Multifunctional binder for aluminum electrolysis as well as preparation method and application of multifunctional binder

Abstract

The invention provides a multifunctional binder for aluminum electrolysis and a preparation method and application thereof, and belongs to the field of electrolytic aluminum. 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 a solvent, 0.5-8 parts of succinic acid and 0.5-5 parts of propylene glycol block polyether. Through reasonable design of chemical components of the binder, polyimide has excellent high-temperature resistance, the binder is endowed with insulativity and weak magnetization characteristics, sodium hydroxide, sodium silicate and a solvent interact to obtain water glass, polyimide and a water glass matrix can form an interpenetrating network, the integrity and mechanical strength of a bonding layer can still be kept at 900 DEG C, and the bonding layer has good mechanical properties. Therefore, a multifunctional binder is provided, the binding force between metal and metal or between metal and ceramic can be improved, and meanwhile, the requirements of heat preservation, insulation, oxidation resistance and weak magnetization during operation of the aluminum electrolysis cell can be met.

Description

Technical Field

[0001] The present application relates to the technical field of aluminum electrolysis, and in particular to a multifunctional binder for aluminum electrolysis and a preparation method and application thereof. Background Art

[0002] Aluminum reduction cells are the core equipment in aluminum electrolysis production. Their design needs to meet the requirements of thermal insulation, insulation, anti-oxidation and weak magnetization, which are closely related to electrolysis efficiency, safety and equipment life.

[0003] Aluminum electrolysis production mainly obtains metallic aluminum by electrolyzing alumina, and this process is usually carried out at high temperatures (about 940℃-980℃). Alumina (Al2O3) in the aluminum electrolysis cell needs to be dissolved in molten cryolite (Na3AlF6) to form an ion state. The presence of the insulation layer can reduce heat loss and ensure that the electrolyte is in a molten state. The electrolysis process has high energy consumption (accounting for 30% to 40% of the production cost), and effective insulation can reduce the need for external heating and reduce energy consumption. If the electrolysis temperature is insufficient, the electrolyte will solidify and form a crust, which will hinder the flow and reaction of aluminum liquid and even cause production accidents.

[0004] The electrolytic cell is fed 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, resulting in a short circuit and energy waste. The insulating lining (such as a carbon cathode, an alumina layer) ensures that all current passes through the electrolyte, promoting the effective reduction of aluminum ions (Al 3+ →Al). In addition, insulation can also prevent the risk of electric shock to operators caused by the tank being electrified.

[0005] There are high-temperature fluoride gases (such as CF4, COF2) and molten salts inside the electrolytic cell, which are highly corrosive to metal materials (such as steel shells). Anti-oxidation coatings (such as aluminum oxide coatings, silicon carbide materials) can slow down the oxidation and corrosion of the cell material and prevent structural damage or leakage. Impurities produced by material oxidation may contaminate the electrolyte and affect the purity of aluminum (such as iron and silicon impurities mixed into the aluminum liquid). Impurities produced by material oxidation may contaminate the electrolyte and affect the purity of aluminum (such as iron and silicon impurities mixed into the aluminum liquid).

[0006] A large current (such as 500KA) flowing in a conductor will generate a strong magnetic field, which may affect the stability of the aluminum liquid layer and the current distribution, causing aluminum liquid fluctuations or even short circuits. For example, by symmetrically arranging the anode guide rods and busbars, or adopting a reverse current compensation design, the magnetic field strength can be weakened to ensure the smooth deposition of aluminum liquid. A weak magnetic field environment can reduce the eddy current loss of aluminum liquid and improve the electrolysis efficiency (under ideal conditions, the current efficiency can reach more than 95%).

