A hydrophilic-lipophilic balance type coal water slurry additive, a preparation method and application thereof

Abstract

This invention provides a hydrophilic-lipophilic balanced coal-water slurry additive, its preparation method, and its application. By weight, the raw materials include: 18-28 parts of gemini-type polyether-modified naphthalene sulfonate, 4-10 parts of zwitterionic nano-hybrid stabilizer, 12-20 parts of sodium lignosulfonate, 6-12 parts of polycarboxylate-based dispersant, 1.5-4 parts of biopolysaccharide rheology modifier, 10-16 parts of low-temperature flowability improver, 2-4 parts of pH adjuster, 2-5 parts of chelating agent, and 35-50 parts of deionized water. The hydrophilic-lipophilic balanced coal-water slurry additive provided by this invention can form an adsorption layer on the surface of coal particles, achieving synergistic dispersion through electrostatic repulsion and steric hindrance. This improves the low-temperature flowability, long-term storage stability, and coal type adaptability of the coal-water slurry, regulates thixotropy, chelates interfering ions, optimizes the effects of each component, and ensures a stable and homogeneous system.

Description

Technical Field

[0001] This invention relates to the field of coal-water slurry additives, specifically to a hydrophilic-lipophilic balanced coal-water slurry additive, its preparation method, and its application. Background Technology

[0002] Coal-water slurry, as an important coal-based fluid fuel for the clean and efficient utilization of coal, is widely used in power, metallurgy, chemical and other industrial fields. The additives added during its preparation are key factors in controlling the slurry concentration, fluidity, and stability, directly affecting its storage, transportation, and combustion performance. Currently, the synergistic utilization of coal and biomass energy is a development trend. In the production of biomass liquid fuels and the processing of biomass compacted fuels, the industry often introduces coal-water slurry preparation processes to achieve the co-production of coal and biomass into a slurry. This places higher demands on the comprehensive performance of coal-water slurry additives. Existing technologies have widely researched and applied coal-water slurry additives such as naphthalene sulfonates, polycarboxylic acid compounds, and lignin sulfonates. These additives achieve slurry dispersion and stability control by forming an adsorption layer on the coal particle surface, providing electrostatic repulsion, or steric hindrance.

[0003] Existing coal-water slurry additives mostly focus on optimizing a single performance. Although they can improve the dispersibility or flowability of coal-water slurry to a certain extent, they are difficult to balance the low-temperature flowability and long-term storage stability of the slurry. In low-temperature environments, the slurry viscosity is prone to increase sharply and the freezing point is too high, resulting in poor flowability of coal-water slurry and failure to meet the requirements of low-temperature operation. At the same time, the adsorption layer formed on the surface of coal particles by conventional coal-water slurry additives is not stable enough and cannot effectively prevent coal particles from agglomerating and settling. This makes the coal-water slurry prone to stratification, water separation and even agglomeration during long-term storage. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides a hydrophilic-lipophilic balanced coal-water slurry additive, its preparation method, and its application.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] This invention discloses a hydrophilic-lipophilic balanced coal-water slurry additive, which, by weight, comprises the following raw materials: 18-28 parts of gemini polyether modified naphthalene sulfonate, 4-10 parts of zwitterionic nano-hybrid stabilizer, 12-20 parts of sodium lignosulfonate, 6-12 parts of polycarboxylic acid dispersant, 1.5-4 parts of biopolysaccharide rheology modifier, 10-16 parts of low-temperature flowability improver, 2-4 parts of pH adjuster, 2-5 parts of chelating agent, and 35-50 parts of deionized water.

[0007] Using the above technical solutions, the gemini polyether-modified naphthalene sulfonate can form an adsorption layer on the surface of coal particles, providing electrostatic repulsion and improving the low-temperature fluidity of the system; the zwitterionic nano-hybrid stabilizer's zwitterionic segments can adaptively adjust their charge polarity according to the surface charge characteristics of the coal particles, achieving efficient adsorption of different coal types and broadening the coal type adaptability; sodium lignosulfonate can play an auxiliary dispersing role, enhancing the system's dispersion effect by adsorbing onto the coal particle surface; polycarboxylic acid-based dispersing aids can provide a synergistic effect of electrostatic repulsion and steric hindrance, inhibiting coal particle agglomeration; biopolysaccharide rheology modifiers can regulate the thixotropic properties of coal-water slurry, making it less prone to sedimentation when standing and quickly recovering fluidity under shear; low-temperature fluidity improvers can lower the system's freezing point, ensuring fluidity under low-temperature conditions; pH adjusters can adjust the system's acidity and alkalinity, optimizing the effects of each component; chelating aids can chelate high-valence metal ions in the system, eliminating their interference with the system's dispersion effect; deionized water, as the dispersion medium, can ensure uniform dispersion and mixing of each component, ensuring the stability and uniformity of the additive system. The compound system of this coal-water slurry additive has a wide range of applications. It can synergistically achieve slurry dispersion and stability control in the production of biomass liquid fuel and the processing of biomass dense shaped fuel, optimize the rheological properties and storage performance of slurry in the preparation of biomass fuel, and improve the processing efficiency and quality of the fuel.

[0008] Preferably, the sodium lignosulfonate has a number average molecular weight of 5000-8000 Da, the biopolysaccharide rheology modifier is one or more of vinca gum, xanthan gum, and gum arabic, the low-temperature flow improver is one or more of ethylene glycol and diethylene glycol, the pH adjuster is one or more of triethanolamine, diethanolamine, and monoisopropanolamine, and the chelating agent is one or more of sodium gluconate, trisodium citrate, and disodium EDTA.

[0009] Using the above technical solution, sodium lignosulfonate with a number average molecular weight of 5000-8000 Da possesses suitable molecular size and solubility, enabling it to rapidly adsorb onto the surface of coal particles and provide initial dispersion force. It works synergistically with other dispersing components to achieve full coverage of different adsorption sites on the coal particle surface. A bio-polysaccharide rheology modifier composed of one or more of xanthan gum, xanthan gum, and gum arabic can form an intermolecular hydrogen bond network, regulating the thixotropic properties of the coal-water slurry. During standing, it increases the yield stress of the system, reducing coal particle sedimentation. During shearing, the hydrogen bond network is rapidly destroyed, thereby reducing the viscosity of the system. A low-temperature flowability improver composed of one or more of ethylene glycol and diethylene glycol contains hydroxyl groups, which can form [a specific reaction] with other components in the system. Intermolecular hydrogen bond networks disrupt the regular arrangement of water molecules, lower the freezing point of the coal-water slurry system, and improve the system's low-temperature flow properties. A pH adjuster composed of one or more of triethanolamine, diethanolamine, and monoisopropanolamine can adjust the system to a suitable pH. The hydroxyl groups in its molecules can form hydrogen bonds with the surface of coal particles, enhancing the adsorption strength of the dispersed components on the coal particle surface without introducing additional sodium ions into the system. A chelating agent composed of one or more of sodium gluconate, trisodium citrate, and disodium ethylenediaminetetraacetate can form stable chelates with high-valence metal ions in the coal slurry and system water, eliminating the charge shielding effect of high-valence metal ions on the anionic dispersant in the system, and improving the dispersion and stability of the coal-water slurry.

[0010] Preferably, the raw materials for preparing the gemini polyether modified naphthalene sulfonate, by weight, include: 20-30 parts of industrial naphthalene, 25-35 parts of concentrated sulfuric acid, 8-12 parts of formaldehyde aqueous solution with a mass fraction of 35%-37%, 25-35 parts of polyether amine, and 0.3-0.5 parts of p-toluenesulfonic acid.

[0011] Using the above technical solution, industrial naphthalene serves as the substrate for the sulfonation reaction, providing a naphthalene ring structure and laying the foundation for the construction of the molecular skeleton of gemini-type polyether-modified naphthalene sulfonate. Concentrated sulfuric acid, as a sulfonating agent, can undergo a sulfonation reaction with industrial naphthalene, introducing sulfonic acid groups onto the naphthalene ring, giving the product a hydrophilic structural characteristic. A 35%-37% formaldehyde aqueous solution, as a condensing agent, can participate in the condensation reaction, achieving the connection between naphthalene sulfonate intermediate molecules and providing structural sites for subsequent grafting of polyether segments. Polyetheramine, as a modifying monomer, can participate in the condensation reaction, introducing polyether segments into the product molecular structure and adjusting the product's molecular chain structure and hydrophilic-lipophilic balance. Toluenesulfonic acid, as a catalyst, can catalyze the condensation reaction in the system, accelerating the condensation reaction rate and increasing the degree of condensation reaction, ensuring the effective formation of the gemini-type polyether-modified naphthalene sulfonate molecular structure.

