A composite dust suppressant for coal mines and its preparation method

Abstract

The present invention relates to a composite dust suppressant for coal mines and a preparation method thereof, belonging to the technical field of dust suppressant compositions. In terms of weight percentage, the composite dust suppressant for coal mines comprises the following components: 0.3-0.7% of modified epoxy resin, 3-6% of polyol compounds, 0.1-0.3% of xanthan gum, 0.05-0.1% of diamine compounds, etc. The present invention mainly subjects bisphenol A epoxy resin with a suitable epoxy equivalent to corona discharge treatment to endow it with amphiphilic properties, which not only maintains the entanglement and consolidation ability of the molecular chain but also enhances its dispersibility in the aqueous phase, thereby enhancing the stability of the entire material system; at the same time, it is combined with a polyol low-temperature synergistic system to reduce the eutectic point of the solution by constructing a hydrogen bond network. Each component synergistically enhances the effect, significantly improving the low-temperature dust suppression effect of the obtained composite dust suppressant for coal mines, and is particularly suitable for scenarios such as open-pit coal mines in alpine regions, coal conveying corridors, and railway transportation of bulk particulate matter.

Description

Technical Field

[0001] The present invention relates to the technical field of dust suppressant compositions, and in particular to a composite dust suppressant for coal mines and a preparation method thereof. Background Art

[0002] During the coal mining and transportation processes, dust pollution is an environmental problem that urgently needs to be solved. Dust not only pollutes the environment but also poses a serious threat to the physical health of miners, such as causing respiratory diseases. Therefore, the application of dust suppressants in the coal mining industry is particularly important.

[0003] Currently, there are various dust suppressants for coal mines on the market, which can reduce the generation and flying of dust to a certain extent. However, with the expansion of the coal mining scale and the diversification of mining environments, especially in open-pit coal mines and coal conveying corridors in alpine regions, higher requirements are put forward for the performance of dust suppressants.

[0004] In scenarios such as open-pit coal mines and coal conveying corridors in alpine regions, the use of existing dust suppressants mainly has the following defects: 1) First, the low-temperature environment will cause some components of the dust suppressant to solidify or lose their activity, thereby affecting its dust suppression performance. Especially under extremely low-temperature conditions, some dust suppressants even completely lose their effectiveness and cannot effectively inhibit the flying of dust. This not only exacerbates environmental pollution but also poses a greater threat to the physical health of miners. 2) Second, scenarios such as open-pit coal mines, railway transportation of bulk particulate matter, and coal conveying corridors in alpine regions are often accompanied by harsh weather conditions such as strong winds and dryness, which makes it more difficult to control dust, resulting in poor dust suppression effects and unable to meet the actual use requirements. Summary of the Invention

[0005] To solve the above problems, the present invention provides a composite dust suppressant for coal mines and a preparation method thereof.

[0006] The technical solutions provided by the present invention are as follows:

[0007] In a first aspect, the present invention provides a composite dust suppressant for coal mines, which, in terms of weight percentage, comprises the following components:

[0008] Modified epoxy resin 0.3 - 0.7%, polyol compounds 3 - 6%, xanthan gum 0.1 - 0.3%, diamine compounds 0.05 - 0.1%, carboxymethyl cellulose 0.8 - 1.5%, surfactant 0.3 - 0.8%, polyvinyl alcohol 0.1 - 0.4%, and the balance is water;

[0009] The modified epoxy resin is obtained by subjecting bisphenol A epoxy resin with an epoxy equivalent of 800 - 900 g / eq to corona discharge treatment;

[0010] The polyol compound is composed of glycerol, pentaerythritol and erythritol.

[0011] Further, in terms of weight percentage, the composite dust suppressant for coal mines includes the following components:

[0012] Modified epoxy resin 0.5%, polyol compound 4.5%, xanthan gum 0.2%, diamine compound 0.08%, carboxymethyl cellulose 1.1%, surfactant 0.5%, polyvinyl alcohol 0.3%, and the balance is water.

[0013] Further, the preparation method of the modified epoxy resin includes the following process:

[0014] Subject the bisphenol A epoxy resin to corona discharge treatment at 7 - 13 kV / m 2 for 15 - 35 seconds to obtain the modified epoxy resin.

