A copper alloy wire based on recycled copper and a method for producing the same

Abstract

The application discloses a copper alloy wire based on recycled copper and a preparation method thereof, and relates to the technical field of conductive materials for electroacoustic devices; the copper alloy wire based on recycled copper and the preparation method thereof can simultaneously realize low carbon emission, high electrical conductivity, high strength and high purity, and can meet the urgent needs of high-end application fields such as electroacoustic devices for green high-performance conductive materials, by taking high-purity recycled cathode copper as a base body, through vacuum smelting precise alloying and two-stage ceramic filtering impurity removal, and combining multi-pass cold drawing and intermediate annealing processes.

Description

Technical Field

[0001] This invention relates to the field of conductive materials for electroacoustic devices, specifically to a copper alloy filament wire based on recycled copper and its preparation method. Background Technology

[0002] Copper alloy filament wire is a key conductive material in electroacoustic devices, high-frequency transmission cables, and precision electronic components, and its performance directly affects the signal transmission quality and lifespan of these devices. Filament wire is typically composed of multiple fine monofilaments concentrically twisted together, with an outer layer coated with a high-temperature resistant insulating material, requiring excellent conductivity, mechanical strength, and high-temperature resistance. Currently, most copper alloy filament wires on the market are made from primary electrolytic copper through processes such as smelting, casting, drawing, stranding, and coating, and their conductivity and mechanical properties are relatively mature. However, with the advancement of global dual-carbon goals and the increasing scarcity of copper resources, how to utilize recycled copper resources to replace primary copper while ensuring product performance has become a crucial issue that the copper processing industry urgently needs to address.

[0003] However, existing recycled copper-based nylon wire technology has significant shortcomings. First, traditional recycled copper raw materials have low purity and high impurity content, resulting in generally low conductivity of the prepared nylon wires, which is difficult to meet the high conductivity (≥102% IACS) requirements of high-end electroacoustic devices. Second, harmful impurities such as lead, arsenic, and bismuth in recycled copper are difficult to remove effectively, and the mass percentage of individual elements often far exceeds the safety limit of 0.0005%, which seriously restricts the application of products in the field of precision electronics. Third, traditional recycled copper processing technology has high carbon emissions, with the carbon footprint emission value per unit mass of copper far exceeding 1.1 kg CO2e / kg. The carbon emissions of the entire process from steps S2 to S4 are usually more than three times that of the primary copper process, which is not in line with the trend of green and low-carbon development. In addition, the alloying precision in traditional processes is insufficient, and the vacuum melting and impurity removal filtration methods are limited, making it impossible to achieve precise addition and uniform distribution of composite alloying elements such as silver and zirconium. As a result, it is difficult to simultaneously achieve high tensile strength and elongation at break of recycled copper alloy monofilaments, and the overall performance of the product still has a significant gap with that of primary copper nylon wire.

[0004] In summary, existing technologies still have significant shortcomings in terms of high purity control, precise alloying, low-carbon manufacturing, and overall performance improvement of recycled copper filament wire. Therefore, the development of a copper alloy filament wire based on recycled copper and its preparation method is of paramount importance. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a copper alloy filament wire based on recycled copper and its preparation method. It can simultaneously achieve low carbon emissions, high conductivity, high strength and high purity copper alloy filament wire and its preparation method by using high-purity recycled cathode copper as the matrix, through precise alloying by vacuum melting and two-stage ceramic filtration to remove impurities, combined with multi-pass cold drawing and intermediate annealing processes, in order to meet the urgent demand for green and high-performance conductive materials in high-end application fields such as electroacoustic devices.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a copper alloy nylon wire based on recycled copper, made from the following raw materials in parts by weight: The stranded core layer is composed of several recycled copper alloy monofilaments concentrically stranded together. The recycled copper alloy monofilaments are based on high-purity recycled cathode copper and also contain composite alloying elements. The total mass percentage of unavoidable impurities in the recycled copper alloy monofilaments is ≤0.005%. The composite alloying elements are selected from at least two of silver, tin, magnesium, and zirconium.

[0007] Furthermore, the high-purity regenerated cathode copper has a copper purity of ≥99.99%, an electrical conductivity of ≥100% IACS, and a carbon footprint emission value of ≤1.1kgCO2e / kg per unit mass of copper.

