Recycled aluminum alloy refining flux and preparation method thereof

Abstract

The invention discloses a secondary aluminum alloy refining flux and a preparation method thereof, the refining flux is composed of the following components in percentage by mass: 34-36% of CaCl2, 18-22% of KF, 15-17% of TiCl4, 8-12% of SrSO4, 9-13% of Na3PO4 and 6-8% of K3BO3, and the preparation method comprises the steps of material preparation, evaporative crystallization, crushing and drying dehydration. The problems that a traditional refining flux is low in gas and slag removal efficiency, large in smoke emission amount, poor in slag-aluminum separation effect and the like are solved, the refining flux has the excellent gas and slag removal effect, the gas and slag content of the regenerated aluminum alloy melt can be remarkably reduced, the problems that the gas and slag content of the regenerated aluminum alloy melt is high, and gas and slag removal is difficult are solved, and the refining flux is suitable for industrial production. The harm of air holes and inclusions is eliminated, and the cleanliness and mechanical property of the regenerated aluminum alloy are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of aluminum alloy refining flux preparation, and specifically relates to a recycled aluminum alloy refining flux and a preparation method thereof. Background Art

[0002] Recycled aluminum alloy is an aluminum alloy obtained by smelting and casting with waste aluminum as the main raw material. Compared with primary aluminum alloy, the energy consumption of recycled aluminum alloy is only 5% of that of primary aluminum alloy, and the carbon emission is only 2.1% of that of primary aluminum alloy. Every ton of aluminum alloy recycled and reused can save 3.4 tons of standard coal, reduce carbon dioxide emissions by 0.8 tons, reduce solid waste emissions by 20 tons, and save 22 cubic meters of water. Therefore, the development of recycled aluminum alloy industry is of great significance to reducing the production cost of aluminum alloy, reducing the mining of bauxite and coal resources, reducing the emission of carbon dioxide and solid waste, and protecting the ecological environment.

[0003] The performance of recycled aluminum alloy is closely related to its cleanliness and organizational state. Porosity and inclusions will split the recycled aluminum alloy matrix, destroy the organizational continuity of the recycled aluminum alloy, cause local stress concentration, and become the crack source and crack extension direction of the recycled aluminum alloy fracture, thereby reducing the strength and plasticity of the recycled aluminum alloy. Coarse grain structure will reduce the casting fluidity, strength and plasticity of the recycled aluminum alloy, while fine and uniform grain structure can improve the casting fluidity, strength and plasticity of the recycled aluminum alloy. Therefore, in the smelting production process, the recycled aluminum alloy melt must be degassed and deslag purified and refined and modified to improve the cleanliness of the recycled aluminum alloy and refine the grain structure of the recycled aluminum alloy.

[0004] The Chinese patent document with publication number CN118086686A discloses a refining agent for recycled aluminum, the refining agent structure is a coated particle, the raw material composition of the outer coating layer includes ZnCl2 and LiCl, and the raw material composition of the inner core includes Li2CO3. The raw material composition of the outer coating layer also includes any one or a mixture of two of Na3AIF6 and CaF2, and any one or a mixture of several of KCl, NaCl, and NaF.

[0005] A Chinese patent document with publication number CN115852192A discloses a recycled aluminum alloy refining agent and a preparation method thereof. The refining agent is composed of the following components in mass percentage: MgCl2 30-35%, KCl 25-30%, CaCl2 10-15%, KBF4 5-10%, K2TiF6 5-10%, BaCO3 5-10%, and YCl3 3-6%. The preparation method includes batching, drying and dehydration, heating and remelting, crushing, screening and packaging.

[0006] The Chinese patent document with publication number CN110241322A discloses a regenerated aluminum alloy refining agent, the components of which are as follows by weight: NaCl 30-40%, KCl 30-35%, MgCl220-25%, NaF 20-25%, Na3AlF6 10-15%, CaF2 2-5%. The preparation method includes mixing the refining agent by weight, adding water and stirring, drying in a fluidized bed after a few days, crushing, drying and dehydrating, and vacuum packaging.