[0015] Further, the polyol compound is composed of glycerol, pentaerythritol and erythritol in a weight ratio of (7 - 11):(1 - 2):(3 - 6).

[0016] Further, the polyol compound is composed of glycerol, pentaerythritol and erythritol in a weight ratio of 8:1:5.

[0017] Further, the diamine compound includes at least one of ethylenediamine and m - xylylenediamine.

[0018] Further, the surfactant includes at least one of sodium dodecylbenzenesulfonate and cocamidopropyl betaine.

[0019] In a second aspect, based on the same inventive concept, the present invention provides a preparation method of the composite dust suppressant for coal mines according to any one of the first aspect, and the preparation method includes the following steps:

[0020] Add the surfactant to water and carry out mechanical stirring to obtain a mixture;

[0021] Add the remaining components to the mixture and carry out ultrasonic stirring to obtain the composite dust suppressant for coal mines.

[0022] Further, the working condition parameters of the mechanical stirring include: the stirring speed is 500 - 800 rpm, and the stirring time is 5 - 10 minutes; the working condition parameters of the ultrasonic stirring include: the ultrasonic power is 800 - 900 W, the stirring speed is 400 - 600 rpm, and the stirring time is 5 - 10 minutes.

[0023] The above technical solutions provided by the embodiments of the present invention have at least the following advantages compared with the prior art:

[0024] The present invention provides a composite dust suppressant for coal mines and a preparation method thereof. The present invention mainly subjects bisphenol A epoxy resin with a suitable epoxy equivalent to corona discharge treatment to endow it with amphiphilic properties, maintaining both the entanglement and consolidation ability of the molecular chain and enhancing its dispersibility in the aqueous phase, thereby enhancing the stability of the entire material system. At the same time, in combination with a polyol low-temperature synergistic system, the eutectic point of the solution is reduced by constructing a hydrogen bond network, and each component synergistically enhances the effect, significantly improving the low-temperature dust suppression effect of the obtained composite dust suppressant for coal mines, which is particularly suitable for scenarios such as open-pit coal mines in alpine regions, coal conveying corridors, and railway transportation of bulk particulate matter, making up for the deficiencies of existing dust suppressants. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings herein are incorporated into the specification and form a part of this specification, showing embodiments in accordance with the present invention and, together with the specification, are used to explain the principles of the present invention.

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0027] Figure 1 It is a flowchart of the preparation method of the composite dust suppressant for coal mines provided by the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0029] Unless otherwise specifically stated, various raw materials, reagents, instruments, and equipment used in the present invention can be obtained through market purchases or can be prepared by existing methods.

[0030] In a first aspect, the present invention provides a composite dust suppressant for coal mines. In terms of weight percentage, the composite dust suppressant for coal mines includes the following components:

[0031] Modified epoxy resin 0.3 - 0.7%, polyol compounds 3 - 6%, xanthan gum 0.1 - 0.3%, diamine compounds 0.05 - 0.1%, carboxymethyl cellulose 0.8 - 1.5%, surfactant 0.3 - 0.8%, polyvinyl alcohol 0.1 - 0.4%, and the balance is water;

[0032] The modified epoxy resin is obtained by subjecting bisphenol A epoxy resin with an epoxy equivalent of 800 - 900 g / eq to corona discharge treatment;

[0033] The polyol compound is composed of glycerol, pentaerythritol, and erythritol.

[0034] The present invention provides a composite dust suppressant for coal mines. The present invention mainly subjects bisphenol A epoxy resin with a suitable epoxy equivalent to corona discharge treatment to endow it with amphiphilic properties, which not only maintain the entanglement and consolidation ability of the molecular chain but also enhance its dispersibility in the aqueous phase, thereby enhancing the stability of the entire material system; at the same time, it is combined with a polyol low-temperature synergistic system to reduce the eutectic point of the solution by constructing a hydrogen bond network, and each component synergistically enhances the effect, significantly improving the low-temperature dust suppression effect of the obtained composite dust suppressant for coal mines, which is particularly suitable for scenarios such as open-pit coal mines in alpine regions, coal conveyor corridors, and railway transportation of bulk particulate matter, making up for the deficiencies of existing dust suppressants.

