Aluminum-based high-entropy oxide electrolytic aluminum anode coating material as well as preparation method and application thereof

Abstract

The invention provides an aluminum-based high-entropy oxide electrolytic aluminum anode coating material. The aluminum-based high-entropy oxide electrolytic aluminum anode coating material is prepared from aluminum-based high-entropy oxide, water, a structure enhancer, a glaze forming agent, a film forming agent and a binder according to a certain proportion. The aluminum-based high-entropy oxide is prepared from aluminum-based high-entropy alloy powder through self-propagating high-temperature synthesis, and the aluminum-based high-entropy alloy powder is formed by mixing aluminum, iron, magnesium, copper and nickel according to a certain metal element molar ratio. The invention also provides a preparation method of the coating material. The aluminum-based high-entropy oxide is used for replacing aluminum oxide in a conventional anode assembly coating material, the comprehensive performance of the coating is improved by adjusting the components of the aluminum-based high-entropy oxide powder and optimally controlling parameters in the preparation method, the coating material is endowed with better corrosion resistance, high temperature resistance and high fracture toughness, and the service life of the coating material is prolonged. And a better protection effect is provided for the electrolytic aluminum anode assembly, the service life of the electrolytic aluminum anode assembly is effectively prolonged, the production cost is reduced, and good application prospects are achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of new metallurgical materials, and specifically relates to an aluminum-based high entropy oxide electrolytic aluminum anode coating material and a preparation method thereof, and also relates to the application of the aluminum-based high entropy oxide electrolytic aluminum anode coating material in the electrolytic aluminum industry. Background Art

[0002] Nowadays, aluminum alloys have been widely used in various industries and have played an indispensable role, so the electrolytic aluminum industry is particularly important. During the electrolysis process, high-quality carbon anode resources are becoming increasingly scarce, and as a result, the carbon anode may be doped with trace metal elements, and the presence of these trace metal elements will accelerate the oxidation of the carbon anode and increase energy consumption and loss of anode carbon blocks. There are currently two solutions to this problem. One is to reduce the content of trace metal elements in the carbon block, and the other is to spray a protective layer on the carbon anode to slow down the oxidation loss of the anode. The feasibility of the former solution is poor, and there is currently no effective way to remove trace metal elements in the carbon anode, while the second solution is technically feasible and is currently more mature.

[0003] When working, the anode carbon blocks have to withstand the high temperature generated during the electrolysis of aluminum for a long time, and also have to deal with the corrosion of oxidizing media such as oxygen, hydrogen fluoride, and cryolite, which leads to continuous loss of anode carbon blocks within a working cycle, resulting in slag falling, hot tanks, cathode damage, increased energy consumption, low yield, impure products and other problems.

[0004] The anode anti-oxidation coating is a coating sprayed on the surface of the carbon anode. It has the characteristics of curing at room temperature, strong mechanical properties and high hardness. In a high temperature environment, the grains shrink and the cracks are reduced, making the structure denser, thereby achieving the effect of oxidation resistance and isolating the carbon anode from the outside world.

[0005] In the existing technology, for example, patent CN 110577758 A proposes to reuse aluminum ash as a raw material for coating, while the base material of the coating in patent CN 113135741 A is aluminum oxide powder. These two solutions are relatively simple in the preparation process, but their base material components are single and may not be able to effectively cope with complex working conditions. Their application in actual industrial production is subject to a certain degree of limitation.

[0006] Based on this, providing an electrolytic aluminum anode coating material with higher strength and higher fracture toughness, which can show better application performance in both high and low temperature environments, is a technical problem that needs to be solved urgently. Summary of the invention

[0007] One of the purposes of the present invention is to provide a method for preparing an aluminum-based high entropy oxide electrolytic aluminum anode coating material.

[0008] A second object of the present invention is to provide an aluminum-based high entropy oxide electrolytic aluminum anode coating material.

[0009] The third purpose of the present invention is to provide an aluminum-based high entropy oxide electrolytic aluminum anode coating material for use in the electrolytic aluminum industry.

[0010] The technical solution adopted by the present invention to achieve one of the purposes is: to provide an aluminum-based high entropy oxide electrolytic aluminum anode coating material, which is composed of the following components by weight percentage: Aluminum-based high entropy oxide 40%-41%; water 30%-31%; structural strengthening agent 20%-23%; glaze forming agent 3%-6%; film forming agent 2%-4%; binder 0.1%-0.4%; The aluminum-based high entropy oxide is prepared from aluminum-based high entropy alloy powder by self-propagating high-temperature synthesis. In the aluminum-based high entropy alloy powder, the molar ratio of aluminum, iron, magnesium, copper and nickel is 0.6-0.63: 0.15-0.17: 0.05-0.06: 0.1-0.11: 0.03-0.1.

