Special coal water slurry additive for water-insoluble inorganic waste doped waste coal slurry containing silane coupling agent

Abstract

The invention relates to a silane-coupling-agent-containing water-coal-slurry additive special for water-insoluble inorganic waste doped waste coal slurry, which comprises a silane coupling agent and a compound, the compound is one or more of sodium lignin sulfonate, a sodium naphthalene sulfonate formaldehyde condensate and a sulfonated acetone-formaldehyde condensate, the weight percentage of the silane coupling agent is 50-90%, the weight percentage of the compound is 50-90%, and the weight percentage of the compound is 50-90%. The weight percentage of the compound is 10%-50%. The coal water slurry additive, the silane coupling agent and the compound have an excellent compounding synergistic effect, the surface tension of inorganic matrix activated carbon can be improved and is larger than the surface tension of organic matrix coal particles, infiltration and expansion of the activated carbon on the surfaces of the coal particles are facilitated, the wetting capacity between matrixes is improved, and the corrosion resistance of the coal water slurry is improved. And the two base materials are well combined together. Meanwhile, the silane coupling agent can form a flexible deformation layer on an interface, so that the flowability and stability of the coal water slurry are effectively enhanced, the interface is broken when the slurry flows, the flowing is not influenced, and the interface is recovered after standing and the slurry is not easy to layer.

Description

Technical Field

[0001] This invention relates to the field of coal-water slurry additives, and in particular to a coal-water slurry additive specifically for non-water-soluble inorganic waste-mixed coal slurry containing a silane coupling agent. Background Technology

[0002] Coal-water slurry is a mixture of coal powder of a certain fineness, water, and coal-water slurry additives. It is a slurry-like coal product with certain stability and fluidity, and is widely used in coal chemical industries such as the synthesis of methanol, ammonia, olefins, fuel oil, and natural gas. Due to its significant technical and economic advantages such as high energy efficiency, low pollution, and low cost, coal-water slurry has become one of the key technologies for my country's clean coal strategy.

[0003] Coal is primarily a hydrophobic, nonpolar hydrocarbon. The role of coal-water slurry additives is to disperse coal powder in water to form a fluid, uniform, and stable slurry. Their dispersion mechanism mainly involves effective adsorption onto the surface of coal particles, increasing the hydrophilicity of the coal particles, and forming an electric double layer and steric hindrance on the coal particle surface. Coal-water slurry additives are broadly classified into two categories: anionic and nonionic surfactants. Considering factors such as performance, cost, and raw material availability, anionic coal-water slurry additives are more common. Currently, widely used additives on the market include lignin-based additives, such as alkali lignin and lignin sulfonates; naphthalene-based additives, such as naphthalene sulfonate formaldehyde condensates; aliphatic additives, such as sulfonated acetone-formaldehyde condensates; or mixtures of two or more of the above products.

[0004] With increasingly stringent national and local environmental protection laws and regulations, coal chemical enterprises have widely adopted the coal-water slurry co-firing process in recent years to fully utilize process waste, slag, and wastewater to reduce the amount of waste and wastewater requiring treatment, lower treatment and discharge pressures, and simultaneously reduce coal gasification production costs. The main co-firing materials added to the coal-water slurry include: waste activated carbon from chemical production, water purification, and gas purification industries; biochemical activated sludge from petrochemical enterprises; waste tar; coal-oil refining residue; as well as methanol-containing wastewater, flare condensate, shift condensate, and process condensate wastewater generated from coal chemical processes; aldehyde-containing wastewater; acetic acid residue; semi-coke powder; process oil residue; and other wastewater and slag from synthetic chemical processes, such as distillation residues, wastewater containing mineral oil, organic solvents or organic resins, and phenol-containing waste.

