Aluminum alloy refining agent for battery foil and preparation method thereof

Abstract

The invention discloses an aluminum alloy refining agent for battery foil and a preparation method of the aluminum alloy refining agent, and relates to the technical field of alloy preparation, and the preparation method comprises the following steps: preparing nanoscale aluminum alloy powder by using a sol-gel method, compounding a nano aluminum alloy with a salt solution by using a solution mixing method, and filtering and drying the obtained suspension to obtain an aluminum alloy nano refining agent. The method has the advantages that nano aluminum oxide is prepared through a sol-gel method, the aluminum alloy easily absorbs gas such as hydrogen in the smelting process, the aluminum alloy nano refining agent can effectively remove hydrogen in molten aluminum, the pore defect in a casting can be greatly reduced, the density and the mechanical property of the aluminum alloy casting can be improved, and the casting quality is improved. In the manufacturing process of some aluminum alloy parts with the high requirement for air tightness, after the nanometer refining agent is used, the porosity of the product is obviously reduced, the requirement for high-end application is met, other gas dissolved in molten aluminum can be removed through the nanometer refining agent, and the molten aluminum is made to be purer.

Description

Technical Field

[0001] The invention relates to the technical field of alloy preparation, in particular to an aluminum alloy refining agent for battery foil and a preparation method thereof. Background Art

[0002] During the aluminum alloy smelting process, various impurities will be generated. On the one hand, the aluminum alloy raw materials themselves may carry impurities, such as oxides, hydrides, etc. Aluminum is easily oxidized in the air, and aluminum oxide (Al2O3) will form on the surface. 2 O 3 ) film. When these aluminum raw materials with oxide films are put into the furnace, the oxide films will be mixed into the melt and become impurities. On the other hand, during the smelting process, the aluminum liquid will react with the surrounding environmental media, such as water vapor in the air, to generate hydrogen (H 2 ), hydrogen dissolved in aluminum liquid may form pores during the solidification process, seriously affecting the quality of aluminum alloy. In addition to gas impurities, there are also solid impurities. For example, the lining material of the smelting equipment may enter the aluminum liquid due to wear and other reasons. These impurities will change the composition and properties of the aluminum alloy, reducing its strength, toughness and corrosion resistance, etc.; Certain components in the refining agent can reduce the surface tension and viscosity of the aluminum alloy melt. Some refining agents containing alkali metal salts can make the structure of the aluminum alloy melt loose, reduce the friction inside the melt, and thus improve the fluidity of the melt. Good fluidity helps the aluminum alloy to better fill the mold cavity during the casting process, and obtain castings with complete shape and good quality; Traditional flux is generally composed of chlorides (such as NaCl, KCl, etc.) and fluorides (such as Na 3 AlF 6 ) are a mixture of these fluxes, which can cover the surface of the aluminum liquid to prevent further oxidation of the aluminum liquid, and can absorb and dissolve some impurities. However, the refining effect of traditional fluxes is limited, and the removal capacity of some tiny impurity particles and gases dissolved in the aluminum liquid is insufficient. In addition, the flux itself may retain some impurities in the aluminum liquid, affecting the purity of the aluminum alloy. For this reason, we propose an aluminum alloy refining agent for battery foil and a preparation method thereof. Summary of the invention

[0003] The object of the present invention is to provide an aluminum alloy refining agent for battery foil and a preparation method thereof.

[0004] In order to solve the problems raised in the above background technology, the present invention provides the following technical solutions: an aluminum alloy refining agent for battery foil and a preparation method thereof, comprising preparing nano-scale aluminum alloy powder by a sol-gel method, compounding nano-aluminum alloy with a salt solution by a solution mixing method, filtering and drying the obtained suspension to obtain an aluminum alloy nano-refining agent, and the specific operation steps of the aluminum alloy refining agent for battery foil and the preparation method thereof are as follows: Step 1: preparing nano-scale powder, inorganic salt and surfactant; Step 2: dissolving an inorganic salt substance in water in a certain proportion to form a salt solution, and dissolving a surfactant in water to form a surfactant solution; Step 3, adding the nano powder into the salt solution and stirring for reaction, after the reaction is completed, adding the surfactant solution into the reaction solution and continuing the reaction; Step 4: filtering the solution after the reaction, and drying the filtered product to obtain a powdery product; Step 5, crushing the powder product and screening the crushed product; Step 6: Test the obtained product and package it after it passes the test.