[0007] Therefore, aluminum electrolytic cells need to be well insulated, insulated, anti-oxidant and weakly magnetized, which can reduce energy waste, reduce electricity consumption per ton of aluminum, ensure long-term, safe and stable operation of equipment, and improve product quality. At present, most research focuses on single-function coatings such as thermal insulation coatings and anti-oxidation coatings, but cannot meet the needs of other parts of aluminum electrolytic cells for anti-oxidation, insulation, weak magnetization, etc. At the same time, the application of existing adhesives is limited to carbon material connection, and is not applicable to metal-metal connection or metal-ceramic bonding. Summary of the invention

[0008] The present application provides a multifunctional binder for aluminum electrolysis and a preparation method and application thereof to solve the following technical problems: to provide a multifunctional binder that can improve the bonding strength between metal and metal or metal and ceramic, and at the same time, after being mixed with functional powder and coated on the required parts of the electrolytic cell, it can meet the requirements of heat preservation, insulation, anti-oxidation and weak magnetization during the operation of the aluminum electrolytic cell.

[0009] In the first aspect, an embodiment of the present application provides a multifunctional binder for aluminum electrolysis. The binder includes the following chemical components, measured in parts by mass: 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 binder further comprises at least one of the following chemical components, measured in parts by mass: 2 to 10 parts of silica gel, 0.01 to 1 part of nonionic polyacrylamide, and 0.01 to 1 part of polyferric sulfate.

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

[0012] In a second aspect, the present application provides a method for preparing the binder according to any one embodiment of the first aspect, the method comprising:

[0013] Obtaining various raw materials of the binder;

[0014] Under stirring conditions, sequentially adding the sodium hydroxide, the sodium silicate and the polyimide to the solvent with a set temperature to obtain a mixed solution;

[0015] The succinic acid, the propylene glycol block polyether, the silica gel, the nonionic polyacrylamide and the polymerized ferric sulfate are added into the mixed solution to obtain the binder.

[0016] Optionally, the set temperature is 60°C to 80°C.

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

[0018] In a third aspect, the present application provides an application of the adhesive according to any one embodiment of the first aspect, wherein the application comprises:

[0019] The adhesive is applied between metal and metal or between metal and ceramic to be used for bonding between metal and metal or between metal and ceramic.

[0020] In a fourth aspect, the present application provides an application of the adhesive according to any one embodiment of the first aspect, the application comprising:

[0021] Mixing the binder with the functional powder to obtain a mixture;

[0022] The mixed material is applied to a set position of an aluminum electrolytic cell and solidified to be used for heat preservation, insulation, oxidation resistance and weak magnetization of the set part.

[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 is performed by room temperature curing or heating curing;

[0025] Wherein, the room temperature curing time is 3h;

[0026] The temperature of the heating and curing is 60° C. to 200° C., and the time of the heating and curing is 0.5 h to 3 h.

[0027] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art:

[0028] The embodiment of the present application provides a multifunctional binder for aluminum electrolysis, which includes the following chemical components by mass: 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. By rationally designing the chemical composition of the binder, the polyimide has excellent high temperature resistance, while giving the binder insulation and weak magnetization properties. The interaction of sodium hydroxide, sodium silicate and solvent can obtain water glass, and the polyimide and water glass matrix can form an interpenetrating network, which can still maintain the integrity and mechanical strength of the bonding layer at 900°C. At the same time, the silicon-oxygen tetrahedron fills the polyimide pyrolysis gap, reduces thermal stress concentration, and avoids high temperature cracking or peeling. Succinic acid is water-resistant and can improve adhesion to the substrate. Propylene glycol block polyether can play a defoaming role. Thus, a multifunctional binder is provided, which can improve the bonding strength between metal and metal or metal and ceramic. At the same time, after being mixed with functional powder and coated on the required parts of the electrolytic cell, it can meet the requirements of thermal insulation, insulation, anti-oxidation and weak magnetization during the operation of the aluminum electrolytic cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings herein are incorporated in and constitute a part of the specification, illustrate embodiments consistent with the present application, and together with the description, are used to explain the principles of the present application.

