High-toughness photovoltaic aluminum profile and waste aluminum regeneration method thereof

Abstract

The invention discloses a high-toughness photovoltaic aluminum profile and a waste aluminum regeneration method thereof. The photovoltaic aluminum profile is prepared from, by mass, 0.86%-0.91% of Mg, 0.42%-0.47% of Si, 0.18%-0.22% of Cu, 0.15%-0.2% of Zn, 0.09%-0.13% of Er, smaller than or equal to 0.2% of Fe and the balance Al and inevitable impurity elements. The waste aluminum regeneration method sequentially comprises the steps of heating and melting aluminum alloy waste, carrying out online detection and adjustment on components of aluminum alloy liquid, carrying out blowing refining degassing and deslagging on the aluminum alloy liquid by adopting a refining agent and mixed gas, carrying out semi-continuous casting on an aluminum alloy round bar, heating and extruding the aluminum alloy round bar, and carrying out aging heat treatment. According to the method, the photovoltaic aluminum profile is regenerated by using the waste aluminum, so that the production cost of the photovoltaic aluminum profile is reduced, the strength and plasticity of the photovoltaic aluminum profile are improved, and the development requirement of light weight of a solar photovoltaic module is met.

Description

Technical Field

[0001] The invention belongs to the technical field of aluminum profile preparation, and specifically relates to a high-strength and toughness photovoltaic aluminum profile and a waste aluminum regeneration method thereof. Background Art

[0002] Solar photovoltaic power generation uses the photovoltaic effect of photovoltaic cells to directly convert solar radiation into electrical energy. The energy of photovoltaic power generation comes from inexhaustible solar energy. Therefore, solar photovoltaic power generation is a clean, safe and renewable energy that will neither pollute the environment nor damage the ecology. In recent years, my country's photovoltaic power generation industry has experienced explosive growth.

[0003] Aluminum profiles are important materials for manufacturing solar photovoltaic components, including solar photovoltaic panel frames and brackets. With the explosive development of my country's photovoltaic power generation industry, there has been a huge demand for photovoltaic aluminum profiles.

[0004] The Chinese patent document with publication number CN111996423A discloses an aluminum alloy profile for solar photovoltaic frames and a preparation method thereof. The aluminum alloy profile is composed of the following alloy elements by mass percentage: Si is 0.50-0.90%, Mg is 0.40-0.80%, Fe is 0.15-0.25%, Ti is 0.015-0.025%, Cu<0.08%, Mn<0.08%, Zn<0.10%, and the rest is Al. The aluminum alloy profile for solar photovoltaic frames is prepared with Al99.7 aluminum ingots and recycled materials, with the mass proportion of Al99.7 aluminum ingots not less than 60% and the mass proportion of recycled materials not more than 40%.

[0005] The Chinese patent document with publication number CN115976375A discloses an aluminum alloy for solar panel frames and a method for producing a profile thereof, wherein the aluminum alloy is composed of the following components in mass percentage: Si 0.59-0.64%, Mg 0.51-0.56%, Mn 0.05-0.15%, Cr 0.05-0.15%, Ti 0.02-0.03%, B 0.004-0.006%, Fe≤0.2%, and the balance is Al and unavoidable impurity elements. The profile production method sequentially includes batching, smelting aluminum alloy liquid, permanent magnetic stirring, furnace spray refining, online grain refinement and degassing filtration outside the furnace, semi-continuous casting, homogenization treatment, heating and extrusion, quenching, stretching straightening and aging treatment.

[0006] A Chinese patent document with publication number CN108165846A discloses an aluminum alloy material for a solar photovoltaic bracket, which is composed of the following components and contents, measured by mass percentage: Si 0.1-0.5%, Cu 0.05-0.25%, Mg 0.5-0.85%, Zr 0.1-0.3%, Ti 0.1-0.25%, Mn 0.01-0.15%, and the rest is aluminum and inevitable impurities, and is made from Si powder, Al-Cu alloy, Al-Mg alloy, Al-Zr alloy, Al-Ti alloy, Al-Mn alloy and aluminum ingots as raw materials.

[0007] The Chinese patent document with publication number CN113073239A discloses a solar photovoltaic frame bracket aluminum alloy material and manufacturing method. The mass percentages of the aluminum alloy components are: Si 0.57-0.63%, Mg 0.45-0.5%, Mn 0.03-0.07%, Cu 0-0.05%, Cr 0-0.02%, Fe 0-0.1%, Zn 0-0.02%, Ti 0.080.12%, and the rest is Al. The manufacturing method includes alloying, smelting, casting, homogenization heat treatment, extrusion, aging, sandblasting, and anodizing.