[0011] The overall idea and inventive principle of the present invention are as follows: Due to its complex composition, high entropy oxides usually exhibit the characteristics of high fracture toughness and high strength. The present invention provides an aluminum-based high entropy oxide electrolytic aluminum anode coating material, which uses aluminum-based high entropy oxide to replace the aluminum oxide in conventional electrolytic aluminum anode protective coatings to improve the application performance of the coating material in harsh environments such as high strength, high temperature and corrosion.

[0012] The aluminum-based high entropy oxide metal provided by the present invention includes five metal elements: aluminum, iron, magnesium, copper and nickel. Among them, aluminum is the same as the metal element of the raw material in the electrolytic cell. As the main component, it can effectively protect the carbon block and the steel claw from corrosion by the aluminum liquid, and at the same time, no impurity elements are introduced, and the aluminum liquid will not be polluted; copper, iron, and nickel, which are common inert anode material components, are selected for doping. The Gibbs free energy of the oxidation reaction of the above metal elements is negative, and the generated oxides are relatively stable, which is conducive to extending the service life of the carbon block and the steel claw; further, according to the coordination requirements of the Hume-Rothery rule, magnesium is selected as one of the components, which can effectively reduce the melting point of the high entropy alloy during the molding process, making the coating easy to prepare.

[0013] Furthermore, the different proportions of each metal element in the aluminum-based high entropy oxide will lead to changes in coating performance, performance, molding conditions and antioxidant mechanism. The present invention combines the coating with the complex working conditions in the electrolytic cell. On the basis of the conventional preparation of high entropy alloys with equimolar ratios of metal elements, the ratio of each metal element in the aluminum-based high entropy oxide is optimized and adjusted: the aluminum element is used as the main component because the raw material in the electrolytic cell is mainly alumina, which protects the carbon block without introducing impurities, and even the detached part can be used as the raw material for electrolytic aluminum. In the Cu-Fe-Ni system in the composition, Cu has a higher mobility during the corrosion process, and will first move to the outside of the anode to react with oxygen to form an oxide layer, which prevents oxygen from reacting with the bulk alloy, and the part lacking Cu can form NiFe 2 O 4 , further preventing Cu from diffusing outward and oxygen from penetrating into the carbon block and steel claws, so the contents of Cu, Fe and Ni need to be maintained within an appropriate range. In addition, under vacuum and high-temperature oxygen atmosphere, aluminum oxide and magnesium oxide films will continue to form on the surface of the Mg and Al systems to prevent the anode from being further oxidized. However, Al is the main element. If too much Mg is added, according to the Hume-Rothery law, the melting point of the material will be too low, affecting the high-temperature performance. At the same time, Mg-based intermetallic compounds will also be generated, increasing the brittleness of the material and making it more prone to cracking. Therefore, based on the above reasons and a large number of previous experimental results, this application limits the molar ratio of the above metal elements to 0.6-0.63: 0.15-0.17: 0.05-0.06: 0.1-0.11: 0.03-0.1.

[0014] Furthermore, the structural reinforcing agent includes quartz sand and / or silica ore. Preferably, the structural reinforcing agent is quartz sand, wherein SiO 2 The content is not less than 99wt.%.

[0015] Furthermore, the glaze forming agent includes at least two of potassium feldspar, talc, sodium feldspar, olivine, and amphibole. These components can form a glaze surface under high temperature conditions, fill the cracks caused by the inconsistent thermal expansion coefficients of the coating, the carbon block, and the steel claw, reduce the contact of the carbon block and the steel claw with the external oxidizing atmosphere, and extend the life of the electrolytic aluminum anode assembly to a certain extent.

[0016] Preferably, the glaze former is a mixture of potassium feldspar and talc, with potassium feldspar accounting for 43 wt.%-51 wt.% and talc accounting for 49 wt.%-57 wt.%.

[0017] Furthermore, the film-forming agent includes ethyl cellulose and / or polydimethylsiloxane; the binder is a silane coupling agent. Due to its unique silicon element structure, the silane coupling agent has an excellent coupling effect on silicon-containing fillers, and improves the interface strength, wear resistance and weather resistance of the composite material through chemical bonding.

[0018] The technical solution adopted by the present invention to achieve the second purpose is: to provide a method for preparing the aluminum-based high entropy oxide electrolytic aluminum anode coating material according to one of the purposes of the present invention, comprising the following steps: S1. Preparing metal powders of aluminum, iron, magnesium, copper and nickel according to the molar ratio of each element, and subjecting them to mechanical alloying treatment to obtain aluminum-based high entropy alloy powder; S2, the aluminum-based high entropy alloy powder is synthesized by self-propagating high temperature synthesis to obtain aluminum-based high entropy oxide powder; S3, mixing the aluminum-based high entropy oxide powder with a binder for coating and modification to obtain a modified aluminum-based high entropy oxide powder; mixing the modified aluminum-based high entropy oxide powder with a structural reinforcing agent for a first ball milling treatment to obtain a first mixture; S4, crushing and second ball-milling the glaze forming agent to obtain a second mixture; mixing the film forming agent with water to obtain a film forming agent suspension; adding the first mixture and the second mixture to the film forming agent suspension to obtain a third mixture; S5. Place the third mixture under certain temperature and pressure conditions to react and obtain an aluminum-based high entropy oxide electrolytic aluminum anode coating material.