[0005] As a further solution of the present invention: in the step 1, the metal aluminum sheet is added to isopropanol, the molar ratio of isopropanol to aluminum is set to 3-5:1, iodine is selected as the catalyst for the reaction, the amount of iodine is 0.05%-0.2% of the amount of aluminum, the reaction temperature is set to 80°C-100°C, the reaction is carried out in an open system, and the reaction equation is:

[0006] The hydrogen produced in the reaction (H 2 ) escapes naturally, and aluminum isopropoxide is obtained after 10h-20h of reaction , nano-alumina was prepared by sol-gel method, aluminum isopropoxide was used as aluminum source for preparing nano-alumina, anhydrous ethanol was selected as solvent, the molar concentration of aluminum isopropoxide in anhydrous ethanol solvent was set to 0.5 mol / L-1.5 mol / L, polyethylene glycol with a molecular weight of 1000 was selected as dispersant, the amount of polyethylene glycol was 0.5%-2% of the amount of aluminum isopropoxide, aluminum isopropoxide, anhydrous ethanol solvent and polyethylene glycol were added into a stirring tank and mixed, the temperature in the stirring tank was set to 55°C-65°C, and the stirring speed was set to 400r / m in-500r / min, after stirring for 4h-6h, the raw materials are mixed into a sol, and after the stirring is completed, the sol is allowed to stand for 4h-6h, and the sol is converted into a gel state. After the gel is formed, it is placed in a drying oven for drying, and the temperature of the drying oven is set to 70℃-90℃. After drying for 12h-24h, a dry gel structure is obtained, and the dry gel is placed in a calcining furnace for calcination, and the heating rate of the calcining furnace is set to 1℃ / min-10℃ / min, the calcination temperature is set to 800℃-1000℃, and the calcination time is set to 2h-6h to convert the gel into γ-Al 2 O 3 , nano alumina is obtained, sodium chloride and potassium chloride are selected as inorganic salts, and sodium dodecyl sulfate is selected as surfactant.

[0007] As a further scheme of the present invention: in the step 2, a salt solution is prepared, sodium chloride and potassium chloride are used in a mass ratio of 1:1, deionized water is selected as a solvent, sodium chloride, potassium chloride and deionized water are added to a magnetic stirrer, the temperature in the magnetic stirrer is set to 40°C-60°C, the stirring speed is set to 100r / min-300r / min, and after stirring for 10min-30min, a sodium chloride-potassium chloride salt solution with a concentration of 50%-70% is formed, and a surfactant solution is prepared, deionized water is selected as a solvent, sodium dodecyl sulfate and deionized water are added to a magnetic stirrer, the temperature in the magnetic stirrer is set to 30°C-50°C, the stirring speed is set to 200r / min-300r / min, the stirring time is set to 10min-30min, and the concentration of the surfactant solution is set to 0.1%-1%.

[0008] As a further scheme of the present invention: in the step three, the nano powder and the sodium chloride-potassium chloride salt solution are compounded by a solution mixing method, the amount of nano alumina is 6%-29% of the total amount of the compounded solution, the amount of the sodium chloride-potassium chloride salt solution is 70%-94% of the total amount of the compounded solution, and the amount of the surfactant solution is 1%-5% of the total amount of the compounded solution. The nano alumina is added to the sodium chloride-potassium chloride salt solution using a powder feeder, the feeding rate is set to 1g / min-2g / min, the temperature in the stirring tank is set to 30℃-60℃, the stirring speed is set to 300r / min-600r / min, and the stirring time is set to 1h-3h. After the stirring is completed, the surfactant solution is slowly added dropwise to the reaction solution, the dropping speed is set to 5mL / min-10mL / min, the stirring temperature is set to 30℃-50℃, the stirring speed is set to 200r / min-400r / min, and the stirring time is set to 2h-4h to obtain an aluminum alloy nano refining agent suspension.

[0009] As a further solution of the present invention: in the step three, the aluminum alloy nano-refining agent suspension is detected by ultrasonic detection, a coupling agent is smeared on the surface of the ultrasonic detector, glycerol is selected as the coupling agent, and then the ultrasonic detector is tightly attached to the surface of the container containing the aluminum alloy nano-refining agent suspension and the ultrasonic detector is started, the ultrasonic frequency of the ultrasonic detector is set to 5MHz-10MHz, and the propagation parameters of the ultrasonic wave are analyzed during the detection, including the sound velocity and the attenuation coefficient, the sound velocity is between 1400m / s-1600m / s, and the attenuation coefficient is between 0.1dB / cm·MHz-1dB / cm·MHz, and the dispersibility and uniformity of the aluminum alloy nano-refining agent in the suspension can be detected by the propagation parameters.

[0010] As a further scheme of the present invention: in the step 4, the aluminum alloy nano-refining agent suspension is filtered by vacuum filtration, a microporous filter membrane of 0.2um-0.45um is selected, the filter membrane is moistened with distilled water, the moistened filter membrane is tightly attached to the bottom of the Buchner funnel, the Buchner funnel is connected to the suction filtration bottle, the vacuum pump is started to control the vacuum degree in the suction filtration bottle between -0.06MPa--0.08MPa, the air tightness of the whole device is checked, and after the inspection is completed, the aluminum alloy nano-refining agent suspension is slowly poured into the Buchner funnel, the pouring speed is set to 3mL / s-5mL / s, the height of the aluminum alloy nano-refining agent suspension is lower than 2 / 3 of the volume of the Buchner funnel, the vacuum pump is started again, the vacuum degree in the suction filtration bottle is set to -0.06MPa--0.08MPa, the filtration time is set to 20min-40min, and after the filtration is completed, the aluminum alloy nano-refining agent filter cake is obtained.