[0007] Since the sources of scrap aluminum are wide and complex, and scrap aluminum carries or contains a large number of inclusions, the gas slag content of the recycled aluminum alloy melt is particularly high, making refining, degassing and deslagging difficult. Based on the results of literature retrieval and production practice experience, the existing refining flux for recycled aluminum alloys still has one or more of the following problems: (1) The degassing and deslagging efficiency of the refining flux is low, which makes it difficult to meet the refining, degassing and deslagging requirements of the recycled aluminum alloy; (2) The refining flux has a single function and does not have the function of refining and modifying, which cannot meet the production needs of high-performance recycled aluminum alloys; (3) The refining flux contains a large amount of fluoride salts and chloride salts, and the emission of irritating smoke during use is large, and the slag-aluminum separation effect is poor, causing serious environmental pollution. Therefore, the existing refining flux for recycled aluminum alloys and its preparation method still need to be improved and developed. Summary of the invention

[0008] In view of the problems and shortcomings mentioned in the background technology, the purpose of the present invention is to provide a recycled aluminum alloy refining flux and a preparation method thereof, which can improve the degassing and slag removal efficiency of the refining flux, reduce the gas slag content of the recycled aluminum alloy, refine the grain structure of the recycled aluminum alloy, improve the cleanliness and mechanical properties of the recycled aluminum alloy, reduce the emission of irritating smoke and aluminum slag, and solve the problems and shortcomings mentioned in the background technology by optimizing the component composition and preparation method of the refining flux.

[0009] The technical solution adopted by the present invention to achieve the above-mentioned purpose is as follows:

[0010] The first aspect of the present invention provides a secondary aluminum alloy refining flux, characterized in that the refining flux consists of the following components in mass percentage: CaCl2 34-36%, KF 18-22%, TiCl4 15-17%, SrSO4 8-12%, Na3PO4 9-13%, and K3BO3 6-8%.

[0011] Among them, CaCl2 is the main component of the refining flux. CaCl2 reacts with the recycled aluminum alloy melt to generate AlCl3 with a boiling point of only 180°C. AlCl3 has a very high vapor pressure and is gaseous in the recycled aluminum alloy melt. During the floating process, AlCl3 bubbles absorb and capture inclusions and hydrogen in the recycled aluminum alloy melt, and then escape from the recycled aluminum alloy melt together, thereby removing slag and hydrogen.

[0012] The main function of KF is to adsorb and dissolve inclusions such as alumina. KF molten salt can first destroy the alumina film, dissolve alumina, and dissolve inclusions such as alumina into the molten salt, thus playing a role in slag removal. Secondly, it can reduce the wettability of the interface between inclusions and the recycled aluminum alloy melt, increase the surface tension between inclusions and the recycled aluminum alloy melt, promote the separation of inclusions such as alumina from the recycled aluminum alloy melt, and enhance the slag removal function of the refining flux.

[0013] The Ti element generated by the reaction of TiCl4 with the recycled aluminum alloy melt directly enters the recycled aluminum alloy melt, plays a role in heterogeneous nucleation during the solidification process of the recycled aluminum alloy, refines the α-Al grains of the recycled aluminum alloy, and transforms the α-Al grains from coarse dendrites to nearly spherical or equiaxed shapes, thereby improving the fluidity, strength and plasticity of the recycled aluminum alloy. The AlCl3 bubbles generated by the reaction can also absorb and capture inclusions and hydrogen in the recycled aluminum alloy melt during the floating process, thereby enhancing the slag and hydrogen removal capabilities of the refining flux.