[0019] Furthermore, in step S1, the mechanical alloying treatment is performed by ball milling, using zirconium oxide balls as ball milling media, with a rotation speed of 250-350 rpm and a time of 2-3 hours.

[0020] Preferably, in step S1, in the raw materials of the aluminum-based high entropy alloy powder, the molar ratio of aluminum, iron, magnesium, copper and nickel is 0.6: 0.15-0.2: 0.05: 0.1: 0.05-0.1; in the ball milling treatment, the ball-to-material ratio is 5: 1, and the number ratio of 5mm, 7mm and 12mm grinding balls is 16-18: 8-11: 2-3.

[0021] Furthermore, in step S2, in the self-propagating high temperature synthesis, a mixture of Al and CuO is used as thermite, and the process is carried out under the conditions of introducing a protective gas and continuously cooling the collecting assembly, and the particle size of the aluminum-based high entropy oxide powder is 200-350 nm.

[0022] Preferably, in the self-propagating high temperature synthesis, the mass percentages of the raw materials are as follows: aluminum-based high entropy alloy powder 45%-58%, Al powder 10%-12.5%, CuO powder 30%-37.5%, CaSO 4The aluminum-based high entropy oxide powder prepared by the present invention has a particle size between 200-350nm, and the powder particle size is small, which is conducive to the uniformity of the composition, and the small particles can achieve the effect of strengthening the structure.

[0023] Furthermore, in step S3, the binder is a silane coupling agent, the coating modification is carried out at room temperature, the coating modification equipment is a coating type powder modification machine, and the coating modification time is 1-2h.

[0024] Furthermore, in step S3, the structural reinforcing agent is quartz sand, and the modified aluminum-based high entropy oxide powder is mixed with quartz sand for a first ball milling treatment for 3-4 hours, with a ball-to-material ratio of 5:1. Zirconia grinding balls with diameters of 5 mm, 7 mm and 12 mm are mixed in a quantitative ratio of (10-12): (2-3): (0.6-1) as ball milling media, and the particle size of the obtained first mixture is 450-550 mesh.

[0025] Furthermore, in step S4, the glaze forming agent is formed by mixing potassium feldspar and talc, and the potassium feldspar and talc are crushed by a roller crusher and then put into a ball mill for ball milling for 1-2 hours, with a ball-to-material ratio of 3.5:1, and 304 stainless steel grinding balls with diameters of 6 mm and 8 mm are mixed in a quantity ratio of (6-10): (2-3) as ball milling media, so that the particle size of the second mixture is 500-650 mesh.

[0026] Furthermore, in step S4, the film-forming agent is ethyl cellulose, and ethyl cellulose is added to water, and stirred in a closed reactor at room temperature and pressure for 0.5-1 h to obtain a suspension of ethyl cellulose.

[0027] Furthermore, in step S5, the reaction is carried out under stirring conditions at a temperature of 130-150° C. and a pressure of 1.4-1.6 MPa, and the reaction time is 2-3 h.

[0028] The third object of the present invention is to provide an aluminum-based high entropy oxide electrolytic aluminum anode coating material according to one of the objects of the present invention or an aluminum-based high entropy oxide electrolytic aluminum anode coating material prepared by the preparation method described in the second object of the present invention for use in the electrolytic aluminum industry.

[0029] Furthermore, the application includes: providing a protective coating on the surface of the anode carbon block and / or steel claw of the electrolytic aluminum anode assembly, wherein the protective coating is made of the aluminum-based high entropy oxide electrolytic aluminum anode coating material provided by one of the purposes of the present invention or the second purpose of the present invention.

[0030] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention provides an aluminum-based high-entropy oxide electrolytic aluminum anode coating material, which uses aluminum-based high-entropy oxide instead of aluminum oxide. Since high-entropy oxide has the characteristics of high strength, high hardness, high wear resistance, etc. similar to high-entropy alloys, it also has excellent corrosion resistance, high temperature resistance and high fracture toughness, which improves the overall performance of the coating. The addition of a glazing agent can form a glaze under high temperature conditions, fill the cracks caused by the inconsistent thermal expansion coefficients of the coating and the carbon block and steel claws, and reduce the contact between the carbon block and the steel claws and the external oxidizing atmosphere. The coating material provided by the present invention can provide better protection for the electrolytic aluminum anode assembly and effectively extend the service life of the electrolytic aluminum anode assembly.