[0011] As a further solution of the present invention: in the step 4, the aluminum alloy nano-refining agent filter cake is washed with a pure solvent, the pure solvent is deionized water, the volume of the deionized water is 1-2 times the volume of the aluminum alloy nano-refining agent filter cake, the pouring speed is set to 1mL / s-2mL / s, and the washing is performed 2-3 times. After the washing is completed, the aluminum alloy nano-refining agent filter cake is placed in a freeze dryer for drying, the temperature of the freeze drying chamber is set to -20°C--40°C, the solvent in the filter cake is frozen into ice, the vacuum pump is turned on, the vacuum degree of the freeze drying chamber is set to -0.09MPa--0.1MPa, the temperature is set to -5°C--20°C, and the time is set to 4h-8h to obtain a dry aluminum alloy nano-refining agent.

[0012] As a further solution of the present invention: in the step 5, the aluminum alloy nano-refining agent is crushed by using an air flow mill, and the aluminum alloy nano-refining agent is added to the air flow mill at a speed of 0.1kg / h-1kg / h, compressed air is selected as the gas, the air flow speed of the air flow mill is set to 500m / s-600m / s, the pressure is set to 0.6MPa-0.8MPa, and the crushing time is set to 10min-20min. After the crushing, the aluminum alloy nano-refining agent is added to a vibrating screen at 5kg / h-10kg / h for screening, the mesh number of the screen is selected to be 300-400 mesh, the vibration frequency of the vibrating screen is set to 30Hz-50Hz, the amplitude is set to 1mm-2mm, and the inclination angle of the screen surface is set to 10°-20°, so as to obtain an aluminum alloy nano-refining agent with a particle size of 40um-48um.

[0013] As a further solution of the present invention: in the step six, atomic absorption spectroscopy is used to detect the metal element content in the aluminum alloy nano-refining agent, infrared spectroscopy is used to analyze the presence and structural characteristics of the surfactant in the refining agent, a transmission electron microscope is used to observe the microscopic morphology and dispersion of the particles, a vacuum degassing method is used to determine the hydrogen content in the solution before and after refining, a chemical analysis method is used to detect the reduction of oxides, and the refining efficiency of the aluminum alloy nano-refining agent is obtained. After the detection is completed, the aluminum alloy nano-refining agent is quantitatively packaged using a moisture-proof and anti-oxidation inner layer packaging, and is filled with inert gas for packaging, the inner layer packaging uses aluminum foil bags, and nitrogen is used as the inert gas, and the packaged aluminum foil bags are placed in cardboard boxes for packaging.

[0014] In addition, the present invention also provides a method for preparing an aluminum alloy refining agent for battery foil: the aluminum alloy refining agent for battery foil is prepared by compounding nano-alumina with a sodium chloride-potassium chloride solution to obtain an aluminum alloy nano-refining agent suspension, and the aluminum alloy nano-refining agent suspension is washed, filtered, and then dried to obtain the aluminum alloy nano-refining agent.

[0015] By adopting the above technical solution, compared with the prior art, the beneficial effects of the present invention are: 1. The present invention prepares nano-alumina by a sol-gel method. Aluminum alloys easily absorb gases such as hydrogen during the smelting process. Aluminum alloy nano-refining agents can effectively remove hydrogen from aluminum liquid, which can greatly reduce the porosity defects in castings and improve the density and mechanical properties of aluminum alloy castings. In the manufacture of some aluminum alloy parts with high air tightness requirements, after using nano-refining agents, the porosity of the product is significantly reduced, meeting the needs of high-end applications. Nano-refining agents can also remove other gases dissolved in aluminum liquid, making the aluminum liquid purer and providing high-quality melt for subsequent processing processes; 2. The present invention prepares nano-alumina by a sol-gel method. In the smelting process of aluminum alloy, some solid impurities such as oxidized slag inclusions are inevitably generated. The nano-refining agent can react physically and chemically with these slag inclusions, making the slag inclusions easy to separate. Through adsorption, aggregation and other effects, the slag inclusions float to the liquid surface of the aluminum solution to form dry slag, which is convenient to remove. Effectively removing the slag inclusions can reduce the inclusion content in the casting and reduce the adverse effects of the slag inclusions on the performance of the casting, such as reducing the generation of cracks, improving the corrosion resistance and fatigue strength of the casting, etc. For some aluminum alloy products with high surface quality requirements, the slag removal effect of the nano-refining agent can make the surface of the casting smoother and flatter; 3. The present invention can improve the fluidity of aluminum liquid through aluminum alloy nano-refining agent, so that aluminum liquid can fill the mold cavity more evenly during the casting process, reducing the occurrence of casting defects such as insufficient pouring and cold shut. This is particularly important for the production of aluminum alloy castings with complex shapes, and can improve the molding quality and production efficiency of castings. Since the nano-refining agent can improve the melting efficiency and improve the quality of castings, it reduces the generation of waste and repeated processing, thereby reducing energy consumption to a certain extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of the aluminum alloy refining agent for battery foil and its preparation steps in an embodiment of the present invention. DETAILED DESCRIPTION

