Method for producing high-magnesium 1050a aluminum alloy ingot by using 5083 aluminum alloy production waste

Abstract

The application belongs to the technical field of aluminum alloy production, and discloses a method for producing high-magnesium 1050A aluminum alloy ingot by using 5083 aluminum alloy production waste, which comprises the following steps: 1) batching: according to the Mg content of 0.05-0.5% and the content of other elements meeting the chemical composition of 1050A aluminum alloy stipulated in the national standard, the mass of 5083 aluminum alloy production waste added to the high-magnesium 1050A aluminum alloy raw material is calculated according to the Mg content in the 5083 aluminum alloy production waste; 2) melting and casting: the melting temperature is 730-750 DEG C, the refining temperature is 720-730 DEG C, the casting temperature is 710-720 DEG C, and homogenization annealing treatment is carried out after casting, and the furnace is cooled to obtain the ingot. The application realizes directional utilization of the magnesium component in the 5083 alloy waste, precisely replaces the magnesium ingot auxiliary material required for the production of high-magnesium 1050A alloy, and forms a new green production mode of "waste resourceization + precise component supply".

Description

Technical Field

[0001] This invention belongs to the field of aluminum alloy production technology, and relates to a method for producing high-magnesium 1050A aluminum alloy ingots using 5083 aluminum alloy production waste. Background Technology

[0002] 1050A aluminum alloy belongs to the pure aluminum series alloys, with an aluminum content of not less than 99.5%, a magnesium content of ≤0.05%, and a manganese content of ≤0.05%. It possesses excellent plasticity, corrosion resistance, electrical conductivity, and thermal conductivity, and is widely used in chemical containers, building decoration, and conductive and heat-conducting components. In conventional industrial production, the magnesium content of 1050A aluminum alloy is typically less than 0.03%. However, in some applications requiring increased strength while retaining basic plasticity and corrosion resistance (such as PS plates), it is necessary to appropriately add pure magnesium ingots to the smelted aluminum ingots to increase the magnesium content of the 1050A aluminum alloy (e.g., increasing the magnesium content to 0.23~0.25%). This utilizes the aluminum-magnesium solid solution strengthening effect to improve the alloy's mechanical properties, but it increases production costs.

[0003] 5083 aluminum alloy belongs to the aluminum-magnesium series of rust-proof aluminum alloys. The magnesium content is usually in the range of 4.0% to 4.9%. During the production and processing of 5083 aluminum alloy, a large amount of solid waste such as scrap, chips, and scrap billets will be generated. These wastes have a high magnesium content, and the content of other impurity elements is also highly compatible with the requirements of 1050A aluminum alloy. If they are directly recycled and remelted, it will waste magnesium resources. Furthermore, improper handling will also cause metal burning and environmental problems.

[0004] Therefore, if 5083 aluminum alloy scrap can be used as a magnesium source to replace the pure magnesium ingots required for casting high-magnesium 1050A aluminum alloy, the cost of magnesium supplementation in the production of high-magnesium 1050A aluminum alloy can be significantly reduced. Summary of the Invention

[0005] This invention addresses the technical problem of increased production costs due to magnesium replenishment in the production of high-magnesium 1050A aluminum alloy. It provides a method for producing high-magnesium 1050A aluminum alloy ingots using waste from the production of 5083 aluminum alloy. This method enables the targeted utilization of magnesium in the 5083 alloy waste, precisely replacing the magnesium ingot auxiliary materials required for the production of high-magnesium 1050A alloy, thus forming a new green production model of "waste resource utilization + precise component replenishment".

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] This invention provides a method for producing high-magnesium 1050A aluminum alloy ingots using 5083 aluminum alloy production waste, comprising the following steps:

[0008] 1) Batching: The Mg content is 0.05~0.5%, and the content of other elements conforms to the chemical composition of 1050A aluminum alloy as specified in GB / T 3190-2020. The mass of 5083 aluminum alloy production waste added to the high magnesium 1050A aluminum alloy raw material is calculated based on the Mg content in the 5083 aluminum alloy production waste.

[0009] 2) Melting and casting: Melting temperature 730~750℃, refining temperature 720~730℃, argon gas powder injection refining, refining agent addition amount is 0.2% of the total mass of furnace charge, standing time 20 min, casting temperature 710~720℃, after casting, homogenization annealing treatment is carried out, and the furnace is cooled to obtain ingots.

[0010] In one technical solution, the specific operation of the homogenization annealing process is as follows: the annealing temperature is 520℃ and the holding time is 6 h.