[0012] Preferably, the preparation method of the gemini polyether modified naphthalene sulfonate includes the following steps:

[0013] 1) Add industrial naphthalene and concentrated sulfuric acid to the reactor, heat to 100-110℃, and stir the reaction at a speed of 200-300r / min for 2-3h;

[0014] 2) Cool the reaction system obtained in step 1) to 80-90℃, stir continuously at a speed of 200-300r / min, and add formaldehyde aqueous solution dropwise at a uniform rate over 30-35min. After the addition is complete, keep the reaction at 80-90℃ for 1.5-2.5h.

[0015] 3) Cool the reaction system obtained in step 2) to 40-50℃, add polyetheramine and p-toluenesulfonic acid, heat to 110-120℃ under nitrogen protection, stir at 150-250 r / min for 3-4 h, cool to 25-30℃, adjust the pH to 8.0-9.0 with 25%-30% sodium hydroxide solution, stir until the system is homogeneous, and obtain gemini polyether modified naphthalene sulfonate.

[0016] Using the above technical solution, industrial naphthalene reacts with concentrated sulfuric acid at 100-110℃ to undergo sulfonation, introducing sulfonic acid groups onto the naphthalene ring and providing a hydrophilic structure for the product. Formaldehyde aqueous solution reacts with the sulfonated product at 80-90℃, linking naphthalene sulfonate molecules through condensation to form a naphthalene sulfonate formaldehyde condensate intermediate. Polyetheramine and p-toluenesulfonic acid react with the intermediate at 110-120℃ under nitrogen protection, introducing polyether segments into the product molecular structure. Nitrogen protection reduces the oxidative loss of organic components in the reaction system and allows two naphthalene sulfonate molecules to form a twin structure through the polyether chain. A 25%-30% sodium hydroxide solution adjusts the pH of the system to 8.0-9.0, neutralizing acidic components and stabilizing the product. Stirring until the system is homogeneous ensures uniform product dispersion, ultimately yielding a twin-type polyether-modified naphthalene sulfonate.

[0017] Preferably, the number average molecular weight of the gemini polyether modified naphthalene sulfonate is 2000-4000 Da, and the degree of sulfonation is 1.4-1.8 mmol / g.

[0018] Using the above technical solution, the number average molecular weight of the gemini polyether modified naphthalene sulfonate is controlled at 2000-4000 Da, which allows its molecular chain to have suitable length and flexibility. This not only forms effective steric hindrance on the surface of coal particles, reducing agglomeration between coal particles, but also ensures good solubility and dispersibility in the aqueous phase. Its degree of sulfonation is 1.4-1.8 mmol / g, which provides an appropriate amount of sulfonic acid groups, giving the molecule suitable hydrophilic-lipophilic balance characteristics. This allows the coal particles to be separated from each other through the electrostatic repulsion of the sulfonic acid groups, and also allows the hydrophobic segments in the molecule to form an effective adsorption effect on the surface of the coal particles, ensuring the stability of the dispersion effect.

[0019] Preferably, the raw materials for preparing the zwitterionic nano-hybrid stabilizer, by weight, include: 5-8 parts of nano-magnesium aluminum layered double hydroxide, 80-100 parts of anhydrous ethanol, 3-5 parts of 3-[(2-aminoethyl)amino]propyltrimethoxysilane, and 2-3 parts of sodium 3-chloro-2-hydroxypropanesulfonate.

[0020] Using the above technical solution, the nano-magnesium-aluminum layered double hydroxide provides a nanoscale supporting structure for the zwitterionic nano-hybrid stabilizer, laying the structural basis for its steric hindrance effect; anhydrous ethanol, as a dispersion medium, can uniformly disperse the nano-magnesium-aluminum layered double hydroxide and reduce particle agglomeration; 3-[(2-aminoethyl)amino]propyltrimethoxysilane can be grafted onto the surface of the nano-magnesium-aluminum layered double hydroxide, providing amino sites for the subsequent formation of zwitterionic structures; sodium 3-chloro-2-hydroxypropanesulfonate can react with the above-mentioned amino groups to introduce sulfonic acid groups, so that the surface of the stabilizer forms a zwitterionic structure containing both amino and sulfonic acid groups, ensuring its charge self-adaptive properties.

[0021] Preferably, the average particle size of the nano-magnesium-aluminum layered double hydroxide is 50-100 nm, and the molar ratio of magnesium to aluminum is (2-3):1.

[0022] Using the above technical solution, the average particle size of the nano-magnesium-aluminum layered double hydroxide is controlled at 50-100nm, which gives it a suitable specific surface area, which is conducive to the surface grafting reaction, and at the same time can exert a moderate steric hindrance effect. The molar ratio of magnesium to aluminum in the nano-magnesium-aluminum layered double hydroxide is (2-3):1, which can form a stable layered crystal structure, ensure its structural integrity, and make the interlayer charge distribution suitable, forming a synergistic effect with the zwitterionic chain segments grafted on the surface.

[0023] Preferably, the preparation method of the zwitterionic nano-hybrid stabilizer includes the following steps:

[0024] (1) Disperse the nano-magnesium aluminum layered double hydroxide in anhydrous ethanol, stir at 150-200 r / min for 10-15 min at 25-30℃, and then ultrasonically disperse for 30-40 min at 300-400 W power and 20-25 kHz frequency to obtain a uniform dispersion.

[0025] (2) Add 3-[(2-aminoethyl)amino]propyltrimethoxysilane to the dispersion obtained in step (1), heat to 60-70℃, and stir at 400-500 r / min for 6-8 h.

[0026] (3) Add sodium 3-chloro-2-hydroxypropanesulfonate to the reaction system obtained in step (2), heat to 70-80℃, adjust the pH to 8.8-9.5 with sodium hydroxide solution with a mass fraction of 25%-30%, and stir the reaction at 300-400r / min at 25-30℃ for 4-6 hours.

[0027] (4) Centrifuge the system obtained in step (3) at a speed of 8000-10000 r / min for 10-14 min. Wash the precipitate with anhydrous ethanol 3-4 times. After each washing, centrifuge at a speed of 6000-8000 r / min for 5-8 min. Place the washed precipitate in a vacuum drying oven and dry it at 50-60℃ and a vacuum of -0.08 MPa to -0.09 MPa for 10-14 h to obtain a zwitterionic nano-hybrid stabilizer.

[0028] Using the above technical solution, the combination of stirring and ultrasonic dispersion can uniformly disperse the nano-magnesium-aluminum layered double hydroxide in anhydrous ethanol, reducing particle agglomeration and providing a uniform reaction interface for subsequent surface grafting reactions. A reaction temperature of 60-70℃ provides suitable thermodynamic conditions for the surface grafting reaction between 3-[(2-aminoethyl)amino]propyltrimethoxysilane and the nano-magnesium-aluminum layered double hydroxide, promoting the effective grafting of the silane coupling agent onto its surface and forming amino reaction sites. Adjusting the system pH to 8.8-9.5 facilitates the reaction between the amino group and sodium 3-chloro-2-hydroxypropanesulfonate. Creating a suitable alkaline reaction environment promotes the reaction between the two and forms an amphoteric structure on the surface of the nano-magnesium-aluminum layered double hydroxide. Centrifugation and washing remove unreacted raw materials and reaction byproducts, improving the purity of the product. Vacuum drying at 50-60℃ removes anhydrous ethanol from the product under mild conditions while ensuring the structural integrity of the product. The synergistic effect of each process step results in a zwitterionic nano-hybrid stabilizer with a uniform surface zwitterionic graft layer and a stable nanoscale structure, ensuring the performance of its surface charge characteristics and steric hindrance effect.

[0029] This invention also discloses a method for preparing a hydrophilic-lipophilic balanced coal-water slurry additive, comprising the following steps:

[0030] S1. Weigh out the gemini polyether modified naphthalene sulfonate, zwitterionic nano-hybrid stabilizer and polycarboxylic acid dispersant according to the proportion, add 60%-70% of the total weight of deionized water, and stir at 400-600 r / min at 40-50℃ for 30-40 min to obtain a premixed dispersion system.

[0031] S2. Add sodium lignosulfonate and chelating agent to the premixed dispersion system, heat to 50-60℃, and stir at 300-400r / min for 20-30min.

[0032] S3. Maintain the system obtained in step S2 at 50-60℃, add the biopolysaccharide rheology modifier, and stir at 500-700 r / min for 40-60 min.

[0033] S4. Add low-temperature flow improver, pH adjuster and remaining deionized water to the system obtained in step S3, and stir at 300-400 r / min for 20-30 min.

[0034] S5. Adjust the pH of the system to 8.5-9.5 using a sodium hydroxide solution with a mass fraction of 25%-30% or a hydrochloric acid solution with a mass fraction of 10%-20%, stir at a speed of 200-300 r / min for 15-20 min, and use a microporous filter membrane with a pore size of 0.5-1.0 μm for vacuum filtration to remove mechanical impurities and insoluble substances in the system, thereby obtaining a hydrophilic-lipophilic balanced coal-water slurry additive.

