Multifunctional coal water slurry additive as well as preparation method and application thereof
By preparing a multifunctional water coal slurry additive, the polycondensation reaction of biphenyldiamine and suberic anhydride and the introduction of hydrophilic groups, and the addition of functional components such as polyvinyl alcohol, the problem of insufficient stability and dispersion of water coal slurry is solved, and the performance improvement of water coal slurry is achieved with an efficient, stable and environmentally friendly water coal slurry.
Patent Information
- Application Number
- CN202411703213.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-26
- Publication Date
- 2025-03-04
AI Technical Summary
During the preparation and use of traditional coal slurry, there are problems such as poor dispersion, insufficient stability, and easy slag and ash accumulation. The existing additives are costly, complex preparation processes and are unfavorable to the environment.
A multifunctional water-coal slurry additive was prepared by heating the biphenyldiamine and subic anhydride in DMF solution, hydrophilic groups were introduced, and polyvinyl alcohol, surfactant, nanosilica and polymer were added.
It significantly improves the dispersion, rheology and stability of water and coal slurry, reduces energy consumption and environmental pollution, and is cheap and has a simple preparation process.
Smart Images
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Abstract
Description
Technical Field
[0001] The invention relates to the field of energy technology, and in particular to a multifunctional coal water slurry additive and a preparation method and application thereof. Background Art
[0002] Coal-water slurry is an innovative coal-based fluid fuel, which is made by finely mixing coal powder, water and specific additives. This fuel has good fluidity, high combustion efficiency and low pollution emissions, so it has been widely used in many fields such as industrial boilers, power station boilers and industrial kilns. The use of coal-water slurry not only helps to improve energy utilization efficiency, but also reduces environmental pollution to a certain extent.
[0003] However, there are some problems that cannot be ignored in the preparation and use of traditional water-coal slurry. For example, the dispersibility of coal powder is often poor, resulting in insufficient stability of water-coal slurry, which affects its combustion efficiency. In addition, water-coal slurry is prone to slagging and ash accumulation during the combustion process. These problems not only reduce the operating efficiency of the equipment, but also increase maintenance costs, thus limiting the widespread application of water-coal slurry.
[0004] To overcome these challenges, researchers and engineers have developed a variety of CWS additives. The purpose of these additives is to improve the performance of CWS, making it more efficient and environmentally friendly in practical applications. Although existing additives have improved some properties of CWS to a certain extent, such as improving combustion efficiency and reducing pollutant emissions, they often have some disadvantages. For example, these additives are expensive, the preparation process is complicated, and they may have adverse effects on the environment.
[0005] Therefore, it is of great practical significance to develop a multifunctional additive that is low-cost, simple in preparation process, environmentally friendly and can significantly improve the performance of water-coal slurry. Such an additive can not only solve the problems of existing additives, but also further promote the widespread application of water-coal slurry in the industrial field. Summary of the invention
[0006] In view of this, the present invention proposes a multifunctional coal water slurry additive and a preparation method and application thereof, aiming to solve the above problems.
[0007] The present invention provides a method for preparing a coal water slurry additive, comprising:
[0008] The diphenylenediamine and suberic anhydride are heated to react in a DMF solution to obtain a reactant; after the reactant is cooled to room temperature, carboxymethyl chloride is added to react to introduce a hydrophilic group; after the reaction is completed, the system is neutralized to neutrality, washed with deionized water, filtered and dried to obtain a solid product, i.e., the coal water slurry additive.
[0009] Preferably, when the benzyl diamine and suberic anhydride are heated in a DMF solution to react and the reactant is obtained, the heating temperature is at least 90°C.
[0010] The present invention also provides a coal water slurry additive, which is prepared according to the above-mentioned method for preparing the coal water slurry additive.
[0011] Preferably, the particle size of the coal water slurry additive is 0.1-1 micron.
[0012] The present invention also proposes an application of the above-mentioned coal water slurry additive, and the application includes at least any one of the following:
[0013] (A1) Application of the coal water slurry additive in preparing a coal water slurry additive composition
[0014] (A2) Application of the coal water slurry additive in improving the performance of coal water slurry.
[0015] The present invention also proposes a multifunctional coal-water slurry additive, which includes the above-mentioned coal-water slurry additive.
[0016] Preferably, the multifunctional coal water slurry additive further comprises polyvinyl alcohol, a surfactant, nano silicon dioxide and a high molecular polymer.