[0035] In some specific embodiments, by weight percentage, the composite dust suppressant for coal mines comprises the following components:

[0036] Modified epoxy resin 0.5%, polyol compound 4.5%, xanthan gum 0.2%, diamine compound 0.08%, carboxymethyl cellulose 1.1%, surfactant 0.5%, polyvinyl alcohol 0.3%, and the balance is water.

[0037] In some specific embodiments, the preparation method of the modified epoxy resin comprises the following process:

[0038] Subject the bisphenol A epoxy resin to corona discharge treatment for 15 - 35 seconds under the condition of 7 - 13 kV / m 2 to obtain the modified epoxy resin; preferably, subject the bisphenol A epoxy resin to corona discharge treatment for 25 seconds under the condition of 10 kV / m 2 to obtain the modified epoxy resin.

[0039] In some specific embodiments, the polyol compound is composed of glycerol, pentaerythritol, and erythritol in a weight ratio of (7 - 11):(1 - 2):(3 - 6).

[0040] In some specific embodiments, the polyol compound is composed of glycerol, pentaerythritol, and erythritol in a weight ratio of 8:1:5.

[0041] In some specific embodiments, the diamine compound includes at least one of ethylenediamine and m-xylenediamine.

[0042] In some specific embodiments, the surfactant includes at least one of sodium dodecylbenzenesulfonate and cocoamidopropyl betaine.

[0043] In a second aspect, based on the same inventive concept, the present invention provides a preparation method of the composite dust suppressant for coal mines according to any one of the first aspect, as Figure 1 shown, the preparation method includes the following steps:

[0044] Add the surfactant to water and carry out mechanical stirring to obtain a mixture;

[0045] Add the remaining components to the mixture and carry out ultrasonic stirring to obtain the composite dust suppressant for coal mines.

[0046] The present invention provides a preparation method of a composite dust suppressant for coal mines. This preparation method is simple to operate, does not require additional specific equipment, and is suitable for batch industrial production. At the same time, this preparation method is realized based on the composite dust suppressant for coal mines according to any one of the first aspect. Therefore, it has at least the beneficial effects of the composite dust suppressant for coal mines according to any one of the first aspect, which will not be elaborated here.

[0047] In some specific embodiments, the working condition parameters of the mechanical stirring include: the stirring speed is 500 - 800 rpm, and the stirring time is 5 - 10 minutes; the working condition parameters of the ultrasonic stirring include: the ultrasonic power is 800 - 900 W, the stirring speed is 400 - 600 rpm, and the stirring time is 5 - 10 minutes.

[0048] It should be noted that for the raw materials involved in the composite dust suppressant for coal mines and its preparation method provided by the present invention, without special limitations or specific descriptions, commercially available products can be directly used or self-made according to the preparation processes disclosed in the prior art. For example, in the following examples and comparative examples, bisphenol A epoxy resin with product model NPES - 904H (epoxy equivalent weight is 840 - 900 g / eq), bisphenol A epoxy resin with product model NPES - 604 (epoxy equivalent weight is 800 - 850 g / eq), or bisphenol A epoxy resin with product model DER671 662E 663U (epoxy equivalent weight is 590 - 630 g / eq) are used; at the same time, for the operation steps and condition parameters involved, without special limitations or specific descriptions, they can be carried out according to the existing dust suppressant preparation processes or using existing equipment. The present invention document will not elaborate one by one.

[0049] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. For the experimental methods without specific conditions noted in the following embodiments, they are generally determined according to national standards. If there is no corresponding national standard, they are carried out according to general international standards, conventional conditions, or the conditions recommended by the manufacturer.

[0050] Example 1

[0051] This example provides a composite dust suppressant for coal mines. In terms of weight percentage, the composite dust suppressant for coal mines includes the following components:

[0052] Modified epoxy resin 0.5%, polyol compounds 4.5%, xanthan gum 0.2%, diamine compounds 0.08%, carboxymethyl cellulose 1.1%, surfactant 0.5%, polyvinyl alcohol 0.3%, and the balance is water;

[0053] The modified epoxy resin is obtained by subjecting bisphenol A epoxy resin with an epoxy equivalent of 840 - 900 g / eq to corona discharge treatment; the specific preparation method includes the following process: subject the bisphenol A epoxy resin to corona discharge treatment at 10 kV / m 2 for 20 seconds to obtain the modified epoxy resin;

[0054] The polyol compounds are composed of glycerol, pentaerythritol, and erythritol in a weight ratio of 8:1:5;

[0055] The diamine compound is ethylenediamine;

[0056] The surfactant is sodium dodecylbenzenesulfonate.