[0008] Furthermore, the recycled copper alloy monofilament is composed of the following components by mass percentage: 99.90%~99.99% high-purity recycled cathode copper and 0.01%~0.10% composite alloying elements.

[0009] Furthermore, in the composite alloy elements, the mass percentage of silver is 40% to 60% of the total mass of the composite alloy elements, and the mass percentage of zirconium is 10% to 20% of the total mass of the composite alloy elements.

[0010] Furthermore, among the unavoidable impurities, the mass percentage of each of the individual elements lead, arsenic, and bismuth is ≤0.0005%.

[0011] Furthermore, the recycled copper alloy monofilament has a diameter of 0.02mm to 0.20mm, an electrical conductivity ≥102%IACS, a tensile strength ≥220MPa, and an elongation at break ≥15%.

[0012] Furthermore, the twisting pitch ratio of the stranded core wire layer is 12 to 18 times, and the twisting direction is left or right.

[0013] Furthermore, the outer covering layer is a high-temperature resistant insulating covering layer, and its material is any one of modified polyurethane, polyimide or polyetheretherketone, with a covering layer thickness of 0.01mm~0.05mm.

[0014] On the other hand, a method for preparing copper alloy filament wire based on recycled copper is characterized by comprising the following steps: S1. Pretreatment of recycled copper raw materials: High-purity recycled cathode copper is selected as raw material. After surface cleaning and drying, oil, oxide layer and impurities on the surface of the raw material are removed to obtain pretreated recycled copper raw materials. S2. Vacuum melting and precision alloying: The pretreated recycled copper raw material is put into a vacuum melting furnace, heated and melted in a vacuum environment, and after holding at the temperature, composite alloying elements are added according to the ratio. The temperature is held and high-purity argon gas is introduced for stirring and degassing. After online impurity removal and filtration, the alloy melt is obtained. S3. Continuous casting: The alloy melt is introduced into the upper continuous casting unit to prepare recycled copper alloy rods. S4. Multi-pass cold drawing and intermediate annealing: The recycled copper alloy casting rod is subjected to multi-pass continuous cold drawing, and 2-3 intermediate annealings are performed during the drawing process to obtain recycled copper alloy monofilament. S5. Stranding: Multiple recycled copper alloy monofilaments are concentrically stranded according to a set pitch ratio and stranding direction to obtain a stranded core wire. S6. Coating and Finished Annealing: The stranded core wire is extruded and coated with a high-temperature resistant insulation layer. After the coating is completed, the finished product is annealed under a protective atmosphere and cooled to obtain the copper alloy nylon wire based on recycled copper.

[0015] Furthermore, the total carbon emissions of steps S2-S4 are ≤1.2kgCO2e / kg finished product, which is less than 30% of the carbon emissions of the same specification copper nylon wire preparation process; the online impurity removal filtration in step S2 adopts two-stage ceramic filter plate filtration, with the first stage filtration accuracy of 50μm and the second stage filtration accuracy of 20μm.

[0016] Compared with existing technologies, this copper alloy filament wire based on recycled copper and its preparation method have the following advantages: I. This invention uses high-purity recycled cathode copper as the base material, with a carbon footprint emission value of ≤1.1kgCO2e / kg per unit mass of copper. Furthermore, the total carbon emission of steps S2-S4 in the preparation process is ≤1.2kgCO2e / kg of the finished product, which is only within 30% of the carbon emission of the same specification nylon wire preparation process using primary copper. This significantly reduces the environmental impact of the product and meets the requirements of green and sustainable development.

[0017] II. This invention achieves a comprehensive improvement in the conductivity, strength, and purity of recycled copper alloy monofilaments by precisely adding composite alloying elements such as silver and zirconium to high-purity recycled cathode copper and employing vacuum melting, two-stage ceramic filtration, and multiple cold drawing and intermediate annealing processes. This results in a conductivity ≥102% IACS, tensile strength ≥220MPa, and elongation at break ≥15% for the recycled copper alloy monofilaments. At the same time, the mass percentage of harmful impurities such as lead, arsenic, and bismuth is controlled to within ≤0.0005%.