[0017] Preferably, the weight ratio of the coal water slurry additive, polyvinyl alcohol, surfactant, nano silicon dioxide and high molecular polymer is 50-65:5-15:3-8:5-7:20-22.
[0018] Preferably, the surfactant is sodium dodecylbenzene sulfonate or alkylphenol polyoxyethylene ether;
[0019] The high molecular polymer is polyethyleneimine or polyacrylamide.
[0020] The present invention also proposes an application of the multifunctional coal water slurry additive in improving the performance of coal water slurry.
[0021] Compared with the prior art, the present invention has the following beneficial effects:
[0022] The present invention firstly elaborates a basic coal water slurry additive and its preparation method. The method mainly involves polycondensation reaction of benzenediamine and suberic anhydride, and successfully prepares an initial coal water slurry additive through this chemical reaction process. The additive not only has excellent dispersibility, but also has good rheological properties, which significantly improves its application effect in coal water slurry.
[0023] On this basis, the present invention further improves and optimizes the basic additives, significantly improving the dispersibility, rheology and stability of the water-coal slurry. The improvement measures include the introduction of functional ingredients such as polyvinyl alcohol, surfactants and nano-silicon dioxide. The addition of these functional ingredients further optimizes the viscosity, dispersion effect and thermal stability of the additives. These improvements ensure that the water-coal slurry can maintain excellent stability and performance under various conditions of use, especially in long-term storage and high temperature environments, the compounded additives show their significant advantages.
[0024] The core advantage of the present invention is that the functionality of the water-coal slurry additive is gradually enhanced through a series of systematic multi-stage improvements. This not only improves the dispersibility, rheology and stability of the water-coal slurry, but also improves its performance under extreme conditions such as high temperature and long-term storage. Compared with the prior art, the present invention provides a more efficient, stable and cost-effective water-coal slurry additive solution with broad application prospects. This additive can not only improve the overall performance of the water-coal slurry, but also reduce energy consumption and environmental pollution in practical applications, with significant economic and environmental benefits. DETAILED DESCRIPTION
[0025] The exemplary embodiments of the present disclosure will be described in more detail below. Although the exemplary embodiments of the present disclosure are shown below, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to be able to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below in conjunction with the embodiments.
[0026] Example 1 Preparation of coal water slurry additive
[0027] The benzyl diamine and suberic anhydride are heated to 90°C in a DMF solution for 4-6 hours to ensure that the main chain polycondensation reaction is fully completed; the reactants are cooled to room temperature, and carboxymethyl chloride is added to introduce hydrophilic groups for 3 hours.
[0028] After the reaction is completed, the system is neutralized to a pH of about 7, washed with deionized water, filtered and dried to obtain a solid product, namely, a water-coal slurry additive.
[0029] The solid product is crushed to control the particle size to 0.1-1 micron, which helps to improve its dispersibility. Drying at 60-70°C ensures that the product remains stable before adding to the water-coal slurry to reduce the effect of hygroscopicity on the dispersion effect.
[0030] Example 2 Preparation of coal water slurry additive
[0031] The benzyl diamine and suberic anhydride are heated to 90°C in a DMF solution for 4-6 hours to ensure that the main chain polycondensation reaction is fully completed; the reactants are cooled to room temperature, and carboxymethyl chloride is added to introduce hydrophilic groups for 3 hours.
[0032] After the reaction is completed, the system is neutralized to a pH of about 7, washed with deionized water, filtered and dried to obtain a solid product, namely, a water-coal slurry additive.
[0033] The solid product is crushed to control the particle size to 0.1-1 micron, which helps to improve its dispersibility. Microwave-assisted drying technology is used to dry the product to ensure that it remains stable before adding it to the water-coal slurry and reduce the impact of hygroscopicity on the dispersion effect.
[0034] Example 3 Preparation of coal water slurry additive
[0035] On the basis of Example 1, further improvements are made:
[0036] When diphenylenediamine and suberic anhydride are heated to 90° C. in a DMF solution for reaction, polyethylene glycol is added for a reaction time of 4-6 hours to ensure that the main chain polycondensation reaction is fully completed; the reactants are cooled to room temperature, and carboxymethyl chloride is added to introduce hydrophilic groups for a reaction time of 3 hours.
[0037] After the reaction is completed, the system is neutralized to a pH of about 7, washed with deionized water, filtered and dried to obtain a solid product, namely, a water-coal slurry additive.
