in an 80℃ water bath for 1h to carry out the grafting reaction, thus obtaining the grafting product II aqueous solution f.

[0082] After adjusting the pH of the graft product II aqueous solution f to neutral, S6 added 0.5g of sorbitol and stirred at room temperature until dissolved to obtain a cross-linked reinforced dust-suppressing material f with high wettability and strong adhesion.

[0083] Example 7

[0084] S1. Add 50 mL of distilled water and 0.4 g of pullulan to a beaker. Place the beaker in a water bath and set the temperature to 70 °C. Perform a first heating and stirring treatment for 1 h to completely dissolve the pullulan in the distilled water, and obtain a pullulan aqueous solution j.

[0085] S2. Add 50 mL of distilled water and 0.4 g of agarose to another beaker in sequence. Place the beaker in a water bath and set the temperature to 90 °C. Perform a second heating and stirring treatment for 1 h to completely dissolve the agarose in the distilled water and obtain an agarose aqueous solution j.

[0086] S3 mix pullulan polysaccharide aqueous solution j and agarose aqueous solution j and stir evenly to obtain complex polysaccharide aqueous solution j; add 1g sodium hydroxide to complex polysaccharide aqueous solution j and stir evenly, then add 0.45g chloroacetic acid, and carry out carboxymethylation reaction in a water bath at 70℃ for 3h to obtain carboxymethyl complex polysaccharide aqueous solution j.

[0087] After adjusting the pH of the carboxymethyl polysaccharide aqueous solution j to 10, 1.5g of ethylene glycol diglycidyl ether was added to it, and the cross-linking reaction was carried out by heating and stirring in a water bath at 50℃ for 6h to obtain the cross-linking product I aqueous solution j.

[0088] S5 adjusted the pH of the crosslinking product I aqueous solution j to 5 with dilute hydrochloric acid, then added 0.5g of malic acid, and heated and stirred in an 80℃ water bath for 1h to carry out the grafting reaction, thus obtaining the grafting product II aqueous solution j.

[0089] After adjusting the pH of the graft product II aqueous solution j to neutral, S6 added 0.5 g of sorbitol and stirred at room temperature until dissolved to obtain a cross-linked reinforced dust-suppressing material j with high wettability and strong adhesion.

[0090] Example 8

[0091] S1. Add 50 mL of distilled water and 0.4 g of pullulan to a beaker. Place the beaker in a water bath and set the temperature to 70 °C. Perform a first heating and stirring treatment for 1 h to completely dissolve the pullulan in the distilled water, and obtain pullulan aqueous solution k.

[0092] S2. Add 50 mL of distilled water and 0.4 g of agarose to another beaker in sequence. Place the beaker in a water bath and set the temperature to 90 °C. Perform a second heating and stirring treatment for 1 h to completely dissolve the agarose in the distilled water and obtain an agarose aqueous solution k.

[0093] S3 mix pullulan polysaccharide aqueous solution k and agarose aqueous solution k and stir evenly to obtain complex polysaccharide aqueous solution k; add 1g sodium hydroxide to complex polysaccharide aqueous solution k and stir evenly, then add 0.5g chloroacetic acid, and carry out carboxymethylation reaction in a water bath at 70℃ for 3h to obtain carboxymethyl complex polysaccharide aqueous solution k.

[0094] After adjusting the pH of the carboxymethyl complex polysaccharide aqueous solution k to 10, 0.5g of ethylene glycol diglycidyl ether was added to it. The cross-linking reaction was carried out in a water bath at 50℃ with stirring for 6h to obtain the cross-linking product I aqueous solution k.

[0095] S5 uses dilute hydrochloric acid to adjust the pH of the crosslinking product I aqueous solution k to 5, then adds 0.6g of malic acid, and heats and stirs in an 80℃ water bath for 1h to carry out the grafting reaction, thus obtaining the grafting product II aqueous solution k.

[0096] After adjusting the pH of the graft product II aqueous solution k to neutral, S6 added 0.5 g of sorbitol and stirred at room temperature until dissolved to obtain a cross-linked reinforced dust-suppressing material k with high wettability and strong adhesion.

[0097] Example 9

[0098] S1. Add 50 mL of distilled water and 0.4 g of pullulan to a beaker. Place the beaker in a water bath and set the temperature to 70 °C. Perform a first heating and stirring treatment for 1 h to completely dissolve the pullulan in the distilled water, and obtain pullulan aqueous solution m.