[0014] The Sr element generated by the reaction of SrSO4 with the recycled aluminum alloy melt enters the recycled aluminum alloy melt, which plays a role in refining the modified eutectic Si phase, transforming the eutectic Si phase from coarse needles to fine particles or fibers, eliminating the harm of coarse eutectic Si phase to the strength and plasticity of the recycled aluminum alloy, and improving the strength and plasticity of the recycled aluminum alloy. The SO2 bubbles obtained by the reaction can also absorb and capture inclusions and hydrogen in the recycled aluminum alloy melt during the floating process, enhancing the slag and hydrogen removal capabilities of the refining flux.

[0015] Na3PO4 reacts with the recycled aluminum alloy melt to generate P element which enters the recycled aluminum alloy melt and can refine the primary Si phase in the recycled aluminum alloy. For hypereutectic recycled aluminum alloy, in addition to the eutectic Si phase, there are also coarse block or lath-shaped primary Si phases. P element can refine the coarse primary Si phase and transform the coarse block or lath-shaped primary Si phase into fine dispersed particles, which can not only improve the strength and plasticity of the recycled aluminum alloy, but also enhance the wear resistance of the recycled aluminum alloy.

[0016] The main function of K3BO3 is to refine the Fe-rich phase in the modified recycled aluminum alloy. Fe is an inevitable impurity element in the recycled aluminum alloy, usually existing in the form of coarse needle-shaped or flaky Fe-rich phases such as Al3Fe and FeSiAl3, which will damage the strength and plasticity of the recycled aluminum alloy. K3BO3 reacts with the recycled aluminum alloy melt to generate B element, which enters the recycled aluminum alloy melt and can transform the coarse needle-shaped or flaky Fe-rich phase into fine dispersed particles, eliminating the harm of the coarse Fe-rich phase to the strength and plasticity of the recycled aluminum alloy, and improving the strength and plasticity of the recycled aluminum alloy.

[0017] Preferably, the refining flux consists of the following components in mass percentage: CaCl2 35.12%, KF 19.84%, TiCl4 16.51%, SrSO4 10.06%, Na3PO4 11.45%, and K3BO3 7.02%.

[0018] A second aspect of the present invention provides a method for preparing a secondary aluminum alloy refining flux, which is characterized by comprising the following steps in sequence:

[0019] Step 1: According to the composition and mass percentage of the refining flux, CaCl2, KF, TiCl4, SrSO4, Na3PO4, and K3BO3 are selected as raw materials for batching;

[0020] Step 2: adding the ingredients into hot water and stirring to dissolve into an aqueous solution, and then heating and evaporating the aqueous solution to obtain a solid crystal;

[0021] Step 3: crushing the solid crystals into particles with a particle size of less than 2 mm, drying and dehydrating the particles to obtain the refining flux.

[0022] Preferably, the purity of CaCl2, KF, TiCl4, SrSO4, Na3PO4 and K3BO3 in step 1 is not less than 99.8%. The raw materials can be industrial products, industrial by-products or naturally occurring minerals, but the purity of the raw materials must be guaranteed and they cannot contain too many impurities, otherwise it will affect the effect of the refining flux and cause secondary pollution to the recycled aluminum alloy.

[0023] Preferably, the temperature of the hot water in step 2 is not less than 80° C., the mass ratio of hot water to ingredients is 1.4-1.6, and the temperature of the aqueous solution during heating and evaporation is 100° C. Too little hot water or too low a temperature will make it difficult to stir and dissolve the ingredients into an aqueous solution, while too much hot water will result in too long a heating and evaporation time, increasing energy consumption and production costs.

[0024] Preferably, the drying and dehydration temperature in step 3 is 190-200°C, and the drying and dehydration time is 2-3 hours. If the temperature is too low or the time is too short, the dehydration will not be thorough. The temperature should not be too high, otherwise the ingredients will decompose and lose their effect. After drying and dehydration, packaging and sealing should be carried out as soon as possible to avoid moisture absorption.