[0031] (2) The present invention provides a method for preparing an aluminum-based high entropy oxide electrolytic aluminum anode coating material, which uses an aluminum-based high entropy alloy powder reaction to obtain an aluminum-based high entropy oxide powder with a particle size between 200-350nm by high-temperature self-propagating synthesis. The powder particles are small in size, which is conducive to the homogenization of the composition. At the same time, small particles can achieve the effect of strengthening the structure. The present invention improves the comprehensive performance of the coating by adjusting the composition of the aluminum-based high entropy oxide powder and optimizing the process parameters in the preparation method, so that it can better meet the application requirements of electrolytic aluminum anode protection and provide better protection for the electrolytic aluminum anode assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A schematic flow chart of a method for preparing an aluminum-based high entropy oxide electrolytic aluminum anode coating material provided by the present invention; Figure 2 A schematic diagram of the structure of a high-temperature self-propagating reaction device used in an embodiment of the present invention; Figure 3 Schematic diagram of the preparation process of aluminum-based high entropy oxide powder in an embodiment of the present invention; Figure 4 This is a SEM scan of the high entropy oxide powder prepared in Example 1 of the present invention; Figure 5 The anode assembly (just sprayed) of the coating material prepared by spraying Example 1 in the application example of the present invention; Figure 6 The anode assembly (after spraying) of the coating material obtained by spraying Example 1 in the application example of the present invention; Among them, 1-graphite crucible; 2-thermites and substances to be reacted; 3-ignition powder; 4-cardboard; 5-waste slag tank; 6-fastening screws; 7-fan; 8-collecting device with corrugated plate; 9-water tank; 10-water cooling pipe; 11-coil electronic ignition head; 12-ignition device capacitor; 13-dry battery. DETAILED DESCRIPTION

[0033] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0034] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0035] An embodiment of the present invention provides an aluminum-based high-entropy oxide electrolytic aluminum anode coating material, which is composed of the following components by weight percentage: 40%-41% aluminum-based high-entropy oxide; 30%-31% water; 20%-23% structural reinforcing agent; 3%-6% glaze former; 2%-4% film former; 0.1%-0.4% binder; the aluminum-based high-entropy oxide is prepared from aluminum-based high-entropy alloy powder by self-propagating high-temperature synthesis, and the molar ratio of aluminum, iron, magnesium, copper and nickel in the aluminum-based high-entropy alloy powder is 0.6-0.63: 0.15-0.17: 0.05-0.06: 0.1-0.11: 0.03-0.1.

[0036] The preparation method of the aluminum-based high entropy oxide electrolytic aluminum anode coating material is as follows: Figure 1 As shown, the following steps are included: Step 1: Prepare aluminum, iron, magnesium, copper, and nickel metal powders according to the molar ratio of each element in the aluminum-based high entropy alloy powder, and obtain aluminum-based high entropy alloy powder by mechanical alloying treatment; the mechanical alloying treatment is ball milling treatment, using zirconium oxide balls as ball milling media, and the ball milling treatment time is 2-3 hours. In the ball milling treatment, the ball-to-material ratio is 5:1, and the number ratio of 5mm, 7mm, and 12mm grinding balls is 16-18:8-11:2-3.

[0037] Step 2: The aluminum-based high entropy alloy powder is synthesized by self-propagating high temperature synthesis to obtain aluminum-based high entropy oxide powder. The reaction involves a device such as Figure 2 As shown, the process diagram is as follows Figure 3 As shown; in the self-propagating high temperature synthesis, a mixture of Al and CuO is used as thermite, and the process is carried out under the conditions of introducing protective gas and continuously cooling the collecting assembly. The particle size of the aluminum-based high entropy oxide powder is 200-350nm; in the self-propagating high temperature synthesis, the mass percentage of each raw material is as follows: 50% aluminum-based high entropy alloy powder, 12% Al powder, 36% CuO powder, and 12% CaSO 4 Powder is 2%.

[0038] Step 3: The aluminum-based high entropy oxide powder is mixed with a binder for coating modification to obtain a modified aluminum-based high entropy oxide powder; the modified aluminum-based high entropy oxide powder is mixed with a structural reinforcing agent for a first ball milling treatment to obtain a first mixture; wherein the binder is a silane coupling agent, the coating modification is carried out at room temperature, the coating modification equipment is a coated powder modification machine, and the coating modification time is 1-2 hours. The structural reinforcing agent is quartz sand, the modified aluminum-based high entropy oxide powder is mixed with quartz sand for a first ball milling treatment for 3-4 hours, the ball-to-material ratio is 5:1, and zirconia grinding balls with diameters of 5mm, 7mm and 12mm are used as ball milling media in a ratio of (10-12): (2-3): (0.6-1), and the particle size of the first mixture obtained is 450-550 mesh.