[0035] Using the above technical solution, premixing at 40-50℃ allows the gemini-type polyether-modified naphthalene sulfonate, zwitterionic nano-hybrid stabilizer, and polycarboxylic acid-based dispersant to be uniformly dispersed in deionized water, laying the foundation for subsequent component mixing. Heating to 50-60℃ and stirring facilitates the dissolution and dispersion of sodium lignosulfonate and chelating agents, enabling them to fully participate in the system's action. High-speed stirring at 50-60℃ promotes the full swelling of the biopolysaccharide rheology modifier, ensuring its rheological regulation effect. The addition and stirring of subsequent components allow the low-temperature flow improver and pH adjuster to fully integrate with the system, ensuring synergistic effects of each component. Adjusting the pH to 8.5-9.5 maintains system stability, and vacuum filtration using a microporous membrane with a pore size of 0.5-1.0 μm removes mechanical impurities and insoluble substances from the system, improving product purity and resulting in a uniformly distributed and stable hydrophilic-lipophilic balanced coal-water slurry additive.

[0036] The present invention also discloses the application of a hydrophilic-lipophilic balanced coal-water slurry additive in the preparation of coal-water slurry, wherein the amount of additive is 0.6%-1.2% of the dry coal mass.

[0037] By adopting the above technical solution, the hydrophilic-oleophilic balanced coal-water slurry additive is applied to the preparation of coal-water slurry at a dosage of 0.6%-1.2% of the dry coal mass. This allows each component in the additive to fully exert its own role and form a synergistic effect. It can ensure the full play of the dispersing effect of the gemini-type polyether modified naphthalene sulfonate, the stabilizing effect of the zwitterionic nano-hybrid stabilizer, and the full play of other auxiliary components, so that the coal-water slurry can obtain a suitable viscosity, a high slurry concentration, and a low water separation rate, thus ensuring the low-temperature fluidity and long-term storage stability of the coal-water slurry. At the same time, it can avoid the problem that the effect of each component is insufficient due to the addition of too little additive, which would lead to the deterioration of the dispersion and stability of the coal-water slurry and poor slurry performance. It can also prevent the waste of raw materials, increased costs, and even abnormal viscosity of the coal-water slurry system caused by excessive dosage. It takes into account both the performance and economic requirements of the industrial preparation of coal-water slurry.

[0038] The beneficial effects of this invention are as follows:

[0039] Gemini polyether-modified naphthalene sulfonate can form an adsorption layer on the surface of coal particles, providing electrostatic repulsion and improving the low-temperature fluidity of the system; zwitterionic nano-hybrid stabilizers can adaptively adjust the charge polarity of their surface segments according to the charge characteristics of coal particles, achieving efficient adsorption of different coal types and broadening the adaptability to different coal types; sodium lignosulfonate can play an auxiliary dispersing role, enhancing the dispersion effect of the system by adsorbing onto the surface of coal particles; polycarboxylic acid-based dispersing aids can provide a synergistic effect of electrostatic repulsion and steric hindrance, inhibiting coal particle agglomeration; biopolysaccharide rheology modifiers can regulate the thixotropic properties of coal-water slurry, making it less prone to sedimentation when standing and quickly recovering fluidity under shear; low-temperature fluidity improvers can lower the freezing point of the system, ensuring fluidity under low-temperature conditions; pH adjusters can adjust the acidity and alkalinity of the system, optimizing the effect of each component; chelating aids can chelate high-valence metal ions in the system, eliminating their interference with the dispersion effect of the system; deionized water, as a dispersion medium, can ensure uniform dispersion and mixing of each component, ensuring the stability and homogeneity of the additive system. The compound system of this coal-water slurry additive has a wide range of applications. It can synergistically achieve slurry dispersion and stability control in the production of biomass liquid fuel and the processing of biomass dense shaped fuel, optimize the rheological properties and storage performance of slurry in the preparation of biomass fuel, and improve the processing efficiency and quality of the fuel. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, 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.

[0041] The specific information on the raw materials used in the embodiments of the present invention is shown in Table 1.

[0042] Table 1

[0043] Components Specification source Industrial naphthalene 99% purity Hangzhou Qifei Chemical Co., Ltd., CAS: 91-20-3 concentrated sulfuric acid 98% purity Guangzhou Tianzhong Chemical Co., Ltd. Formaldehyde aqueous solution The quality fraction is 35%-37%. Sinopharm Chemical Reagent Co., Ltd. polyetheramine 99% purity Shandong Shengteng Chemical Co., Ltd., CAS: 9046-10-0 p-Toluenesulfonic acid 99% purity Shandong Xinheng Chemical Co., Ltd., CAS: 104-15-4 Nano-magnesium aluminum layered double hydroxide The average particle size is 50-100 nm, the molar ratio of magnesium to aluminum is (2-3):1, and the purity is 99%. Xi'an Ruixi Biotechnology Co., Ltd. Anhydrous ethanol Analytical Pure Sinopharm Chemical Reagent Co., Ltd. 3-[(2-aminoethyl)amino]propyltrimethoxysilane 98% purity Hubei Hengjingrui Chemical Co., Ltd., CAS: 1760-24-3 Sodium 3-chloro-2-hydroxypropanesulfonate 99% purity Shandong Xinheng Chemical Co., Ltd., CAS: 143218-48-8 Sodium lignosulfonate Number average molecular weight is 5000-8000 Da Fuchen (Tianjin) Chemical Reagent Co., Ltd., CAS: 8061-51-6 Polycarboxylate dispersants Polycarboxylate-based high-performance water-reducing agent, solid content 40%. Jiangsu Subote New Material Co., Ltd., Model PCA-I Biological polysaccharide rheology modifiers Warm roller adhesive, viscosity ≥1500mPa·s (1% aqueous solution, 25℃), food grade. Hebei Xinhe Biochemical Co., Ltd. Xanthan gum, viscosity ≥600 mPa·s (1% aqueous solution, 25℃), food grade Hebei Xinhe Biochemical Co., Ltd. Gum arabic, 99% purity Shanghai Aladdin Biochemical Technology Co., Ltd., CAS: 9000-01-5 Low temperature flow improver Ethylene glycol, 99.9% purity. Liaocheng Tongda Chemical Co., Ltd., CAS: 107-21-1 Diethylene glycol, 98% purity Shanghai Baishun Biotechnology Co., Ltd., CAS: 111-46-6 pH adjuster Triethanolamine, 99% purity Jinan Renyuan Chemical Co., Ltd., CAS: 102-71-6 Diethanolamine, 99% purity Jinan Renyuan Chemical Co., Ltd., CAS: 111-42-2 Monoisopropanolamine, 99% purity Jinan Renyuan Chemical Co., Ltd., CAS: 78-96-6 Chelating aids Sodium gluconate, 99% purity Jinan Renyuan Chemical Co., Ltd., CAS: 527-07-1 Trisodium citrate, 99% purity Shandong Xinhe New Materials Co., Ltd., CAS: 68-04-2 Disodium ethylenediaminetetraacetate, purity 99.5% Shandong Xinhe New Materials Co., Ltd., CAS: 60-00-4

[0044] Example 1:

[0045] This embodiment discloses a hydrophilic-lipophilic balanced coal-water slurry additive. By weight, its preparation raw materials include: 18 parts of gemini-type polyether-modified naphthalene sulfonate, 4 parts of zwitterionic nano-hybrid stabilizer, 12 parts of sodium lignosulfonate with a number-average molecular weight of 5000 Da, 6 parts of polycarboxylic acid-based dispersant, 1.5 parts of biopolysaccharide rheology modifier, 10 parts of low-temperature flowability improver, 2 parts of pH adjuster, 2 parts of chelating agent, and 35 parts of deionized water. The biopolysaccharide rheology modifier is gum arabic, the low-temperature flowability improver is diethylene glycol, the pH adjuster is isopropanolamine, and the chelating agent is disodium ethylenediaminetetraacetate.

[0046] The raw materials for preparing the Gemini polyether modified naphthalene sulfonate, by weight, include: 20 parts industrial naphthalene, 25 parts concentrated sulfuric acid, 8 parts formaldehyde aqueous solution with a mass fraction of 35%, 25 parts polyether amine, and 0.3 parts p-toluenesulfonic acid.

[0047] The preparation method of gemini polyether modified naphthalene sulfonate includes the following steps:

[0048] 1) Add industrial naphthalene and concentrated sulfuric acid to the reactor, heat to 100℃, and stir at 200r / min for 2h.

[0049] 2) Cool the reaction system obtained in step 1) to 80°C, stir continuously at 200 r / min, and add formaldehyde aqueous solution dropwise at a uniform rate over 30 min. After the addition is complete, keep the reaction at 80°C for 1.5 h.

[0050] 3) Cool the reaction system obtained in step 2) to 40°C, add polyetheramine and p-toluenesulfonic acid, heat to 110°C under nitrogen protection, stir at 150 r / min for 3 h, cool to 25°C, adjust the pH to 8.0 with 25% sodium hydroxide solution, stir until the system is homogeneous, and obtain a gemini polyether modified naphthalene sulfonate with a number average molecular weight of 2000 Da and a sulfonation degree of 1.4 mmol / g.