[0038] The solid product is crushed to control the particle size to 0.1-1 micron, which helps to improve its dispersibility. Drying at 60-70°C ensures that the product remains stable before adding to the water-coal slurry to reduce the effect of hygroscopicity on the dispersion effect.
[0039] Example 4 Preparation of Coal Water Slurry Additive
[0040] Based on Example 3, further improvements are made:
[0041] When diphenylenediamine and suberic anhydride are heated to 90° C. in a DMF solution for reaction, polyethylene glycol is added for a reaction time of 4-6 hours to ensure that the main chain polycondensation reaction is fully completed; the reactants are cooled to room temperature, and carboxymethyl chloride is added to introduce hydrophilic groups for a reaction time of 3 hours.
[0042] After the reaction is completed, the system is neutralized to a pH of about 7, washed with deionized water, filtered and dried to obtain a solid product, namely, a water-coal slurry additive.
[0043] The solid product is crushed to control the particle size to 0.1-1 micron, which helps to improve its dispersibility. Microwave-assisted drying technology is used to dry the product to ensure that it remains stable before adding it to the water-coal slurry and reduce the impact of hygroscopicity on the dispersion effect.
[0044] Test Example 1 Exploration of the Optimal Addition Ratio of Coal-Water Slurry Additives to Coal-Water Slurry
[0045] 1. Purpose of the experiment
[0046] The addition ratio is set in the range of 0.5%-2.5% (mass ratio, measured as the percentage of the mass of the additive to the total mass of the water-coal slurry). This ratio range helps to achieve better economy and effect while ensuring the stability, fluidity and dispersibility of the water-coal slurry.
[0047] 2. Experimental process
[0048] 1. Sample configuration
[0049] The coal water slurry additives prepared in Examples 1-4 were respectively added into the coal water slurry at a ratio of 0.5%, 1.0%, 1.5%, 2.0% and 2.5%, and stirred evenly for later use.
[0050] 2. Dispersion test
[0051] Take the prepared water-coal slurry sample, use ultrasonic dispersion for 5 minutes, and then measure the average particle size of the water-coal slurry to evaluate the effect of the dispersant on the dispersion of the water-coal slurry particles.
[0052] 3. Viscosity test
[0053] The apparent viscosity of the coal water slurry was measured using a rotational viscometer at 25 ° C. The viscosity values at different addition ratios were recorded to evaluate the effect of the dispersant on the rheological properties of the coal water slurry.
[0054] 4. Stability test
[0055] The coal-water slurry sample was allowed to stand for 7 days, the height of the supernatant was recorded, and the stratification rate was calculated (supernatant liquid height / total coal-water slurry height*100%). The lower the stratification rate, the better the stability of the coal-water slurry.
[0056] 5. Results
[0057] The test results of the optimal addition ratio of the water-coal slurry additive to the water-coal slurry of Examples 1-4 are shown in Table 1.
[0058] Table 1
[0059]
[0060]
[0061] Conclusion
[0062] According to the test results in Table 1, the following conclusions can be drawn:
[0063] For Examples 1-4, as the additive addition ratio increases, the average particle size of the water-coal slurry shows a trend of first decreasing and then increasing, indicating that the dispersibility is improved within a certain range, but excessive addition may lead to an increase in particle size.
[0064] The apparent viscosity shows a trend of first decreasing and then stabilizing with the increase of the additive ratio, which shows that the appropriate amount of additives can effectively reduce the viscosity of water-coal slurry and improve its fluidity.
[0065] The stratification rate shows a downward trend with the increase of the additive ratio, indicating that the stability of the water-coal slurry is improved, especially at an addition ratio of 1.5%, the stratification rate is the lowest, indicating that the stability of the water-coal slurry is the best at this time.
[0066] Taking dispersibility, viscosity and stability into consideration, in Examples 1-4, the addition ratio of 1.5% is optimal, which can ensure that the coal water slurry has good comprehensive performance. Therefore, it is recommended that the optimal addition ratio of the multifunctional coal water slurry additive to the coal water slurry is 1.5%.
[0067] Example 5
[0068] Based on the coal water slurry additive of Example 4, a multifunctional coal water slurry additive was compounded.
[0069] 1. Raw materials
[0070] The multifunctional coal water slurry additive of Example 4 is synthesized by polycondensation reaction of benzenediamine and suberic anhydride, and has good dispersibility and rheological properties.