[0039] Step 4: crushing and second ball milling the glaze forming agent to obtain a second mixture; mixing the film forming agent with water to obtain a film forming agent suspension; adding the first mixture and the second mixture to the film forming agent suspension to obtain a third mixture; the glaze forming agent is a mixture of potassium feldspar and talc (potassium feldspar accounts for 43wt.%-51wt.%, and talc accounts for 49wt.%-57wt.%), the potassium feldspar and talc are crushed by a roller crusher and then put into a ball mill for ball milling for 1-2h, the ball-to-material ratio is 3.5:1, and 304 stainless steel grinding balls with diameters of 6mm and 8mm are used as ball milling media in a ratio of (6-10): (2-3), and the particle size of the second mixture is 500-650 mesh. The film forming agent is ethyl cellulose, and ethyl cellulose is added to water, and stirred in a closed reactor at room temperature and pressure for 0.5-1h to obtain a suspension of ethyl cellulose.

[0040] Step 5: Place the third mixture under certain temperature and pressure conditions for reaction. The reaction is carried out under stirring conditions at a temperature of 130-150°C and a pressure of 1.4-1.6MPa. The reaction time is 2-3h to obtain an aluminum-based high entropy oxide electrolytic aluminum anode coating material.

[0041] In the above step 2, the schematic diagram of the structure of the device used in the self-propagating synthesis reaction is as follows Figure 2As shown. The device consists of a waste slag tank 5, a graphite crucible 1, a collection component with a corrugated plate, and an electronic ignition component. The waste slag tank 5 is provided with a groove, on which a cardboard 4 is placed, the graphite crucible 1 contains thermite and a substance to be reacted 2, and an ignition powder 3 is sprinkled on the surface, the graphite crucible 1 is placed above the cardboard 4, and a slag discharge hole is opened at the bottom. The ignition powder 3 is ignited by the electronic ignition component, thereby initiating a self-propagating reaction below. The electronic ignition component includes a coil electronic ignition head 11, an ignition device capacitor 12, and a dry battery 13. The collection component with a corrugated plate includes a top wall and a side wall, and the side wall is detachably connected to the waste slag tank. The top wall is provided with a water tank 9, and the side walls include a pair of first side walls in an inverted right-angle trapezoid, a second side wall arranged in the vertical direction, and a third side wall arranged obliquely; the second side wall is provided with an air pump and a fan 7 for conveying protective gas toward the third side wall; the third side wall is provided with a water cooling pipe 10, and the inlet of the water cooling pipe 10 is connected to the outlet of the water tank 9. Corrugated plates for collecting products are respectively arranged on the top wall and the side of the third side wall facing the graphite crucible.

[0042] The above device adds structures such as fans, water tanks, and water cooling pipes, which are conducive to the generation of finer high-entropy oxide particles during the reaction. While the oxidation is relatively complete and aggregation is not likely to occur, it is conducive to the generation of high-entropy oxide products with smaller particle sizes and more uniform distribution. At the same time, the device also connects the four corners of the collection component and the waste slag tank with fastening screws. During the reaction, the waste slag tank and the collection device are an integrated structure, which can effectively prevent the huge pressure generated by the reaction from washing away the collection device, ensuring the smooth progress of the reaction.

[0043] The present invention will be further described below in conjunction with specific embodiments, but the present invention is not limited thereto.

[0044] The molar ratios of the components of the aluminum-based high entropy alloy powders and the contents of the components in the coating materials in Examples 1-3 of the present invention are shown in Table 1, respectively.

[0045] Table 1

[0046] Embodiment 1: 100kg of aluminum-based high entropy oxide electrolytic aluminum anode coating, the components are: 40kg aluminum-based high entropy oxide powder, accounting for 40% of the total mass, 20kg of quartz sand, accounting for 20% of the total mass, 30kg of water, accounting for 30% of the total mass, Glaze forming agent: potassium feldspar 2.58kg, accounting for 2.58% of the total mass, talc 3.42kg, accounting for 3.42% of the total mass, Film former: 3.9 kg of ethyl cellulose, accounting for 3.9% of the total mass. Binder: 0.1 kg of silane coupling agent, accounting for 0.1% of the total mass.

[0047] The method for preparing aluminum-based high entropy oxide electrolytic aluminum anode coating in this embodiment includes the following steps: 1. Mix aluminum powder, iron powder, magnesium powder, copper powder, and nickel powder in a molar ratio of 0.6:0.17:0.06:0.11:0.03, and then use a high-temperature self-propagating reaction to obtain high-entropy oxide powder, and then take out 40 kg.

[0048] 2. The aluminum-based high entropy oxide powder prepared in step 1 and 0.1 kg of silane coupling agent are placed in a coated powder modifier at room temperature and continuously modified for 0.5-1.5 hours to obtain the modified high entropy oxide powder.