[0099] S2. Add 50 mL of distilled water and 0.4 g of agarose to another beaker in sequence. Place the beaker in a water bath and set the temperature to 90 °C. Perform a second heating and stirring treatment for 1 h to completely dissolve the agarose in the distilled water and obtain an agarose aqueous solution m.

[0100] S3 mix pullulan polysaccharide aqueous solution m and agarose aqueous solution m and stir evenly to obtain composite polysaccharide aqueous solution m; add 1g sodium hydroxide to composite polysaccharide aqueous solution m and stir evenly, then add 0.75g chloroacetic acid, and carry out carboxymethylation reaction in a water bath at 70℃ for 3h to obtain carboxymethyl composite polysaccharide aqueous solution m.

[0101] After adjusting the pH of the carboxymethyl complex polysaccharide aqueous solution m to 10, 1g of ethylene glycol diglycidyl ether was added to it, and the cross-linking reaction was carried out by heating and stirring in a water bath at 50℃ for 6h to obtain the cross-linking product I aqueous solution m.

[0102] S5 adjusted the pH of the crosslinking product I aqueous solution m to 5 with dilute hydrochloric acid, then added 0.4g of malic acid, and heated and stirred in an 80℃ water bath for 1h to carry out the grafting reaction, thus obtaining the grafting product II aqueous solution m.

[0103] After adjusting the pH of the graft product II aqueous solution m to neutral, S6 added 0.5g of sorbitol and stirred at room temperature until dissolved to obtain a cross-linked reinforced dust-suppressing material m with high wettability and strong adhesion.

[0104] Comparative Example 1

[0105] Add 50 mL of distilled water to a beaker, dissolve 0.3 g of pullulan in the water, place the beaker in a water bath at 70 °C, and heat and stir for 1 hour until the pullulan is completely dissolved, obtaining pullulan aqueous solution A. Add 50 mL of distilled water to another beaker, dissolve 0.3 g of agarose in the water, place the beaker in a water bath at 90 °C, and heat and stir for 1 hour until the agarose is completely dissolved, obtaining agarose aqueous solution A. Mix pullulan aqueous solution A and agarose aqueous solution A and stir with a magnetic stirrer until homogeneous, obtaining dust-suppressing material A prepared in Comparative Example 1.

[0106] Comparative Example 2

[0107] Dissolve 0.6g of malic acid in 100mL of distilled water and stir in an 80℃ water bath for 1h until completely dissolved to obtain dust-suppressing material B prepared in Comparative Example 2.

[0108] Performance testing

[0109] The dust-suppressing materials prepared in Examples 1-9 and Comparative Examples 1-2 were subjected to simulated spray dust suppression efficiency, secondary dust suppression efficiency, and wettability tests.

[0110] The dust suppression efficiency test method is as follows: Based on the airflow-droplet-dust coupling experimental platform, under the same wind speed conditions, 50g of dried hydrophobic coal powder was taken and quantitatively and stably emitted using a dust generator to simulate dust dispersion. A dust sampler was used to sample and weigh the dust, obtaining the initial total dust concentration and respirable dust concentration C0. The dust suppression materials prepared in Examples 1-9 and Comparative Examples 1-2 were added to a spray aqueous solution, and the dust suppression material solution was sprayed using a swirling atomizing nozzle at the same pressure to settle the dust. The dust sampler was used again to sample and weigh the dust, obtaining the total dust concentration and respirable dust concentration C1 at this time. All data were the average of three measurements. The dust suppression efficiency was calculated using the following formula.

[0111]

[0112] Where μ represents the dust suppression efficiency (%), and C0 represents the total dust concentration and respirable dust concentration (μg / m³) before spraying the dust suppression solution. 3 C1 represents the total dust concentration and respirable dust concentration (μg / m³) after spraying the dust-suppressing solution. 3 ).

[0113] Dust reduction efficiency test results: Please refer to Figure 2 , Figure 2 This is a comparison chart of the dust reduction efficiency of the dust reduction materials prepared in Examples 1-9 and Comparative Examples 1-2 of the present invention; Figure 2It can be seen that Examples 1-9 have good dust reduction efficiency, with total dust settling efficiency all exceeding 80% and respirable dust settling efficiency all exceeding 70%. Comparative Examples 1 and 2 have total dust reduction efficiencies of 59% and 65%, and respirable dust reduction efficiencies of 50% and 55%, respectively, significantly lower than Examples 1-9. This is because the dust reduction material prepared in this invention introduces a large number of carboxyl groups through carboxymethylation and grafting reactions, significantly improving the wetting performance of the dust reduction material on coal dust. Combined with the superior adhesion properties of the composite polysaccharide, the dust reduction material can better wet and agglomerate coal dust, thereby improving dust reduction efficiency.