[0008] With the rapid development of the solar photovoltaic industry and increasingly fierce market competition, on the one hand, the requirements for the mechanical properties and oxidation properties of photovoltaic aluminum profiles are getting higher and higher to meet the lightweight needs of photovoltaic modules and improve the safety and service life of photovoltaic power generation devices. On the other hand, the processing fee requirements for photovoltaic aluminum profiles are getting lower and lower to reduce the production cost of photovoltaic modules and improve the market competitiveness of photovoltaic modules. From the results of literature retrieval and production practice experience, the strength and plasticity of existing photovoltaic aluminum profiles are still relatively low, and it is increasingly difficult to meet the development requirements of lightweight photovoltaic modules. In addition, in order to meet the high requirements of photovoltaic aluminum profiles, pure aluminum ingots are currently used as raw materials to manufacture photovoltaic aluminum profiles, resulting in high costs for photovoltaic aluminum profiles. Therefore, existing photovoltaic aluminum profiles and their manufacturing methods still need to be improved and developed. Summary of the invention

[0009] In view of the problems and shortcomings mentioned in the background technology, the present invention provides a high-strength and toughness photovoltaic aluminum profile and a method for recycling waste aluminum thereof. By optimizing the component composition of the aluminum profile, the degassing and impurity removal of the aluminum alloy liquid, and the extrusion production process, the strength and plasticity of the photovoltaic aluminum profile are improved to meet the development demand of lightweight photovoltaic modules, reduce the production cost of photovoltaic aluminum profiles, and improve the market competitiveness of photovoltaic modules.

[0010] The present invention achieves the above-mentioned purpose by adopting the following technical solutions:

[0011] The first aspect of the present invention provides a high-strength and toughness photovoltaic aluminum profile, which is characterized in that the photovoltaic aluminum profile is composed of the following components in mass percentage: Mg 0.86-0.91%, Si 0.42-0.47%, Cu 0.18-0.22%, Zn 0.15-0.2%, Er 0.09-0.13%, Fe≤0.2%, and the remainder is Al and unavoidable impurity elements, the individual content of the unavoidable impurity elements is ≤0.05%, and the total amount of impurity elements is ≤0.15%.

[0012] Mg, Si, Cu, and Zn are the main strengthening elements of photovoltaic aluminum profiles. Mg, Si, and Zn can form Mg2Si phase and MgZn2 phase respectively to enhance the strength of aluminum profiles, and Cu can form CuAl2 phase to enhance the strength of aluminum profiles. Insufficient content of Mg, Si, Cu, and Zn will lead to insufficient strength of aluminum profiles. The higher the content of Mg, Si, Cu, and Zn, the higher the strength of the aluminum profile, but it will also reduce the plasticity of the aluminum profile, increase the difficulty of extrusion of the aluminum profile, and increase the production cost. Therefore, it is necessary to strictly limit the content of Mg, Si, Cu, and Zn. The main function of adding 0.09-0.13% of Er element is to refine the grains of aluminum alloy castings and improve the uniformity of the organizational composition of aluminum alloy castings.

[0013] The second aspect of the present invention provides a method for recycling waste aluminum of high-strength and tough photovoltaic aluminum profiles, which is characterized by comprising the following steps in sequence:

[0014] Step 1: heating and melting the aluminum alloy waste into aluminum alloy liquid;

[0015] Step 2: Online detection and adjustment of the chemical composition of the aluminum alloy liquid;

[0016] Step 3: using argon gas and refining agent to spray and refine the aluminum alloy liquid to remove slag;

[0017] Step 4: Use mixed gas to spray, refine and remove hydrogen from the aluminum alloy liquid;

[0018] Step 5: semi-continuously casting the aluminum alloy liquid into aluminum alloy round bars;

[0019] Step 6: Heat the aluminum alloy round bar and extrude it into photovoltaic aluminum profile;

[0020] Step seven: Perform aging heat treatment on the photovoltaic aluminum profile to obtain the high-strength and high-toughness photovoltaic aluminum profile.

[0021] Preferably, step one is to use a regenerative gas-fired aluminum melting furnace to heat and melt the aluminum alloy waste, and the heating and melting temperature is 720-740°C. In addition to using a regenerative gas-fired aluminum melting furnace, a resistance-type aluminum melting furnace or an electromagnetic induction aluminum melting furnace can also be used to heat and melt the aluminum alloy waste. Since the regenerative gas-fired aluminum melting furnace has the advantages of high efficiency and energy saving, it is beneficial to reduce production costs. Therefore, a regenerative gas-fired aluminum melting furnace is preferably used to heat and melt the aluminum alloy waste. The heating and melting temperature should not be lower than 720°C, otherwise it will cause the aluminum alloy waste to heat and melt slowly, affecting production efficiency. The heating and melting temperature of the aluminum alloy waste should not be higher than 740°C, otherwise it will aggravate the oxidation and burning of the aluminum alloy waste and the aluminum alloy liquid, and will also increase production costs.

[0022] Preferably, the online detection of the chemical composition of the aluminum alloy liquid in step 2 is to cast the aluminum alloy liquid into an aluminum alloy sample, and after turning and flattening, a desktop direct-reading spectrometer or a handheld spectrometer is used to detect the chemical composition of the aluminum alloy sample on site. The online adjustment of the chemical composition of the aluminum alloy liquid is to compare the chemical composition of the aluminum alloy sample with the chemical composition of the photovoltaic aluminum profile. If the content of a certain chemical element in the aluminum alloy liquid is lower than the chemical composition requirement of the photovoltaic aluminum profile, the content of the chemical element in the aluminum alloy liquid is increased by adding pure metal or alloy of the chemical element. If the content of a chemical element exceeds the chemical composition requirement of the photovoltaic aluminum profile, the content of the element in the aluminum alloy liquid is diluted by adding aluminum ingots, so that the chemical composition of the aluminum alloy liquid meets the chemical composition of the photovoltaic aluminum profile.

[0023] Furthermore, in step three, the purity of the argon gas is ≥99.99%, the amount of the refining agent is 0.1-0.2% of the weight of the aluminum alloy liquid, and the injection refining time is 10-20 minutes.