[0011] The chemical composition of 1050A aluminum alloy as specified in GB / T 3190-2020 ("Chemical Composition of Wrought Aluminum and Aluminum Alloys") is as follows: Si≤0.25%, Fe≤0.40%, Cu≤0.05%, Mn≤0.05%, Mg≤0.05%, Zn≤0.07%, Ti≤0.05%, with the remainder being Al and unavoidable impurities. The high-magnesium 1050A aluminum alloy ingot referred to in this invention refers to a 1050A aluminum alloy ingot with a Mg content of 0.05~0.5%, and the contents of other elements such as Si, Fe, Cu, Mn, and Zn all conforming to the chemical composition specified in GB / T 3190-2020.

[0012] In one feasible technical solution, the chemical composition of the 5083 aluminum alloy scrap used is as follows: Si 0.12%, Fe 0.28%, Cu 0.04%, Mn 0.22%, Mg 4.55%, Zn 0.06%, with the remainder being Al and unavoidable impurities. Based on the Mg content in the 1050A aluminum alloy raw material ingot and the target Mg content in high-magnesium 1050A aluminum alloy, and further based on the Mg content in the 5083 aluminum alloy production scrap, the required mass of 5083 aluminum alloy production scrap can be calculated.

[0013] A company produces 5,000 tons of high-magnesium 1050A aluminum alloy ingots per month. This corresponds to approximately 83 heats (5,000 tons ÷ 60 tons / heat), with each heat producing 60 tons. Assuming a Mg content of 0.24% in the high-magnesium 1050A aluminum alloy, each heat requires 60 tons × 0.24% = 144 kg of pure magnesium ingots according to the standard high-magnesium 1050A aluminum alloy batching. If the current market price of pure magnesium ingots is 18 yuan / kg (18,000 yuan / ton), then the monthly cost of pure magnesium ingots per heat is 144 kg × 18 yuan / kg = 2,592 yuan / heat. Therefore, the company's annual cost of pure magnesium ingots is approximately 2,592 yuan × 83 heats × 12 months ≈ 2,581,600 yuan. If the magnesium component from 5083 aluminum alloy scrap is used to replace the pure magnesium ingots required for casting high-magnesium 1050A aluminum alloy, then the amount of 5083 aluminum alloy scrap required per furnace is 144 kg ÷ 4.55% = 3164.84 kg ≈ 3.2 t. Therefore, the company consumes approximately 3.2 t × 83 furnaces = 265.6 t of 5083 aluminum alloy scrap per month, and approximately 265.6 t × 12 months = 3187.2 t of 5083 aluminum alloy scrap per year. If the current recycling price of 5083 aluminum alloy scrap is approximately 14,000 yuan / ton, then the monthly cost saving per furnace for 5083 aluminum alloy scrap processing is 3.2 tons × 14,000 yuan / ton = 44,800 yuan, the monthly cost saving is 265.6 tons × 14,000 yuan / ton = 3,718,400 yuan, and the annual cost saving is 3,187.2 tons × 14,000 yuan / ton = 44,620,800 yuan. Therefore, using the magnesium component from 5083 aluminum alloy scrap to replace the pure magnesium ingots required for high-magnesium 1050A aluminum alloy casting can significantly reduce the auxiliary material cost in the magnesium element replenishment process, achieve closed-loop utilization of waste resources, reduce the cost of waste stacking and recycling, and form a virtuous cycle of "alloy scrap reuse - precise magnesium element replenishment - cost saving - efficiency improvement".

[0014] It is worth noting that the technical concept of this invention, which uses magnesium from 5083 aluminum alloy scrap to replace the pure magnesium ingot auxiliary material required for casting high-magnesium 1050A aluminum alloy, can be used to adjust the Mg content in high-magnesium 1050A aluminum alloy within the range of 0.05~0.5%. However, the following points should be noted when applying this process in industrial production: First, the composition of the 5083 aluminum alloy scrap needs to be tested in advance to strictly control the content of impurity elements, especially the manganese content. If the manganese content of the scrap itself is high, the addition ratio needs to be appropriately reduced to avoid the finished product exceeding the standard requirements for manganese. Second, the timing of scrap addition needs to be properly controlled. It is recommended to add block scrap when the original aluminum ingot is completely melted and the molten pool temperature is stable at 720~730℃ to avoid adding at low temperatures, which would cause the molten pool to cool down, and also to avoid the scrap carrying oil and water, which could cause molten pool splashing. Third, the amount of 5083 aluminum alloy scrap added needs to be adjusted based on the actual burn-off situation in production. Different factories have different casting processes and furnace conditions, resulting in variations in magnesium burn-off rates. Two to three process tests are required before production to determine the actual magnesium yield before stabilizing production and avoiding compositional fluctuations. Fourth, if a higher magnesium content is required for 1050A aluminum alloy, the proportion of 5083 aluminum alloy scrap added can be increased to a maximum of 10%. At this point, the magnesium content is approximately 0.45%, and the manganese content is approximately 0.022%, still meeting the standard requirements for 1050A aluminum alloy. The strength can be increased by more than double, and corresponding grades can be developed for specific applications.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0016] This invention breaks through the traditional model of relying on pure magnesium ingots to replenish magnesium for 1050A alloys, and realizes the targeted utilization of magnesium components in 5083 alloy scrap. It precisely replaces the magnesium ingot auxiliary materials required for the production of high-magnesium 1050A alloy ingots, which not only solves the problem of alloy scrap resource utilization, but also specifically meets the magnesium replenishment needs of low-magnesium alloys, forming a new green production model of "scrap resource utilization + precise component replenishment". Detailed Implementation