[0030] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0031] Figure 1 A schematic diagram of a process for preparing a binder provided in an embodiment of the present application. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0033] Various embodiments of the present application may be presented in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be understood as a rigid limitation on the scope of the present application; therefore, the range description should be considered to have specifically disclosed all possible sub-ranges and single numerical values ​​within the range. For example, the range description from 1 to 6 should be considered to have 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., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which apply regardless of the range. In addition, whenever a numerical range is indicated herein, it is meant to include any cited number (fractional or integer) within the indicated range.

[0034] In addition, in the description of the specification of the present application, the terms "including", "comprising", etc. mean "including but not limited to". In this article, relational terms such as "first" and "second", etc. are only used 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 article, "and / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. Wherein A and B can be singular or plural. In this article, "at least one" means one or more, and "plurality" means two or more. "At least one", "the following at least one item (items)" or similar expressions refer to any combination of these items, including any combination of single items (items) or plural items (items). For example, "at least one of a, b, or c", or "at least one of a, b, and c", can all represent: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, c can be single or multiple. "Parts" such as parts by weight and parts by mass indicate the proportional relationship between the components. In the proportional relationship involved in this article, the parameters that need to be described by proportion should be understood as the first term of the proportional formula in the order of description, and the proportional numbers should be understood as the second term of the proportional formula. For example, the mass ratio of substance A, substance B, and substance C is 1:2:3, then substance A, substance B, and substance C should correspond one-to-one with the proportional numbers in the proportional formula 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, various raw materials, reagents, instruments and equipment used in this application can be purchased from the market or prepared by existing methods.

[0036] The present application provides a multifunctional binder for aluminum electrolysis. The binder includes the following chemical components, measured by mass: 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.

[0037] In some embodiments, the solvent is deionized water or the like.

[0038] The present invention reasonably designs 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 bonding layer at 900°C, and at the same time give the binder insulation and weak magnetization properties, and inhibit electronic conduction through the 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, deionized water: Sodium hydroxide can form a Na2O·nSiO2 type water glass matrix with sodium silicate and deionized water. At the same time, the alkaline environment provided by sodium hydroxide can promote the formation of a silicate network, while adjusting the pH value of the system, sodium silicate can form an inorganic ceramic structure, and the thermal expansion coefficient can match the metal substrate. In addition, the polyimide molecular chain forms an interpenetrating network with the water glass ceramic phase, and the silicon oxygen tetrahedron fills the polymer pyrolysis gap to achieve gradient heat resistance. Exemplarily, the mass parts of the sodium hydroxide can be 8 parts, 10 parts, 12 parts, 14 parts, 18 parts, 20 parts, etc., the mass parts of sodium silicate can be 22 parts, 25 parts, 30 parts, 35 parts, 40 parts, 45 parts, etc., and the mass parts of deionized water can be 40 parts, 45 parts, 50 parts, 55 parts, 60 parts, etc.

[0041] Succinic acid: The carboxyl group of succinic acid complexes with the hydroxyl group on the metal surface to improve the interfacial binding energy, thereby improving the adhesion to the substrate. At the same time, succinic acid also has water resistance. Exemplarily, the mass parts of the succinic acid can be 0.5 parts, 1 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, etc.

[0042] Propylene glycol block polyether: can reduce the surface tension of the system and eliminate micron-sized bubbles. At the same time, the decomposition temperature of propylene glycol block polyether is >250°C, and a protective volatile layer can be formed at high temperature. Exemplarily, the mass fraction of the propylene glycol block polyether can be 0.5 parts, 1 parts, 2 parts, 3 parts, 4 parts, or 5 parts.