[0017] The specific embodiments of the present invention are further described below in conjunction with the accompanying drawings. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0018] The aluminum alloy refining agent for battery foil and the preparation method thereof of the present invention include preparing nano-grade aluminum alloy powder by a sol-gel method, compounding nano-aluminum alloy with a salt solution by a solution mixing method, filtering and drying the obtained suspension to obtain an aluminum alloy nano-refining agent. The specific operation steps of the aluminum alloy refining agent for battery foil and the preparation method thereof are as follows: Step 1: preparing nano-scale powder, inorganic salt and surfactant; Step 2: dissolving an inorganic salt substance in water in a certain proportion to form a salt solution, and dissolving a surfactant in water to form a surfactant solution; Step 3, adding the nano powder into the salt solution and stirring for reaction, after the reaction is completed, adding the surfactant solution into the reaction solution and continuing the reaction; Step 4: filtering the solution after the reaction, and drying the filtered product to obtain a powdery product; Step 5, crushing the powder product and screening the crushed product; Step 6: Test the obtained product and package it after it passes the test.

[0019] In one embodiment of the present invention: in step 1, a metal aluminum sheet is added to isopropanol, the molar ratio of isopropanol to aluminum is set to 3-5:1, iodine is selected as a catalyst for the reaction, the amount of iodine is 0.05%-0.2% of the amount of aluminum, the reaction temperature is set to 80°C-100°C, the reaction is carried out in an open system, and the reaction equation is:

[0020] The hydrogen produced in the reaction (H 2 ) escapes naturally, and aluminum isopropoxide is obtained after 10h-20h of reaction , nano-alumina was prepared by sol-gel method, aluminum isopropoxide was used as aluminum source for preparing nano-alumina, anhydrous ethanol was selected as solvent, the molar concentration of aluminum isopropoxide in anhydrous ethanol solvent was set to 0.5 mol / L-1.5 mol / L, polyethylene glycol with a molecular weight of 1000 was selected as dispersant, the amount of polyethylene glycol was 0.5%-2% of the amount of aluminum isopropoxide, aluminum isopropoxide, anhydrous ethanol solvent and polyethylene glycol were added into a stirring tank and mixed, the temperature in the stirring tank was set to 55°C-65°C, and the stirring speed was set to 400r / m in-500r / min, after stirring for 4h-6h, the raw materials are mixed into a sol, and after the stirring is completed, the sol is allowed to stand for 4h-6h, and the sol is converted into a gel state. After the gel is formed, it is placed in a drying oven for drying, and the temperature of the drying oven is set to 70℃-90℃. After drying for 12h-24h, a dry gel structure is obtained, and the dry gel is placed in a calcining furnace for calcination, and the heating rate of the calcining furnace is set to 1℃ / min-10℃ / min, the calcination temperature is set to 800℃-1000℃, and the calcination time is set to 2h-6h to convert the gel into γ-Al 2 O 3 , nano alumina is obtained, sodium chloride and potassium chloride are selected as inorganic salts, and sodium dodecyl sulfate is selected as surfactant.

[0021] In one embodiment of the present invention: in step 2, a salt solution is prepared, sodium chloride and potassium chloride are used in a mass ratio of 1:1, deionized water is selected as a solvent, sodium chloride, potassium chloride and deionized water are added to a magnetic stirrer, the temperature in the magnetic stirrer is set to 40°C-60°C, the stirring speed is set to 100r / min-300r / min, and after stirring for 10min-30min, a sodium chloride-potassium chloride salt solution with a concentration of 50%-70% is formed, a surfactant solution is prepared, deionized water is selected as a solvent, sodium dodecyl sulfate and deionized water are added to a magnetic stirrer, the temperature in the magnetic stirrer is set to 30°C-50°C, the stirring speed is set to 200r / min-300r / min, the stirring time is set to 10min-30min, and the concentration of the surfactant solution is set to 0.1%-1%.

[0022] In one embodiment of the present invention: in step three, the nano powder is compounded with the sodium chloride-potassium chloride salt solution by a solution mixing method, the amount of nano alumina is 6%-29% of the total amount of the compounded solution, the amount of the sodium chloride-potassium chloride salt solution is 70%-94% of the total amount of the compounded solution, and the amount of the surfactant solution is 1%-5% of the total amount of the compounded solution. The nano alumina is added to the sodium chloride-potassium chloride salt solution using a powder feeder, the feeding rate is set to 1g / min-2g / min, the temperature in the stirring tank is set to 30℃-60℃, the stirring speed is set to 300r / min-600r / min, and the stirring time is set to 1h-3h. After the stirring is completed, the surfactant solution is slowly added dropwise to the reaction solution, the dropping speed is set to 5mL / min-10mL / min, the stirring temperature is set to 30℃-50℃, the stirring speed is set to 200r / min-400r / min, and the stirring time is set to 2h-4h to obtain an aluminum alloy nano refining agent suspension.