[0051] The raw materials for preparing the zwitterionic nano-hybrid stabilizer, by weight, include: 5 parts of nano-magnesium-aluminum layered double hydroxide, 80 parts of anhydrous ethanol, 3 parts of 3-[(2-aminoethyl)amino]propyltrimethoxysilane, and 2 parts of sodium 3-chloro-2-hydroxypropanesulfonate. The average particle size of the nano-magnesium-aluminum layered double hydroxide is 50 nm, and the molar ratio of magnesium to aluminum is 2:1.

[0052] The preparation method of zwitterionic nano-hybrid stabilizers includes the following steps:

[0053] (1) The nano-magnesium aluminum layered double hydroxide was dispersed in anhydrous ethanol, stirred at 150 r / min for 10 min at 25 °C, and then ultrasonically dispersed for 30 min at 300 W power and 20 kHz frequency to obtain a uniform dispersion.

[0054] (2) Add 3-[(2-aminoethyl)amino]propyltrimethoxysilane to the dispersion obtained in step (1), heat to 60°C, and stir at 400 r / min for 6 h.

[0055] (3) Add sodium 3-chloro-2-hydroxypropanesulfonate to the reaction system obtained in step (2), heat to 70°C, adjust the pH to 8.8 with a 25% sodium hydroxide solution, and stir at 300 r / min for 4 h at 25°C.

[0056] (4) Centrifuge the system obtained in step (3) at 8000 r / min for 10 min. Wash the precipitate with anhydrous ethanol three times. After each washing, centrifuge at 6000 r / min for 5 min. Place the washed precipitate in a vacuum drying oven and dry it at 50℃ and vacuum degree -0.08 MPa for 10 h to obtain zwitterionic nano-hybrid stabilizer.

[0057] This embodiment also discloses a method for preparing a hydrophilic-lipophilic balanced coal-water slurry additive, comprising the following steps:

[0058] S1. Weigh out the gemini polyether modified naphthalene sulfonate, zwitterionic nano-hybrid stabilizer and polycarboxylic acid dispersant according to the proportion, add 60% of the total weight of deionized water, and stir at 400 r / min for 30 min at 40℃ to obtain a premixed dispersion system.

[0059] S2. Add sodium lignosulfonate and chelating agent to the premixed dispersion system, heat to 50℃, and stir at 300r / min for 20min.

[0060] S3. Maintain the system obtained in step S2 at 50°C, add the biopolysaccharide rheology modifier, and stir at 500 r / min for 40 min.

[0061] S4. Add low-temperature flow improver, pH adjuster and remaining deionized water to the system obtained in step S3, and stir at 300 r / min for 20 min.

[0062] S5. Adjust the pH of the system to 8.5 using a 25% sodium hydroxide solution or a 10% hydrochloric acid solution, stir at 200 r / min for 15 min, and use a 0.5 μm microporous membrane for vacuum filtration to remove mechanical impurities and insoluble matter from the system, thus obtaining a hydrophilic-lipophilic balanced coal-water slurry additive.

[0063] This embodiment also discloses the application of a hydrophilic-lipophilic balanced coal-water slurry additive in the preparation of coal-water slurry, wherein the amount of additive is 0.6% of the dry coal mass.

[0064] Example 2:

[0065] This embodiment discloses a hydrophilic-lipophilic balanced coal-water slurry additive. By weight, its preparation raw materials include: 28 parts of gemini-type polyether-modified naphthalene sulfonate, 10 parts of zwitterionic nano-hybrid stabilizer, 20 parts of sodium lignosulfonate with a number-average molecular weight of 8000 Da, 12 parts of polycarboxylate-based dispersant, 4 parts of biopolysaccharide rheology modifier, 16 parts of low-temperature flowability improver, 4 parts of pH adjuster, 5 parts of chelating agent, and 50 parts of deionized water. The biopolysaccharide rheology modifier is xanthan gum, the low-temperature flowability improver is ethylene glycol, the pH adjuster is diethanolamine, and the chelating agent is trisodium citrate.

[0066] The raw materials for preparing the Gemini polyether modified naphthalene sulfonate, by weight, include: 30 parts of industrial naphthalene, 35 parts of concentrated sulfuric acid, 12 parts of a 37% formaldehyde aqueous solution, 35 parts of polyether amine, and 0.5 parts of p-toluenesulfonic acid.

[0067] The preparation method of gemini polyether modified naphthalene sulfonate includes the following steps:

[0068] 1) Add industrial naphthalene and concentrated sulfuric acid to the reactor, heat to 110°C, and stir at 300 r / min for 3 h;

[0069] 2) Cool the reaction system obtained in step 1) to 90°C, stir continuously at 300 r / min, and add formaldehyde aqueous solution dropwise at a uniform rate over 35 min. After the addition is complete, keep the reaction at 90°C for 2.5 h.

[0070] 3) Cool the reaction system obtained in step 2) to 50°C, add polyetheramine and p-toluenesulfonic acid, heat to 120°C under nitrogen protection, stir at 250 r / min for 4 h, cool to 30°C, adjust the pH to 9.0 with 30% sodium hydroxide solution, stir until the system is homogeneous, and obtain a gemini polyether modified naphthalene sulfonate with a number average molecular weight of 4000 Da and a sulfonation degree of 1.8 mmol / g.

[0071] The raw materials for preparing the zwitterionic nano-hybrid stabilizer, by weight, include: 8 parts of nano-magnesium-aluminum layered double hydroxide, 100 parts of anhydrous ethanol, 5 parts of 3-[(2-aminoethyl)amino]propyltrimethoxysilane, and 3 parts of sodium 3-chloro-2-hydroxypropanesulfonate. The average particle size of the nano-magnesium-aluminum layered double hydroxide is 100 nm, and the molar ratio of magnesium to aluminum is 3:1.

[0072] The preparation method of zwitterionic nano-hybrid stabilizers includes the following steps:

[0073] (1) The nano-magnesium aluminum layered double hydroxide was dispersed in anhydrous ethanol, stirred at 200 r / min for 15 min at 30 °C, and then ultrasonically dispersed for 40 min at 400 W power and 25 kHz frequency to obtain a uniform dispersion.

[0074] (2) Add 3-[(2-aminoethyl)amino]propyltrimethoxysilane to the dispersion obtained in step (1), heat to 70°C, and stir at 500 r / min for 8 h.

[0075] (3) Add sodium 3-chloro-2-hydroxypropanesulfonate to the reaction system obtained in step (2), heat to 80°C, adjust the pH to 9.5 with 30% sodium hydroxide solution, and stir at 400 r / min for 6 h at 30°C.

[0076] (4) Centrifuge the system obtained in step (3) at 10000 r / min for 14 min. Wash the precipitate with anhydrous ethanol 4 times. After each washing, centrifuge at 8000 r / min for 8 min. Place the washed precipitate in a vacuum drying oven and dry it at 60℃ and vacuum degree -0.09MPa for 14 h to obtain zwitterionic nano-hybrid stabilizer.

[0077] This embodiment also discloses a method for preparing a hydrophilic-lipophilic balanced coal-water slurry additive, comprising the following steps:

[0078] S1. Weigh out the gemini polyether modified naphthalene sulfonate, zwitterionic nano-hybrid stabilizer and polycarboxylic acid dispersant according to the proportion, add 70% of the total weight of deionized water, and stir at 600 r / min at 50℃ for 40 min to obtain a premixed dispersion system.

[0079] S2. Add sodium lignosulfonate and chelating agent to the premixed dispersion system, heat to 60℃, and stir at 400r / min for 30min.

[0080] S3. Maintain the system obtained in step S2 at 60°C, add the biopolysaccharide rheology modifier, and stir at 700 r / min for 60 min.

[0081] S4. Add low-temperature flow improver, pH adjuster and remaining deionized water to the system obtained in step S3, and stir at 400 r / min for 30 min.

[0082] S5. Adjust the pH of the system to 9.5 using a 30% sodium hydroxide solution or a 20% hydrochloric acid solution, stir at 300 r / min for 20 min, and vacuum filter using a 1.0 μm microporous membrane to remove mechanical impurities and insoluble matter from the system, thus obtaining a hydrophilic-lipophilic balanced coal-water slurry additive.

[0083] This embodiment also discloses the application of a hydrophilic-lipophilic balanced coal-water slurry additive in the preparation of coal-water slurry, wherein the amount of additive is 1.2% of the dry coal mass.

[0084] Example 3:

[0085] This embodiment discloses a hydrophilic-lipophilic balanced coal-water slurry additive. By weight, its preparation raw materials include: 23 parts of gemini-type polyether-modified naphthalene sulfonate, 7 parts of zwitterionic nano-hybrid stabilizer, 16 parts of sodium lignosulfonate with a number-average molecular weight of 6500 Da, 9 parts of polycarboxylic acid-based dispersant, 2.5 parts of biopolysaccharide rheology modifier, 13 parts of low-temperature flowability improver, 3 parts of pH adjuster, 3.5 parts of chelating agent, and 44 parts of deionized water. The biopolysaccharide rheology modifier is styrene, the low-temperature flowability improver is ethylene glycol, the pH adjuster is triethanolamine, and the chelating agent is sodium gluconate.