[0024] Since the surface of aluminum alloy waste is inevitably covered with oil, paint, oxide film, etc., and is embedded or sandwiched with plastic, paper, soil and other inclusions, and inevitably contains water vapor, heating and melting aluminum alloy waste will cause a large amount of gas slag in the aluminum alloy liquid. The gas is mainly hydrogen, and the slag is mainly aluminum oxide. If degassing and deslagging are not performed, the gas slag will remain inside the photovoltaic aluminum profile to form defects such as pores and looseness, which will seriously reduce the strength and plasticity of the photovoltaic aluminum profile, resulting in the mechanical properties of the photovoltaic aluminum profile not meeting the standards. This is also the main reason why it is difficult to use aluminum alloy waste to prepare photovoltaic aluminum profiles.

[0025] The spray refining adopts a powder spraying tank and a metal tube, uses argon as a carrier, sprays the powder refining agent into the aluminum alloy liquid, makes the refining agent fully contact and react with the aluminum alloy liquid, and then takes the gas slag in the aluminum alloy liquid out of the aluminum alloy liquid. The effect of spray refining is related to the purity of argon, the amount of refining agent and the spray refining time. The higher the purity of argon, the better the spray refining effect, but the production cost will increase accordingly. The spray refining time cannot be too short, and the amount of refining agent cannot be too little, otherwise the degassing and deslagging effect cannot be achieved. The spray refining time cannot be too long, otherwise the oxidation and burning of the aluminum alloy liquid will increase. The amount of refining agent cannot be too much, otherwise the alkali metal content in the aluminum alloy liquid will exceed the standard. After the spray refining is completed and the scum on the surface of the aluminum alloy liquid is removed, a covering agent should be sprinkled on the surface of the aluminum alloy liquid in time to avoid oxidation and burning of the aluminum alloy liquid and re-inhalation.

[0026] Furthermore, the refining agent in step three is composed of the following components in mass percentage: NaCl 35.12%, NaF 19.84%, TiCl3 16.51%, SrSO4 10.06%, KPO3 11.45%, and Na2B4O7 7.02%. The preparation method of the refining agent comprises the following steps in sequence: (1) according to the composition and mass percentage of the refining agent, NaCl, NaF, TiCl3, SrSO4, KPO3, and Na2B4O7 with a purity of ≥99.8% are selected as raw materials for batching; (2) the ingredients are added into water at a temperature of 70°C and stirred to dissolve into an aqueous solution, the mass ratio of water to ingredients being 1.2, and then the aqueous solution is heated to 100°C to evaporate to obtain solid crystals; (3) the solid crystals are crushed into powders with a particle size of less than 2 mm, and the powders are dried and dehydrated at 160°C for 4 hours to obtain the refining agent.

[0027] The effect of spray refining is closely related to the composition and preparation method of the refining agent. Existing refining agents are mainly fluoride salts and chloride salts, which are directly mixed after crushing. The components of the refining agent exist independently of each other, resulting in a high melting point of the refining agent and low degassing and slag removal efficiency. In addition, the existing refining agent has a single function and does not have the function of refining and modifying. Refining agents and modifying agents must be added separately, thereby increasing the production cost of photovoltaic aluminum profiles.

[0028] In view of the problems and shortcomings of existing refining agents, the present invention has developed a high-efficiency multifunctional powder refining agent, which is prepared by solution evaporation method, so that the components re-solidify and recrystallize to form a eutectic with a lower melting point. For example, the melting point of NaCl is 801°C, and the melting point of NaF is 993°C. When the two form NaCl·NaF eutectic, the melting point drops to 698°C, thereby greatly reducing the melting point of the refining agent, making the refining agent easier to dissolve in the aluminum alloy liquid, and enhancing the degassing and slag removal effect of the refining agent. Among them, NaCl reacts with the aluminum alloy liquid to generate AlCl3 with a boiling point of only 180°C. During the floating process, AlCl3 bubbles absorb and capture inclusions and hydrogen to escape from the aluminum alloy liquid, which plays a role in degassing and slag removal. NaF molten salt can destroy the aluminum oxide film, dissolve inclusions such as aluminum oxide into the molten salt, increase the surface tension between the inclusions and the aluminum alloy liquid, promote the separation of inclusions such as aluminum oxide from the aluminum alloy liquid, and enhance the deslag removal function of the refining agent. The Ti element generated by the reaction of TiCl3 with the aluminum alloy liquid directly enters the aluminum alloy liquid, which can refine the grains of the aluminum alloy casting rods, improve the plasticity and uniformity of the organizational composition of the aluminum alloy casting rods, and avoid the additional addition of refiners to increase the production cost of photovoltaic aluminum profiles. The generated AlCl3 bubbles can also absorb and capture inclusions and hydrogen in the aluminum alloy liquid during the floating process, enhancing the degassing and slag removal effect of the refining agent. The Sr and P elements generated by the reaction of SrSO4 and KPO3 with the aluminum alloy liquid enter the aluminum alloy liquid, which can refine the modified Si phase, eliminate the damage of the coarse Si phase to the strength and plasticity of the photovoltaic aluminum profile, and improve the strength and plasticity of the photovoltaic aluminum profile. The SO2 bubbles obtained by the reaction can also absorb and capture inclusions and hydrogen in the aluminum alloy liquid during the floating process, enhancing the degassing and slag removal ability of the refining agent. Na2B4O7 reacts with the aluminum alloy liquid to generate B elements and enter the aluminum alloy liquid, which can refine the modified Fe-rich phase, eliminate the damage of the coarse Fe-rich phase to the strength and plasticity of the photovoltaic aluminum profile, and improve the strength and plasticity of the photovoltaic aluminum profile.