[0023] In one embodiment of the present invention: in step three, the aluminum alloy nano-refining agent suspension is detected by ultrasonic detection, a coupling agent is applied to the surface of an ultrasonic detector, glycerol is selected as the coupling agent, and then the ultrasonic detector is tightly attached to the surface of a container containing the aluminum alloy nano-refining agent suspension and the ultrasonic detector is started. The ultrasonic frequency of the ultrasonic detector is set to 5MHz-10MHz, and the propagation parameters of the ultrasonic wave are analyzed during the detection, including the sound velocity and the attenuation coefficient. The sound velocity is between 1400m / s-1600m / s, and the attenuation coefficient is between 0.1dB / cm·MHz-1dB / cm·MHz. The dispersion and uniformity of the aluminum alloy nano-refining agent in the suspension can be detected through the propagation parameters.

[0024] In one embodiment of the present invention: in step 4, the aluminum alloy nano-refining agent suspension is filtered by vacuum filtration, a microporous filter membrane of 0.2um-0.45um is selected, the filter membrane is moistened with distilled water, the moistened filter membrane is tightly attached to the bottom of the Buchner funnel, the Buchner funnel is connected to the suction filtration bottle, the vacuum pump is started to control the vacuum degree in the suction filtration bottle between -0.06MPa- -0.08MPa, the air tightness of the entire device is checked, and after the inspection is completed, the aluminum alloy nano-refining agent suspension is slowly poured into the Buchner funnel, the pouring speed is set to 3mL / s-5mL / s, the height of the aluminum alloy nano-refining agent suspension is lower than 2 / 3 of the volume of the Buchner funnel, the vacuum pump is started again, the vacuum degree in the suction filtration bottle is set to -0.06MPa- -0.08MPa, the filtration time is set to 20min-40min, and after the filtration is completed, the aluminum alloy nano-refining agent filter cake is obtained.

[0025] In one embodiment of the present invention: in step 4, the aluminum alloy nano-refining agent filter cake is washed with a pure solvent, the pure solvent is deionized water, the volume of the deionized water is 1-2 times the volume of the aluminum alloy nano-refining agent filter cake, the pouring speed is set to 1mL / s-2mL / s, and the washing is performed 2-3 times. After the washing is completed, the aluminum alloy nano-refining agent filter cake is placed in a freeze dryer for drying, the temperature of the freeze drying chamber is set to -20°C--40°C, the solvent in the filter cake is frozen into ice, the vacuum pump is turned on, the vacuum degree of the freeze drying chamber is set to -0.09MPa--0.1MPa, the temperature is set to -5°C--20°C, and the time is set to 4h-8h to obtain a dry aluminum alloy nano-refining agent.

[0026] In one embodiment of the present invention: in step five, the aluminum alloy nano-refining agent is crushed by using an air flow mill, and the aluminum alloy nano-refining agent is added to the air flow mill at a speed of 0.1kg / h-1kg / h, compressed air is selected as the gas, the air flow speed of the air flow mill is set to 500m / s-600m / s, the pressure is set to 0.6MPa-0.8MPa, and the crushing time is set to 10min-20min. After the crushing, the aluminum alloy nano-refining agent is added to a vibrating screen at 5kg / h-10kg / h for screening, the mesh number of the screen is selected to be 300-400 mesh, the vibration frequency of the vibrating screen is set to 30Hz-50Hz, the amplitude is set to 1mm-2mm, and the inclination angle of the screen surface is set to 10°-20° to obtain an aluminum alloy nano-refining agent with a particle size of 40um-48um.

[0027] In one embodiment of the present invention: in step six, atomic absorption spectroscopy is used to detect the metal element content in the aluminum alloy nano-refining agent, infrared spectroscopy is used to analyze the presence and structural characteristics of the surfactant in the refining agent, a transmission electron microscope is used to observe the microscopic morphology and dispersion of the particles, a vacuum degassing method is used to determine the hydrogen content in the solution before and after refining, a chemical analysis method is used to detect the reduction of oxides, and the refining efficiency of the aluminum alloy nano-refining agent is obtained. After the detection is completed, the aluminum alloy nano-refining agent is quantitatively packaged using a moisture-proof and anti-oxidation inner layer packaging, and is filled with inert gas for packaging. The inner layer packaging uses aluminum foil bags, and nitrogen is used as the inert gas. The packaged aluminum foil bags are placed in cardboard boxes for packaging.