[0049] 3. The modified high entropy oxide powder and 20 kg of quartz sand were put into a ball mill and continuously ball milled for 3-4 hours. The ball-to-material ratio was 5:1. Zirconia grinding balls with diameters of 5 mm, 7 mm and 12 mm were mixed in a quantitative ratio of (10-12): (2-3): (0.6-1) as ball milling media. The obtained product particle size was 450-550 mesh.

[0050] 4. 2.58 kg of potassium feldspar and 3.42 kg of talc were crushed by a roll crusher and put into a ball mill for ball milling for 1-2 hours. The ball-to-material ratio was 3.5:1. 304 stainless steel grinding balls with diameters of 6 mm and 8 mm were mixed in a ratio of (6-10): (2-3) as ball milling media to obtain a product with a particle size of 500-650 mesh.

[0051] 5. Add 3.9 kg of ethyl cellulose to 30 kg of water, and stir for 0.5-1 h at room temperature and pressure in a closed reactor to obtain a suspension of ethyl cellulose.

[0052] 6. Add the ball-milled mixture in steps 3 and 4 to the solution in step 5, and stir the mixture in a reactor at 130-150° C. and 1.4-1.6 MPa for 2-3 hours to obtain the finished product.

[0053] Example 2 100kg of aluminum-based high entropy oxide electrolytic aluminum anode coating, the components are: 41kg aluminum-based high entropy oxide powder, accounting for 41% of the total mass, 23kg of quartz sand, accounting for 23% of the total mass, Water 30.6kg, accounting for 31% of the total mass, Glaze forming agent: potassium feldspar 1.29kg, accounting for 1.29% of the total mass, talc 1.71kg, accounting for 1.71% of the total mass, Film-forming agent: 2kg of ethyl cellulose, accounting for 2% of the total mass. Adhesive phase: 0.4 kg of silane coupling agent, accounting for 0.4% of the total mass.

[0054] The method for preparing aluminum-based high entropy oxide electrolytic aluminum anode coating in this embodiment includes the following steps: 1. Aluminum powder, iron powder, magnesium powder, copper powder, and nickel powder were mixed in a molar ratio of 0.6:0.15:0.05:0.1:0.1, and then high-entropy oxide powder was obtained by high-temperature self-propagating reaction, and 41 kg was taken out.

[0055] 2. The aluminum-based high entropy oxide powder prepared in step 1 and 0.4 kg of silane coupling agent are placed in a coated powder modifier at room temperature and continuously modified for 0.5-1.5 hours to obtain the modified high entropy oxide powder.

[0056] 3. The modified high entropy oxide powder and 23 kg of quartz sand were put into a ball mill and continuously ball milled for 3-4 hours. The ball-to-material ratio was 5:1. Zirconia grinding balls with diameters of 5 mm, 7 mm and 12 mm were mixed in a quantitative ratio of (10-12): (2-3): (0.6-1) as ball milling media. The obtained product particle size was 450-550 mesh.

[0057] 4. 1.29 kg of potassium feldspar and 1.71 kg of talc were crushed by a roll crusher and put into a ball mill for ball milling for 1-2 hours. The ball-to-material ratio was 3.5:1. 304 stainless steel grinding balls with diameters of 6 mm and 8 mm were mixed in a ratio of (6-10): (2-3) as ball milling media to obtain a product with a particle size of 500-650 mesh.

[0058] 5. Add 2 kg of ethyl cellulose to 30.6 kg of water, and stir for 0.5-1 h at room temperature and pressure in a closed reactor to obtain a suspension of ethyl cellulose.

[0059] 6. Add the ball-milled mixture in steps 3 and 4 to the solution in step 5, and stir the mixture in a reactor at 130-150° C. and 1.4-1.6 MPa for 2-3 hours to obtain the finished product.

[0060] Example 3 100kg of aluminum-based high entropy oxide electrolytic aluminum anode coating, the components are: 40.5kg aluminum-based high entropy oxide powder, accounting for 40.5% of the total mass, 23kg of quartz sand, accounting for 23% of the total mass, Water 30.5kg, accounting for 30.5% of the total mass, Glaze forming agent: potassium feldspar 1.29kg, accounting for 1.29% of the total mass, talc 1.71kg, accounting for 1.71% of the total mass, Film-forming agent: 2.8 kg of ethyl cellulose, accounting for 2.8% of the total mass. Adhesive phase: 0.2 kg of silane coupling agent, accounting for 0.2% of the total mass.

[0061] The method for preparing aluminum-based high entropy oxide electrolytic aluminum anode coating in this embodiment includes the following steps: 1. Aluminum powder, iron powder, magnesium powder, copper powder and nickel powder were mixed in a molar ratio of 0.6:0.15:0.05:0.1:0.1, and then high entropy oxide powder was prepared by high temperature self-propagating reaction, and 40.5 kg was taken out.