[0029] Furthermore, the mixed gas in step 4 is a mixed gas consisting of argon with a purity of ≥99.99%, sulfur hexafluoride and carbon monoxide, the volume percentage of sulfur hexafluoride in the mixed gas is 9-11%, the volume percentage of carbon monoxide is 3-5%, the flow rate of the mixed gas is 1-2 cubic meters / minute, the pressure of the mixed gas is 0.2-0.3MPa, and the injection refining time is 10-20 minutes.

[0030] After the refining agent spray refining in the furnace, the gas slag content of the aluminum alloy liquid has been greatly reduced, but the aluminum alloy liquid still contains gas slag. Although the refining agent spray refining also has the effect of removing hydrogen, the dehydrogenation effect is limited. The reason is that the refining agent inevitably contains water, which will be brought in during the spray refining, causing the aluminum alloy liquid to absorb hydrogen again, so that the dehydrogenation of the refining agent spray refining is always in a dynamic equilibrium process. Usually, it is difficult to reduce the hydrogen content of the aluminum alloy liquid to below 0.1ml / 100gAl by refining agent spray refining. Therefore, in order to obtain a highly clean aluminum alloy liquid, it is also necessary to ventilate and carry out spray refining.

[0031] Ventilation spray refining can be carried out by using stainless steel pipes or degassing machines. In the existing ventilation spray refining technology, the degassing medium introduced is usually inert gas nitrogen or argon, or a mixture of inert gas and chlorine. Since the relative molecular mass of nitrogen, argon and chlorine is small, the gas density is small. Among them, the relative molecular mass of nitrogen is 28.01 and the density is 1.25kg / m 3 The relative molecular mass of argon is 39.94 and the density is 1.78 kg / m 3 The relative molecular mass of chlorine is 70.91 and the density is 3.21kg / m 3 This causes the bubbles to float faster in the aluminum alloy liquid, and the contact time between the bubbles and the aluminum alloy liquid is shorter, which greatly affects the degassing effect of the degassing box. In addition, although the relative density of chlorine is relatively large, chlorine is a toxic gas with a strong pungent odor, which will not only seriously corrode the equipment, but also cause environmental pollution.

[0032] In view of the problems and shortcomings of the existing ventilation injection refining technology, in order to improve the refining effect, the present invention creatively introduces a mixed gas consisting of argon with a purity of ≥99.99%, sulfur hexafluoride and carbon monoxide, wherein sulfur hexafluoride is a high-density, high-stability gas, and sulfur hexafluoride is non-toxic, non-combustible and non-corrosive. The relative molecular mass of sulfur hexafluoride is 146.05 and the density is 6.5kg / m 3 , adding 9-11% by volume of sulfur hexafluoride to the mixed gas can significantly slow down the floating speed of bubbles in the aluminum alloy liquid, increase the contact time between the bubbles and the aluminum alloy liquid, and enable the bubbles to capture and absorb more hydrogen and inclusions, thereby improving the degassing effect of the degassing box. Adding 3-5% by volume of carbon monoxide to the mixed gas is to allow carbon monoxide to capture oxygen in the aluminum alloy liquid to form carbon dioxide, prevent oxygen from forming an aluminum oxide film on the bubble surface again with aluminum, enhance the ability of the bubbles to capture and absorb hydrogen and inclusions, and improve the degassing effect. Through mixed gas refining, the hydrogen content of the aluminum alloy liquid can be reduced to below 0.1ml / 100gAl, greatly improving the cleanliness of the aluminum alloy liquid.

[0033] Furthermore, during the semi-continuous casting in step five, the temperature of the aluminum alloy liquid is 690-710° C., the speed of the semi-continuous casting is 100-150 mm / min, and the diameter of the aluminum alloy round rod is 100-200 mm.

[0034] The semi-continuous casting is to pour the aluminum alloy liquid into the crystallizer of the semi-continuous casting machine, and under the action of cooling water, the aluminum alloy liquid is pulled out of the crystallizer while solidifying, and finally forms an aluminum alloy round bar. The temperature of the aluminum alloy liquid cannot be lower than 690°C, and the semi-continuous casting speed cannot be lower than 100 mm / min, otherwise it is easy to cause the aluminum alloy liquid to solidify too quickly, causing defects such as cold shut on the surface of the aluminum alloy round bar, and reducing the surface quality of the aluminum alloy round bar. The temperature of the aluminum alloy liquid should not exceed 710°C, and the speed of the semi-continuous casting should not exceed 150 mm / min, otherwise it is easy to cause the aluminum alloy liquid to solidify untimely, resulting in leakage and aluminum liquid leakage accidents. Therefore, in order to obtain high-quality aluminum alloy round bars and to prevent aluminum liquid leakage accidents, it is necessary to strictly abide by the operating procedures of semi-continuous casting and strictly control the process parameters of semi-continuous casting.

[0035] Furthermore, in step six, the heating temperature of the aluminum alloy round bar is 460-470°C, the preheating temperature of the extrusion die is 380-400°C, the preheating temperature of the extrusion cylinder is 320-330°C, and the speed of the extrusion main cylinder is 15-20 mm / s.