[0028] In addition, the present invention also provides a method for preparing an aluminum alloy refining agent for battery foil: the aluminum alloy refining agent for battery foil is prepared by compounding nano alumina with a sodium chloride-potassium chloride solution to obtain an aluminum alloy nano refining agent suspension, and the aluminum alloy nano refining agent suspension is washed, filtered, and then dried to obtain the aluminum alloy nano refining agent.

[0029] Example 1: Nano-alumina gel was prepared by sol-gel method. Drying at 80°C for 16h can make the gel lose most of the solvent under mild conditions to form a relatively stable dry gel structure, avoiding cracks in the gel due to rapid volatilization of the solvent. When preparing nano-alumina gel, a heating rate of 5°C / min can make the gel perform precursor decomposition and crystal transformation more smoothly during the calcination process. If the heating rate is too fast, a large temperature gradient will be generated inside the gel, resulting in stress concentration, causing gel cracking or uneven product crystal form. The calcination temperature is set to 900°C and the calcination time is set to 4h to convert the gel into γ-Al 2 O 3 , and obtain nano alumina.

[0030] Example 2: Slowly add nano-alumina powder to the salt solution, so as to avoid rapid agglomeration of the nano-alumina powder due to excessive local concentration. When the nano-alumina powder is added to the sodium chloride-potassium chloride salt solution, use a powder feeder to add the nano-alumina powder at a rate of 1 g / min to ensure that the nano-alumina powder can be evenly dispersed in the salt solution. The reaction temperature is maintained at 50°C, which helps to promote the interaction between the nano-alumina powder and the salt solution, while avoiding agglomeration of the nano-alumina powder or excessive evaporation of the solvent in the salt solution due to excessive temperature. The active sites on the surface of the nano-alumina powder can better adsorb or exchange with the ions in the salt solution. The stirring speed is controlled at 500 r / min to ensure that the nano-alumina powder is fully dispersed in the salt solution and in full contact with the salt solution. Stirring for 3 hours can enable the reaction to proceed more fully.

[0031] Example 3: When the surfactant solution is added, it should also be added slowly to prevent the local concentration from being too high. The dropping speed is controlled at 5 mL / min, so that the surfactant is evenly distributed in the reaction system and fully mixed with the reacted nanopowder and salt solution. The temperature is appropriately reduced to 40°C. Lowering the temperature helps the adsorption process of the surfactant on the surface of the nanopowder to proceed more stably. The stirring speed is appropriately reduced to 400 r / min, and the stirring time is extended to 4 h. This is because the interaction between the surfactant and the nanopowder is relatively complex, and sufficient time is required to ensure that the surfactant can effectively coat the nanopowder and improve its dispersibility and stability. After the sodium dodecyl sulfate solution is added, the sodium dodecyl sulfate molecules can form a stable adsorption layer on the surface of the nanopowder through long-term slow stirring.

[0032] Embodiment 4: The aluminum alloy nano-refining agent is added to the air flow mill at a speed of 1kg / h, and compressed air is selected as the gas. The air flow speed of the air flow mill is set to 500m / s. The higher air flow speed can give the material greater kinetic energy, so that it collides and rubs against each other in the crushing chamber with greater force, thereby improving the crushing efficiency and refinement degree. The pressure is set to 0.6MPa, and the crushing time is set to 15min. After the crushing, the aluminum alloy nano-refining agent is added to the vibrating screen at 10kg / h for screening. The mesh number of the screen is selected to be 300 mesh, the vibration frequency of the vibrating screen is set to 30Hz-50Hz, and the amplitude is set to 1mm, so that the aluminum alloy nano-refining agent has enough movement space on the screen, which is conducive to the aluminum alloy nano-refining agent particles passing through the sieve hole. The inclination angle of the screen surface is set to 10°, while ensuring the screening accuracy, the screening speed is increased to obtain an aluminum alloy nano-refining agent with a particle size of 40um.

[0033] As attached Figure 1 As shown, nano-alumina is prepared by using the sol-gel method, and various functional nano-materials can be compounded into the refining agent through the solvent mixing method, so that it has multiple functions such as degassing, slag removal, and grain refinement, thereby improving the comprehensive performance of the refining agent.

[0034] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions and variations of these embodiments are made without departing from the principles and spirit of the present invention, and still fall within the scope of protection of the present invention.

[0035] In the description of the specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0036] The above contents are merely examples and explanations of the present invention. Various modifications or additions to the specific embodiments described or replacements in similar ways by technicians in the technical field shall fall within the protection scope of the present invention as long as they do not deviate from the invention or exceed the scope defined by the claims.

