Multifunctional binder for aluminum electrolysis and preparation method and application thereof

Abstract

The application provides a multifunctional binder for aluminum electrolysis and a preparation method and application thereof, and belongs to the field of aluminum electrolysis. The binder comprises the following chemical components: 5-20 parts of polyimide, 8-20 parts of sodium hydroxide, 22-45 parts of sodium silicate, 40-60 parts of solvent, 0.5-8 parts of succinic acid and 0.5-5 parts of propylene glycol block polyether. Through reasonable design of the chemical components of the binder, the polyimide has superior high-temperature resistance, and at the same time, the binder is endowed with insulation and weak magnetization characteristics; the interaction of sodium hydroxide, sodium silicate and the solvent can obtain water glass, the polyimide and the water glass matrix can form an interpenetrating network, and the binder layer can still maintain the integrity and mechanical strength at 900 DEG C, thereby providing a multifunctional binder, which can improve the bonding force between metals or between metal and ceramic, and at the same time, can meet the requirements of heat preservation, insulation, oxidation resistance and weak magnetization during the operation of the aluminum electrolysis cell.

Description

Technical Field

[0001] This application relates to the field of aluminum electrolysis technology, and in particular to a multifunctional binder for aluminum electrolysis, its preparation method, and its application. Background Technology

[0002] The aluminum electrolysis cell is the core equipment in aluminum electrolysis production. Its design needs to meet the requirements of heat preservation, insulation, oxidation resistance and weak magnetization, which are closely related to electrolysis efficiency, safety and equipment life.

[0003] Aluminum electrolysis primarily produces metallic aluminum by electrolyzing alumina, a process typically carried out at high temperatures (approximately 940℃-980℃). Inside the electrolysis cell, alumina (Al₂O₃) must dissolve in molten cryolite (Na₃AlF₆) to form ionic states. The presence of an insulation layer reduces heat loss and ensures the electrolyte remains in a molten state. Electrolysis is energy-intensive (accounting for 30%–40% of production costs); effective insulation reduces the need for external heating and lowers energy consumption. Insufficient electrolysis temperature can lead to electrolyte solidification, forming a crust that hinders the flow of molten aluminum and the reaction process, potentially even causing production accidents.

[0004] Electrolytic cells are supplied with direct current (up to hundreds of kiloamperes). If the cell material is conductive, the current will bypass the electrolyte and flow directly into the cell, leading to short circuits and energy waste. Insulating linings (such as carbon cathodes and alumina layers) ensure that all current flows through the electrolyte, promoting the effective reduction of aluminum ions (Al). 3+ →Al). In addition, insulation can also prevent the tank from becoming electrified and causing electric shock to operators.

[0005] The electrolytic cell contains high-temperature fluoride gases (such as CF4 and COF2) and molten salts, which are highly corrosive to metallic materials (such as steel shells). Anti-oxidation coatings (such as alumina coatings and silicon carbide materials) can slow down the oxidation and corrosion of the cell materials, preventing structural damage or leakage. Impurities generated from material oxidation may contaminate the electrolyte, affecting the purity of aluminum (e.g., iron or silicon impurities mixed into the molten aluminum).

[0006] A large current (e.g., 500kA) flowing through a conductor generates a strong magnetic field, which may affect the stability and current distribution of the molten aluminum layer, leading to fluctuations or even short circuits. To mitigate this, the magnetic field strength can be weakened by symmetrically arranging the anode conductors and busbars, or by employing a reverse current compensation design, ensuring stable aluminum deposition. A weak magnetic field environment can reduce eddy current losses in the molten aluminum and improve electrolysis efficiency (under ideal conditions, current efficiency can reach over 95%).

[0007] Therefore, aluminum electrolytic cells need to be well-insulated, electrically insulating, oxidation-resistant, and weakly magnetized to reduce energy waste, lower electricity consumption per ton of aluminum, ensure long-term, safe, and stable operation of the equipment, and improve product quality. Currently, most research focuses on single-function coatings such as insulating and anti-oxidation coatings, which cannot meet the needs of other parts of the aluminum electrolytic cell for oxidation resistance, insulation, and weak magnetization. Furthermore, existing adhesives are limited to carbon material bonding and are not suitable for metal-to-metal or metal-to-ceramic bonding. Summary of the Invention

[0008] This application provides a multifunctional binder for aluminum electrolysis, its preparation method, and its application, to solve the following technical problems: providing a multifunctional binder that can improve the bonding force between metals or between metals and ceramics, and when mixed with functional powder and coated on the required parts of the electrolytic cell, it can meet the requirements of heat preservation, insulation, oxidation resistance, and weak magnetization during the operation of the aluminum electrolytic cell.