[0017] The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of protection of the present invention. Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art. Unless otherwise specified, the test methods in the following embodiments are conventional methods.

[0018] Example 1 verifies the feasibility of replacing magnesium ingots in high-magnesium 1050A aluminum alloy raw materials with 5083 aluminum alloy scrap.

[0019] (1) Comparison of raw material components

[0020] The raw materials used in the experiment were divided into two categories: 1050A aluminum alloy raw material aluminum ingots (Al content 99.70% aluminum ingots) and 5083 aluminum alloy scrap (recycled aluminum internally by Henan Mingtai). The specific composition test results are shown in Table 1.

[0021] Table 1 Raw materials used in the experiment

[0022]

[0023] As shown in Table 1, the composition analysis results of the 5083 aluminum alloy scrap indicate that, except for magnesium and manganese which are slightly higher than the standard requirements for 1050A aluminum alloy, the contents of other elements comply with the requirements for 1050A aluminum alloy in the "Chemical Composition of Wrought Aluminum and Aluminum Alloys" (GB / T 3190-2020). The maximum allowable content of Mn in 1050A aluminum alloy is 0.05%, Cu is 0.05%, and Zn is 0.07%. Therefore, the Cu and Zn content introduced from the 5083 aluminum alloy scrap meets the requirements. Only the manganese content needs to be controlled by adjusting the proportion of manganese added to the 5083 aluminum alloy scrap to avoid exceeding its standard upper limit.

[0024] (2) Experiment

[0025] Each furnace has a production capacity of 60 tons. Eleven experimental groups with different addition ratios were set up, namely, adding 0.5%, 1.0%, 2.0%, 3.0%, 4.0%, 5.0%, 6.0%, 7.0%, 8.0%, 9.0%, and 10.0% of 5083 aluminum alloy scrap according to the total furnace charge mass. The target magnesium content in the corresponding 1050A aluminum alloy was 0.05%, 0.07%, 0.11%, 0.16%, 0.20%, 0.24%, 0.28%, 0.32%, 0.36%, 0.40%, and 0.44%, respectively.

[0026] The melting and casting process parameters are as follows: melting temperature 730℃-750℃, refining temperature 720~730℃, argon gas powder injection refining, refining agent addition amount is 0.2% of the total mass of furnace charge, standing time 20 min, casting temperature 710~720℃, homogenization annealing treatment after casting, annealing process is 520℃ holding for 6 h, and cooling with furnace.

[0027] Hot-rolled billet preheating and annealing: metal temperature 480~490℃, holding for 6 h; hot rolling roughing: 25 passes of continuous rolling finishing rolling, finished product thickness 5.0 mm.

[0028] Chemical composition, mechanical properties, and corrosion resistance were tested on each group of 1050A aluminum alloy plates. The variation patterns of various indicators under different additive ratios were analyzed to verify the feasibility of the process. Composition analysis was performed using a direct-reading spectrometer, with three different locations measured for each sample and the average value taken. Tensile test specimens were prepared according to GB / T 228.1-2010 and subjected to room temperature tensile testing on a universal testing machine. Corrosion resistance was tested using a neutral salt spray test for 500 hours to evaluate changes in corrosion rate.

[0029] (3) Experimental results and analysis

[0030] 1) Chemical composition analysis and magnesium yield analysis

[0031] The results of component analysis and magnesium yield calculation for each experimental group are shown in Table 2.