[0005] Water-coal slurry additives are surfactants. Their working principle involves utilizing the hydrophilic and hydrophobic groups in their molecules to orient themselves in aqueous solutions, altering the interfacial state of the solution system and significantly reducing its surface tension. Due to the complex composition of co-firing materials such as activated carbon, waste residue, and wastewater, their poor compatibility with the water-coal system significantly increases the difficulty of slurry preparation, resulting in lower coal slurry concentration, poor fluidity and stability, and severely reduced gasification efficiency. In particular, non-water-soluble inorganic wastes such as activated carbon, being inorganic themselves, are difficult to bind with the hydrophobic groups of additives like coal particles, and their non-water-soluble nature makes them difficult to bind with hydrophilic groups. Therefore, these wastes are difficult to disperse in the water-coal slurry system. To address this unfavorable operating condition, it is essential to select water-coal slurry additives that are fully adapted to this specific process to ensure the long-term, high-load, safe, and stable operation of the water-coal slurry co-firing preparation unit.

[0006] Silane coupling agents, also known as silane treatment agents, are a class of low-molecular-weight organosilicon compounds with a special structure containing two or more different reactive groups. Their molecular formula is generally R-Si-X3, where R is an organic functional group, such as oxygen, mercapto, vinyl, epoxy, amide, aminopropyl, etc.; and X is a hydrolyzable silaneoxy group, such as halogen, alkoxy, acyloxy, etc. Silane coupling agents are compounds that can enhance the affinity between inorganic and organic polymers. They can form chemical bonds between inorganic and organic materials, increasing the interfacial adhesion strength between different materials, improving the incompatibility between organic and inorganic substances, and playing a role in connection and modification. They have a significant effect on improving the dispersibility and interfacial bonding of materials in composite systems. The amount of silane coupling agent added is generally 1%-5% of the matrix. Relying on molecular diffusion, the coupling agent molecules migrate to the bonding interface to generate coupling. Currently, there are no reports on the application and research of silane coupling agents in the field of coal-water slurry additives.

[0007] Patent CN111575069A discloses a method for preparing a composite coal-water slurry additive. Specifically, it discloses mixing a template agent and a composite solvent in a specific mass ratio, adjusting the pH with ammonia, adding tetraethyl orthosilicate and a silane coupling agent, ultrasonically vibrating, adjusting the pH again, and heating. After heating, the mixture is allowed to stand, centrifuged, washed, dried, and the dried material is collected. The dried material, additive, and water are then ball-milled in a specific mass ratio, and the ball-milled mixture is collected. Based on weight, water, the ball-milled mixture, and the monomer are placed in a reaction vessel under nitrogen protection, stirred, preheated, and then... Add an initiator, heat, stir and react, cool to room temperature, discharge, spray dry, wash with ethanol, and collect the washings; mix the washings with papermaking black liquor by mass ratio, let stand, filter, and collect the filter residue; mix the filter residue, sodium hydroxide solution, and dispersant by mass ratio, add an auxiliary agent, heat, stir and mix, freeze dry, and collect the freeze-dried product; mix the freeze-dried product and water by mass ratio, add sodium thiosulfate, heat, cool, add formaldehyde, stir, adjust the pH, let stand, spray dry, and collect the spray-dried product to obtain the composite coal-water slurry additive.

[0008] In this scheme, the role of the silane coupling agent is to act as an auxiliary agent for porous particles, polymerize with acrylamide monomers to form a flocculant, and settle the black liquor of papermaking to obtain lignin. However, this scheme still cannot solve the problem of compatibility between non-water-soluble inorganic waste and coal-water slurry, especially the problem that non-water-soluble inorganic waste such as activated carbon is difficult to disperse in the coal-water slurry system. Summary of the Invention

[0009] The purpose of this invention is to address the problem that existing coal-water slurry additives described in the background art cannot solve the compatibility issue between non-water-soluble inorganic waste and coal-water slurry, and to provide a coal-water slurry additive specifically for non-water-soluble inorganic waste mixed with coal slurry containing a silane coupling agent.

[0010] To achieve the above objectives, the present invention provides the following technical solution: A water-coal slurry additive for non-water-soluble inorganic waste-mixed coal slurry containing a silane coupling agent, comprising a silane coupling agent and a compound, wherein the compound is one or more of sodium lignosulfonate, sodium naphthalenesulfonate formaldehyde condensate, and sulfonated acetone-formaldehyde condensate, wherein the weight percentage of the silane coupling agent is 50%-90%, and the weight percentage of the compound is 10%-50%.