[0062] 2. The aluminum-based high entropy oxide powder prepared in step 1 and 0.2 kg of silane coupling agent are placed in a coated powder modifier at room temperature and continuously modified for 0.5-1.5 hours to obtain the modified high entropy oxide powder.

[0063] 3. The modified high entropy oxide powder and 23 kg of quartz sand were put into a ball mill and continuously ball milled for 3-4 hours. The ball-to-material ratio was 5:1. Zirconia grinding balls with diameters of 5 mm, 7 mm and 12 mm were mixed in a quantitative ratio of (10-12): (2-3): (0.6-1) as ball milling media. The obtained product particle size was 450-550 mesh.

[0064] 4. 1.29 kg of potassium feldspar and 1.71 kg of talc were crushed by a roll crusher and put into a ball mill for ball milling for 1-2 hours. The ball-to-material ratio was 3.5:1. 304 stainless steel grinding balls with diameters of 6 mm and 8 mm were mixed in a ratio of (6-10): (2-3) as ball milling media to obtain a product with a particle size of 500-650 mesh.

[0065] 5. Add 2.8 kg of ethyl cellulose to 30.5 kg of water, and stir for 0.5-1 h at room temperature and pressure in a closed reactor to obtain a suspension of ethyl cellulose.

[0066] 6. Add the ball-milled mixture in steps 3 and 4 to the solution in step 5, and stir the mixture in a reactor at 130-150° C. and 1.4-1.6 MPa for 2-3 hours to obtain the finished product.

[0067] Application Examples The coating material prepared in Example 1 of the present invention is sprayed on the anode steel claw and the anode carbon block, with a spray thickness of 0.95 mm on the anode carbon block and 0.75 mm on the surface of the anode steel claw. The anode carbon block and the anode steel claw coated with the coating are tested for application performance. The test items include high temperature burning test, cryolite oxidation test, conductivity test, adhesion performance, aluminum liquid contamination degree and service life. The specific test methods and test results are as follows: The experiment was conducted in a 350KA electrolytic cell of an aluminum power enterprise in Ningxia. After testing, the coating prepared by the present invention adhered well to the carbon block and the anode steel claw, and the surface was smooth without obvious holes or cracks. Figure 5 The service life of the carbon block without the coating of the present invention is 27-28 days, and the service life of the carbon block with the coating of the present invention is 30-31 days, and it maintains good working condition after spraying. Figure 6 The specific experimental process is as follows: Three carbon blocks sprayed with the coating of the present invention, numbered A1, A2, A3, and three carbon blocks not sprayed with the coating, numbered A4, A5, A6, were placed in a muffle furnace together, and the temperature was controlled at 970°C. After burning for 10 hours, the weight loss of the carbon blocks was measured. It was found that the weight loss of the carbon blocks not sprayed with the coating of the present invention was more serious, as shown in Table 2: Table 2

[0068] The three carbon blocks sprayed with the coating of the present invention were numbered B1, B2, and B3, and the three carbon blocks not sprayed with the coating were numbered B4, B5, and B6. The six carbon blocks were buried in 1000 g of cryolite, respectively, and burned in a muffle furnace at 970 degrees Celsius for 8 hours. Then, the corrosion weight loss of the carbon blocks was checked, and it was found that the carbon blocks not sprayed with the coating of the present invention had a more serious weight loss, as shown in Table 3: Table 3

[0069] The three carbon blocks sprayed with the coating of the present invention are numbered C1, C2, and C3, and the three carbon blocks not sprayed with the coating are numbered C4, C5, and C6. The above carbon blocks are connected to two electrodes, and a 350kA constant current source is connected to both ends of the electrodes. The voltage across each carbon block is measured, and it is found that the conductivity of the two groups of carbon blocks is relatively close, as shown in Table 4: Table 4

[0070] Six carbon blocks sprayed with the coating prepared in Example 1 of the present invention were numbered D1, D2, D3, D4, D5, and D6, and the adhesion was tested according to the national standard GB / T 5210. The test results all reached level 0, as shown in Table 5: Table 5

[0071] Three carbon blocks sprayed with the coating of the present invention are numbered E1, E2, and E3, and three carbon blocks not sprayed with the coating are numbered E4, E5, and E6. These carbon blocks are respectively installed on the anode steel claws. Since this experiment is a destructive experiment, the degree of aluminum liquid pollution is characterized while testing the life span. The aluminum liquid pollution is characterized on the 7th day of the test life experiment, and it is found that the aluminum liquid pollution degree is low (no significant difference with the carbon blocks not sprayed with the coating). The service life of the carbon blocks not sprayed with the coating of the present invention is only 27-28 days, while the service life of the carbon blocks sprayed with the coating of the present invention can reach 30-31 days. The aluminum liquid pollution degree and the life test are shown in Table 6 and Table 7 respectively: Table 6