[0043] In some embodiments, the binder further comprises at least one of the following chemical components, measured in parts by mass: 2 to 10 parts of silica gel, 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] Silica gel: Physical anchoring effect is achieved through nano-scale pores to improve shear strength. Silicone hydroxyl groups on the surface of silica gel form a hydrogen bond network with polyimide amino groups. At the same time, silica gel partially melts at 900°C to form a SiO2 transition layer, reducing the thermal stress concentration coefficient. In addition, silica gel has a good adsorption capacity and can be used to supplement the adhesive effect when preparing the adhesive. Exemplarily, the mass parts of the silica gel 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 by polymer chain entanglement. At the same time, three-dimensional steric hindrance can be formed to keep the Zeta potential of the functional powder stable. In addition, nonionic polyacrylamide has good adhesion and dispersion effects. If a binder with a higher viscosity is required, it can be added for use. Exemplarily, the mass parts of the nonionic polyacrylamide can be 0.01 parts, 0.1 parts, 0.2 parts, 0.4 parts, 0.6 parts, 0.8 parts, 1 parts, etc.

[0047] Polyferric sulfate: Fe 3+ Hydrolysis generates [Fe(OH)] 2+ Colloid, passivating the metal substrate. At the same time, it forms a Fe-OOCR complex with succinic acid to improve the dispersion of the powder. It can react with sodium silicate at high temperature to generate Fe2(SiO3)3, and the porosity is reduced. In addition, polyferric sulfate also has a certain dispersing effect. When adding corrosion-resistant powder, it can improve the corrosion resistance. Exemplarily, the mass parts of the polyferric sulfate can be 0.01 parts, 0.1 parts, 0.2 parts, 0.4 parts, 0.6 parts, 0.8 parts, 1 parts, etc.

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

[0049] It should be noted that propylene glycol block polyether is a type of non-ionic surfactant, belonging to the polyether polymer compound. Its model (such as L35, L45, L64, L65, etc.) usually reflects the block ratio and molecular weight difference of ethylene oxide and propylene oxide in the molecular structure. L35 has a low ethylene oxide content and strong hydrophobicity; L45 has a slightly higher ethylene oxide content than L35, a medium HLB value, and a good hydrophilic-hydrophobic balance; L64 has a higher ethylene oxide content, an HLB value of about 18-20, and significantly enhanced hydrophilicity; L65 has the highest ethylene oxide content, a higher HLB value (20-24), and strong hydrophilicity.

[0050] Figure 1 A schematic diagram of a process for preparing a binder provided in an embodiment of the present application.

[0051] like Figure 1 As shown, the present application provides a method for preparing the binder described in any one of the above embodiments, the method comprising:

[0052] S1, obtaining various raw materials of the binder;

[0053] S2. Under stirring conditions, sequentially adding the sodium hydroxide, the sodium silicate and the polyimide to the solvent with a set temperature to obtain a mixed solution;

[0054] S3, adding the succinic acid, the propylene glycol block polyether, the silica gel, the nonionic polyacrylamide and the polymerized ferric sulfate into the mixed solution to obtain the binder.

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

[0056] When preparing the multifunctional binder, constant temperature heating is required during the stirring and dissolving process. The heating temperature range is 60-80°C, which can improve the dissolution efficiency of polyimide and avoid solvent volatilization; at the same time, it can balance the hydrolysis rate of sodium silicate and the acid-base neutralization rate to prevent gelation; in addition, it can also avoid the high-temperature precipitation of propylene glycol block polyether (such as L64) or polymer degradation. Exemplarily, the 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 binder is 2 g / min to 10 g / min.

[0058] When preparing the multifunctional binder, the speed of adding raw materials is a small amount and uniform, maintained at 2g / min to 10g / min, which can ensure the uniform dispersion of the raw materials and reduce undissolved particles or agglomeration; at the same time, it can delay the heat release of the neutralization reaction of succinic acid and NaOH; in addition, it can make silica gel and polyacrylamide gradually form a uniform network to avoid viscosity mutation. Exemplarily, the feeding speed of each raw material of the binder can be 2g / min, 4g / min, 6g / min, 8g / min, 9g / min, 10g / min, etc.