[0009] In a first aspect, embodiments of this application provide a multifunctional binder for aluminum electrolysis, wherein the binder comprises the following chemical components by weight: 5 to 20 parts of polyimide, 8 to 20 parts of sodium hydroxide, 22 to 45 parts of sodium silicate, 40 to 60 parts of solvent, 0.5 to 8 parts of succinic acid, and 0.5 to 5 parts of propylene glycol block polyether.

[0010] Optionally, the adhesive may further include, by weight, at least one of the following chemical components: 2 to 10 parts of silicone, 0.01 to 1 part of nonionic polyacrylamide, and 0.01 to 1 part of polyferric sulfate.

[0011] Optionally, the propylene glycol block polyether may be of at least one of the following types: L35, L45, L64, and L65.

[0012] Secondly, this application provides a method for preparing the adhesive according to any embodiment of the first aspect, the method comprising:

[0013] The various raw materials for obtaining the adhesive are obtained;

[0014] Under stirring conditions, the sodium hydroxide, sodium silicate, and polyimide are sequentially added to the solvent at a set temperature to obtain a mixture;

[0015] The succinic acid, the propylene glycol block polyether, the silica gel, the nonionic polyacrylamide, and the polyferric sulfate are added to the mixture to obtain the adhesive.

[0016] Optionally, the set temperature is 60℃~80℃.

[0017] Optionally, the feeding rate of each raw material of the adhesive is 2 g / min to 10 g / min.

[0018] Thirdly, this application provides an application of the adhesive described in any embodiment of the first aspect, the application including:

[0019] The adhesive is applied between metals or between metals and ceramics for bonding between metals or between metals and ceramics.

[0020] Fourthly, this application provides an application of the adhesive described in any embodiment of the first aspect, the application including:

[0021] The binder is mixed with functional powder to obtain a mixture;

[0022] The mixture is applied to a designated area of ​​the aluminum electrolytic cell and cured for heat preservation, insulation, oxidation resistance, and weak magnetization of the designated area.

[0023] Optionally, the particle size of the functional powder is 0.5μm to 35μm, and the functional powder includes at least one of the following: alumina powder, aluminum silicate powder, silica aerogel powder, zirconium oxide powder, silicon carbide powder, aluminum nitride powder, graphite powder, mica powder, nickel powder, nickel-chromium alloy powder, nickel-chromium-iron alloy powder, nickel-aluminum powder, copper powder, cobalt powder, and iron powder.

[0024] Optionally, the curing process can be performed at room temperature or by heating.

[0025] The curing time at room temperature is 3 hours.

[0026] The temperature for heat curing is 60℃~200℃, and the time for heat curing is 0.5h~3h.

[0027] The technical solutions provided in this application have the following advantages compared with the prior art:

[0028] This application provides a multifunctional adhesive for aluminum electrolysis. By weight, the adhesive comprises the following chemical components: 5-20 parts polyimide, 8-20 parts sodium hydroxide, 22-45 parts sodium silicate, 40-60 parts solvent, 0.5-8 parts succinic acid, and 0.5-5 parts propylene glycol block polyether. Through the rational design of the adhesive's chemical composition, the polyimide exhibits excellent high-temperature resistance while also imparting insulation and weak magnetization properties. The interaction of sodium hydroxide, sodium silicate, and solvent yields water glass, allowing the polyimide and water glass matrix to form an interpenetrating network, maintaining the integrity and mechanical strength of the adhesive layer even at 900°C. Simultaneously, silicon-oxygen tetrahedra fill the pyrolysis voids in the polyimide, reducing thermal stress concentration and preventing high-temperature cracking or peeling. Succinic acid is water-resistant and enhances adhesion to the substrate. Propylene glycol block polyether acts as an antifoaming agent. This provides a multifunctional adhesive that can improve the bonding strength between metals or between metals and ceramics. When mixed with functional powders and applied to the required parts of the electrolytic cell, it can meet the needs of heat preservation, insulation, oxidation resistance and weak magnetization during the operation of aluminum electrolytic cells. Attached Figure Description

[0029] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0030] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic flowchart illustrating the preparation method of the adhesive provided in the embodiments of this application. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0033] Various embodiments of this application may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a rigid limitation on the scope of this application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Furthermore, whenever a numerical range is referred to herein, it means including any referenced number (fraction or integer) within the referred range.