[0011] In the above scheme, the silane coupling agent is an amino-based silane coupling agent, an epoxy-based silane coupling agent, a vinyl-based silane coupling agent, or a mercapto-based silane coupling agent.

[0012] In the above scheme, the amino-based silane coupling agent is KH550, KH792 or KH602; the epoxy-based silane coupling agent is KH560, KH570 or KH151; the vinyl-based silane coupling agent is A151 or A171; and the mercapto-based silane coupling agent is KH580 or KH590.

[0013] In the above scheme, the weight percentage of the silane coupling agent is 50%-75%, and the weight percentage of the compound is 25%-50%.

[0014] This invention has positive effects: the present invention is a water-coal slurry additive for non-water-soluble inorganic waste-mixed coal slurry containing silane coupling agent.

[0015] This invention utilizes the property of silane coupling agents to connect inorganic and organic matrices, providing a highly efficient method for developing a coal-water slurry additive specifically for non-water-soluble inorganic waste-blended coal slurry. It also offers the advantage of environmental friendliness. Non-water-soluble inorganic wastes such as activated carbon are difficult to combine with the hydrophobic and hydrophilic groups of ordinary coal-water slurry additives, making them difficult to disperse in coal-water slurry systems. Activated carbon surfaces possess various oxygen-containing functional groups, such as carboxyl groups, and these active sites provide the possibility of improving the dispersibility of activated carbon in coal particles. Silane coupling agents can enhance the interaction between activated carbon and coal particles, improving their dispersibility in coal particle systems. When silane coupling agents couple activated carbon to coal particles, the silane groups first undergo hydrolysis to generate silanetriols, releasing the byproduct alcohol. Then, the silane alcohol groups react with the hydroxyl groups on the surface of the inorganic activated carbon particles, forming hydrogen bonds and condensing into covalent bonds. At the same time, the silanol molecules of silane associate and aggregate to form a network structure film covering the surface of the powder particles, making the surface of the inorganic matrix organic, and then combining with the organic matrix coal particles to achieve the purpose of mixing and dispersion.

[0016] This invention also discloses the synergistic effect of a silane coupling agent combined with sodium lignosulfonate, and / or sodium naphthalenesulfonate formaldehyde condensate, and / or sulfonated acetone-formaldehyde condensate. The silane coupling agent can increase the surface tension of inorganic matrix activated carbon, even making it greater than the surface tension of organic matrix coal particles, thereby facilitating the wetting and spreading of activated carbon on the surface of coal particles, improving the wetting ability between the matrices, and enabling the two matrix materials to bond better together. Simultaneously, the silane coupling agent is plastic at the interface, forming a flexible deformable layer. When the modulus of this deformable layer is between that of the inorganic and organic matrices, stress can be uniformly transmitted, giving it the ability to self-heal when damaged. This not only relaxes the prestress at the interface but also prevents crack propagation and improves the bonding strength of the interface. This effectively enhances the fluidity and stability of the coal-water slurry, ensuring that interface breakage during slurry flow does not affect flow, and that the interface recovers after settling, preventing slurry delamination. The formulation of this invention is environmentally friendly, effectively reducing environmental pollution and fully meeting green and ecological protection requirements. Detailed Implementation

[0017] The technical solution of the present invention will be clearly and completely described below through embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] Example 1 A water-coal slurry additive for non-water-soluble inorganic waste-blended coal slurry containing a silane coupling agent is disclosed. The additive comprises a silane coupling agent and sodium lignosulfonate, with the silane coupling agent comprising 75% by weight and the sodium lignosulfonate comprising 25% by weight. The silane coupling agent and sodium lignosulfonate are stirred evenly in water at a specific mass ratio to obtain the water-coal slurry additive for non-water-soluble inorganic waste-blended coal slurry containing a silane coupling agent. The silane coupling agent used in this invention can be a common silane coupling agent, including but not limited to amino silane coupling agents KH550, KH792, and KH602; epoxy silane coupling agents KH560, KH570, and KH151; vinyl silane coupling agents A151 and A171; and mercapto silane coupling agents KH580 and KH590. In this embodiment, amino silane coupling agent KH550 can be used.