[0057] The preparation method of the above-provided composite dust suppressant for coal mines includes the following steps:

[0058] Add the surfactant to water and carry out mechanical stirring at a stirring speed of 750 rpm for 8 minutes to obtain a mixture;

[0059] Add the remaining components to the mixture and carry out ultrasonic stirring at an ultrasonic power of 850 W, a stirring speed of 500 rpm, and a stirring time of 7 minutes to obtain the composite dust suppressant for coal mines.

[0060] Example 2

[0061] This example provides a composite dust suppressant for coal mines. In terms of weight percentage, the composite dust suppressant for coal mines includes the following components:

[0062] Modified epoxy resin 0.3%, polyol compounds 3%, xanthan gum 0.1%, diamine compounds 0.05%, carboxymethyl cellulose 0.8%, surfactant 0.3%, polyvinyl alcohol 0.1%, the balance being water;

[0063] The modified epoxy resin is obtained by subjecting bisphenol A epoxy resin with an epoxy equivalent of 800 - 850 g / eq to corona discharge treatment; the specific preparation method includes the following process: subjecting the bisphenol A epoxy resin to corona discharge treatment at 7 kV / m 2 for 35 seconds to obtain the modified epoxy resin;

[0064] The polyol compounds are composed of glycerol, pentaerythritol and erythritol in a weight ratio of 11:1:6;

[0065] The diamine compound is m - xylylenediamine;

[0066] The surfactant is composed of sodium dodecylbenzenesulfonate and cocamidopropyl betaine in a weight ratio of 3:1.

[0067] The preparation method of the above - provided composite dust suppressant for coal mines includes the following steps:

[0068] Add the surfactant to water and carry out mechanical stirring at a stirring speed of 500 rpm for 10 minutes to obtain a mixture;

[0069] Add the remaining components to the mixture and carry out ultrasonic stirring at an ultrasonic power of 800 W, a stirring speed of 400 rpm for 10 minutes to obtain the composite dust suppressant for coal mines.

[0070] Example 3

[0071] This example provides a composite dust suppressant for coal mines. In terms of weight percentage, the composite dust suppressant for coal mines includes the following components:

[0072] Modified epoxy resin 0.7%, polyol compounds 6%, xanthan gum 0.3%, diamine compounds 0.1%, carboxymethyl cellulose 1.5%, surfactant 0.8%, polyvinyl alcohol 0.4%, the balance being water;

[0073] The modified epoxy resin is obtained by subjecting bisphenol A epoxy resin with an epoxy equivalent of 800 - 850 g / eq to corona discharge treatment; the specific preparation method includes the following process: subjecting the bisphenol A epoxy resin to corona discharge treatment at 13 kV / m 2 for 15 seconds to obtain the modified epoxy resin;

[0074] The polyol compounds are composed of glycerol, pentaerythritol and erythritol in a weight ratio of 7:2:3;

[0075] The diamine compound is ethylenediamine;

[0076] The surfactant is sodium dodecylbenzenesulfonate.

[0077] The preparation method of the provided composite dust suppressant for coal mines comprises the following steps:

[0078] Add the surfactant into water and carry out mechanical stirring at a stirring speed of 800 rpm for 5 minutes to obtain a mixture;

[0079] Add the remaining components to the mixture and carry out ultrasonic stirring at an ultrasonic power of 900 W, a stirring speed of 600 rpm, and a stirring time of 5 minutes to obtain the composite dust suppressant for coal mines.

[0080] Comparative Example 1

[0081] This example provides a composite dust suppressant for coal mines. In terms of weight percentage, the composite dust suppressant for coal mines comprises the following components:

[0082] Epoxy resin 0.5%, polyol compound 4.5%, xanthan gum 0.2%, diamine compound 0.08%, carboxymethyl cellulose 1.1%, surfactant 0.5%, polyvinyl alcohol 0.3%, and the balance is water;

[0083] The epoxy resin is a bisphenol A epoxy resin with an epoxy equivalent of 840 - 900 g / eq;

[0084] The polyol compound is glycerol;

[0085] The diamine compound is ethylenediamine;

[0086] The surfactant is sodium dodecylbenzenesulfonate.