[0018] Other advantages, objectives and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination or study, or may be learned from the practice of the invention. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0020] Figure 1 A flowchart illustrating a copper alloy filament wire based on recycled copper; Figure 2 This is a flowchart of a copper alloy filament wire based on recycled copper and its preparation method. Detailed Implementation

[0021] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0022] Example 1 This embodiment provides a copper alloy filament wire based on recycled copper and its preparation method. Specifically, it employs a binary composite alloy system with optimized matching process, using high-purity recycled cathode copper as the matrix. Through precise alloying and a low-emission preparation process throughout the entire process, a copper alloy filament wire with high conductivity, high strength, and high elongation is obtained, while significantly reducing carbon emissions throughout the entire process. This embodiment fully covers the core technical features of product structure, raw material composition, and preparation method, presenting a complete and directly implementable technical solution.

[0023] The base material used in this embodiment is high-purity recycled cathode copper. Specifically, the high-purity recycled cathode copper has a copper purity of 99.995%, an electrical conductivity of 101.2% IACS, and a carbon footprint emission value of 0.92 kgCO2e / kg per unit mass of copper, meeting the core performance requirements of the raw material. The composite alloying element used in this embodiment is a binary combination of silver and zirconium. By mass percentage, the composition of the recycled copper alloy monofilament includes 99.95% high-purity recycled cathode copper and 0.05% composite alloying element. Among the composite alloying element, the mass ratio of silver is 50% of the total mass of the composite alloying element, the mass ratio of zirconium is 15% of the total mass of the composite alloying element, and the balance is unavoidable impurities, with the total mass ratio of unavoidable impurities being 0.0032%. The mass ratio of lead, arsenic, and bismuth is no more than 0.0003% for each individual element, meeting the impurity control requirements.

[0024] The preparation method of this embodiment includes the following steps: S1 Pretreatment of recycled copper raw materials. Specifically, high-purity recycled cathode copper that meets the requirements is selected as raw material. First, the surface is mechanically polished. 240-mesh silicon carbide sandpaper is used to uniformly polish the surface of the cathode copper plate to remove the oxide scale and attached solid impurities. After polishing, the copper plate is cut into blocks of 100mm×50mm×10mm. Then, the blocks are ultrasonically degreased and cleaned. The raw material is completely immersed in a neutral degreasing agent aqueous solution at a temperature of 55℃. The mass concentration of the neutral degreasing agent is 8%. The ultrasonic power is set to 300W, and the ultrasonic treatment time is 25min to completely remove the oil and residual impurities attached to the surface of the raw material. After ultrasonic degreasing, the raw material is rinsed three times countercurrently with deionized water. Each rinse lasts for no less than 3min to completely remove the residual degreasing agent from the surface of the raw material. After rinsing, the raw material is placed in a hot air circulating drying oven for drying at 120℃ for 90 minutes. After drying, it is cooled to room temperature with the furnace to obtain pretreated recycled copper raw material. Mechanical surface polishing quickly removes the hard oxide layer and attached solid impurities from the cathode copper surface, preventing the introduction of non-metallic impurities during subsequent smelting that could affect the purity of the alloy melt. Ultrasonic degreasing deeply removes residual oil from the raw material surface, preventing the oil from decomposing into gases and carbon impurities during high-temperature smelting, thus ensuring the conductivity of the base material. Countercurrent rinsing completely removes residual degreasing agent from the surface, preventing its components from being introduced into the smelting process and affecting the precision of the alloy composition. Hot air circulating drying thoroughly removes moisture from the surface and pores of the raw material, preventing moisture from entering the vacuum melting furnace and affecting the vacuum level, while also preventing the decomposition of moisture at high temperatures to produce hydrogen and oxygen impurities that could lead to porosity defects in the cast rod.