[0034] Furthermore, in the description of this application, the terms "comprising," "including," etc., mean "including but not limited to." In this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. In this document, "and / or" describes the relationship between related objects, indicating that three relationships can exist; for example, A and / or B can represent: A alone, A and B simultaneously, or B alone. A and B can be singular or plural. In this document, "at least one" means one or more, and "more than" means two or more. "At least one," "at least one of the following," or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, "at least one of a, b, or c" or "at least one of a, b, and c" can both represent: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple. "Parts representation" such as parts by weight or parts by mass indicates the proportional relationship between components. In the proportional relationships discussed in this article, the parameters that need to be described by proportion should be understood as the first term of the proportion in the order of description, and the proportion number should be understood as the second term. For example, if the mass ratio of substance A, substance B, and substance C is 1:2:3, then substances A, B, and C should correspond one-to-one with the proportion number in the proportion in the order of description, that is, the mass of substance A : the mass of substance B : the mass of substance C = 1:2:3.

[0035] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this application can be purchased from the market or prepared by existing methods.

[0036] This application provides a multifunctional binder for aluminum electrolysis, which, by weight, comprises the following chemical components: 5 to 20 parts polyimide, 8 to 20 parts sodium hydroxide, 22 to 45 parts sodium silicate, 40 to 60 parts solvent, 0.5 to 8 parts succinic acid, and 0.5 to 5 parts propylene glycol block polyether.

[0037] In some embodiments, the solvent is deionized water or an analogue of deionized water.

[0038] The embodiments of this application rationally design the components of the multifunctional adhesive, and the functions of each component are as follows:

[0039] Polyimide: It can provide high-temperature structural stability, maintain the integrity and mechanical strength of the adhesive layer at 900°C, and at the same time impart insulation and weak magnetization properties to the adhesive, suppressing electron conduction through its aromatic heterocyclic structure. For example, the mass parts of the polyimide can be 5 parts, 7 parts, 10 parts, 12 parts, 16 parts, 18 parts, 20 parts, etc.

[0040] Sodium hydroxide, sodium silicate, and deionized water: Sodium hydroxide can form a Na₂O·nSiO₂ type water glass matrix with sodium silicate and deionized water. Simultaneously, the alkaline environment provided by sodium hydroxide promotes the formation of a silicate network and adjusts the pH of the system. Sodium silicate can form an inorganic ceramic structure with a thermal expansion coefficient that matches the metal substrate. Furthermore, the polyimide molecular chains form an interpenetrating network with the water glass ceramic phase, while silicon-oxygen tetrahedra fill the pyrolysis voids of the polymer, achieving gradient heat resistance. For example, the mass fractions of sodium hydroxide can be 8 parts, 10 parts, 12 parts, 14 parts, 18 parts, 20 parts, etc.; the mass fractions of sodium silicate can be 22 parts, 25 parts, 30 parts, 35 parts, 40 parts, 45 parts, etc.; and the mass fractions of deionized water can be 40 parts, 45 parts, 50 parts, 55 parts, 60 parts, etc.

[0041] Succinic acid: The carboxyl groups of succinic acid complex with the hydroxyl groups on the metal surface, increasing the interfacial bonding energy and thus improving adhesion to the substrate. Succinic acid also exhibits water resistance. For example, the mass fraction of this succinic acid can be 0.5 parts, 1 part, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, etc.

[0042] Propylene glycol block polyether: It can reduce the surface tension of the system and eliminate micron-sized bubbles. Simultaneously, the decomposition temperature of propylene glycol block polyether is >250℃, and a protective volatile layer can be formed at high temperatures. For example, the mass fraction of this propylene glycol block polyether can be 0.5 parts, 1 part, 2 parts, 3 parts, 4 parts, or 5 parts.