[0032] Table 2. Results of component analysis and magnesium yield of each experimental group

[0033]

[0034] The following conclusions can be drawn from the test results: 1) Using 5083 aluminum alloy scrap as a magnesium source can stably increase the magnesium content of high-magnesium 1050A aluminum alloy. As the proportion of 5083 aluminum alloy scrap added increases, the actual magnesium content shows a linear increasing trend, with a high correlation, indicating good process controllability. 2) The magnesium yield decreases slightly with the increase of scrap addition ratio, from 92% when 0.5% is added to 79.3% when 10% is added. This pattern is consistent with the general rule of magnesium element burn-off during the melting and casting process: magnesium element has a low melting point and high vapor pressure. During the melting and casting process, as the total magnesium content increases, the amount of interfacial volatilization and burn-off increases, so the yield decreases slowly. However, even with the addition of 10% 5083 aluminum alloy scrap, the magnesium yield still remains above 79.3%, indicating good burn-off control and high resource utilization. 3) The manganese content introduced by the addition of 5083 aluminum alloy scrap is far below the upper limit of 0.05% of the 1050A aluminum alloy standard. Even with the addition of 10% 5083 aluminum alloy scrap, the manganese content in the high-magnesium 1050A aluminum alloy finished product is only 0.024%, which does not exceed the requirements of the 1050A aluminum alloy standard. This indicates that the composition control meets the national standard requirements and there is no risk of impurities exceeding the standard.

[0035] 2) Mechanical property analysis

[0036] After homogenization annealing, the experimental products of each group were processed into tensile specimens, and the results of room temperature tensile tests are shown in Table 3.

[0037] Table 3 Mechanical properties of each group

[0038]

[0039] The mechanical property results show that with the increase of magnesium content, the tensile strength and yield strength of high-magnesium 1050A aluminum alloy exhibit a significant upward trend, while the elongation after fracture only slightly decreases. When the magnesium content is increased to 0.169%, the tensile strength increases from 78 MPa in the control group to 118 MPa, an increase of over 50%, and the yield strength increases from 32 MPa to 58 MPa, an increase of over 80%, while the elongation after fracture remains at 32%. When the magnesium content is increased to 0.349%, the tensile strength increases from 78 MPa in the control group to 152 MPa, an increase of over 90%, and the yield strength increases from 32 MPa to 86 MPa, an increase of over 160%, while the elongation after fracture remains at 26%, far exceeding the requirements for the plasticity of high-magnesium 1050A aluminum alloy in industrial applications. This indicates that the solid solution strengthening effect achieved by increasing the magnesium content is very significant, while retaining the original excellent plasticity of high-magnesium 1050A aluminum alloy. The reason for this change is that the atomic radii of magnesium and aluminum atoms are quite different. When magnesium is dissolved in the aluminum matrix, it will cause lattice distortion, increase the resistance to dislocation movement, and thus improve the strength of the alloy. When the magnesium content is low, magnesium exists entirely in a solid solution state and will not generate second-phase particles. Therefore, it has little effect on plasticity, which is consistent with the change pattern obtained in this experiment.

[0040] 3) Corrosion resistance analysis

[0041] Each group of samples was subjected to a 500-h neutral salt spray test. After the test, the corrosion products were removed and the corrosion rate was calculated. The results are shown in Table 4.

[0042] Table 4 Corrosion Resistance Test

[0043]

[0044] The corrosion resistance test results show that as the magnesium content increases, the corrosion rate of high-magnesium 1050A aluminum alloy only increases slightly. When the magnesium content increases to 0.169%, the corrosion rate only increases from 0.0082 g / (m³) to 0.169%. 2 The concentration of ·h) increased to 0.0094 g / (m 2 The increase in magnesium content (h) is less than 15%, remaining within the extremely low corrosion rate range. This indicates that increasing the magnesium content to within 0.169% has minimal impact on the corrosion resistance of high-magnesium 1050A aluminum alloy and will not affect its application in conventional corrosion-resistant scenarios. This is because when the magnesium content is low, the magnesium is completely dissolved in the aluminum matrix and does not form second-phase particles, thus preventing galvanic corrosion and significantly reducing the alloy's corrosion resistance. Only when the magnesium content exceeds 2% will the Mg5Al8 second phase be formed, causing a significant decrease in corrosion resistance. Therefore, when the magnesium content in high-magnesium 1050A aluminum alloy is below 0.169%, its corrosion resistance remains good.

[0045] 4) Economic Benefit Analysis

[0046] In current industrial production, to increase the magnesium content in high-magnesium 1050A aluminum alloy, the common method is to add pure magnesium ingots or Al-Mg master alloys. Compared to using 5083 aluminum alloy scrap, the cost difference is significant. The following cost calculation is based on producing 1 ton of high-magnesium 1050A aluminum alloy with a target magnesium content of 0.24%.