[0037] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for preparing an aluminum alloy refining agent for battery foil, comprising preparing nano-grade aluminum alloy powder by a sol-gel method, compounding a nano-aluminum alloy with a salt solution by a solution mixing method, filtering and drying the obtained suspension to obtain an aluminum alloy nano-refining agent, characterized in that: The specific operation steps of the aluminum alloy refining agent for battery foil and the preparation method thereof are as follows: Step 1: preparing nano-scale powder, inorganic salt and surfactant; Step 2: dissolving an inorganic salt substance in water in a certain proportion to form a salt solution, and dissolving a surfactant in water to form a surfactant solution; Step 3, adding the nano powder into the salt solution and stirring for reaction, after the reaction is completed, adding the surfactant solution into the reaction solution and continuing the reaction; Step 4: filtering the solution after the reaction, and drying the filtered product to obtain a powdery product; Step 5, crushing the powder product and screening the crushed product; Step 6: Test the obtained product and package it after it passes the test.

2. The method for preparing an aluminum alloy refining agent for battery foil according to claim 1, characterized in that: In the step 1, the metal aluminum sheet is added to isopropanol, the molar ratio of isopropanol to aluminum is set to 3-5:1, iodine is selected as the catalyst for the reaction, the amount of iodine is 0.05%-0.2% of the amount of aluminum, the reaction temperature is set to 80°C-100°C, the reaction is carried out in an open system, and the reaction equation is: ； The hydrogen (H2) produced in the reaction escapes naturally, and aluminum isopropoxide is obtained after 10h-20h of reaction. , use the sol-gel method to prepare nano-alumina, use aluminum isopropoxide as the aluminum source for preparing nano-alumina, use anhydrous ethanol as the solvent, the molar concentration of aluminum isopropoxide in the anhydrous ethanol solvent is set to 0.5 mol / L-1.5 mol / L, use polyethylene glycol with a molecular weight of 1000 as the dispersant, and the amount of polyethylene glycol is 0.5%-2% of the amount of aluminum isopropoxide. Add aluminum isopropoxide, anhydrous ethanol solvent and polyethylene glycol into a stirring tank and mix them. The temperature in the stirring tank is set to 55°C-65°C, the stirring speed is set to 400r / min-500r / min, and the raw materials are stirred for 4h-6h. The mixture is mixed into a sol, and after stirring, the sol is allowed to stand for 4 hours to 6 hours, and the sol is converted into a gel state. After the gel is formed, it is placed in a drying oven for drying, and the temperature of the drying oven is set to 70°C-90°C. After drying for 12 hours to 24 hours, a dry gel structure is obtained, and the dry gel is placed in a calcining furnace for calcination. The heating rate of the calcining furnace is set to 1°C / min-10°C / min, the calcination temperature is set to 800°C-1000°C, and the calcination time is set to 2 hours to 6 hours to convert the gel into γ-Al2O3 to obtain nano alumina. Sodium chloride and potassium chloride are selected as inorganic salts, and sodium dodecyl sulfate is selected as a surfactant.

3. The method for preparing an aluminum alloy refining agent for battery foil according to claim 2, characterized in that: In the step 2, a salt solution is prepared, sodium chloride and potassium chloride are used in a mass ratio of 1:1, deionized water is selected as a solvent, sodium chloride, potassium chloride and deionized water are added to a magnetic stirrer, the temperature in the magnetic stirrer is set to 40°C-60°C, the stirring speed is set to 100r / min-300r / min, and after stirring for 10min-30min, a sodium chloride-potassium chloride salt solution with a concentration of 50%-70% is formed, and a surfactant solution is prepared, deionized water is selected as a solvent, sodium dodecyl sulfate and deionized water are added to a magnetic stirrer, the temperature in the magnetic stirrer is set to 30°C-50°C, the stirring speed is set to 200r / min-300r / min, the stirring time is set to 10min-30min, and the concentration of the surfactant solution is set to 0.1%-1%.

4. The method for preparing an aluminum alloy refining agent for battery foil according to claim 3, characterized in that: In the step three, the nano powder and the sodium chloride-potassium chloride salt solution are compounded by a solution mixing method, the amount of nano alumina is 6%-29% of the total amount of the compounded solution, the amount of the sodium chloride-potassium chloride salt solution is 70%-94% of the total amount of the compounded solution, and the amount of the surfactant solution is 1%-5% of the total amount of the compounded solution. The nano alumina is added to the sodium chloride-potassium chloride salt solution using a powder feeder, the feeding rate is set to 1g / min-2g / min, the temperature in the stirring tank is set to 30°C-60°C, the stirring speed is set to 300r / min-600r / min, and the stirring time is set to 1h-3h. After the stirring is completed, the surfactant solution is slowly added dropwise to the reaction solution, the dropping speed is set to 5mL / min-10mL / min, the stirring temperature is set to 30°C-50°C, the stirring speed is set to 200r / min-400r / min, and the stirring time is set to 2h-4h to obtain an aluminum alloy nano refining agent suspension.