[0086] The raw materials for preparing the Gemini polyether modified naphthalene sulfonate, by weight, include: 25 parts industrial naphthalene, 30 parts concentrated sulfuric acid, 10 parts formaldehyde aqueous solution with a mass fraction of 36%, 30 parts polyether amine, and 0.4 parts p-toluenesulfonic acid.

[0087] The preparation method of gemini polyether modified naphthalene sulfonate includes the following steps:

[0088] 1) Add industrial naphthalene and concentrated sulfuric acid to the reactor, heat to 105℃, and stir at 250 r / min for 2.5 h;

[0089] 2) Cool the reaction system obtained in step 1) to 85°C, stir continuously at 250 r / min, and add formaldehyde aqueous solution dropwise at a uniform rate over 32 min. After the addition is complete, keep the reaction at 85°C for 2 h.

[0090] 3) Cool the reaction system obtained in step 2) to 45°C, add polyetheramine and p-toluenesulfonic acid, heat to 115°C under nitrogen protection, stir at 200 r / min for 3.5 h, cool to 28°C, adjust the pH to 8.5 with 27% sodium hydroxide solution, stir until the system is homogeneous, and obtain a gemini polyether modified naphthalene sulfonate with a number average molecular weight of 3000 Da and a sulfonation degree of 1.6 mmol / g.

[0091] The raw materials for preparing the zwitterionic nano-hybrid stabilizer, by weight, include: 6.5 parts of nano-magnesium-aluminum layered double hydroxide, 90 parts of anhydrous ethanol, 4 parts of 3-[(2-aminoethyl)amino]propyltrimethoxysilane, and 2.5 parts of sodium 3-chloro-2-hydroxypropanesulfonate. The average particle size of the nano-magnesium-aluminum layered double hydroxide is 75 nm, and the molar ratio of magnesium to aluminum is 2.5:1.

[0092] The preparation method of zwitterionic nano-hybrid stabilizers includes the following steps:

[0093] (1) The nano-magnesium aluminum layered double hydroxide was dispersed in anhydrous ethanol, stirred at 175 r / min for 12 min at 27 °C, and then ultrasonically dispersed for 35 min at 350 W power and 22 kHz frequency to obtain a uniform dispersion.

[0094] (2) Add 3-[(2-aminoethyl)amino]propyltrimethoxysilane to the dispersion obtained in step (1), heat to 65°C, and stir at 450 r / min for 7 h.

[0095] (3) Add sodium 3-chloro-2-hydroxypropanesulfonate to the reaction system obtained in step (2), heat to 75°C, adjust the pH to 9.1 with sodium hydroxide solution with a mass fraction of 28%, and stir the reaction at 350 r / min at 28°C for 5 h.

[0096] (4) Centrifuge the system obtained in step (3) at 9000 r / min for 12 min. Wash the precipitate with anhydrous ethanol 4 times. After each washing, centrifuge at 7000 r / min for 6 min. Place the washed precipitate in a vacuum drying oven and dry it at 55℃ and vacuum degree -0.085 MPa for 12 h to obtain zwitterionic nano-hybrid stabilizer.

[0097] This embodiment also discloses a method for preparing a hydrophilic-lipophilic balanced coal-water slurry additive, comprising the following steps:

[0098] S1. Weigh out the gemini polyether modified naphthalene sulfonate, zwitterionic nano-hybrid stabilizer and polycarboxylic acid dispersant according to the proportion, add 65% of the total weight of deionized water, and stir at 500 r / min for 35 min at 45℃ to obtain a premixed dispersion system.

[0099] S2. Add sodium lignosulfonate and chelating agent to the premixed dispersion system, heat to 55℃, and stir at 350r / min for 25min.

[0100] S3. Maintain the system obtained in step S2 at 55°C, add the biopolysaccharide rheology modifier, and stir at 600 r / min for 50 min.

[0101] S4. Add low-temperature flow improver, pH adjuster and remaining deionized water to the system obtained in step S3, and stir at 350 r / min for 25 min.

[0102] S5. Adjust the pH of the system to 9.0 using a 27% sodium hydroxide solution or a 15% hydrochloric acid solution, stir at 250 r / min for 17 min, and use a 0.7 μm microporous membrane for vacuum filtration to remove mechanical impurities and insoluble matter from the system, thus obtaining a hydrophilic-lipophilic balanced coal-water slurry additive.

[0103] This embodiment also discloses the application of a hydrophilic-lipophilic balanced coal-water slurry additive in the preparation of coal-water slurry, wherein the amount of additive is 0.8% of the dry coal mass.

[0104] Comparative Example 1:

[0105] A hydrophilic-lipophilic balanced coal-water slurry additive, its preparation method and application, differs from Example 3 only in that: the gemini polyether modified naphthalene sulfonate is not added, but is replaced by an equal amount of sodium naphthalene sulfonate formaldehyde condensate (purchased from Hubei Xinyuhong Biomedical Technology Co., Ltd., CAS: 26545-58-4, number average molecular weight of 4000 Da).

[0106] Comparative Example 2:

[0107] A hydrophilic-lipophilic balanced coal-water slurry additive, its preparation method, and its application, differs from Example 3 only in that: no zwitterionic nano-hybrid stabilizer is added; instead, an equal amount of fumed silica nanoparticles (purchased from Evonik Specialty Chemicals (Shanghai) Co., Ltd., model AEROSIL R974, specific surface area 200±25m²) are added. 2 / g).

[0108] Comparative Example 3:

[0109] A hydrophilic-lipophilic balanced coal-water slurry additive, its preparation method and application, differs from Example 3 only in that: no biopolysaccharide rheology modifier is added.

[0110] Comparative Example 4:

[0111] A hydrophilic-lipophilic balanced coal-water slurry additive, its preparation method and application, differs from Example 3 only in that: no low-temperature flowability improver is added.

[0112] Comparative Example 5:

[0113] A hydrophilic-lipophilic balanced coal-water slurry additive, its preparation method and application, differs from Example 3 only in that the pH adjuster is replaced with an equal amount of 30% sodium hydroxide solution.

[0114] Comparative Example 6:

[0115] A hydrophilic and oleophilic balanced coal-water slurry additive, its preparation method and application, differs from Example 3 only in that the stirring temperature in step S1 is changed from 45°C to 85°C.

[0116] Comparative Example 7:

[0117] A hydrophilic-lipophilic balanced coal-water slurry additive, its preparation method and application, differs from Example 3 only in that sodium lignosulfonate is not added.

[0118] Comparative Example 8:

[0119] A hydrophilic-lipophilic balanced coal-water slurry additive, its preparation method and application, differs from Example 3 only in that no chelating agent is added.

[0120] Comparative Example 9:

[0121] A hydrophilic-lipophilic balanced coal-water slurry additive, its preparation method and application, differs from Example 3 only in that the low-temperature flowability improver is replaced by an equal amount of ethylene glycol with 1,2-propanediol (99% purity, purchased from Jinan Renyuan Chemical Co., Ltd., CAS: 57-55-6).

[0122] The coal-water slurry additives obtained in Examples 1-3 and Comparative Examples 1-9 were used to prepare coal-water slurry according to the following methods and their relevant performance was tested.

[0123] (I) Method for preparing coal-water slurry

[0124] Using bituminous coal from Yulin, Shaanxi Province, the industrial analysis results are as follows: air-dried basis moisture content M a d=1.45%, air-dried basis volatile matter V a d=28.35%, air-dried ash content A ad=9.65%, air-dried fixed carbon FC a d=60.55%; and Jincheng anthracite, M a d=2.85%, V a d=8.20%, A a d=16.50%, FC a d=72.45%. The fineness of the coal powder is controlled to be -200 mesh ≥75%. According to the mass ratio of coal powder:water:additive=70:29.2:0.8, the coal-water slurry is prepared by stirring at 1000 r / min for 20 min in a high-speed mixer, and then set aside for 10 min to remove foam.

[0125] (ii) Determination of pulp concentration

[0126] The test was performed according to GB / T 18856.2-2008, "Test Methods for Coal-Water Slurry – Part 2: Determination of Concentration". The drying method was employed, with the coal-water slurry sample placed in a drying oven at 105±2℃ and dried to constant weight. The concentration was calculated based on the mass difference.

[0127] Calculation formula:

[0128] C = m1 / m0 × 100%

[0129] In the formula: C is the concentration of coal-water slurry, %; m0 is the mass of coal-water slurry sample, g; m1 is the mass of dried coal powder, g.