[0071] Polyvinyl alcohol (PVA): Enhances viscosity control and stability of coal-water slurry.
[0072] Surfactant (sodium dodecylbenzene sulfonate): enhances the dispersibility and hydrophilicity of water-coal slurry.
[0073] Nano-silicon dioxide (SiO2): Improves the rheological properties and thickening effect of water-coal slurry.
[0074] High molecular polymer (polyacrylamide): improves the fluidity and stability of water-coal slurry and helps disperse particles.
[0075] 2. Compounding process
[0076] Dissolve polyvinyl alcohol: Dissolve an appropriate amount of polyvinyl alcohol in deionized water and stir until it is completely dissolved to form a transparent aqueous solution.
[0077] Mixing additives: Add the coal water slurry additive, surfactant, nano-silicon dioxide, and high molecular polymer of Example 4 to the dissolved polyvinyl alcohol solution according to the mass ratio, stir evenly, and ensure that the components are fully mixed. Among them, the weight ratio of the coal water slurry additive, surfactant, nano-silicon dioxide, high molecular polymer and polyvinyl alcohol solution is 60:10:5:5:20.
[0078] Adjust pH: Add appropriate amount of sodium hydroxide or hydrochloric acid to the mixture to adjust the pH to 6.5-7.0 to ensure the stability of the final product.
[0079] High shear mixing: Use a high shear mixer to stir the compound system for about 30 minutes to ensure that all ingredients are fully dissolved and evenly dispersed.
[0080] Drying and crushing: The compounded liquid additive solution is subjected to microwave-assisted drying or low-temperature drying to obtain a granular multifunctional water-coal slurry additive. The particle size is controlled between 0.1 and 1 micron.
[0081] Example 6
[0082] Based on the coal water slurry additive of Example 4, a multifunctional coal water slurry additive was compounded.
[0083] 1. Raw materials
[0084] The multifunctional coal water slurry additive of Example 4 is synthesized by polycondensation reaction of benzenediamine and suberic anhydride, and has good dispersibility and rheological properties.
[0085] Polyvinyl alcohol (PVA): Enhances viscosity control and stability of coal-water slurry.
[0086] Surfactant (alkylphenol polyoxyethylene ether): enhances the dispersibility and hydrophilicity of water-coal slurry.
[0087] Nano-silicon dioxide (SiO2): Improves the rheological properties and thickening effect of water-coal slurry.
[0088] High molecular weight polymer (polyethyleneimine): improves the fluidity and stability of water-coal slurry and helps disperse particles.
[0089] 2. Compounding process
[0090] Dissolve polyvinyl alcohol: Dissolve an appropriate amount of polyvinyl alcohol in deionized water and stir until it is completely dissolved to form a transparent aqueous solution.
[0091] Mixing additives: Add the multifunctional coal water slurry additive, surfactant, nano-silicon dioxide, and high molecular polymer of Example 4 to the dissolved polyvinyl alcohol solution according to the mass ratio, stir evenly, and ensure that the components are fully mixed. Among them, the weight ratio of the coal water slurry additive, surfactant, nano-silicon dioxide, high molecular polymer and polyvinyl alcohol solution is 50:15:8:5:22.
[0092] Adjust pH: Add appropriate amount of sodium hydroxide or hydrochloric acid to the mixture to adjust the pH to 6.5-7.0 to ensure the stability of the final product.
[0093] High shear mixing: Use a high shear mixer to stir the compound system for about 30 minutes to ensure that all ingredients are fully dissolved and evenly dispersed.
[0094] Drying and crushing: The compounded liquid additive solution is subjected to microwave-assisted drying or low-temperature drying to obtain a granular multifunctional water-coal slurry additive. The particle size is controlled between 0.1 and 1 micron.
[0095] Example 7
[0096] Based on the coal water slurry additive of Example 4, a multifunctional coal water slurry additive was compounded.
[0097] 1. Raw materials
[0098] The multifunctional coal water slurry additive of Example 4 is synthesized by polycondensation reaction of benzenediamine and suberic anhydride, and has good dispersibility and rheological properties.
[0099] Polyvinyl alcohol (PVA): Enhances viscosity control and stability of coal-water slurry.
[0100] Surfactant (sodium dodecylbenzene sulfonate): enhances the dispersibility and hydrophilicity of water-coal slurry.
[0101] Nano-silicon dioxide (SiO2): Improves the rheological properties and thickening effect of water-coal slurry.