[0043] In some embodiments, the adhesive further includes, by weight, at least one of the following chemical components: 2 to 10 parts of silicone, 0.01 to 1 part of nonionic polyacrylamide, and 0.01 to 1 part of polyferric sulfate.

[0044] Specifically, the functions of each component are as follows:

[0045] Silicone: It achieves a physical anchoring effect through nanoscale pores, enhancing shear strength. The silanol groups on the silicone surface form a hydrogen bond network with the amino groups of the polyimide. Simultaneously, the silicone partially melts at 900°C to form a SiO2 transition layer, reducing the thermal stress concentration factor. Furthermore, silicone has good adsorption capacity, which can additionally supplement the adhesive effect when preparing binders. For example, the mass fraction of this silicone can be 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 9 parts, 10 parts, etc.

[0046] Nonionic polyacrylamide: Viscosity is increased through polymer chain entanglement. Simultaneously, it can form three-dimensional steric hindrance, maintaining the stability of the zeta potential of functional powders. Furthermore, nonionic polyacrylamide has good adhesive and dispersing properties; it can be added when a high-viscosity binder is required. For example, the mass fraction of this nonionic polyacrylamide can be 0.01 parts, 0.1 parts, 0.2 parts, 0.4 parts, 0.6 parts, 0.8 parts, 1 part, etc.

[0047] Polyferric sulfate: Fe 3+ Hydrolysis produces [Fe(OH)] 2+ It is a colloid that passivates metal substrates. Simultaneously, it forms a Fe-OOCR complex with succinic acid, improving the dispersion of the powder. It can react with sodium silicate at high temperatures to form Fe2(SiO3)3, reducing porosity. Furthermore, polyferric sulfate also has a certain dispersing effect; when added to corrosion-resistant powders, it can improve corrosion resistance. For example, the mass fraction of this polyferric sulfate can be 0.01 parts, 0.1 parts, 0.2 parts, 0.4 parts, 0.6 parts, 0.8 parts, 1 part, etc.

[0048] In some embodiments, the propylene glycol block polyether includes at least one of the following types: L35, L45, L64, and L65.

[0049] It should be noted that propylene glycol block polyethers are a type of nonionic surfactant, belonging to the polyether polymer family. Their designations (such as L35, L45, L64, L65, etc.) typically reflect the difference in the block ratio and molecular weight of ethylene oxide and propylene oxide in their molecular structure. L35 has a low ethylene oxide content and strong hydrophobicity; L45 has a slightly higher ethylene oxide content than L35, a moderate HLB value, and a good hydrophilic-hydrophobic balance; L64 has a higher ethylene oxide content, an HLB value of approximately 18-20, and significantly enhanced hydrophilicity; L65 has the highest ethylene oxide content, a high HLB value (20-24), and strong hydrophilicity.

[0050] Figure 1 This is a schematic flowchart illustrating the preparation method of the adhesive provided in the embodiments of this application.

[0051] like Figure 1 As shown, this application provides a method for preparing the adhesive according to any one of the above embodiments, the method comprising:

[0052] S1. Obtain the various raw materials of the adhesive;

[0053] S2. Under stirring conditions, the sodium hydroxide, sodium silicate and polyimide are added sequentially to the solvent at a set temperature to obtain a mixture;

[0054] S3. Add the succinic acid, the propylene glycol block polyether, the silica gel, the nonionic polyacrylamide, and the polyferric sulfate to the mixture to obtain the adhesive.

[0055] In some embodiments, the set temperature is 60°C to 80°C.

[0056] During the preparation of the multifunctional adhesive, constant temperature heating is required during the stirring and dissolution process. A heating temperature range of 60–80°C can improve the dissolution efficiency of polyimide and prevent solvent evaporation. Simultaneously, it can balance the hydrolysis rate of sodium silicate and the acid-base neutralization rate, preventing gelation. Furthermore, it can prevent the high-temperature precipitation of propylene glycol block polyethers (such as L64) or polymer degradation. For example, this set temperature can be 60°C, 65°C, 70°C, 75°C, 80°C, etc.

[0057] In some embodiments, the feeding rate of each raw material of the adhesive is 2 g / min to 10 g / min.