[0025] The third aspect of the present invention also provides a method for using a refining flux for recycled aluminum alloy, wherein the amount of the refining flux used is 0.1-0.2% of the weight of the recycled aluminum alloy.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] (1) The refining flux of the present invention has a lower melting point and a better degassing and slag removal effect. Existing refining fluxes are usually obtained by directly mixing chloride salts and fluoride salts after mechanical crushing. The components exist independently of each other. When used, there is a lack of synergistic promotion between the components, which ultimately leads to a high melting point of the refining flux and a low degassing and slag removal efficiency. The present invention breaks through the tradition and adopts a solution evaporation method to prepare the refining flux. Through solution evaporation, the components are re-solidified and recrystallized to form a eutectic with a lower melting point. For example, the melting point of CaCl2 is 772°C, and the melting point of KF is 885°C. When the two form a CaCl2·KF eutectic, the melting point drops to 684°C, thereby greatly reducing the melting point of the refining flux, making it easier for the refining flux to dissolve in the recycled aluminum alloy melt, resulting in a better degassing and slag removal effect.

[0028] (2) The refining flux of the present invention has the dual functions of degassing and deslagging and refining and modification. The existing refining flux of recycled aluminum alloy usually only contains NaCl, KCl, KF, CaF, C2Cl6 and other components. Although it has the function of degassing and deslagging, it does not have the function of refining and modification. In order to refine and modify the recycled aluminum alloy, it is also necessary to add a refining and modification agent, which not only increases the production cost but also increases the production process. In addition to the conventional CaCl2 and KF, the refining flux of the present invention also contains TiCl4, SrSO4, Na3PO4, K3BO3. These components not only increase the degassing and deslagging functions of the refining flux, but also release trace amounts of Ti, Sr, P, and B elements into the recycled aluminum alloy melt, and respectively refine and modify the α-Al grains, eutectic Si phase, primary Si phase and Fe-rich phase during the solidification process, which can eliminate the harm of coarse α-Al grains, eutectic Si phase, primary Si phase and Fe-rich phase to the mechanical properties of the recycled aluminum alloy, and improve the strength and plasticity of the recycled aluminum alloy.

[0029] (3) The use of the refining flux of the present invention is more environmentally friendly and has lower production costs. Existing refining fluxes mainly contain chloride salts and fluoride salts such as NaCl, KCl, KF, CaF, C2Cl6 as main components. During use, a large amount of irritating and unpleasant smoke and corrosive gases will be generated, which seriously pollute the environment and endanger the health of workers. Due to the low efficiency of degassing and slag removal of existing refining fluxes, in order to obtain cleaner recycled aluminum alloys, the amount of refining flux has to be increased. The amount of refining flux usually accounts for 0.3-0.5% of the weight of the recycled aluminum alloy melt. However, increasing the amount of refining flux will increase production costs, increase the emission of aluminum slag, cause more serious environmental pollution, and also cause the content of alkali metal elements such as Na, Ca, and K in the recycled aluminum alloy to exceed the standard, deteriorating the mechanical properties of the recycled aluminum alloy. The refining flux of the present invention reduces the content of fluorine salt and chloride salt, can reduce the emission of smoke, and reduce the amount of refining flux used, so that not only highly clean recycled aluminum alloy can be obtained, but also the emission of aluminum slag can be reduced, and the content of alkali metals such as Na, Ca, K in the recycled aluminum alloy can be avoided to exceed the standard. Therefore, the use is more environmentally friendly and is also conducive to reducing the production cost of the recycled aluminum alloy. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 The microstructure of the recycled aluminum alloy after refining using the refining flux of Example 1 of the present invention.

[0031] Figure 2 The microstructure of the recycled aluminum alloy after refining using the commercially available conventional refining flux of Comparative Example 2. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present invention are 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.