[0036] Extrusion is an important process for obtaining high-quality photovoltaic aluminum profiles, and the shape and size of photovoltaic aluminum profiles must be guaranteed. In order to obtain photovoltaic aluminum profiles that meet the requirements in shape and size, it is necessary to reasonably match the extrusion process parameters, including the heating temperature of the aluminum alloy round bar, the preheating temperature of the extrusion die, the preheating temperature of the extrusion barrel, and the speed of the extrusion main cylinder. The heating temperature of the aluminum alloy round bar is lower than 460°C, the preheating temperature of the extrusion die is lower than 380°C, the preheating temperature of the extrusion barrel is lower than 320°C, and the speed of the extrusion main cylinder is greater than 20 mm / s, which may cause extrusion difficulties or even suffocation. The heating temperature of the aluminum alloy round bar should not be higher than 470°C, the preheating temperature of the extrusion die should not be higher than 400°C, the preheating temperature of the extrusion barrel should not be higher than 330°C, and the speed of the extrusion main cylinder should not be lower than 15 mm / s, otherwise it is easy to cause the surface quality of the photovoltaic aluminum profile to deteriorate and the mechanical properties to be insufficient. The photovoltaic aluminum profile after extrusion should be cooled quickly to obtain a supersaturated solid solution and enhance the aging strengthening effect.

[0037] Furthermore, the temperature of the aging heat treatment in step seven is 170-180° C., and the aging heat treatment time is 4-5 hours.

[0038] Aging heat treatment is an important measure to further improve the strength of photovoltaic aluminum profiles. If the temperature of aging heat treatment is lower than 170℃ or the aging heat treatment time is less than 4 hours, the photovoltaic aluminum profile will be under-aged and insufficient in strength. The temperature of aging heat treatment cannot be higher than 180℃, and the aging heat treatment time cannot be more than 5 hours, otherwise it will cause the photovoltaic aluminum profile to be over-aged, which will also lead to insufficient strength of the photovoltaic aluminum profile.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] The present invention optimizes the composition of photovoltaic aluminum profiles, adopts refining agent spraying and mixed gas spraying refining to aluminum alloy liquid, eliminates the harm of gas slag to the mechanical properties of photovoltaic aluminum profiles, improves the strength and plasticity of photovoltaic aluminum profiles, and the tensile strength of photovoltaic aluminum profiles is greater than 350MPa, the yield strength is greater than 310MPa, and the elongation after fracture is greater than 12%, which meets the development requirements of lightweight solar photovoltaic modules and is conducive to improving the safety and service life of photovoltaic power generation devices. The present invention also realizes the use of aluminum alloy waste to regenerate photovoltaic aluminum profiles, which not only improves the utilization value of aluminum alloy waste, but also reduces the production cost of photovoltaic aluminum profiles, which is conducive to improving the market competitiveness of photovoltaic modules. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is a process flow chart of waste aluminum recycling for the high-strength and tough photovoltaic aluminum profile of the present invention. DETAILED DESCRIPTION

[0042] The technical solution of the present invention is described clearly and completely below. 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 creative work are within the scope of protection of the present invention.

[0043] Embodiment 1:

[0044] The photovoltaic aluminum profile is composed of the following components in mass percentage: Mg 0.89%, Si 0.45%, Cu 0.19%, Zn0.17%, Er 0.11%, Fe≤0.2%, and the balance is Al and unavoidable impurity elements, the individual content of the unavoidable impurity elements is ≤0.05%, and the total amount of impurity elements is ≤0.15%. The waste aluminum regeneration method comprises the following steps in sequence: step 1: using a regenerative gas-fired aluminum melting furnace to heat and melt the aluminum alloy waste at 730°C into aluminum alloy liquid; step 2: using a desktop direct-reading spectrometer to perform online detection and adjustment of the chemical composition of the aluminum alloy liquid, so that the chemical composition of the aluminum alloy liquid meets the composition requirements of photovoltaic aluminum profiles; step 3: using argon with a purity of 99.99% and a refining agent of 0.15% by weight of the aluminum alloy liquid to spray and refine the aluminum alloy liquid for 15 minutes to remove slag; step 4: using a mixed gas to spray and refine the aluminum alloy liquid for 15 minutes to remove hydrogen, the mixed gas is a mixed gas composed of argon with a purity of 99.99%, sulfur hexafluoride and carbon monoxide, and the hexafluoride in the mixed gas is 0.15% by weight. The volume percentage of sulfur fluoride is 10%, the volume percentage of carbon monoxide is 4%, the flow rate of the mixed gas is 1.5 cubic meters per minute, and the pressure of the mixed gas is 0.25 MPa; Step five: semi-continuously cast the 700°C aluminum alloy liquid into an aluminum alloy round rod with a diameter of 150 mm, and the semi-continuous casting speed is 160 mm per minute; Step six: Under the conditions of the aluminum alloy round rod heating temperature of 465°C, the extrusion die preheating temperature of 390°C, the extrusion barrel preheating temperature of 325°C, and the extrusion main cylinder speed of 18 mm per second, the aluminum alloy round rod is heated and extruded into a photovoltaic aluminum profile; Step seven: subject the photovoltaic aluminum profile to aging heat treatment at 175°C for 4.5 hours to obtain a high-strength and toughness photovoltaic aluminum profile.