[0059] The product prepared by the method for preparing the adhesive is the above-mentioned adhesive. The chemical composition of the adhesive prepared by the method for preparing the adhesive can refer to the above-mentioned embodiment. Since the method for preparing the adhesive adopts part or all of the technical solutions of the adhesive embodiment, it at least has all the beneficial effects brought by the technical solutions of the adhesive embodiment, which will not be described one by one here.

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

[0061] The adhesive is applied between metal and metal or between metal and ceramic to be used for bonding between metal and metal or between metal and ceramic.

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

[0063] Mixing the binder with the functional powder to obtain a mixture;

[0064] The mixed material is coated on a set part of an aluminum electrolytic cell and solidified to be used for heat preservation, insulation, oxidation resistance and weak magnetization of the set part.

[0065] It should be noted that the coating method can be manual coating or coating with the aid of a spraying machine.

[0066] In some embodiments, the particle size of the functional powder is 0.5 μm to 35 μm, 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 has the best performance when the particle size is graded. If the particle size is greater than 35 μm, the surface will be uneven after curing; if the particle size is less than 0.5 μm, it is easy to agglomerate, which will affect its overall performance after curing. For example, the particle size of the functional powder 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 by room temperature curing or heating curing;

[0069] Wherein, the room temperature curing time is 3h;

[0070] The temperature of the heating and curing is 60° C. to 200° C., and the time of the heating and curing is 0.5 h to 3 h.

[0071] The heating curing treatment method is one or both of an infrared heating module and a far infrared heater to ensure that the coating is completely cured.

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

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

[0074] (1) Excellent high-temperature performance: Polyimide and water glass matrix (Na2O·nSiO2) form an interpenetrating network, which can still maintain the integrity and mechanical strength of the bonding layer at 900°C, significantly better than traditional organic adhesives. At the same time, silicon-oxygen tetrahedron fills the pyrolysis gaps of polyimide, reduces thermal stress concentration, and avoids high-temperature cracking or peeling.

[0075] (2) Multifunctional synergistic effect: The aromatic heterocyclic structure of polyimide inhibits electronic conduction, giving the binder insulation and weak magnetization properties, making it suitable for electromagnetic 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 to enhance the interfacial binding energy; the nanopores of silica gel achieve physical anchoring and enhance shear strength.

[0076] (3) Environmental protection and process controllability: Deionized water is used as the main solvent to avoid volatile organic matter pollution and meet environmental protection requirements. At the same time, the constant temperature control of 60℃~80℃ combined with the uniform feeding of 2~10g / min ensures the 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 used on metal / metal or metal / ceramic interfaces. At the same time, it can be mixed with powders such as alumina and silicon carbide to customize thermal insulation, insulation, and anti-oxidation coatings.

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

[0079] (6) Significant economic benefits: Inorganic raw materials such as sodium silicate and sodium hydroxide account for a high proportion, and the material cost is reduced by 40% to 50% compared with the all-organic system. At the same time, when the binder is used in aluminum electrolytic cells, the life of the anti-oxidation coating is increased by 2 to 3 times, reducing the frequency of shutdown maintenance.

[0080] The present application will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are intended only to illustrate the present application and are not intended to limit the scope of the present application. The experimental methods for which specific conditions are not specified in the following examples are usually measured according to industry standards. If there is no corresponding industry standard, then the conditions recommended by the manufacturer are followed.

[0081] Example 1

[0082] 8 parts of sodium hydroxide are added to 50 parts of deionized water at 65°C in a stirring state at a speed of 10 g / min. After the mixture is completely dissolved, 10 parts of sodium silicate are added at a speed of 5 g / min and stirred until the mixture is completely dissolved. Then 20 parts of polyimide (CAS No.: 26023-21-2) are added at a speed of 10 g / min and dissolved until the mixture is completely dissolved. Then 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) are added in sequence and stirred and mixed to obtain a multifunctional adhesive.