[0033] Embodiment 1:

[0034] The recycled aluminum alloy refining flux is composed of the following components in mass percentage: CaCl2 35.12%, KF 19.84%, TiCl4 16.51%, SrSO4 10.06%, Na3PO4 11.45%, and K3BO3 7.02%. The preparation method of the refining flux comprises the following steps in sequence: Step 1: According to the composition and mass percentage of the refining flux, CaCl2, KF, TiCl4, SrSO4, Na3PO4, and K3BO3 with a purity of 99.8% are selected as raw materials for batching; Step 2: Add the ingredients into 85°C hot water and stir to dissolve into an aqueous solution, the mass ratio of hot water to the ingredients is 1.5, and then heat the aqueous solution to 100°C for evaporation to obtain solid crystals; Step 3: Crushing the solid crystals into particles with a particle size of less than 2 mm, drying and dehydrating the particles at 195°C for 2.5 hours to obtain the refining flux.

[0035] Embodiment 2:

[0036] The recycled aluminum alloy refining flux is composed of the following components in mass percentage: CaCl2 34.03%, KF 21.96%, TiCl4 15.03%, SrSO4 11.79%, Na3PO4 9.22%, and K3BO3 7.97%. The preparation method of the refining flux comprises the following steps in sequence: Step 1: According to the composition and mass percentage of the refining flux, CaCl2, KF, TiCl4, SrSO4, Na3PO4, and K3BO3 with a purity of 99.8% are selected as raw materials for batching; Step 2: Add the ingredients into 80°C hot water and stir to dissolve into an aqueous solution, the mass ratio of hot water to the ingredients is 1.6, and then heat the aqueous solution to 100°C for evaporation to obtain solid crystals; Step 3: Crushing the solid crystals into particles with a particle size of less than 2 mm, drying and dehydrating the particles at 190°C for 3 hours to obtain the refining flux.

[0037] Embodiment 3:

[0038] The recycled aluminum alloy refining flux is composed of the following components in mass percentage: CaCl2 35.95%, KF 19.01%, TiCl4 16.97%, SrSO4 9.03%, Na3PO4 12.85%, and K3BO3 6.19%. The preparation method of the refining flux comprises the following steps in sequence: Step 1: According to the composition and mass percentage of the refining flux, CaCl2, KF, TiCl4, SrSO4, Na3PO4, and K3BO3 with a purity of 99.8% are selected as raw materials for batching; Step 2: Add the ingredients into 90°C hot water and stir to dissolve into an aqueous solution, the mass ratio of hot water to the ingredients is 1.4, and then heat the aqueous solution to 100°C for evaporation to obtain solid crystals; Step 3: Crushing the solid crystals into particles with a particle size of less than 2 mm, drying and dehydrating the particles at 200°C for 2 hours to obtain the refining flux.

[0039] Comparative Example 1:

[0040] The recycled aluminum alloy refining flux is composed of the following components in mass percentage: CaCl2 35.12%, KF 19.84%, TiCl4 16.51%, SrSO4 10.06%, Na3PO4 11.45%, and K3BO3 7.02%. The preparation method of the refining flux comprises the following steps in sequence: Step 1: According to the component composition and mass percentage of the refining flux, CaCl2, KF, TiCl4, SrSO4, Na3PO4, and K3BO3 with a purity of 99.8% are selected as raw materials for batching; Step 2: Crushing the ingredients into particles with a particle size of less than 2 mm, drying and dehydrating the particles at 195° C. for 2.5 hours to obtain the refining flux.

[0041] Comparative Example 2:

[0042] The refining flux of recycled aluminum alloy currently on the market is composed of the following components in mass percentage: NaCl 36.13%, KCl 15.42%, CaF2 16.84%, NaF 19.24%, C2Cl6 12.37%. The refining flux is obtained by directly crushing and mixing the raw materials after drying and dehydration.

[0043] Verification Example 1:

[0044] The melting points of the refining flux of Example 1, the refining flux of Comparative Example 1 and the refining flux of Comparative Example 2 were respectively detected by differential scanning calorimeter, and the results are shown in Table 1. As can be seen from Table 1, the melting point of the refining flux of Example 1 is significantly lower than the melting points of the refining fluxes of Comparative Example 1 and Comparative Example 2, indicating that the refining flux of the present invention has a lower melting point and is more easily dissolved in the recycled aluminum alloy melt, which is not only beneficial to lowering the refining temperature of the recycled aluminum alloy melt and reducing the oxidation and burning of the recycled aluminum alloy melt, but also more conducive to exerting the degassing and slag removal function of the refining flux and improving the degassing and slag removal efficiency.