[0045] Embodiment 2:

[0046] The photovoltaic aluminum profile is composed of the following components in mass percentage: Mg 0.87%, Si 0.46%, Cu 0.21%, Zn0.18%, Er 0.12%, Fe≤0.2%, and the balance is Al and unavoidable impurity elements, the individual content of the unavoidable impurity elements is ≤0.05%, and the total amount of impurity elements is ≤0.15%. The waste aluminum regeneration method comprises the following steps in sequence: step 1: using a regenerative gas-fired aluminum melting furnace to heat and melt the aluminum alloy waste at 730°C into aluminum alloy liquid; step 2: using a desktop direct-reading spectrometer to perform online detection and adjustment of the chemical composition of the aluminum alloy liquid, so that the chemical composition of the aluminum alloy liquid meets the composition requirements of photovoltaic aluminum profiles; step 3: using argon with a purity of 99.99% and a refining agent of 0.18% by weight of the aluminum alloy liquid to spray and refine the aluminum alloy liquid for 18 minutes to remove slag; step 4: using a mixed gas to spray and refine the aluminum alloy liquid for 16 minutes to remove hydrogen, the mixed gas is a mixed gas composed of argon with a purity of 99.99%, sulfur hexafluoride and carbon monoxide, and the hexafluoride in the mixed gas is 0.18% by weight. The volume percentage of sulfur fluoride is 9.5%, the volume percentage of carbon monoxide is 4.5%, the flow rate of the mixed gas is 1.8 cubic meters per minute, and the pressure of the mixed gas is 0.27 MPa; Step 5: Semi-continuously cast the 695°C aluminum alloy liquid into an aluminum alloy round rod with a diameter of 180 mm, and the semi-continuous casting speed is 120 mm per minute; Step 6: Under the conditions of the aluminum alloy round rod heating temperature of 465°C, the extrusion die preheating temperature of 385°C, the extrusion barrel preheating temperature of 325°C, and the extrusion main cylinder speed of 17 mm per second, the aluminum alloy round rod is heated and extruded into a photovoltaic aluminum profile; Step 7: Perform aging heat treatment on the photovoltaic aluminum profile at 175°C for 4 hours to obtain a high-strength and toughness photovoltaic aluminum profile.

[0047] Embodiment 3:

[0048] The photovoltaic aluminum profile is composed of the following components in mass percentage: Mg 0.86%, Si 0.47%, Cu 0.18%, Zn0.2%, Er 0.09%, Fe≤0.2%, the balance is Al and unavoidable impurity elements, the individual content of the unavoidable impurity elements is ≤0.05%, and the total amount of impurity elements is ≤0.15%. The method for regenerating solar photovoltaic aluminum profile waste to maintain grade includes the following steps in sequence: Step 1: using a regenerative gas-fired aluminum melting furnace to heat and melt the aluminum alloy waste at 740°C into aluminum alloy liquid; Step 2: using a desktop direct-reading spectrometer to perform online detection and adjustment of the chemical composition of the aluminum alloy liquid, so that the chemical composition of the aluminum alloy liquid meets the composition requirements of photovoltaic aluminum profiles; Step 3: using argon with a purity of 99.99% and a refining agent of 0.2% of the weight of the aluminum alloy liquid to spray and refine the aluminum alloy liquid for 20 minutes to remove slag; Step 4: using a mixed gas to spray and refine the aluminum alloy liquid for 10 minutes to remove hydrogen, and the mixed gas is a mixture of argon with a purity of 99.99%, sulfur hexafluoride and carbon monoxide. The volume percentage of sulfur hexafluoride in the mixed gas is 11%, the volume percentage of carbon monoxide is 3%, the flow rate of the mixed gas is 2 cubic meters per minute, and the pressure of the mixed gas is 0.2 MPa; Step five: semi-continuously cast the 710°C aluminum alloy liquid into an aluminum alloy round rod with a diameter of 100 mm, and the semi-continuous casting speed is 150 mm per minute; Step six: under the conditions of the aluminum alloy round rod heating temperature of 470°C, the extrusion die preheating temperature of 380°C, the extrusion barrel preheating temperature of 330°C, and the extrusion main cylinder speed of 15 mm per second, the aluminum alloy round rod is heated and extruded into a photovoltaic aluminum profile; Step seven: subject the photovoltaic aluminum profile to aging heat treatment at 170°C for 5 hours to obtain a high-strength and toughness photovoltaic aluminum profile.

[0049] Embodiment 4:

[0050] The photovoltaic aluminum profile is composed of the following components in mass percentage: Mg 0.91%, Si 0.42%, Cu 0.22%, Zn0.15%, Er 0.13%, Fe≤0.2%, the balance is Al and unavoidable impurity elements, the individual content of the unavoidable impurity elements is ≤0.05%, and the total amount of impurity elements is ≤0.15%. The method for regenerating solar photovoltaic aluminum profile waste includes the following steps in sequence: Step 1: using a regenerative gas-fired aluminum melting furnace to heat and melt the aluminum alloy waste at 720-740°C into aluminum alloy liquid; Step 2: using a desktop direct-reading spectrometer to perform online detection and adjustment of the chemical composition of the aluminum alloy liquid, so that the chemical composition of the aluminum alloy liquid meets the composition requirements of the photovoltaic aluminum profile; Step 3: using argon with a purity of 99.99% and a refining agent of 0.1% by weight of the aluminum alloy liquid to spray and refine the aluminum alloy liquid for 10 minutes to remove slag; Step 4: using a mixed gas to spray and refine the aluminum alloy liquid for 20 minutes to remove hydrogen, the mixed gas is a mixture of argon with a purity of 99.99%, sulfur hexafluoride and carbon monoxide. mixed gas, the volume percentage of sulfur hexafluoride in the mixed gas is 9%, the volume percentage of carbon monoxide is 5%, the flow rate of the mixed gas is 1 cubic meter / minute, and the pressure of the mixed gas is 0.3MPa; Step five: semi-continuously cast the 690°C aluminum alloy liquid into an aluminum alloy round rod with a diameter of 200 mm, and the semi-continuous casting speed is 100 mm / minute; Step six: under the conditions of the aluminum alloy round rod heating temperature of 460°C, the extrusion die preheating temperature of 400°C, the extrusion barrel preheating temperature of 320°C, and the extrusion main cylinder speed of 20 mm / second, the aluminum alloy round rod is heated and extruded into a photovoltaic aluminum profile; Step seven: subject the photovoltaic aluminum profile to aging heat treatment at 180°C for 4 hours to obtain a high-strength and toughness photovoltaic aluminum profile.

[0051] The refining agent used in step 3 of Examples 1-4 of the present invention is composed of the following components in mass percentage: NaCl 35.12%, NaF 19.84%, TiCl 3 16.51%, SrSO 4 10.06%, KPO 3 11.45%, Na 2 B 4 O 7 7.02%. The preparation method of the refining agent comprises the following steps in sequence:

[0052] (1) According to the composition and mass percentage of the refining agent, NaCl, NaF, TiCl3, SrSO4, KPO3, and Na2B4O7 with a purity of 99.8% are selected as raw materials for batching; (2) the ingredients are added into water at a temperature of 70° C. and stirred to dissolve into an aqueous solution, wherein the mass ratio of water to the ingredients is 1.2, and then the aqueous solution is heated to 100° C. to evaporate and obtain solid crystals; (3) the solid crystals are crushed into powders with a particle size of less than 2 mm, and the powders are dried and dehydrated at 160° C. for 4 hours to obtain the refining agent.

[0053] Comparative Example 1:

[0054] The components and mass percentages of the photovoltaic aluminum profiles in this comparative example and the waste aluminum regeneration steps are the same as those in Example 1, except that the refining agent used in step three is a conventional refining agent available on the market, and the refining agent is composed of the following components in mass percentages: NaCl 36.13%, KCl 15.42%, CaF2 16.84%, NaF 19.24%, and C2Cl6 12.37%, and the refining agent is obtained by directly crushing and mixing the raw materials.

[0055] Comparative Example 2:

[0056] The components and mass percentages of the photovoltaic aluminum profiles in this comparative example and the steps of waste aluminum regeneration are the same as those in Example 1, with the difference being that in step four, argon gas with a purity of 99.99% is introduced for spray refining instead of a mixed gas composed of argon gas with a purity of 99.99%, sulfur hexafluoride and carbon monoxide.

[0057] Comparative Example 3:

[0058] The composition and mass percentage of the photovoltaic aluminum profile in this comparative example and the waste aluminum regeneration steps are the same as those in Example 1, except that the heating temperature of the aluminum alloy round rod in step six is ​​500°C.

[0059] Comparative Example 4:

[0060] The composition and mass percentage of the photovoltaic aluminum profile in this comparative example and the waste aluminum regeneration steps are the same as those in Example 1, except that the aging heat treatment time of the aluminum profile in step seven is 6 hours.

[0061] Verification example:

[0062] The hydrogen content and slag content of the aluminum alloy liquid before semi-continuous casting of Examples 1-4 and Comparative Examples 1-2 were measured using a HDA-V hydrogen meter and an Analyze PoDFA slag meter. The results are shown in Table 1. As can be seen from Table 1, the hydrogen content of the aluminum alloy liquid before semi-continuous casting of Examples 1-4 is less than 0.08 ml / 100 gAl, and the slag content is less than 0.05 mm 2 / kgAl. Comparative Example 1 uses commercially available conventional refining agent for refining by spraying, and Comparative Example 2 does not use mixed gas for refining by spraying, resulting in a relatively high gas slag content in the aluminum alloy liquid. By comparison, it can be seen that the use of the technical solution of the present invention can significantly reduce the gas slag content in the aluminum alloy liquid and improve the cleanliness of the photovoltaic aluminum profile.

[0063] Table 1 Hydrogen content and slag content of aluminum alloy liquid

[0064] Hydrogen content / (ml / 100gAl) <![CDATA[Sludge content / (mm 2 / kg Al)]]> Example 1 0.072 0.038 Example 2 0.061 0.032 Example 3 0.079 0.046 Example 4 0.063 0.037 Comparative Example 1 0.149 0.118 Comparative Example 2 0.173 0.136

[0065] Samples were taken from the photovoltaic aluminum profiles obtained in Examples 1-4 and Comparative Examples 1-4 to test the room temperature tensile mechanical properties of the photovoltaic aluminum profiles, and the results are shown in Table 2. As can be seen from Table 2, the tensile strength of the photovoltaic aluminum profiles in Examples 1-4 is greater than 350MPa, the yield strength is greater than 310MPa, and the elongation after fracture is greater than 12%. Comparative Example 1 uses a commercially available conventional refining agent for spray refining, Comparative Example 2 does not use a mixed gas for spray refining, Comparative Example 3 has a heating temperature of the aluminum alloy round bar higher than 470°C, and Comparative Example 4 has an aging heat treatment time of more than 5 hours, resulting in the strength of the photovoltaic aluminum profiles in Comparative Examples 1-4 being lower than 320MPa, the yield strength being lower than 290MPa, and the elongation after fracture being lower than 10%. By comparison, it can be seen that the strength and plasticity of the photovoltaic aluminum profiles can be greatly improved by using the technical solution of the present invention.