[0047] Option 1: Adjusting the magnesium content using pure magnesium ingots: Since the magnesium content in 1050A raw material aluminum ingots is 0.021%, approximately 1 t × (0.24% - 0.021%) = 0.00219 t of pure magnesium ingots needs to be added. The current market price of pure magnesium ingots is approximately RMB 18,000 / t, so the additional cost is RMB 0.00219 t × RMB 18,000 / t = RMB 39.42 / t. However, pure magnesium has a high burn-off loss, and the actual magnesium yield is approximately 80%. The actual amount of magnesium needed to be added is approximately 0.00219 t ÷ 80% ≈ 0.00274 t, and the actual cost is approximately RMB 0.00274 t × RMB 18,000 / t ≈ RMB 49.32 / t. At the same time, pure magnesium has a low density and is prone to floating on the surface of the molten pool, resulting in a high risk of composition fluctuations due to burn-off losses.

[0048] Option 2: Adjusting with Al-10%Mg master alloy: Approximately 1 t × (0.24% - 0.021%) ÷ 10% = 0.0219 t of master alloy needs to be added. The market price of Al-10%Mg master alloy is approximately RMB 16,000 / t, so the additional cost is approximately 0.0219 t × RMB 16,000 / t = RMB 350.4 / t. The magnesium yield is approximately 85%, and the actual cost is approximately RMB 412 / ton.

[0049] Option 3: Adjusting with 5083 aluminum alloy scrap: Currently, the recycling price of 5083 aluminum alloy scrap is approximately RMB 14,000 / ton, while the price of raw aluminum ingots is approximately RMB 15,000 / ton. The price of 5083 aluminum alloy scrap is lower than that of raw aluminum ingots. Adding 2% 5083 aluminum alloy scrap to replace raw aluminum ingots not only does not increase costs but can actually reduce raw material costs by approximately RMB 20 / ton, while simultaneously achieving the required magnesium content. The cost advantage is extremely significant.

[0050] In addition, the use of 5083 aluminum alloy scrap has enabled the resource utilization of solid waste, reduced the energy consumption and pollutant emissions of waste recycling and separation, and has good environmental benefits, which is in line with the current development direction of circular economy in the aluminum processing industry.

[0051] In summary, using 5083 aluminum alloy scrap as a magnesium source to increase the magnesium content in 1050A aluminum alloy is technologically feasible, with good compositional controllability. When the addition ratio does not exceed 6%, the magnesium yield remains stable at over 84%, and all impurity elements meet the national standards for 1050A aluminum alloy, posing no risk of exceeding composition limits. Increasing the magnesium content can significantly improve the strength of 1050A aluminum alloy. When the magnesium content is increased to 0.169%, the tensile strength increases by more than 50%, the yield strength increases by more than 80%, the elongation after fracture remains at 32%, and the corrosion resistance only decreases slightly. The overall performance is more suitable for applications requiring a certain strength. Compared with the traditional method of adding pure magnesium or Al-Mg master alloy, this process has a significant cost advantage, while realizing the resource utilization of 5083 aluminum alloy scrap, resulting in good economic and environmental benefits, and is suitable for widespread application in industrial production.

[0052] The embodiments described above are merely preferred embodiments of the present invention and are only used to explain the present invention. They are not intended to limit the scope of the present invention. For those skilled in the art, other implementation methods can be easily made by substitution or modification based on the technical content disclosed in this specification. Therefore, all changes and improvements made on the principle of the present invention should be included within the scope of the patent application of the present invention.

Claims

1. A method of producing high magnesium 1050A aluminum alloy ingot from 5083 aluminum alloy production scrap, characterized by, Includes the following steps: 1) Batching: The Mg content is 0.05~0.5%, and the content of other elements conforms to the chemical composition of 1050A aluminum alloy as specified in GB / T 3190-2020. The mass of 5083 aluminum alloy production waste added to the high magnesium 1050A aluminum alloy raw material is calculated based on the Mg content in the 5083 aluminum alloy production waste. 2) Melting and casting: Melting temperature 730~750℃, refining temperature 720~730℃, standing time 20 min, casting temperature 710~720℃, after casting, homogenization annealing treatment is carried out, and the furnace is cooled to obtain ingots.

2. The method according to claim 1, characterized in that, The specific operation of the homogenization annealing process is as follows: the annealing temperature is 520℃ and the holding time is 6 h.

3. The method according to claim 1, characterized in that, The chemical composition of the 5083 aluminum alloy production waste is as follows: Si 0.12%, Fe 0.28%, Cu 0.04%, Mn 0.22%, Mg 4.55%, Zn 0.06%, with the remainder being Al and unavoidable impurities.

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