[0045] Table 1 Melting point of refining flux

[0046] Example 1 Comparative Example 1 Comparative Example 2 Melting point / ℃ 684 1046 1014

[0047] Verification Example 2:

[0048] The refining flux of Examples 1-3 and Comparative Examples 1-2 was used to refine ADC11 recycled aluminum alloy melt under the same conditions. The experimental furnace was a 20-ton regenerative gas aluminum melting furnace. The weight of the recycled aluminum alloy melt was 20 tons. The refining flux was sprayed into the recycled aluminum alloy melt using argon gas with a purity of 99.9% as the carrier medium. The temperature of the recycled aluminum alloy melt during refining was 700°C, the refining time was 20 minutes, and the amount of refining flux added was 0.15% of the weight of the recycled aluminum alloy melt. Moreover, according to the actual use, the amount of refining flux added can also be 0.1%, 0.2% or other percentage content of the weight of the recycled aluminum alloy melt. During the experiment, the use of the refining flux was recorded, including the combustion of the recycled aluminum alloy melt, the smoke emission, the smoke smell, the slag-aluminum separation, and the viscosity of the aluminum slag. Finally, the aluminum slag was collected and weighed. The smaller the weight of the aluminum slag, the better the slag-aluminum separation effect of the refining flux. The results are shown in Table 2. It can be seen from Table 2 that the refining flux prepared in Examples 1-3 has a small emission during refining, low smoke irritation, slight combustion of molten aluminum during refining, easy separation of slag and aluminum, loose aluminum slag, and a small amount of aluminum slag. The refining flux of Comparative Example 1 is not prepared by solution evaporation method, but is directly crushed and mixed, so the slag and aluminum separation effect is slightly poor, and the amount of aluminum slag is slightly large. The commercially available conventional refining flux used in Comparative Example 2 has pungent smoke during refining, large emission, severe combustion of molten aluminum, difficulty in separating slag and aluminum, viscous aluminum slag, and large aluminum slag emission. By comparison, it can be seen that the refining flux of the present invention is more environmentally friendly when used, the slag and aluminum separation effect is easier, and it is beneficial to reduce the loss of recycled aluminum alloy and the emission of aluminum slag.

[0049] Table 2 Comparison of refining conditions of refining flux

[0050]

[0051] Verification Example 3:

[0052] The hydrogen content and slag content of the regenerated aluminum alloy melt in the furnace before and after refining in Example 2 were tested on site using a hydrogen meter and a slag meter. The hydrogen content and slag content of the regenerated aluminum alloy melt in the furnace before refining were respectively subtracted from the hydrogen content and slag content of the regenerated aluminum alloy melt in the furnace after refining, and then divided by the hydrogen content and slag content of the regenerated aluminum alloy melt in the furnace before refining, respectively, to obtain the degassing rate and slag removal rate of the refining flux, and the results are shown in Table 3 and Table 4. It can be seen from Table 3 and Table 4 that the degassing rate of the refining flux of Examples 1-3 reaches more than 57%, and the slag removal rate reaches more than 50%, while the degassing rate of the refining flux of Comparative Example 1 is 50.6%, and the slag removal rate is 46.8%, and the degassing rate of the commercially available refining flux of Comparative Example 2 is only 47.6%, and the slag removal rate is only 42.1%. By comparison, it can be seen that the refining flux of the present invention has a higher degassing and slag removal efficiency.