[0058] During the preparation of the multifunctional binder, the raw materials are added at a small, uniform rate, maintained between 2 g / min and 10 g / min. This ensures uniform dispersion of the raw materials and reduces undissolved particles or agglomeration. Simultaneously, it delays the heat release from the neutralization reaction of succinic acid and NaOH. Furthermore, it allows silica gel and polyacrylamide to gradually form a uniform network, avoiding abrupt viscosity changes. For example, the addition rates of the various raw materials in the binder can be 2 g / min, 4 g / min, 6 g / min, 8 g / min, 9 g / min, 10 g / min, etc.

[0059] The product prepared by the method of preparing the adhesive is the adhesive described above. The chemical composition of the adhesive prepared by the method of preparing the adhesive can be referred to the above embodiments. Since the method of preparing the adhesive adopts some or all of the technical solutions of the adhesive embodiments, it has at least all the beneficial effects brought about by the technical solutions of the adhesive embodiments, which will not be elaborated here.

[0060] Based on a general inventive concept, this application provides an application of the adhesive described in any of the above embodiments, the application including:

[0061] The adhesive is applied between metals or between metals and ceramics for bonding between metals or between metals and ceramics.

[0062] Based on a general inventive concept, this application provides an application of the adhesive described in any of the above embodiments, the application including:

[0063] The binder is mixed with functional powder to obtain a mixture;

[0064] The mixture is applied to a designated area of ​​the aluminum electrolytic cell and cured for heat preservation, insulation, oxidation resistance, and weak magnetization of the designated area.

[0065] It should be noted that the coating can be applied manually or using a spraying machine.

[0066] In some embodiments, the particle size of the functional powder is 0.5μm to 35μm, and the functional powder includes at least one of the following: alumina powder, aluminum silicate powder, silica aerogel powder, zirconium oxide powder, silicon carbide powder, aluminum nitride powder, graphite powder, mica powder, nickel powder, nickel-chromium alloy powder, nickel-chromium-iron alloy powder, nickel-aluminum powder, copper powder, cobalt powder, and iron powder.

[0067] The powder exhibits optimal performance at the optimal particle size distribution. Particle sizes larger than 35 μm result in an uneven surface after curing; particle sizes smaller than 0.5 μm are prone to agglomeration, which affects the overall performance after curing. For example, the particle sizes of functional powders can be 0.5 μm, 3 μm, 5 μm, 10 μm, 15 μm, 20 μm, 30 μm, 35 μm, etc.

[0068] In some embodiments, the curing is performed at room temperature or by heating.

[0069] The curing time at room temperature is 3 hours.

[0070] The temperature for heat curing is 60℃~200℃, and the time for heat curing is 0.5h~3h.

[0071] The heat curing process uses one or both of the following methods: infrared heating module and far-infrared heater, to ensure complete curing of the coating.

[0072] The adhesive prepared in this application embodiment can be directly applied for bonding; or functional powder can be added, mixed evenly, and then applied to the required parts of the aluminum electrolytic cell to play the roles of heat preservation, insulation, anti-oxidation, and weak magnetization.

[0073] In summary, the multifunctional binder for aluminum electrolysis, its preparation method, and its application provided in this application have the following advantages:

[0074] (1) Excellent high-temperature performance: Polyimide forms an interpenetrating network with water glass matrix (Na2O·nSiO2), which can maintain the integrity and mechanical strength of the adhesive layer at 900℃, which is significantly better than traditional organic adhesives. At the same time, silicon-oxygen tetrahedra fill the pyrolysis voids of polyimide, reduce thermal stress concentration, and avoid high-temperature cracking or peeling.

[0075] (2) Multifunctional synergistic effect: The aromatic heterocyclic structure of polyimide inhibits electron conduction, endowing the adhesive with insulation and weak magnetization properties, making it suitable for electromagnetically sensitive environments (such as aluminum electrolysis cells). At the same time, succinic acid complexes with the hydroxyl groups on the metal surface through carboxyl groups, thereby improving the interfacial bonding energy; the nanopores of silicone achieve physical anchoring, thereby improving shear strength.

[0076] (3) Environmental protection and process controllability: Deionized water is used as the main solvent to avoid volatile organic compound pollution and meet environmental protection requirements. At the same time, constant temperature control of 60℃~80℃ combined with uniform feeding of 2~10g / min ensures uniform dispersion of raw materials, avoids gelation or thermal degradation, and improves the yield of finished products.