[0130] (III) Apparent viscosity determination

[0131] The test was performed according to GB / T 18856.4-2008, "Test Methods for Coal-Water Slurry – Part 4: Determination of Apparent Viscosity". An NXS-4C rotational viscometer was used, with a shear rate of 100 s⁻¹. -1 Measurements were taken at temperatures of 25℃ and -5℃.

[0132] (iv) Stability determination (water separation rate)

[0133] The procedure was performed according to GB / T 18856.5-2008 Test Methods for Coal-Water Slurry – Part 5: Determination of Stability. The prepared coal-water slurry was placed in a 100 mL stoppered graduated cylinder and allowed to stand for 7 days and 30 days, respectively. The percentage of precipitated water in the total slurry volume was then measured.

[0134] Calculation formula:

[0135] Water separation rate (%) = V1 / V0 × 100%

[0136] In the formula: V0 is the total volume of coal-water slurry, mL; V1 is the volume of precipitated water, mL.

[0137] (v) Low-temperature fluidity test

[0138] Place a 200 mL sample of additive in a -15℃ environment and let it stand for 48 hours. Observe whether crystallization, layering, or obvious thickening occurs.

[0139] Rating criteria:

[0140] Advantages: Maintains a homogeneous fluid state, no crystallization, and can flow freely;

[0141] Good: Slightly thickened but still flowable, no crystallization;

[0142] Poor: Crystallization or solidification occurs, or there is obvious stratification.

[0143] (vi) Determination of inorganic salt content

[0144] The sodium sulfate and total sodium ion content were determined according to GB / T 8077-2012 Test Method for Homogeneity of Concrete Admixtures, and converted to the total inorganic salt content.

[0145] (vii) Tank sedimentation test

[0146] The additive was left to stand in a 50L simulated storage tank for 60 days, and samples were taken from the bottom to determine the mass fraction of the precipitate.

[0147] Calculation formula:

[0148] Sediment content (%) = m² / m³ × 100%

[0149] In the formula: m3 is the total mass of the bottom sample, g; m2 is the mass of the precipitate, g.

[0150] (viii) Coal type adaptability test

[0151] The highest slurry concentration of Jincheng anthracite was determined under the same additive dosage (0.8% of dry coal mass) and viscosity ≤1200 mPa·s.

[0152] (ix) Liquidity rating assessment

[0153] The prepared coal-water slurry was placed in a 25℃ constant temperature water bath for 30 min, then poured into a 500 mL standard beaker to the mark. The beaker was tilted at 45° on a horizontal table, and the flow of the slurry from the mouth was observed. The rating criteria are defined as follows:

[0154] Grade A: The slurry flows out in a continuous band, with smooth and uninterrupted flow, and no cracks or accumulations on the surface;

[0155] Grade B: The slurry flows intermittently as drips or in thin streams, with slight stagnation, but can eventually be completely poured out;

[0156] Grade C: The slurry is almost non-flowing, or only exhibits localized creep at the edges, failing to form a continuous outflow. Three parallel samples were tested in each group, and the grade with the highest frequency was taken as the final result.

[0157] The test results are shown in Tables 2 and 3.

[0158] Table 2. Test results of basic properties of coal-water slurry (using Yulin bituminous coal as raw material)

[0159] Group Pulp concentration (wt%) Viscosity at 25℃ (mPa·s) Viscosity at -5℃ (mPa·s) 7-day water separation rate (%) 30-day water separation rate (%) Liquidity rating (25°C) Example 1 68.5 812 1056 2.5 4.2 Grade A Example 2 69.8 768 985 2.0 3.5 Grade A Example 3 70.8 745 968 1.8 3.2 Grade A Comparative Example 1 66.2 1180 1520 5.5 8.8 Grade B Comparative Example 2 70.5 760 972 6.2 9.5 Grade A Comparative Example 3 70.6 738 955 8.5 12.3 Grade A Comparative Example 4 70.7 748 1285 1.9 3.4 Grade A Comparative Example 5 69.5 820 995 2.6 4.5 Grade A Comparative Example 6 67.5 985 1245 3.2 5.8 Grade B Comparative Example 7 69.2 792 1025 3.5 5.5 Grade A Comparative Example 8 70.1 758 975 3.2 5.2 Grade A Comparative Example 9 70.6 752 1150 1.9 3.3 Grade A

[0160] Table 3. Test results of additive intrinsic properties and environmental performance.

[0161] Group -15℃ fluidity Inorganic salt content (wt%) 60-day sediment content (wt%) in storage tank Jincheng anthracite slurry concentration (wt%) Example 1 excellent 0.48 0.06 64.2 Example 2 excellent 0.45 0.04 65.0 Example 3 excellent 0.42 0.03 65.8 Comparative Example 1 Difference 2.85 0.15 60.5 Comparative Example 2 excellent 0.38 0.25 65.5 Comparative Example 3 excellent 0.40 0.75 65.6 Comparative Example 4 good 0.41 0.05 65.7 Comparative Example 5 excellent 1.95 0.04 64.8 Comparative Example 6 excellent 0.46 0.08 64.5 Comparative Example 7 excellent 0.35 0.06 64.8 Comparative Example 8 excellent 0.43 0.05 65.2 Comparative Example 9 good 0.44 0.04 65.6

[0162] Using Example 3 as the control group, the performance differences and causes of Comparative Examples 1-9 are analyzed as follows:

[0163] Comparative Example 1: Without the addition of gemini polyether-modified naphthalene sulfonate, an equal amount was replaced with sodium naphthalene sulfonate formaldehyde condensate.

[0164] The slurry concentration decreased from 70.8 wt% to 66.2 wt%, a decrease of 6.5%; the viscosity at 25℃ increased from 745 mPa·s to 1180 mPa·s, an increase of 58.4%; the viscosity at -5℃ increased from 968 mPa·s to 1520 mPa·s, an increase of 57.0%; the 7-day water separation rate increased from 1.8% to 5.5%, an increase of 205.6%; the 30-day water separation rate increased from 3.2% to 8.8%, an increase of 175.0%; the flowability rating at -15℃ decreased from excellent to poor; the inorganic salt content increased from 0.42 wt% to 2.85 wt%, an increase of 578.6%; the 60-day sediment content in the storage tank increased from 0.03 wt% to 0.15 wt%, an increase of 400.0%; the slurry concentration of Jincheng anthracite decreased from 65.8 wt% to 60.5 wt%, a decrease of 8.1%, and the flowability rating decreased from A to B. Gemini polyether-modified naphthalene sulfonate, as the core dispersing component, can form a high-density adsorption layer on the surface of coal particles due to its twin structure. The flexible steric hindrance effect of the polyether segments is far superior to that of traditional single-chain naphthalene sulfonates, and it can form a hydrogen bond network with low-temperature flowability improvers to disrupt the regular arrangement of water molecules. In contrast, commercially available sodium naphthalene sulfonate formaldehyde condensate has a regular molecular structure, is prone to crystallization at low temperatures, and has weak adsorption density and steric hindrance effect, making it unable to achieve efficient dispersion. After this component is replaced, the dispersed adsorption layer on the surface of coal particles is not dense, and the tendency for particle aggregation is enhanced, resulting in a significant decrease in slurry concentration and a substantial increase in viscosity. The molecular regularity leads to crystallization at low temperatures, causing flowability failure at -15℃, and making pipelines and storage tanks prone to crystallization blockage. At the same time, traditional naphthalene sulfonates rely on inorganic salts to improve dispersion stability, resulting in a sharp increase in the inorganic salt content of the system, poor surface compatibility with different coal types, and a significant decrease in the slurry concentration of anthracite.

[0165] Comparative Example 2: No zwitterionic nano-hybrid stabilizer was added; instead, fumed silica nanoparticles were used.

[0166] The slurry concentration decreased from 70.8 wt% to 70.5 wt%, a decrease of 0.4%; the viscosity at 25℃ increased from 745 mPa·s to 760 mPa·s, an increase of 2.0%; the viscosity at -5℃ increased from 968 mPa·s to 972 mPa·s, an increase of 0.4%; the 7-day water separation rate increased from 1.8% to 6.2%, an increase of 244.4%; the 30-day water separation rate increased from 3.2% to 9.5%, an increase of 196.9%; the 60-day sediment content in the storage tank increased from 0.03 wt% to 0.25 wt%, an increase of 733.3%; other indicators remained unchanged. Amphoteric nano-hybrid stabilizers are the key stabilizing components. The zwitterionic segments grafted onto their surfaces can adaptively adjust their charge properties, forming dynamic electrostatic repulsion on the coal particle surface. Their nanoscale layered structure constructs a three-dimensional physical network, hindering coal particle sedimentation and synergistically achieving ionic stability in conjunction with chelating agents. In contrast, fumed silica nanoparticles lack charge-adaptive properties and can only provide weak steric hindrance, failing to form a dynamically stable adsorption layer and physical network. After this component replacement, the core dispersion function remained unaffected, resulting in no significant changes in dispersion-related indicators such as slurry concentration and viscosity. However, the long-term stable physical network and dynamic electrostatic repulsion disappeared, making coal particles prone to sedimentation and flocculation during settling. This led to a sharp increase in water separation rate and tank sediment content, significantly reducing long-term storage stability.