[0083] The prepared adhesive was applied with a brush on two clean iron sheets with a size of 100 mm × 50 mm × 2 mm, and then the two iron sheets were bonded together and placed in a constant temperature drying oven at 100°C for 1 hour. After being taken out, the two iron sheets were firmly bonded, with strong bonding strength and adhesion level 0 (GB / T 9286).

[0084] Example 2

[0085] 10 parts of sodium hydroxide were added to 60 parts of deionized water at 70°C in a stirring state at a rate of 10 g / min. After the water was completely dissolved, 8 parts of sodium silicate were added at a rate of 5 g / min and stirred until the water was completely dissolved. Then 10 parts of polyimide were added at a rate of 10 g / min until the water was completely dissolved. Then 10 parts of silica gel, 1 part of propylene glycol block polyether (L64) and 1 part of succinic acid were added in sequence and the mixture was stirred and mixed to obtain a multifunctional adhesive.

[0086] The prepared binder was mixed with alumina powder and mica powder in a mass ratio of 1:1:1 and stirred evenly, and then coated on a common aluminum alloy slot cover plate with a clean surface with a coating thickness of 1 mm, and then cured at room temperature for 2 hours.

[0087] The prepared thermal insulation ordinary aluminum alloy tank cover has a smooth surface without peeling or cracking, strong bonding strength, adhesion level 0 (GB / T 9286), and the weight is equivalent to that of ordinary tank covers. After being used on the electrolytic cell, the surface temperature is equivalent to 3 / 4 of the original temperature, effectively reducing the heat dissipation of the upper part of the electrolytic cell.

[0088] Example 3

[0089] 8 parts of sodium hydroxide were added to 40 parts of deionized water at 60°C in a stirring state at a rate of 10 g / min. After the mixture was completely dissolved, 15 parts of sodium silicate were added at a rate of 5 g / min and stirred until the mixture was completely dissolved. Then 16 parts of polyimide were added at a rate of 10 g / min until the mixture was completely dissolved. Then 10 parts of silica gel, 8 parts of succinic acid, and 3 parts of propylene glycol block polyether (L64) were added in sequence and the mixture was stirred and mixed 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, and then coated on a common aluminum alloy slot cover plate with a clean surface with a coating thickness of 0.5 mm, and then cured at room temperature for 2 hours.

[0091] The prepared magnetic shielding ordinary aluminum alloy slot cover has a smooth surface without peeling or cracking, strong bonding strength, and adhesion level 0 (GB / T 9286). The weight is equivalent to that of an ordinary slot cover. The magnetic field after shielding is equivalent to 1 / 16 of the original magnetic field strength, effectively shielding the magnetic field on the upper part of the electrolytic cell.

[0092] Example 4

[0093] 6 parts of sodium hydroxide were added to 50 parts of deionized water at 75°C in a stirring state at a rate of 10 g / min. After the water was completely dissolved, 10 parts of sodium silicate were added at a rate of 5 g / min and stirred until the water was completely dissolved. Then 18 parts of polyimide were added at a rate of 10 g / min until the water was completely dissolved. Then 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 in sequence and stirred and mixed 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, and then coated on a carbon block of Φ35mm×20mm in thickness. The mixture was then placed in a constant temperature drying oven and maintained at 100°C for 0.5h.

[0095] The prepared antioxidant carbon block has a smooth surface without peeling or cracking, strong bonding force, and adhesion level 0 (GB / T9286). After being kept together with ordinary carbon blocks at a high temperature of 950°C for 24 hours, the mass loss rate is only 4.9%, and the antioxidant performance is 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 of Example 1, the following modifications are made:

[0098] No succinic acid was added to the binder.

[0099] The prepared adhesive was applied with a brush on two clean iron sheets with a size of 100 mm × 50 mm × 2 mm, and then the two iron sheets were bonded together and placed in a constant temperature drying oven at 100 ° C for 1 hour. After being taken out, the two iron sheets were firmly bonded, and the adhesion was level 1 (GB / T 9286).