[0077] (4) Application flexibility and adaptability: It can be directly applied to metal / metal or metal / ceramic interfaces. At the same time, it can be mixed with powders such as alumina and silicon carbide to create customized heat-insulating, insulating, and anti-oxidation coatings.

[0078] (5) Corrosion resistance and long-term stability: Polyferric sulfate hydrolyzes to generate a colloidal passivating metal substrate, which forms a Fe-OOCR complex with succinic acid, improving corrosion resistance. At the same time, propylene glycol block polyether volatilizes at high temperature to form a protective layer, thereby maintaining the bonding strength.

[0079] (6) Significant economic benefits: The high proportion of inorganic raw materials such as sodium silicate and sodium hydroxide reduces material costs by 40% to 50% compared to an all-organic system. At the same time, when the binder is used in aluminum electrolysis cells, the lifespan of the anti-oxidation coating is increased by 2 to 3 times, reducing the frequency of downtime maintenance.

[0080] The present application is further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the application. Experimental methods in the following embodiments that do not specify specific conditions are generally determined according to industry standards. If there is no corresponding industry standard, then common international standards, conventional conditions, or conditions recommended by the manufacturer are followed.

[0081] Example 1

[0082] Eight parts of sodium hydroxide were added to 50 parts of deionized water at 65°C under stirring at a rate of 10 g / min. After complete dissolution, 10 parts of sodium silicate were added at a rate of 5 g / min and stirred until completely dissolved. Then, 20 parts of polyimide (CAS No.: 26023-21-2) were added at a rate of 10 g / min and dissolved until completely dissolved. Next, 8 parts of silica gel (CAS No.: 14808-60-7), 2 parts of succinic acid (CAS No.: 110-15-6), 1 part of propylene glycol block polyether (L64), 0.5 parts of nonionic polyacrylamide (CAS No.: 62649-23-4), and 0.5 parts of polyferric sulfate (CAS No.: 10028-22-5) were added sequentially and stirred until homogeneous to obtain a multifunctional adhesive.

[0083] The prepared adhesive was brushed onto two clean iron sheets measuring 100mm × 50mm × 2mm. The two iron sheets were then bonded together and placed in a constant temperature drying oven at 100℃ for 1 hour. After removal, the two iron sheets were firmly bonded together with strong adhesion, achieving an adhesion grade of 0 (GB / T 9286).

[0084] Example 2

[0085] Ten parts of sodium hydroxide were added to 60 parts of deionized water at 70°C under stirring at a rate of 10 g / min. After complete dissolution, eight parts of sodium silicate were added at a rate of 5 g / min and stirred until completely dissolved. Then, ten parts of polyimide were added at a rate of 10 g / min and dissolved until completely dissolved. Next, ten parts of silica gel, one part of propylene glycol block polyether (L64), and one part of succinic acid were added sequentially, and the mixture was stirred until homogeneous to obtain a multifunctional adhesive.

[0086] The prepared adhesive was mixed with alumina powder and mica powder in a mass ratio of 1:1:1 and stirred evenly. The mixture was then coated onto a clean ordinary aluminum alloy trough cover plate with a coating thickness of 1 mm and cured at room temperature for 2 hours.

[0087] The prepared thermal insulation aluminum alloy tank cover plate has a smooth surface without peeling or cracking, strong bonding force, and an adhesion grade of 0 (GB / T 9286). Its weight is comparable to that of ordinary tank covers. When used on an electrolytic cell, its surface temperature is reduced to 3 / 4 of the original temperature, effectively reducing heat dissipation from the top of the electrolytic cell.

[0088] Example 3

[0089] Eight parts of sodium hydroxide were added to 40 parts of deionized water at 60°C under stirring at a rate of 10 g / min. After complete dissolution, 15 parts of sodium silicate were added at a rate of 5 g / min and stirred until completely dissolved. Then, 16 parts of polyimide were added at a rate of 10 g / min and dissolved until completely dissolved. Next, 10 parts of silica gel, 8 parts of succinic acid, and 3 parts of propylene glycol block polyether (L64) were added sequentially, and the mixture was stirred until homogeneous to obtain a multifunctional adhesive.