[0114] The secondary dust suppression efficiency test method is as follows: Secondary dust suppression efficiency is determined through a wind erosion experiment. Equal amounts of dried coal powder are weighed and placed in petri dishes, then placed on a wind erosion simulation platform with a wind speed of 10 m / s. First, a handheld laser particle counter is used to detect the initial concentrations C0 of PM2.5 and PM10. Then, equal amounts of dust-suppressing materials from Examples 1-9 and Comparative Examples 1-2 are uniformly sprayed into the petri dishes, placed in a constant-temperature drying oven at 50°C until completely dry, and then placed back on the wind erosion simulation platform. A handheld laser particle counter is used to detect the PM2.5 and PM10 concentrations after spraying the dust-suppressing solution, and this concentration is recorded as C1. The data is the average of three measurements. The dust suppression efficiency is calculated according to the following formula.

[0115]

[0116] Where μ represents the dust suppression efficiency (%), and C0 represents the initial concentrations of PM2.5 and PM10 (μg / m³). 3 C1 represents the concentrations of PM2.5 and PM10 after spraying the solution (μg / m³). 3 ).

[0117] Secondary dust suppression efficiency test results: Please refer to Figure 3 , Figure 3 This is a comparison chart showing the secondary dust suppression efficiency of the dust-suppressing materials prepared in Examples 1-9 and Comparative Examples 1-2 of the present invention. Figure 3 It can be seen that the dust suppression efficiency of Examples 1-9 for PM10 and PM2.5 is significantly higher than that of Comparative Examples 1 and 2. This is because the dust suppression material prepared in this invention crosslinks carboxymethyl pullulan polysaccharide molecules with carboxymethyl agarose molecules through ethylene glycol diglycidyl ether, so that they are entangled to form a three-dimensional covalent crosslinked network, which significantly improves the mechanical properties of the dust suppression material, enhances the strength of the coal dust solidification layer after drying, can effectively resist secondary dust caused by wind erosion, and improves the dust suppression efficiency.

[0118] The wetting performance test method is as follows: First, 5g of coal powder is compressed into coal blocks at 30MPa for 5 minutes on a tablet press. Then, the coal blocks are placed on the test platform of the droplet shape analyzer, and the dust-suppressing materials prepared in Examples 1-9 and Comparative Examples 1-2 are dropped on them respectively. The contact angle of each group of dust-suppressing materials on the coal blocks is measured using a DSA100 contact angle measuring instrument. The contact angles of the examples and comparative examples at 0s and 2s when they are dropped on the coal cake are recorded respectively.

[0119] Wettability test results: Please refer to Table 1, which shows the contact angle test results of the dust-suppressing materials prepared in Examples 1-9 and Comparative Examples 1-2 of this invention.

[0120] Table 1

[0121]

[0122] As shown in Table 1, the contact angles of Examples 1-9 and Comparative Example 2 are significantly smaller than those of Comparative Example 1. The contact angle of Example 5 after 2 seconds is only 12.27°, while the contact angle of Comparative Example 1 after 2 seconds is still 56.98°. This is because Comparative Example 2 is an aqueous solution of malic acid, which contains a large number of carboxyl groups, thus exhibiting good wetting properties. Comparative Example 1 is an aqueous solution of a complex polysaccharide, containing a large number of hydroxyl groups. Due to its higher viscosity and the fact that hydroxyl groups are less hydrophilic than carboxyl groups, Comparative Example 1 has a larger contact angle but poorer wetting properties. In contrast, the dust-suppressing material solutions of Examples 1-9 are all complex polysaccharides that have undergone carboxylmethylation and malic acid grafting, thus also possessing a large number of carboxyl groups, resulting in a significant improvement in wetting properties compared to Comparative Example 1.