[0087] The preparation method of the provided composite dust suppressant for coal mines is the same as that in Example 1.

[0088] Comparative Example 2

[0089] This example provides a composite dust suppressant for coal mines. In terms of weight percentage, the composite dust suppressant for coal mines comprises the following components:

[0090] Modified epoxy resin 0.5%, polyol compound 4.5%, xanthan gum 0.2%, diamine compound 0.08%, carboxymethyl cellulose 1.1%, surfactant 0.5%, polyvinyl alcohol 0.3%, and the balance is water;

[0091] The modified epoxy resin is obtained by subjecting bisphenol A epoxy resin with an epoxy equivalent of 840 - 900 g / eq to corona discharge treatment; the specific preparation method includes the following process: subject the bisphenol A epoxy resin to corona discharge treatment at 10 kV / m 2 for 20 seconds to obtain the modified epoxy resin;

[0092] The polyol compound is glycerol;

[0093] The diamine compound is ethylenediamine;

[0094] The surfactant is sodium dodecylbenzenesulfonate.

[0095] The preparation method of the provided composite dust suppressant for coal mines is the same as that of Example 1.

[0096] Comparative Example 3

[0097] This example provides a composite dust suppressant for coal mines, which, by weight percentage, includes the following components:

[0098] Epoxy resin 0.5%, polyol compound 4.5%, xanthan gum 0.2%, diamine compound 0.08%, carboxymethyl cellulose 1.1%, surfactant 0.5%, polyvinyl alcohol 0.3%, and the balance is water;

[0099] The epoxy resin is bisphenol A epoxy resin with an epoxy equivalent of 840 - 900 g / eq;

[0100] The polyol compound is composed of glycerol, pentaerythritol, and erythritol in a weight ratio of 8:1:5;

[0101] The diamine compound is ethylenediamine;

[0102] The surfactant is sodium dodecylbenzenesulfonate.

[0103] The preparation method of the provided composite dust suppressant for coal mines is the same as that of Example 1.

[0104] Comparative Example 4

[0105] This example provides a composite dust suppressant for coal mines, which, by weight percentage, includes the following components:

[0106] Modified epoxy resin 0.5%, polyol compound 4.5%, xanthan gum 0.2%, diamine compound 0.08%, carboxymethyl cellulose 1.1%, surfactant 0.5%, polyvinyl alcohol 0.3%, and the balance is water;

[0107] The modified epoxy resin is obtained by subjecting bisphenol A epoxy resin with an epoxy equivalent of 590 - 630 g / eq to corona discharge treatment; the specific preparation method includes the following process: subjecting the bisphenol A epoxy resin to corona discharge treatment at 10 kV / m 2 for 20 seconds to obtain the modified epoxy resin;

[0108] The polyol compound is composed of glycerol, pentaerythritol, and erythritol with a weight ratio of 8:1:5;

[0109] The diamine compound is ethylenediamine;

[0110] The surfactant is sodium dodecylbenzenesulfonate.

[0111] The preparation method of the above - provided coal - mine composite dust suppressant is the same as that of Example 1.

[0112] Test Example

[0113] In this example, according to the method of wind erosion experiment in "Technical Conditions for Dust Suppression in Railway Coal Transportation - Part 1: Dust Suppressant" (TB / T 3201.1 - 2020), the dust suppression effects of the coal - mine composite dust suppressants obtained in the above Examples 1 - 3 and Comparative Examples 1 - 4 were measured at - 20°C, and the test results are shown in Table 1.

[0114] Table 1

[0115]

[0116] As can be seen from Table 1:

[0117] 1) Compared with Comparative Examples 1 - 4, the dust suppression effects of the coal - mine composite dust suppressants provided in Examples 1 - 3 of the present invention at - 20°C are > 95%, indicating that their low - temperature dust suppression effects are more excellent and can meet the usage requirements of scenarios such as open - pit coal mines and coal - conveying corridors in alpine regions.

[0118] 2) By comparing the test results of Example 1 and Comparative Examples 1 - 4, it can be seen that the present invention uses a specific modified epoxy resin and a polyol low - temperature synergistic system in combination, and the two synergistically enhance the effect, thereby improving the low - temperature dust suppression effect of the obtained coal - mine composite dust suppressant.