[0019] Example 2 A water-coal slurry additive for non-water-soluble inorganic waste-blended coal slurry containing a silane coupling agent is disclosed. The additive comprises a silane coupling agent and a sodium naphthalenesulfonate formaldehyde condensate. The silane coupling agent comprises 75% by weight, and the sodium naphthalenesulfonate formaldehyde condensate comprises 25% by weight. The silane coupling agent and the sodium naphthalenesulfonate formaldehyde condensate are stirred evenly in water at a specific mass ratio to obtain the water-coal slurry additive for non-water-soluble inorganic waste-blended coal slurry containing a silane coupling agent. In this embodiment, an epoxy-based silane coupling agent, KH560, can be used.

[0020] Example 3 A water-coal slurry additive for non-water-soluble inorganic waste-blended coal slurry containing a silane coupling agent is disclosed. The additive comprises a silane coupling agent and a sulfonated acetone-formaldehyde condensate. The silane coupling agent comprises 75% by weight, and the sulfonated acetone-formaldehyde condensate comprises 25% by weight. The silane coupling agent and the sulfonated acetone-formaldehyde condensate are stirred evenly in water at a specific mass ratio to obtain the water-coal slurry additive for non-water-soluble inorganic waste-blended coal slurry containing a silane coupling agent. In this embodiment, a vinyl silane coupling agent A151 can be used.

[0021] Example 4 A water-coal slurry additive for non-water-soluble inorganic waste-blended coal slurry containing a silane coupling agent is disclosed. The additive comprises a silane coupling agent, sodium lignosulfonate, and a sodium naphthalenesulfonate formaldehyde condensate. The weight percentages of the silane coupling agent, sodium lignosulfonate, and sodium naphthalenesulfonate formaldehyde condensate are 50%, 25%, and 25%, respectively. The silane coupling agent, sodium lignosulfonate, and sodium naphthalenesulfonate formaldehyde condensate are stirred evenly in water according to the specified mass ratio to obtain the water-coal slurry additive for non-water-soluble inorganic waste-blended coal slurry containing a silane coupling agent. In this embodiment, a mercapto-based silane coupling agent, KH580, can be used.

[0022] Example 5 A water-coal slurry additive for non-water-soluble inorganic waste-blended coal slurry containing a silane coupling agent is disclosed. The additive comprises a silane coupling agent, sodium lignosulfonate, and sulfonated acetone-formaldehyde condensate. The weight percentages of the silane coupling agent, sodium lignosulfonate, and sodium naphthalenesulfonate-formaldehyde condensate are 50%, 25%, and 25%, respectively. The silane coupling agent, sodium lignosulfonate, and sulfonated acetone-formaldehyde condensate are stirred evenly in water according to the specified mass ratio to obtain the water-coal slurry additive for non-water-soluble inorganic waste-blended coal slurry containing a silane coupling agent. In this embodiment, a mercapto-based silane coupling agent, KH580, can be used.

[0023] Comparative Example 1 The amino-based silane coupling agent KH550 was dissolved in water and stirred evenly to serve as a water-coal slurry additive specifically for inorganic waste-blended coal slurry.

[0024] Comparative Example 2 Sodium lignosulfonate is dissolved in water and stirred evenly to serve as a water-coal slurry additive specifically for inorganic waste-mixed coal slurry.

[0025] Comparative Example 3 Sodium naphthalene sulfonate formaldehyde condensate was dissolved in water and stirred evenly to serve as a water-coal slurry additive specifically for inorganic waste-mixed coal slurry.

[0026] Comparative Example 4 Sulfonated acetone-formaldehyde condensate was dissolved in water and stirred evenly to serve as a water-coal slurry additive specifically for inorganic waste-blended coal slurry.

[0027] Comparative Example 5 A water-coal slurry additive specifically for inorganic waste-mixed coal slurry is prepared by dissolving sodium lignosulfonate and sodium naphthalenesulfonate in formaldehyde condensate and stirring evenly in water.