[0123] This invention, by designing different formulations, tested the wettability, secondary dust suppression efficiency, and dust reduction efficiency of the dust-suppressing materials prepared in Examples 1-9. Notably, Example 6 exhibited an excellent wetting effect on the experimental coal sample, with a contact angle of 30.29° at 0s and 12.94° at 2s. Furthermore, in the dust reduction and secondary dust suppression efficiency tests, it demonstrated the highest settling efficiency for both total dust and respirable dust, and also the highest secondary dust suppression efficiency for PM10. Therefore, under the condition of 100mL distilled water, the preferred formulation includes 0.3g pullulan, 0.3g agarose, 1g sodium hydroxide, 0.75g chloroacetic acid, 1g ethylene glycol diglycidyl ether, 0.6g malic acid, and 0.5g water-retaining agent. The dust-suppressing material prepared under this preferred formulation exhibits superior wettability, adhesion, and dust reduction effect.

[0124] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A cross-linked reinforced dust-suppressing material with high wetting and strong adhesion, characterized in that, The dust-suppressing material comprises the following raw materials in parts by weight: 2-5 parts pullulan, 2-5 parts agarose, 5-15 parts sodium hydroxide, 5-15 parts chloroacetic acid, 5-15 parts ethylene glycol diglycidyl ether, 3-11 parts malic acid, 5-10 parts water-retaining agent, 5-10 parts dilute hydrochloric acid, and 1000-2500 parts distilled water.

2. The dust-suppressing material according to claim 1, characterized in that, The water-retaining agent is one or more of glycerin, propylene glycol, butylene glycol, dipropylene glycol, and sorbitol; the concentration of the dilute hydrochloric acid is 3%.

3. The dust-suppressing material according to claim 1, characterized in that, When the amount of distilled water is 100 mL, the preferred weights of the other raw materials are as follows: 0.3 g pullulan, 0.3 g agarose, 1 g sodium hydroxide, 0.75 g chloroacetic acid, 1 g ethylene glycol diglycidyl ether, 0.6 g malic acid and 0.5 g water-retaining agent.

4. A method for preparing a cross-linked reinforced dust-suppressing material with high wettability and strong adhesion as described in any one of claims 1-3, characterized in that, The preparation method includes the following steps: S1. Distilled water and pullulan are added to a beaker in sequence. The beaker is placed in a water bath for the first heating and stirring treatment, so that the pullulan is completely dissolved in the distilled water to obtain a pullulan aqueous solution. S2 adds distilled water and agarose to another beaker in sequence, and places the beaker in a water bath for a second heating and stirring process to completely dissolve the agarose in the distilled water, thus obtaining an agarose aqueous solution; S3 mixes pullulan polysaccharide aqueous solution and agarose aqueous solution and stirs until uniform to obtain complex polysaccharide aqueous solution; first add sodium hydroxide to complex polysaccharide aqueous solution and stir until uniform, then add chloroacetic acid, and perform a third heating and stirring treatment in a water bath to obtain carboxymethyl complex polysaccharide aqueous solution; After adjusting the pH of the carboxymethyl polysaccharide aqueous solution to 10, ethylene glycol diglycidyl ether was added to it, and the cross-linking reaction was carried out by heating and stirring in a water bath to obtain the cross-linking product I aqueous solution. S5 uses dilute hydrochloric acid to adjust the pH of the crosslinking product I aqueous solution to 5, then adds malic acid, and heats and stirs in a water bath to carry out the grafting reaction, obtaining the grafting product II aqueous solution. After adjusting the pH of the graft product II aqueous solution to neutral, S6 added a water-retaining agent and stirred at room temperature until dissolved to obtain a cross-linked reinforced dust-suppressing material with high wettability and strong adhesion.

5. The preparation method according to claim 4, characterized in that, In step S1, the temperature of the first heating and stirring treatment is 60-70℃, and the time is 1-2 hours.

6. The preparation method according to claim 4, characterized in that, In step S2, the temperature of the second heating and stirring treatment is 80-90℃, and the time is 1-2 hours.

7. The preparation method according to claim 4, characterized in that, The carboxymethylation reaction in step S3 is carried out at a temperature of 70-80°C for 3-4 hours.

8. The preparation method according to claim 4, characterized in that, The cross-linking reaction in step S4 is carried out at a temperature of 50-60°C for 6-8 hours.

9. The preparation method according to claim 4, characterized in that, The grafting reaction in step S5 is carried out at a temperature of 80-90℃ for 1-2 hours.

10. The application of a cross-linked enhanced dust-suppressing material with high wettability and strong adhesion as described in any one of claims 1-3 in dust suppression during coal mining.

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