[0167] Comparative Example 3: No biopolysaccharide rheology modifier added

[0168] The slurry concentration decreased from 70.8 wt% to 70.6 wt%, a decrease of 0.3%; the viscosity at 25℃ decreased from 745 mPa·s to 738 mPa·s, a decrease of 0.9%; the viscosity at -5℃ decreased from 968 mPa·s to 955 mPa·s, a decrease of 1.3%; the 7-day water separation rate increased from 1.8% to 8.5%, an increase of 372.2%; the 30-day water separation rate increased from 3.2% to 12.3%, an increase of 284.4%; the 60-day sediment content in the storage tank increased from 0.03 wt% to 0.75 wt%, an increase of 2400%; other indicators remained unchanged. Biopolysaccharide rheology modifiers are the core components for thixotropic regulation. They can form a weak hydrogen bond network between molecules, generating high yield stress when static to prevent hard sedimentation of coal particles. When sheared, the network is destroyed, causing a rapid decrease in viscosity and restoring fluidity. Without this component, the system lacks a thixotropic regulation mechanism. Dispersion-related slurry concentration and viscosity are slightly optimized due to the lack of thickening effect, but under static conditions, coal particles lose the support of the weak network structure and rapidly settle and stratify under gravity. As a result, the water separation rate and the content of sediment in the storage tank increase sharply, and the stability during medium- and long-term storage is severely deteriorated, failing to meet the requirements for industrial storage.

[0169] Comparative Example 4: No low-temperature flowability improver added

[0170] The slurry concentration decreased from 70.8 wt% to 70.7 wt%, a decrease of 0.1%; the viscosity at 25℃ increased from 745 mPa·s to 748 mPa·s, an increase of 0.4%; the viscosity at -5℃ increased from 968 mPa·s to 1285 mPa·s, an increase of 32.7%; the flowability rating at -15℃ decreased from excellent to good; other indicators remained unchanged. The low-temperature flowability improver and the polyether segments of the gemini polyether modified naphthalene sulfonate form a synergistic anti-crystallization function at low temperatures. The two can form a network through intermolecular hydrogen bonds, disrupting the regular arrangement of water molecules, inhibiting ice crystal formation, and lowering the freezing point of the system to below -20℃. The dispersion and stabilization functions at room temperature were not affected after the absence of this component, so the slurry concentration, room temperature viscosity, and water separation rate did not change significantly. However, the polyether segments lacked the synergistic effect of hydrogen bonds, and water molecules easily formed regular crystal forms at low temperatures, resulting in a significant increase in system viscosity, slight thickening at -15℃, and a decrease in low-temperature flowability, which could not meet the transportation requirements of low-temperature environments in winter.

[0171] Comparative Example 5: The pH adjuster was replaced with an equal volume of 30% sodium hydroxide solution.

[0172] The slurry concentration decreased from 70.8 wt% to 69.5 wt%, a decrease of 1.8%; the viscosity at 25℃ increased from 745 mPa·s to 820 mPa·s, an increase of 10.1%; the viscosity at -5℃ increased from 968 mPa·s to 995 mPa·s, an increase of 2.8%; the 7-day water separation rate increased from 1.8% to 2.6%, an increase of 44.4%; the 30-day water separation rate increased from 3.2% to 4.5%, an increase of 40.6%; the inorganic salt content increased from 0.42 wt% to 1.95 wt%, an increase of 364.3%; the slurry concentration of Jincheng anthracite decreased from 65.8 wt% to 64.8 wt%, a decrease of 1.5%; other indicators remained unchanged. Coal particles contain polar groups such as hydroxyl and carboxyl groups on their surface, which form intermolecular hydrogen bonds with the hydroxyl groups in the pH adjuster, increasing the adsorption sites of the dispersed components on the coal particle surface without introducing additional sodium ions. However, sodium hydroxide is an inorganic base, and adjusting the pH introduces a large amount of sodium ions, leading to a sharp increase in the inorganic salt content of the system. Sodium ions also exert a charge shielding effect on the anionic dispersant, weakening the adsorption strength of the dispersant on the coal particle surface and the electrostatic repulsion it generates. After replacing the pH adjuster with an equal amount of 30% sodium hydroxide solution, the adsorption strength of the dispersant decreases, the stability of the adsorption layer on the coal particle surface decreases, resulting in a slight decrease in slurry concentration, a slight increase in viscosity, and a slight increase in water separation rate. The charge shielding effect of sodium ions also reduces the surface compatibility with anthracite, causing a slight decrease in the anthracite slurry concentration. At the same time, the introduction of a large amount of sodium ions leads to a significant increase in the inorganic salt content, increasing the wastewater treatment load.

[0173] Comparative Example 6: The stirring temperature in step S1 was changed from 45℃ to 85℃.

[0174] The slurry concentration decreased from 70.8 wt% to 67.5 wt%, a decrease of 4.7%; the viscosity at 25℃ increased from 745 mPa·s to 985 mPa·s, an increase of 32.2%; the viscosity at -5℃ increased from 968 mPa·s to 1245 mPa·s, an increase of 28.6%; the 7-day water separation rate increased from 1.8% to 3.2%, an increase of 77.8%; the 30-day water separation rate increased from 3.2% to 5.8%, an increase of 81.3%; the 60-day sediment content in the storage tank increased from 0.03 wt% to 0.08 wt%, an increase of 166.7%; the slurry concentration of Jincheng anthracite decreased from 65.8 wt% to 64.5 wt%, a decrease of 2.0%; the fluidity rating decreased from A to B; other indicators remained unchanged. Step S1 is the premixing and dispersion stage of the core dispersing component and the stabilizing component. A mild temperature of 40-50℃ is beneficial to protect the activity of the components. The polyether segments of the gemini-type polyether modified naphthalene sulfonate are prone to oxidative degradation at high temperatures. The organic graft layer on the surface of the zwitterionic nano-hybrid stabilizer may partially detach at 85℃. The organic graft layer is a reaction product of silane coupling agent and sodium 3-chloro-2-hydroxypropanesulfonate, which is prone to hydrolysis at 85℃, leading to the detachment of the graft layer and loss of zwitterionic properties. After high-temperature premixing, the adsorption and steric hindrance effects of the dispersing component decrease, and the charge self-adaptation and physical network construction ability of the stabilizing component weaken. Therefore, the dispersion efficiency of the system decreases, the slurry concentration decreases, the viscosity increases, the stability is slightly weakened, the water separation rate and sediment content increase slightly, and the coal type adaptability also decreases slightly.

[0175] Comparative Example 7: No sodium lignosulfonate added

[0176] The slurry concentration decreased from 70.8 wt% to 69.2 wt%, a decrease of 2.3%; the viscosity at 25℃ increased from 745 mPa·s to 792 mPa·s, an increase of 6.3%; the viscosity at -5℃ increased from 968 mPa·s to 1025 mPa·s, an increase of 5.9%; the 7-day water separation rate increased from 1.8% to 3.5%, an increase of 94.4%; the 30-day water separation rate increased from 3.2% to 5.5%, an increase of 71.9%; the slurry concentration of Jincheng anthracite decreased from 65.8 wt% to 64.8 wt%, a decrease of 1.5%; other indicators remained unchanged. Sodium lignosulfonate serves as an auxiliary dispersant. Its low molecular weight allows for excellent low-temperature solubility, enabling it to rapidly adsorb at different energy sites on the surface of coal particles. It competes with the adsorption of gemini-type polyether-modified naphthalene sulfonate, achieving comprehensive coverage of the coal particle surface. When this component is missing, some adsorption sites on the coal particle surface are not covered by the dispersant, forming local agglomeration sites. The adsorption coverage efficiency of the core dispersant decreases, resulting in a slight weakening of dispersion performance, a slight decrease in slurry concentration, a slight increase in viscosity, and a slight increase in water separation rate due to local agglomeration. The surface coverage adaptability for anthracite is also slightly reduced.

[0177] Comparative Example 8: No chelating agent added

[0178] The slurry concentration decreased from 70.8 wt% to 70.1 wt%, a decrease of 1.0%; the viscosity at 25℃ increased from 745 mPa·s to 758 mPa·s, an increase of 1.7%; the viscosity at -5℃ increased from 968 mPa·s to 975 mPa·s, an increase of 0.7%; the 7-day water separation rate increased from 1.8% to 3.2%, an increase of 77.8%; the 30-day water separation rate increased from 3.2% to 5.2%, an increase of 62.5%; the slurry concentration of Jincheng anthracite decreased from 65.8 wt% to 65.2 wt%, a decrease of 0.9%; other indicators showed no significant changes. The chelating agent can chelate high-valence metal ions such as calcium and magnesium ions in coal slurry and water, eliminating the charge shielding effect of these metal ions on the anionic dispersant; after the absence of this component, the high-valence metal ions (Ca...) in the system... 2+ Mg 2+ The chelating agent forms ionic bonds with the sulfonic acid and carboxyl groups of the anionic dispersant, causing the dispersant molecules to aggregate, reducing its solubility in the aqueous phase and the amount of adsorption on the surface of coal particles, and slightly weakening the dispersion stability. Therefore, the various indicators of the system only change slightly, without significant failure, indicating that the chelating agent is an auxiliary optimization component and has no decisive impact on the core performance, but it can improve the efficiency of dispersion stability.