[0028] Comparative Example 6 Sodium lignosulfonate and sulfonated acetone-formaldehyde condensate are dissolved in water and stirred evenly to serve as a water-coal slurry additive specifically for inorganic waste-blended coal slurry.

[0029] Comparative Experiment 1 The coal-water slurry additives of Examples 1-5 and Comparative Examples 1-5 were used as special coal-water slurry additives for inorganic waste-blended coal slurry. Coal samples were crushed to obtain coal particles within a certain particle size range. The coal particles and activated carbon waste were mixed evenly at a dry basis ratio of 4:1. At different set coal slurry concentrations, the coal particle-activated carbon mixture, pulverized water, and the special additives were mixed at high speed to form a slurry. The quality technical indicators of the prepared coal-water slurry, such as concentration, viscosity, fluidity, and 48-hour stability, were tested. The test results are shown in the table below. Table 1. Detection results of Examples 1-6; Table 2 shows the test results of comparative examples 1-6;

[0030] The comparison shows that the coal-water slurry additives of Examples 1-6 of the present invention, as additives for coal-water slurry containing non-water-soluble inorganic waste, can significantly reduce the apparent viscosity of the coal-water slurry, improve its fluidity, enable continuous flow, and make the coal-water slurry more stable, with no hard sediment after standing for 48 hours. In contrast, the coal-water slurry additives prepared in Comparative Examples 1-6 have higher apparent viscosity, poorer fluidity of the coal-water slurry, and form a small amount of hard sediment after standing for 48 hours.

[0031] The comparative experiments described above demonstrate that the silane coupling agent in this invention exhibits a significant synergistic effect with sodium lignosulfonate, and / or sodium naphthalenesulfonate formaldehyde condensate, and / or sulfonated acetone-formaldehyde condensate. The silane coupling agent can increase the surface tension of the inorganic matrix activated carbon, even making it greater than the surface tension of the organic matrix coal particles. This facilitates the wetting and spreading of activated carbon on the coal particle surface, improves the wetting ability between the matrices, and allows the two matrix materials to bond better together. Simultaneously, the silane coupling agent is plastic at the interface, forming a flexible deformable layer. When the modulus of this deformable layer is between that of the inorganic and organic matrices, stress can be uniformly transmitted, giving it the ability to self-heal when damaged. This not only relaxes the prestress at the interface but also prevents crack propagation and improves the interfacial bonding strength. This effectively enhances the fluidity and stability of the coal-water slurry, ensuring that interface breakage during slurry flow does not affect flow, and that the interface recovers after settling, preventing slurry stratification. Furthermore, the formulation of this invention is environmentally friendly, effectively reducing environmental pollution and fully meeting green and ecological protection requirements.

[0032] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A water-coal slurry additive specifically for non-water-soluble inorganic waste-mixed coal slurry containing a silane coupling agent, characterized in that, It includes silane coupling agents and compound products. The compound products are one or more of sodium lignosulfonate, sodium naphthalenesulfonate formaldehyde condensate, and sulfonated acetone-formaldehyde condensate. The weight percentage of the silane coupling agent is 50%-90%, and the weight percentage of the compound products is 10%-50%.

2. The water-coal slurry additive for non-water-soluble inorganic waste-mixed coal slurry containing silane coupling agent according to claim 1, characterized in that: The silane coupling agent is an amino-based silane coupling agent, an epoxy-based silane coupling agent, a vinyl-based silane coupling agent, or a mercapto-based silane coupling agent.

3. The water-coal slurry additive for non-water-soluble inorganic waste-mixed coal slurry containing silane coupling agent according to claim 2, characterized in that: The amino-based silane coupling agent is KH550, KH792 or KH602; the epoxy-based silane coupling agent is KH560, KH570 or KH151; the vinyl-based silane coupling agent is A151 or A171; and the mercapto-based silane coupling agent is KH580 or KH590.

4. The water-coal slurry additive for non-water-soluble inorganic waste-mixed coal slurry containing silane coupling agent according to claim 1, characterized in that: The weight percentage of the silane coupling agent is 50%-75%, and the weight percentage of the compound is 25%-50%.

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