[0090] The prepared adhesive was mixed with nickel powder and iron powder in a mass ratio of 2:1:1 and stirred evenly. The mixture was then coated onto a clean ordinary aluminum alloy trough cover plate with a coating thickness of 0.5 mm and cured at room temperature for 2 hours.

[0091] The prepared magnetically shielded ordinary aluminum alloy tank cover plate has a smooth surface without peeling or cracking, strong bonding force, and adhesion grade 0 (GB / T 9286). Its weight is comparable to that of ordinary tank cover plates, and the magnetic field after shielding is equivalent to 1 / 16 of the original magnetic field strength, effectively shielding the magnetic field above the electrolytic cell.

[0092] Example 4

[0093] Six parts of sodium hydroxide were added to 50 parts of deionized water at 75°C under stirring at a rate of 10 g / min. After complete dissolution, 10 parts of sodium silicate were added at a rate of 5 g / min and stirred until completely dissolved. Then, 18 parts of polyimide were added at a rate of 10 g / min and dissolved until completely dissolved. Next, 5 parts of silica gel, 5 parts of succinic acid, 5 parts of propylene glycol block polyether (L64), and 1 part of nonionic polyacrylamide were added sequentially, and the mixture was stirred until homogeneous to obtain a multifunctional adhesive.

[0094] The prepared binder was mixed with alumina powder and zirconium oxide powder in a mass ratio of 10:7:3 and stirred evenly. The mixture was then coated onto a carbon block with a size of Φ35mm×20mm and a coating thickness of 1mm. The block was then placed in a constant temperature drying oven and kept at 100℃ for 0.5h.

[0095] The prepared antioxidant carbon block has a smooth surface without peeling or cracking, strong bonding force, and an adhesion grade of 0 (GB / T9286). After being kept together with ordinary carbon blocks at a high temperature of 950℃ for 24 hours, the mass loss rate was only 4.9%, and the antioxidant performance was improved by 84.1% compared with ordinary carbon blocks, effectively improving the antioxidant performance of the carbon blocks.

[0096] Comparative Example 1

[0097] Based on the disclosure in Example 1, the following modifications are made:

[0098] Succinic acid is not added to the adhesive.

[0099] The prepared adhesive was brushed onto two clean iron sheets measuring 100mm × 50mm × 2mm. The two iron sheets were then bonded together and placed in a constant temperature drying oven at 100℃ for 1 hour. After removal, the two iron sheets were firmly bonded, with an adhesion grade of 1 (GB / T 9286).

[0100] Comparative Example 2

[0101] Based on the disclosure in Example 2, the following modifications are made:

[0102] No polyimide is added to the adhesive.

[0103] The prepared adhesive was mixed with alumina powder and mica powder in a mass ratio of 1:1:1 and stirred evenly. The mixture was then coated onto a clean ordinary aluminum alloy trough cover plate with a coating thickness of 1 mm and cured at room temperature for 2 hours.

[0104] The prepared thermal insulation aluminum alloy tank cover plate has a smooth surface without peeling or cracking, strong bonding force, and an adhesion grade of 0 (GB / T 9286). Its weight is comparable to that of ordinary tank covers. When used on an electrolytic cell, its surface temperature is equivalent to 4 / 5 of the original temperature, slightly reducing heat dissipation from the top of the electrolytic cell.

[0105] Comparative Example 3

[0106] Based on the disclosure in Example 3, the following modifications are made:

[0107] No propylene glycol block polyether is added to the adhesive.

[0108] The prepared adhesive was mixed with nickel powder and iron powder in a mass ratio of 2:1:1 and stirred evenly. The mixture was then coated onto a clean ordinary aluminum alloy trough cover plate with a coating thickness of 0.5 mm and cured at room temperature for 2 hours.

[0109] The prepared magnetically shielded ordinary aluminum alloy tank cover plate has blistering and peeling on its surface, with an adhesion level of 1 (GB / T9286). Its weight is comparable to that of an ordinary tank cover plate. The magnetic field after shielding is equivalent to 1 / 12 of the original magnetic field strength, which can shield the magnetic field above the electrolytic cell.