[0119] In summary, the present invention provides a composite dust suppressant for coal mines and a preparation method thereof. The present invention mainly subjects bisphenol A epoxy resin with a suitable epoxy equivalent to corona discharge treatment to endow it with amphiphilic properties, which not only maintain the entanglement and consolidation ability of the molecular chain but also enhance its dispersibility in the aqueous phase, thereby enhancing the stability of the entire material system. At the same time, in combination with a polyol low-temperature synergistic system, the eutectic point of the solution is reduced by constructing a hydrogen bond network, and each component synergistically enhances the effect, significantly improving the low-temperature dust suppression effect of the obtained composite dust suppressant for coal mines, which is particularly suitable for scenarios such as open-pit coal mines in alpine regions, coal conveying corridors, and railway transportation of bulk particulate matter, making up for the deficiencies of existing dust suppressants.

[0120] The various embodiments of the present invention may exist in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity and should not be construed as a rigid limitation on the scope of the present invention; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and individual values within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and individual numbers within the range, such as 1, 2, 3, 4, 5, and 6, and this applies regardless of the range. Additionally, whenever a numerical range is indicated herein, it means including any cited number (fraction or integer) within the indicated range.

[0121] The above are only specific embodiments of the present invention, enabling those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein but will conform to the broadest scope consistent with the principles and novel features claimed herein.

Claims

1. A composite dust suppressant for coal mines, characterized in that: The composite dust suppressant for coal mines is composed of the following components in weight percentage: Modified epoxy resin 0.3~0.7%, polyol compound 3~6%, xanthan gum 0.1~0.3%, diamine compound 0.05~0.1%, carboxymethyl cellulose 0.8~1.5%, surfactant 0.3~0.8%, polyvinyl alcohol 0.1~0.4%, and the balance is water; The modified epoxy resin is obtained by subjecting a bisphenol A epoxy resin having an epoxy equivalent of 800 to 900 g / eq to corona discharge treatment; The polyol compound is composed of glycerol, pentaerythritol and erythritol.

2. The composite dust suppressant for coal mines according to claim 1, characterized in that: The composite dust suppressant for coal mines is composed of the following components in weight percentage: 0.5% modified epoxy resin, 4.5% polyol compound, 0.2% xanthan gum, 0.08% diamine compound, 1.1% carboxymethyl cellulose, 0.5% surfactant, 0.3% polyvinyl alcohol, and the balance is water.

3. The composite dust suppressant for coal mines according to claim 1, characterized in that: The preparation method of the modified epoxy resin comprises the following process: The bisphenol A epoxy resin is subjected to 7-13 kV / m 2 The modified epoxy resin is obtained by performing corona discharge treatment for 15 to 35 seconds under the following conditions.

4. The composite dust suppressant for coal mines according to claim 1, characterized in that: The polyol compound is composed of propylene glycol, pentaerythritol and erythritol in a weight ratio of (7-11): (1-2): (3-6).

5. The composite dust suppressant for coal mines according to claim 1, characterized in that: The polyol compound is composed of glycerol, pentaerythritol and erythritol in a weight ratio of 8:1:

5.

6. The composite dust suppressant for coal mines according to claim 1, characterized in that: The diamine compound includes at least one of ethylenediamine and meta-xylylenediamine.

7. The composite dust suppressant for coal mines according to claim 1, characterized in that: The surfactant includes at least one of sodium dodecylbenzene sulfonate and cocamidopropyl betaine.

8. A method for preparing the composite dust suppressant for coal mines according to any one of claims 1 to 7, characterized in that: The preparation method comprises the following steps: adding a surfactant into water and mechanically stirring the water to obtain a mixture; The remaining components are added to the mixture and ultrasonically stirred to obtain the composite dust suppressant for coal mines.

9. The method for preparing a composite dust suppressant for coal mines according to claim 8, characterized in that: The working condition parameters of the mechanical stirring include: a stirring speed of 500-800 rpm, and a stirring time of 5-10 minutes; the working condition parameters of the ultrasonic stirring include: an ultrasonic power of 800-900 W, a stirring speed of 400-600 rpm, and a stirring time of 5-10 minutes.

Images