5. The method for preparing an aluminum alloy refining agent for battery foil according to claim 4, characterized in that: In the step three, the aluminum alloy nano-refining agent suspension is detected by ultrasonic detection, a coupling agent is applied to the surface of an ultrasonic detector, glycerol is selected as the coupling agent, and then the ultrasonic detector is tightly attached to the surface of a container containing the aluminum alloy nano-refining agent suspension and the ultrasonic detector is started. The ultrasonic frequency of the ultrasonic detector is set to 5MHz-10MHz, and the propagation parameters of the ultrasonic wave are analyzed during the detection, including the sound velocity and the attenuation coefficient. The sound velocity is between 1400m / s-1600m / s, and the attenuation coefficient is between 0.1dB / cm·MHz-1dB / cm·MHz. The dispersibility and uniformity of the aluminum alloy nano-refining agent in the suspension can be detected through the propagation parameters.

6. The method for preparing an aluminum alloy refining agent for battery foil according to claim 4, characterized in that: In the step 4, the aluminum alloy nano-refining agent suspension is filtered by vacuum filtration, a microporous filter membrane of 0.2um-0.45um is selected, the filter membrane is moistened with distilled water, the moistened filter membrane is closely attached to the bottom of the Buchner funnel, the Buchner funnel is connected to the suction filtration bottle, the vacuum pump is started to control the vacuum degree in the suction filtration bottle to between -0.06MPa and -0.08MPa, the air tightness of the entire device is checked, and after the inspection is completed, the aluminum alloy nano-refining agent suspension is slowly poured into the Buchner funnel, the pouring speed is set to 3mL / s-5mL / s, the height of the aluminum alloy nano-refining agent suspension is lower than 2 / 3 of the volume of the Buchner funnel, the vacuum pump is started again, the vacuum degree in the suction filtration bottle is set to -0.06MPa--0.08MPa, the filtration time is set to 20min-40min, and after the filtration is completed, the aluminum alloy nano-refining agent filter cake is obtained.

7. The method for preparing an aluminum alloy refining agent for battery foil according to claim 6, characterized in that: In the step 4, the aluminum alloy nano-refining agent filter cake is washed with a pure solvent, the pure solvent is deionized water, the volume of the deionized water is 1-2 times the volume of the aluminum alloy nano-refining agent filter cake, the pouring speed is set to 1mL / s-2mL / s, and the washing is performed 2-3 times. After the washing is completed, the aluminum alloy nano-refining agent filter cake is placed in a freeze dryer for drying, the temperature of the freeze drying chamber is set to -20°C--40°C, the solvent in the filter cake is frozen into ice, the vacuum pump is turned on, the vacuum degree of the freeze drying chamber is set to -0.09MPa--0.1MPa, the temperature is set to -5°C--20°C, and the time is set to 4h-8h to obtain a dry aluminum alloy nano-refining agent.

8. The method for preparing an aluminum alloy refining agent for battery foil according to claim 7, characterized in that: In the step 5, the aluminum alloy nano-refining agent is crushed by using an air flow mill, and the aluminum alloy nano-refining agent is added to the air flow mill at a speed of 0.1kg / h-1kg / h, compressed air is selected as gas, the air flow speed of the air flow mill is set to 500m / s-600m / s, the pressure is set to 0.6MPa-0.8MPa, and the crushing time is set to 10min-20min. After the crushing, the aluminum alloy nano-refining agent is added to a vibrating screen at 5kg / h-10kg / h for screening, the mesh number of the screen is selected to be 300-400 mesh, the vibration frequency of the vibrating screen is set to 30Hz-50Hz, the amplitude is set to 1mm-2mm, and the inclination angle of the screen surface is set to 10°-20°, so as to obtain an aluminum alloy nano-refining agent with a particle size of 40um-48um.

9. The method for preparing an aluminum alloy refining agent for battery foil according to claim 8, characterized in that: In the step six, atomic absorption spectroscopy is used to detect the metal element content in the aluminum alloy nano-refining agent, infrared spectroscopy is used to analyze the presence and structural characteristics of the surfactant in the refining agent, a transmission electron microscope is used to observe the microscopic morphology and dispersion of the particles, a vacuum degassing method is used to determine the hydrogen content in the solution before and after refining, a chemical analysis method is used to detect the reduction of oxides, and the refining efficiency of the aluminum alloy nano-refining agent is obtained. After the detection is completed, the aluminum alloy nano-refining agent is quantitatively packaged using a moisture-proof and anti-oxidation inner layer packaging, and is filled with inert gas for packaging. The inner layer packaging uses aluminum foil bags, and nitrogen is used as the inert gas. The packaged aluminum foil bags are placed in cardboard boxes for packaging.

10. An aluminum alloy refining agent for battery foil suitable for the method for preparing an aluminum alloy refining agent for battery foil according to any one of claims 1 to 9, characterized in that: The aluminum alloy refining agent for battery foil is prepared by compounding nano aluminum oxide with sodium chloride-potassium chloride solution to obtain an aluminum alloy nano refining agent suspension, and the aluminum alloy nano refining agent suspension is washed, filtered, and then dried to obtain the aluminum alloy nano refining agent.

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