[0072] Table 7

[0073] According to the above test results, The present invention provides an aluminum-based high entropy oxide electrolytic aluminum anode coating material, which is used in the protection of electrolytic aluminum anode components. The high-temperature burning experiment verifies that the coating material has the performance of high temperature resistance. The cryolite corrosion experiment shows that the coating material has better corrosion resistance and ability to withstand harsh environments. The adhesion performance shows that the coating material is not easy to fall off under complex working conditions. At the same time, the aluminum liquid pollution experiment and the service life experiment reflect that the coating material has excellent comprehensive performance. Its high strength, high temperature resistance, corrosion resistance and other performance advantages can provide stronger protection for the electrolytic aluminum anode components, effectively extend the service life of the anode components and reduce production costs under complex working conditions in the electrolytic aluminum industry.

[0074] The above are only preferred embodiments of the present invention, and are not intended to limit the implementation methods and protection scope of the present invention. Those skilled in the art should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the contents of the specification of the present invention should be included in the protection scope of the present invention.

Claims

1. An aluminum-based high entropy oxide electrolytic aluminum anode coating material, characterized in that: The composition is as follows: aluminum-based high entropy oxide 40%-41%; water 30%-31%; structural strengthening agent 20%-23%; glaze forming agent 3%-6%; film forming agent 2%-4%; binder 0.1%-0.4%; The aluminum-based high entropy oxide is prepared from aluminum-based high entropy alloy powder by self-propagating high-temperature synthesis. In the aluminum-based high entropy alloy powder, the molar ratio of aluminum, iron, magnesium, copper and nickel is 0.6-0.63: 0.15-0.17: 0.05-0.06: 0.1-0.11: 0.03-0.

1.

2. The aluminum-based high entropy oxide electrolytic aluminum anode coating material according to claim 1, characterized in that: The structural reinforcing agent includes quartz sand and / or silica ore.

3. The aluminum-based high entropy oxide electrolytic aluminum anode coating material according to claim 1, characterized in that: The glaze former includes at least two of potassium feldspar, talc, sodium feldspar, olivine and amphibole.

4. The aluminum-based high entropy oxide electrolytic aluminum anode coating material according to claim 1, characterized in that: The film-forming agent includes ethyl cellulose and / or polydimethylsiloxane; and the binder is a silane coupling agent.

5. A method for preparing an aluminum-based high entropy oxide electrolytic aluminum anode coating material according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1. Preparing metal powders of aluminum, iron, magnesium, copper and nickel according to the molar ratio of the elements as shown in claim 1, and subjecting them to mechanical alloying treatment to obtain aluminum-based high entropy alloy powder; S2, the aluminum-based high entropy alloy powder is synthesized by self-propagating high temperature synthesis to obtain aluminum-based high entropy oxide powder; S3, mixing the aluminum-based high entropy oxide powder with a binder for coating and modification to obtain a modified aluminum-based high entropy oxide powder; mixing the modified aluminum-based high entropy oxide powder with a structural reinforcing agent for a first ball milling treatment to obtain a first mixture; S4, crushing and second ball-milling the glaze forming agent to obtain a second mixture; mixing the film forming agent with water to obtain a film forming agent suspension; adding the first mixture and the second mixture to the film forming agent suspension to obtain a third mixture; S5. Place the third mixture under certain temperature and pressure conditions to react and obtain an aluminum-based high entropy oxide electrolytic aluminum anode coating material.

6. The preparation method according to claim 5, characterized in that In step S1, the mechanical alloying treatment is performed by ball milling, using zirconium oxide balls as the ball milling medium, with a rotation speed of 250-350 rpm and a time of 2-3 hours.

7. The preparation method according to claim 5, characterized in that: In step S2, in the self-propagating high temperature synthesis, a mixture of Al and CuO is used as thermite, and the process is carried out under the conditions of introducing a protective gas and continuously cooling the collecting assembly, and the particle size of the aluminum-based high entropy oxide powder is 200-350 nm.

8. The preparation method according to claim 5, characterized in that: In step S3, the particle size of the first mixture is 450-550 mesh; in step S4, the particle size of the second mixture is 500-650 mesh.

9. The preparation method according to claim 5, characterized in that: In step S5, the reaction is carried out under stirring conditions at a temperature of 130-150° C. and a pressure of 1.4-1.6 MPa, and the reaction time is 2-3 h.

10. Application of the aluminum-based high entropy oxide electrolytic aluminum anode coating material according to any one of claims 1-4 or the aluminum-based high entropy oxide electrolytic aluminum anode coating material prepared by the preparation method according to any one of claims 5-9 in the electrolytic aluminum industry.

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