[0179] Comparative Example 9: The low-temperature flowability improver was replaced by an equal amount of 1,2-propanediol instead of ethylene glycol.

[0180] The slurry concentration decreased from 70.8 wt% to 70.6 wt%, a decrease of 0.3%; the viscosity at 25℃ increased from 745 mPa·s to 752 mPa·s, an increase of 0.9%; the viscosity at -5℃ increased from 968 mPa·s to 1150 mPa·s, an increase of 18.8%; the flowability rating at -15℃ decreased from excellent to good; the slurry concentration of Jincheng anthracite decreased from 65.8 wt% to 65.6 wt%, a decrease of 0.3%; other indicators remained unchanged. The core function of the low-temperature flowability improver is to form a hydrogen bond network with the polyether segments of the gemini-type polyether modified naphthalene sulfonate. The hydroxyl spacing in the molecular structure of ethylene glycol matches the hydroxyl groups of the polyether segments best, resulting in the strongest hydrogen bond bonding ability. However, due to the steric hindrance effect of the methyl group in the 1,2-propanediol molecule, which is a hydrophobic group, the probability of hydrogen bond bonding with the hydroxyl groups of the polyether segments is reduced. At the same time, the steric hindrance hinders the formation of the hydrogen bond network and cannot effectively disrupt the regular arrangement of water molecules. After replacing ethylene glycol with 1,2-propanediol in equal amounts, the dispersion and stabilization functions at room temperature were not affected, so the slurry concentration, room temperature viscosity, and water separation rate did not change significantly. However, the formation efficiency of hydrogen bond networks decreased at low temperatures, and the regular arrangement of water molecules could not be effectively destroyed, resulting in a slight increase in low-temperature viscosity, slight turbidity at -15℃, and a slight decrease in low-temperature fluidity.

[0181] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A hydrophile-lipophile balance type coal water slurry additive, characterized by, The preparation raw materials of the gemini polyether modified naphthalene sulfonate by weight parts include: 18-28 parts of gemini polyether modified naphthalene sulfonate, 4-10 parts of zwitterionic nano hybrid stabilizer, 12-20 parts of sodium lignosulfonate, 6-12 parts of polycarboxylic acid dispersing aid, 1.5-4 parts of biological polysaccharide rheological modifier, 10-16 parts of low temperature fluidity improver, 2-4 parts of pH regulator, 2-5 parts of chelating aid, and 35-50 parts of deionized water.

2. The hydrophile-lipophile balance type coal water slurry additive according to claim 1, characterized by, The number average molecular weight of the sodium lignosulfonate is 5000-8000 Da, the biological polysaccharide rheological modifier is one or more of xanthan gum, xanthan gum, and arabic gum, the low temperature fluidity improver is one or more of ethylene glycol and diethylene glycol, the pH regulator is one or more of triethanolamine, diethanolamine, and mono-isopropanolamine, and the chelating aid is one or more of sodium gluconate, trisodium citrate, and disodium ethylenediaminetetraacetate.

3. The hydrophile-lipophile balance type coal water slurry additive according to claim 1, characterized by, The preparation raw materials of the gemini polyether modified naphthalene sulfonate by weight parts include: 20-30 parts of industrial naphthalene, 25-35 parts of concentrated sulfuric acid, 8-12 parts of 35%-37% mass fraction formaldehyde aqueous solution, 25-35 parts of polyether amine, and 0.3-0.5 parts of p-toluenesulfonic acid.

4. The hydrophile-lipophile balance type coal water slurry additive according to claim 3, characterized by, The preparation method of the gemini polyether modified naphthalene sulfonate includes the following steps: 1) industrial naphthalene and concentrated sulfuric acid are added to a reaction kettle, the temperature is raised to 100-110℃, and the reaction is stirred at a speed of 200-300r / min for 2-3h; 2) the reaction system obtained in step 1) is cooled to 80-90℃, the stirring is continuously carried out at a speed of 200-300r / min, the formaldehyde aqueous solution is added at a uniform speed within 30-35min, after the addition is completed, the reaction is carried out at 80-90℃ for 1.5-2.5h; 3) the reaction system obtained in step 2) is cooled to 40-50℃, the polyether amine and p-toluenesulfonic acid are added, the temperature is raised to 110-120℃ under nitrogen protection, the reaction is stirred at a speed of 150-250r / min for 3-4h, after the temperature is lowered to 25-30℃, the pH is adjusted to 8.0-9.0 by using 25%-30% mass fraction sodium hydroxide solution, and the gemini polyether modified naphthalene sulfonate is obtained.

5. The hydrophile-lipophile balanced coal water slurry additive according to claim 4, characterized by, The number average molecular weight of the gemini polyether modified naphthalene sulfonate is 2000-4000 Da, and the sulfonation degree is 1.4-1.8mmol / g.

6. The hydrophile-lipophile balanced coal water slurry additive according to claim 1, characterized by, The preparation raw materials of the zwitterionic nano hybrid stabilizer by weight parts include: 5-8 parts of nano magnesium aluminum layered double hydroxide, 80-100 parts of anhydrous ethanol, 3-5 parts of 3-[(2-aminoethyl)amino]propyl trimethoxysilane, and 2-3 parts of 3-chloro-2-hydroxypropanesulfonic acid sodium.

7. The hydrophile-lipophile balanced coal water slurry additive according to claim 6, characterized by, The average particle size of the nano magnesium aluminum layered double hydroxide is 50-100nm, and the molar ratio of magnesium to aluminum is (2-3):

1.

8. The hydrophile-lipophile balance coal water slurry additive according to claim 7, characterized by, The preparation method of the zwitterionic nano hybrid stabilizer includes the following steps: (1) dispersing the nano magnesium aluminum layered double hydroxide in anhydrous ethanol, stirring at a speed of 150-200 r / min for 10-15 min at 25-30℃, and then ultrasonic dispersing for 30-40 min under the conditions of power 300-400 W and frequency 20-25 kHz to obtain a uniformly dispersed solution; (2) adding 3-[(2-aminoethyl)amino]propyl trimethoxysilane to the dispersed solution obtained in step (1), and stirring at a speed of 400-500 r / min for 6-8 h while heating to 60-70℃; (3) adding 3-chloro-2-hydroxypropanesulfonic acid sodium to the reaction system obtained in step (2), and stirring at a speed of 300-400 r / min for 4-6 h while heating to 70-80℃ and adjusting the pH to 8.8-9.5 with a 25%-30% by mass sodium hydroxide solution; (4) centrifuging the system obtained in step (3) at a speed of 8000-10000 r / min for 10-14 min, washing the precipitate with anhydrous ethanol for 3-4 times, centrifuging at a speed of 6000-8000 r / min for 5-8 min after each washing, and drying the washed precipitate in a vacuum drying oven under the conditions of 50-60℃ and a vacuum degree of -0.08 MPa to -0.09 MPa for 10-14 h to obtain the amphoteric nano hybrid stabilizer.

9. A process for the preparation of hydrophile-lipophile balance coal water slurry additive according to any one of claims 1 to 8, characterized in that, The method comprises the following steps: S1. weighing the gemini polyether modified naphthalene sulfonate, the amphoteric nano hybrid stabilizer and the polycarboxylic acid dispersing aid according to the proportion, adding deionized water accounting for 60%-70% of the total weight of the deionized water, and stirring at a speed of 400-600 r / min for 30-40 min at 40-50℃ to obtain a premixed dispersion system; S2. adding the sodium lignosulfonate and the chelating aid to the premixed dispersion system, heating to 50-60℃, and stirring at a speed of 300-400 r / min for 20-30 min; S3. maintaining the system obtained in step S2 at 50-60℃, adding the biological polysaccharide rheological modifier, and stirring at a speed of 500-700 r / min for 40-60 min; S4. adding the low-temperature flowability improver, the pH regulator and the remaining deionized water to the system obtained in step S3, and stirring at a speed of 300-400 r / min for 20-30 min; S5. adjusting the pH of the system to 8.5-9.5, stirring at a speed of 200-300 r / min for 15-20 min, and performing vacuum filtration with a microporous filter membrane having a pore size of 0.5-1.0 μm to obtain the hydrophile-lipophile balance water coal slurry additive.

10. Application of the hydrophile-lipophile balance water coal slurry additive according to any one of claims 1-8 in the preparation of water coal slurry, and the amount of the additive is 0.6%-1.2% of the mass of dry coal.