[0053] Table 3 Hydrogen content of recycled aluminum alloy melt before and after refining and degassing rate of refining flux

[0054]

[0055]

[0056] Table 4 Slag content of recycled aluminum alloy melt before and after refining and slag removal rate of refining flux

[0057]

[0058] Verification Example 4:

[0059] The microstructures of the recycled aluminum alloys refined by the refining flux of Example 1 and the commercially available refining flux of Comparative Example 2 were tested, and the results were as follows: Figure 1 and Figure 2 As shown. Figure 1 It can be seen that after refining with the refining flux of the present invention, the grain structure of the recycled aluminum alloy is fine and uniform, and there are no coarse dendritic α-Al grains, needle-like Si phases, and Fe-rich phases. Figure 2 It can be seen that after refining with the conventional refining flux available on the market, the grain structure of the recycled aluminum alloy is coarse, the α-Al grains are coarse dendrites, and the Si phase and the Fe-rich phase are coarse needles or laths. By comparison, it can be seen that the refining flux of the present invention has an obvious refining and modification effect on the α-Al grains, Si phase and Fe-rich phase of the recycled aluminum alloy.

[0060] Verification Example 5:

[0061] The recycled aluminum alloy melt in the furnace after refining in Verification Example 2 was sampled and cast into recycled aluminum alloy, and the tensile mechanical properties of the recycled aluminum alloy were tested, and the results are shown in Table 5. As can be seen from Table 5, the strength and plasticity of the recycled aluminum alloy refined by the refining flux prepared in Examples 1-3 are significantly higher than those of the recycled aluminum alloy refined by the refining fluxes in Comparative Examples 1 and 2, indicating that the use of the refining flux of the present invention to refine the recycled aluminum alloy melt can significantly improve the cleanliness of the recycled aluminum alloy, refine the modified coarse α-Al grains, Si phase and Fe-rich phase, and ultimately significantly improve the strength and plasticity of the recycled aluminum alloy.

[0062] Table 5 Tensile mechanical properties of recycled aluminum alloy after refining

[0063]

[0064]

Claims

1. A secondary aluminum alloy refining flux, characterized in that: The refining flux consists of the following components in mass percentage: CaCl2 34-36%, KF 18-22%, TiCl4 15-17%, SrSO4 8-12%, Na3PO4 9-13%, and K3BO3 6-8%.

2. The recycled aluminum alloy refining flux according to claim 1, characterized in that: The refining flux consists of the following components in percentage by mass: CaCl2 35.12%, KF 19.84%, TiCl4 16.51%, SrSO4 10.06%, Na3PO4 11.45%, and K3BO3 7.02%.

3. A method for preparing the secondary aluminum alloy refining flux as claimed in claim 1, characterized in that: The following steps are included in sequence: Step 1: According to the composition and mass percentage of the refining flux, CaCl2, KF, TiCl4, SrSO4, Na3PO4, and K3BO3 are selected as raw materials for batching; Step 2: adding the ingredients into hot water and stirring to dissolve into an aqueous solution, and then heating and evaporating the aqueous solution to obtain a solid crystal; Step 3: crushing the solid crystals into particles with a particle size of less than 2 mm, drying and dehydrating the particles to obtain the refining flux.

4. The method for preparing the secondary aluminum alloy refining flux according to claim 3, characterized in that: The purity of CaCl2, KF, TiCl4, SrSO4, Na3PO4 and K3BO3 in step 1 is not less than 99.8%.

5. The method for preparing the secondary aluminum alloy refining flux according to claim 3, characterized in that: The temperature of the hot water in step 2 is not less than 80°C, the mass ratio of hot water to ingredients is 1.4-1.6, and the temperature of the aqueous solution during heating and evaporation is 100°C.

6. The method for preparing the secondary aluminum alloy refining flux according to claim 3, characterized in that: The drying and dehydration temperature in step 3 is 190-200° C., and the drying and dehydration time is 2-3 hours.

7. A method for using the recycled aluminum alloy refining flux as claimed in any one of claims 1 to 6, characterized in that: The amount of the refining flux used is 0.1-0.2% of the weight of the recycled aluminum alloy.

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