[0066] Table 2 Room temperature tensile mechanical properties of photovoltaic aluminum profiles

[0067]

Claims

1. A high-strength and tough photovoltaic aluminum profile, characterized in that: The photovoltaic aluminum profile is composed of the following components in mass percentage: Mg 0.86-0.91%, Si 0.42-0.47%, Cu0.18-0.22%, Zn 0.15-0.2%, Er 0.09-0.13%, Fe≤0.2%, and the balance is Al and unavoidable impurity elements, the individual content of the unavoidable impurity elements is ≤0.05%, and the total amount of impurity elements is ≤0.15%.

2. A method for recycling waste aluminum of high-strength and tough photovoltaic aluminum profiles as claimed in claim 1, characterized in that: The following steps are included in sequence: Step 1: heating and melting the aluminum alloy waste into aluminum alloy liquid; Step 2: Online detection and adjustment of the chemical composition of the aluminum alloy liquid; Step 3: using argon gas and refining agent to spray and refine the aluminum alloy liquid to remove slag; Step 4: using mixed gas to spray and refine the aluminum alloy liquid to remove hydrogen; Step 5: semi-continuously casting the aluminum alloy liquid into aluminum alloy round bars; Step 6: Heat the aluminum alloy round bar and extrude it into photovoltaic aluminum profile; Step seven: Perform aging heat treatment on the photovoltaic aluminum profile to obtain the high-strength and high-toughness photovoltaic aluminum profile.

3. The method for recycling waste aluminum of high-strength and tough photovoltaic aluminum profiles according to claim 2, characterized in that: The first step is to use a regenerative gas aluminum melting furnace to heat and melt the aluminum alloy waste, and the heating and melting temperature is 720-740°C.

4. The method for recycling waste aluminum of high-strength and tough photovoltaic aluminum profiles according to claim 2, characterized in that: The purity of the argon gas in step 3 is ≥99.99%, the amount of the refining agent is 0.1-0.2% of the weight of the aluminum alloy liquid, and the spray refining time is 10-20 minutes.

5. The method for recycling waste aluminum of high-strength and tough photovoltaic aluminum profiles according to claim 2, characterized in that: The refining agent in step 3 is composed of the following components in mass percentage: NaCl 35.12%, NaF 19.84%, TiCl 3 16.51%, SrSO 4 10.06%, KPO 3 11.45%, and Na 2 B 4 O 7 7.02%. The preparation method of the refining agent comprises the following steps in sequence: (1) according to the composition and mass percentage of the refining agent, NaCl, NaF, TiCl 3, SrSO 4, KPO 3, and Na 2 B 4 O 7 with a purity of ≥99.8% are selected as raw materials for batching; (2) the ingredients are added into water at a temperature of 70° C. and stirred to dissolve into an aqueous solution, the mass ratio of water to ingredients being 1.2, and then the aqueous solution is heated to 100° C. to evaporate to obtain solid crystals; (3) the solid crystals are crushed into powders with a particle size of less than 2 mm, and the powders are dried and dehydrated at 160° C. for 4 hours to obtain the refining agent.

6. The method for recycling waste aluminum of high-strength and tough photovoltaic aluminum profiles according to claim 2, characterized in that: The mixed gas in step 4 is composed of argon gas with a purity of ≥99.99%, sulfur hexafluoride and carbon monoxide, the volume percentage of sulfur hexafluoride in the mixed gas is 9-11%, and the volume percentage of carbon monoxide is 3-5%.

7. The method for recycling waste aluminum of high-strength and tough photovoltaic aluminum profiles according to claim 2, characterized in that: The flow rate of the mixed gas in step 4 is 1-2 cubic meters per minute, the pressure of the mixed gas is 0.2-0.3 MPa, and the injection refining time is 10-20 minutes.

8. The method for recycling waste aluminum of high-strength and tough photovoltaic aluminum profiles according to claim 2, characterized in that: During the semi-continuous casting in step 5, the temperature of the aluminum alloy liquid is 690-710° C., the speed of the semi-continuous casting is 100-150 mm / min, and the diameter of the aluminum alloy round rod is 100-200 mm.

9. The method for recycling waste aluminum of high-strength and tough photovoltaic aluminum profiles according to claim 2, characterized in that: In step six, the heating temperature of the aluminum alloy round bar is 460-470° C., the preheating temperature of the extrusion die is 380-400° C., the preheating temperature of the extrusion cylinder is 320-330° C., and the speed of the extrusion main cylinder is 15-20 mm / s.

10. The method for recycling waste aluminum of high-strength and tough photovoltaic aluminum profiles according to claim 2, characterized in that: The temperature of the aging heat treatment in step seven is 170-180° C., and the aging heat treatment time is 4-5 hours.

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