[0102] High molecular weight polymer (polyethyleneimine): improves the fluidity and stability of water-coal slurry and helps disperse particles.
[0103] 2. Compounding process
[0104] Dissolve polyvinyl alcohol: Dissolve an appropriate amount of polyvinyl alcohol in deionized water and stir until it is completely dissolved to form a transparent aqueous solution.
[0105] Mixing additives: Add the multifunctional coal water slurry additive, surfactant, nano-silicon dioxide, and high molecular polymer of Example 4 to the dissolved polyvinyl alcohol solution according to the mass ratio, stir evenly, and ensure that the components are fully mixed. Among them, the weight ratio of the coal water slurry additive, surfactant, nano-silicon dioxide, high molecular polymer and polyvinyl alcohol solution is 65:5:3:7:20.
[0106] Adjust pH: Add appropriate amount of sodium hydroxide or hydrochloric acid to the mixture to adjust the pH to 6.5-7.0 to ensure the stability of the final product.
[0107] High shear mixing: Use a high shear mixer to stir the compound system for about 30 minutes to ensure that all ingredients are fully dissolved and evenly dispersed.
[0108] Drying and crushing: The compounded liquid additive solution is subjected to microwave-assisted drying or low-temperature drying to obtain a granular multifunctional water-coal slurry additive. The particle size is controlled between 0.1 and 1 micron.
[0109] Test Example 2
[0110] The performance of the multifunctional coal water slurry additive compounded in Examples 5-7 was tested.
[0111] 1. Test Method
[0112] 1. Stability test
[0113] The compounded multifunctional coal water slurry additive was added into the coal water slurry according to the standard method, and its stability at different time intervals was observed, and the stratification and precipitation were recorded.
[0114] 2. Rheological properties test
[0115] The viscosity of coal water slurry was measured using a rotational viscometer to evaluate the effects of additives on the rheological properties of coal water slurry.
[0116] 3. Dispersion performance test
[0117] The dispersion of solid particles in the water-coal slurry was observed under a microscope to evaluate the dispersion effect of the additive.
[0118] 4. Thermal stability test
[0119] Heat the water-coal slurry at different temperatures, observe the changes in its thermal stability, and record the changes in viscosity and whether precipitation occurs.
[0120] 2. Test Results
[0121] The test results are shown in Table 2.
[0122] Table 2
[0123]
[0124]
[0125] According to the data in Table 2, compared with Example 4, the compounded multifunctional additive exhibits significant advantages in many aspects:
[0126] 1. Improved stability
[0127] Examples 5, 6, and 7: These compound additives showed excellent stability in coal water slurry, especially in long-term testing, almost no stratification or precipitation was observed. This shows that the compound multifunctional additives can significantly improve the long-term stability of coal water slurry and effectively avoid precipitation problems during storage or use.
[0128] Example 4: Although the dispersibility and rheological properties are good, there may be a certain risk of stratification and precipitation under certain extreme conditions (such as long-term storage, different ambient temperature and humidity).
[0129] 2. Enhanced rheological properties (viscosity)
[0130] Examples 5, 6, and 7: The compounded additives increased the viscosity of the water-coal slurry, especially in the formulation of Example 6, where the viscosity reached 1200 mPa·s, compared with Example 4 (viscosity of about 1000-1100 mPa·s), indicating that the compounded additives can enhance the rheology and suspension ability of the water-coal slurry, thereby improving the dispersion effect of the coal powder.
[0131] Example 4: Although the rheological properties are good, its viscosity may be slightly lower than the compounded formula due to the lack of compounding additives.
[0132] 3. Improved dispersion
[0133] Examples 5, 6, and 7: By adding a variety of surfactants, nano-silicon dioxide, etc., the compounded additives provide stronger dispersibility and further reduce the particle aggregation phenomenon. Microscope observation shows that the solid particles in the water-coal slurry are more evenly dispersed and have higher dispersibility.
[0134] Example 4: Although the dispersion effect is good, under extreme conditions, the performance may be slightly inferior to that of compound additives.
[0135] 4. Enhanced thermal stability
[0136] Examples 5, 6, and 7: The compounded water-coal slurry exhibits better thermal stability during heating, with less viscosity change and no precipitation. Even in high temperature environments, these compounded additives can maintain the stability of the water-coal slurry.