[0100] Comparative Example 2

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

[0102] No polyimide is added to the adhesive.

[0103] The prepared binder was mixed with alumina powder and mica powder in a mass ratio of 1:1:1 and stirred evenly, and then coated on a common aluminum alloy slot cover plate with a clean surface with a coating thickness of 1 mm, and then cured at room temperature for 2 hours.

[0104] The prepared thermal insulation ordinary aluminum alloy tank cover has a smooth surface without peeling or cracking, strong bonding strength, adhesion level 0 (GB / T 9286), and the weight is equivalent to that of ordinary tank covers. The surface temperature after use on the electrolytic cell is equivalent to 4 / 5 of the original temperature, slightly reducing the heat dissipation of the upper part of the electrolytic cell.

[0105] Comparative Example 3

[0106] Based on the disclosure of 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, and then coated on a common aluminum alloy slot cover plate with a clean surface with a coating thickness of 0.5 mm, and then cured at room temperature for 2 hours.

[0109] The surface of the prepared magnetic shielding ordinary aluminum alloy slot cover has blistering and peeling, and the adhesion is level 1 (GB / T9286). The weight is equivalent to that of the ordinary slot cover. The magnetic field after shielding is equivalent to 1 / 12 of the original magnetic field strength, which can shield the magnetic field on the upper part of the electrolytic cell.

[0110] Comparative Example 4

[0111] Based on the disclosure of 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, and then coated on a carbon block of Φ35mm×20mm in thickness of 1mm, and then placed in a constant temperature drying oven at 100°C for 0.5h.

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

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

[0116] In the embodiments of the present application, a multifunctional binder for aluminum electrolysis is prepared, which has a simple preparation method, strong bonding properties, can bond metals, metals and ceramics, etc., and has a low production cost.

[0117] In the embodiments of the present application, the prepared multifunctional binder for aluminum electrolysis can be effectively filled with corrosion-resistant powder, thermal insulation powder, insulating powder and magnetic shielding powder, etc., and coated on the required parts of the electrolytic cell. It has the functions of heat prevention, insulation, anti-oxidation and weak magnetization, which promotes the efficient, low-consumption and energy-saving operation of the aluminum electrolytic cell, saves production costs and improves economic benefits.

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

[0119] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A multifunctional binder for aluminum electrolysis, which comprises the following chemical components, measured by mass: 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.

2. The adhesive according to claim 1, characterized in that In parts by mass, the binder further comprises at least one of the following chemical components: 2 to 10 parts of silica gel, 0.01 to 1 part of nonionic polyacrylamide, and 0.01 to 1 part of polymerized ferric sulfate.

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

4. A method for preparing the binder according to any one of claims 1 to 3, comprising: Obtaining various raw materials of the binder; Under stirring conditions, sequentially adding the sodium hydroxide, the sodium silicate and the polyimide to the solvent with a set temperature to obtain a mixed solution; The succinic acid, the propylene glycol block polyether, the silica gel, the nonionic polyacrylamide and the polymerized ferric sulfate are added into the mixed solution to obtain the binder.

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

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

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

8. An application of the adhesive according to any one of claims 1 to 3, comprising: Mixing the binder with the functional powder to obtain a mixture; The mixed material is coated on a set part of an aluminum electrolytic cell and solidified to be used for heat preservation, insulation, oxidation resistance and weak magnetization of the set part.

9. The use according to claim 8, characterized in that: The particle size of the functional powder is 0.5 μm to 35 μm, 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 use according to claim 8, characterized in that: The curing is performed by room temperature curing or heating curing; Wherein, the room temperature curing time is 3h; The temperature of the heating and curing is 60° C. to 200° C., and the time of the heating and curing is 0.5 h to 3 h.

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