[0110] Comparative Example 4

[0111] Based on the disclosure in Example 1, the following modifications are made:

[0112] No polyimide is added to the adhesive.

[0113] The multifunctional binder was mixed with alumina powder and zirconium oxide powder in a mass ratio of 10:7:3 and stirred evenly. The mixture was then coated onto a carbon block with a size of Φ35mm×20mm and a coating thickness of 1mm. The block was then placed in a constant temperature drying oven and kept at 100℃ for 0.5h.

[0114] The prepared antioxidant carbon blocks had a smooth surface without peeling or cracking. After being kept together with ordinary carbon blocks at a high temperature of 950℃ for 24 hours, the mass loss rate was 28.3%, and the antioxidant performance was improved by 60.7% compared with ordinary carbon blocks, thus improving the antioxidant performance of the carbon blocks.

[0115] Furthermore, one or more technical solutions in the embodiments of this application have at least the following technical effects or advantages:

[0116] In the embodiments of this application, the multifunctional binder for aluminum electrolysis is prepared by a simple method, has strong adhesion, can bond metals, metals and ceramics, etc., and has low production cost.

[0117] In this embodiment, the multifunctional binder for aluminum electrolysis can effectively fill corrosion-resistant powder, heat-insulating powder, insulating powder, and magnetic shielding powder, etc., and be coated on the required parts of the electrolytic cell. It has functions such as heat dissipation prevention, insulation, oxidation resistance, and weak magnetization, promoting the efficient, low-consumption, and energy-saving operation of the aluminum electrolytic cell, saving production costs, and improving economic benefits.

[0118] In the embodiments of this application, the multifunctional binder for aluminum electrolysis prepared by adding functional powder has a simple and convenient coating method and can also be applied to other technical fields besides aluminum electrolysis technology, and has broad application prospects.

[0119] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A multifunctional binder for aluminum electrolysis, comprising, by weight, the following chemical components: 5-20 parts polyimide, 8-20 parts sodium hydroxide, 22-45 parts sodium silicate, 40-60 parts solvent, 0.5-8 parts succinic acid, 0.5-5 parts propylene glycol block polyether, and 2-10 parts silicone.

2. The adhesive according to claim 1, characterized in that, The adhesive, by weight, further includes at least one of the following chemical components: 0.01 to 1 part of nonionic polyacrylamide and 0.01 to 1 part of polyferric sulfate.

3. The adhesive according to claim 1, characterized in that, The propylene glycol block polyethers include at least one of the following types: L35, L45, L64, and L65.

4. A method for preparing the adhesive according to any one of claims 1 to 3, the method comprising: The various raw materials for obtaining the adhesive are obtained; Under stirring conditions, the sodium hydroxide, sodium silicate, and polyimide are sequentially added to the solvent at a set temperature to obtain a mixture; The succinic acid, the propylene glycol block polyether, the silica gel, the nonionic polyacrylamide, and the polyferric sulfate are added to the mixture to obtain the adhesive.

5. The method according to claim 4, characterized in that, The set temperature is 60℃~80℃.

6. The method according to claim 4, characterized in that, The feeding rate of each raw material of the adhesive is 2g / min to 10g / min.

7. An application of the adhesive according to any one of claims 1 to 3, the application comprising: The adhesive is applied between metals or between metals and ceramics for bonding between metals or between metals and ceramics.

8. An application of the adhesive according to any one of claims 1 to 3, the application comprising: The binder is mixed with functional powder to obtain a mixture; The mixture is applied to a designated area of ​​the aluminum electrolytic cell and cured for heat preservation, insulation, oxidation resistance, and weak magnetization of the designated area.

9. The application according to claim 8, characterized in that, The particle size of the functional powder is 0.5μm~35μm, and the functional powder includes at least one of the following: alumina powder, aluminum silicate powder, silica aerogel powder, zirconium oxide powder, silicon carbide powder, aluminum nitride powder, graphite powder, mica powder, nickel powder, nickel-chromium alloy powder, nickel-chromium-iron alloy powder, nickel-aluminum powder, copper powder, cobalt powder, and iron powder.

10. The application according to claim 8, characterized in that, The curing process is performed at room temperature or by heating. The curing time at room temperature is 3 hours. The temperature for heat curing is 60℃~200℃, and the time for heat curing is 0.5h~3h.

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