[0137] Example 4: Although it has a certain degree of thermal stability, under high temperature conditions, there may be a slight increase in viscosity or precipitation compared to the compounded additives.
[0138] 5. Diversification and optimization of functions
[0139] Examples 5, 6, and 7: By compounding more functional ingredients (such as different types of surfactants and nano-silica), these compound additives have been significantly optimized in terms of dispersibility, rheology, and stability, and are more adaptable and can cope with different usage conditions and requirements.
[0140] Example 4: As a basic additive, although it provides good dispersibility and rheology, it lacks compounded functional ingredients and may not be able to show the comprehensive advantages of compounded additives in certain specific applications.
[0141] In summary, the present invention proposes a series of innovative solutions based on Examples 1 to 7 by gradually improving the preparation method of the multifunctional water-coal slurry additive.
[0142] In Example 1, the most basic and excellent additive preparation process was designed, and an initial water-coal slurry additive with good dispersibility and rheology was formed through the polycondensation reaction of benzyl diamine and suberic anhydride. This scheme provides a solid foundation for subsequent improvements.
[0143] On the basis of Examples 2 to 4, the dispersibility, rheology and stability of the water-coal slurry were further improved by optimizing the ingredients of the additives. Specific improvements include adding functional ingredients such as polyvinyl alcohol, surfactants, and nano-silicon dioxide to optimize the viscosity, dispersion effect and thermal stability of the additives. These improvements enable the water-coal slurry to exhibit stronger stability and excellent performance under different conditions of use, especially under long-term storage and high-temperature environments, where the compound additives show significant advantages.
[0144] Examples 5 to 7 are further optimized on the basis of Example 4. By adding different types of surfactants and high molecular polymers, the rheological properties, dispersibility and thermal stability of the water-coal slurry are further enhanced. The use of multifunctional compound additives can better meet the different application requirements of water-coal slurry and improve its applicability and stability in various industrial productions.
[0145] In summary, the present invention provides an efficient, stable and economical multifunctional coal water slurry additive preparation scheme by gradually optimizing the composition and preparation process of the coal water slurry additive. This scheme not only meets the basic requirements of coal water slurry in terms of dispersibility, rheology and stability, but also further improves its performance in different application environments, so that the coal water slurry additive of the present invention has a wide range of application prospects and market potential.
[0146] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.
Claims
1. A method for preparing a coal water slurry additive, characterized in that: include: The diphenylenediamine and suberic anhydride are heated to react in a DMF solution to obtain a reactant; after the reactant is cooled to room temperature, carboxymethyl chloride is added to react to introduce a hydrophilic group; after the reaction is completed, the system is neutralized to neutrality, washed with deionized water, filtered and dried to obtain a solid product, i.e., the coal water slurry additive.
2. The method for preparing the coal water slurry additive according to claim 1, characterized in that: The heating temperature of the diphenylenediamine and suberic anhydride in a DMF solution to obtain a reactant is at least 90°C.
3. A coal water slurry additive, characterized in that: The coal water slurry additive is prepared according to the preparation method of the coal water slurry additive according to claim 1 or 2.
4. The coal water slurry additive according to claim 3, characterized in that: The particle size of the coal water slurry additive is 0.1-1 micron.
5. An application of the coal water slurry additive according to claim 3, characterized in that: The application includes at least one of the following: (A1) Application of the coal water slurry additive in preparing a coal water slurry additive composition (A2) Application of the coal water slurry additive in improving the performance of coal water slurry.
6. A multifunctional coal water slurry additive, characterized in that: The multifunctional coal-water slurry additive comprises the coal-water slurry additive according to claim 3.
7. The multifunctional coal water slurry additive according to claim 6, characterized in that: The multifunctional coal water slurry additive also includes polyvinyl alcohol, surfactant, nano silicon dioxide and high molecular polymer.
8. The multifunctional coal water slurry additive according to claim 7, characterized in that: The weight ratio of the coal water slurry additive, polyvinyl alcohol, surfactant, nano silicon dioxide and high molecular polymer described in claim 3 is 50-65:5-15:3-8:5-7:20-22.
9. The multifunctional coal water slurry additive according to claim 7, characterized in that: The surfactant is sodium dodecylbenzene sulfonate or alkylphenol polyoxyethylene ether; The high molecular polymer is polyethyleneimine or polyacrylamide.
10. Use of the multifunctional coal water slurry additive according to claim 6 in improving the performance of coal water slurry.