[0025] Specifically, in S2 vacuum melting and precision alloying, pre-treated recycled copper raw materials are placed into a graphite crucible in a high-vacuum medium-frequency melting furnace. After the furnace is closed, the vacuum system is activated to evacuate the furnace until the vacuum level reaches 5×10⁻⁶. -3 Pa was then applied, followed by activation of the medium-frequency heating system to heat the raw material at a heating rate of 15℃ / min until it was completely melted, with the melting temperature controlled at 1180℃. After complete melting, the material was held at this temperature for 20 minutes to homogenize the melt temperature and promote the escape of residual gaseous impurities. After holding, high-purity silver particles and high-purity zirconium particles were added to the melt according to a pre-set composition ratio, with the high-purity silver particles having a purity of 99.99% and the high-purity zirconium particles having a purity of 99.99%. After adding the materials, the melt was held at 1180℃ for another 15 minutes to ensure that the alloying elements were completely dissolved in the copper matrix. After heat preservation, high-purity argon gas (99.999%) is introduced into the furnace until the furnace pressure returns to atmospheric pressure. Then, a graphite stirring device is activated to stir the alloy melt at a speed of 80 r / min for 10 minutes. This ensures uniform dispersion of alloying elements in the melt and promotes the escape of dissolved hydrogen and other gaseous impurities with the argon gas bubbles, completing the degassing process. After degassing, the alloy melt is introduced into an online impurity removal and filtration system. The online filtration uses two-stage ceramic filter plates in series. The first-stage filter plate has a filtration accuracy of 50 μm, and the second-stage filter plate has a filtration accuracy of 20 μm. This two-stage filtration completely removes residual non-metallic inclusions and incompletely dissolved alloy particles from the melt, resulting in an alloy melt with uniform composition and meeting purity standards. The high-vacuum melting environment prevents oxidation of the copper matrix at high temperatures and promotes the escape of gaseous impurities from the melt, reducing the risk of porosity defects in the cast rod. Gradient heating melting avoids element volatilization caused by localized overheating of the raw materials, ensuring the purity of the copper base. Precise temperature control and holding ensure uniform melt temperature, providing a stable temperature environment for the uniform dissolution of subsequent alloying elements. High-purity argon stirring and degassing achieves uniform dispersion of alloying elements and efficient removal of gaseous impurities within the melt without introducing oxidation impurities, ensuring the uniformity of alloy composition and melt purity. Two-stage gradient ceramic filtration removes inclusions of different particle sizes from the melt step by step, preventing large inclusions from entering the subsequent casting process and causing internal defects in the cast rod, while also preventing small inclusions from causing single-wire breakage during subsequent drawing, ensuring the stability of the drawing process.

[0026] Specifically, in S3 continuous casting, the filtered alloy melt is introduced into the holding furnace of the upward drawing continuous casting unit through a sealed guide pipe. The melt temperature in the holding furnace is controlled at 1160℃, and high-purity argon gas is continuously introduced into the furnace for atmosphere protection to prevent oxidation of the melt. The upward drawing continuous casting unit uses a graphite crystallizer with an inner diameter of 17mm. The upward drawing speed is set to 180mm / min, and the drawing mode is intermittent, specifically 3 seconds of drawing followed by a 1-second pause. Continuous drawing produces recycled copper alloy rods with a diameter of 17mm. During the drawing process, the cooling water inlet temperature of the crystallizer is controlled at 25℃, and the temperature difference between the inlet and outlet water is controlled within 5℃ to ensure stable cooling intensity of the crystallizer and achieve directional solidification and grain refinement of the rod. The resulting recycled copper alloy rods are free of oxidation, cracks, porosity, slag inclusions, and other defects on the surface, and have a uniform and dense internal structure, providing qualified billets for subsequent cold drawing processes. The upward continuous casting process enables the continuous production of cast rods under a closed protective atmosphere, preventing oxidation caused by contact with air during casting and ensuring the surface quality and internal purity of the rods. Precise control of the melt temperature and traction speed matches the solidification characteristics of copper alloys, achieving grain refinement and homogenization in the cast rods, improving their plasticity and reducing the risk of fracture during subsequent drawing. The intermittent traction mode effectively eliminates internal stress during solidification, preventing internal cracks and defects. Stable crystallizer cooling parameters ensure consistency in the solidification process, resulting in uniform and stable rod microstructure and properties.

[0027] Specifically, the S4 multi-pass cold drawing and intermediate annealing process involves subjecting the prepared recycled copper alloy cast rod to multi-pass continuous cold drawing. A high-precision CNC wire drawing machine is used, and polycrystalline diamond dies are employed, with the die aperture decreasing progressively with each drawing pass. In this embodiment, the total number of cold drawing passes is 13, with a total deformation of 99.98%, drawing the 17mm diameter cast rod to a 0.08mm diameter recycled copper alloy single wire. Specifically, the first 6 passes draw the cast rod from 17mm to 2.0mm in diameter, with the deformation per pass controlled between 25% and 30%. The middle 4 passes draw the wire from 2.0mm to 0.2mm in diameter, with the deformation per pass controlled between 20% and 25%. The last 3 passes draw the wire from 0.2mm to 0.08mm in diameter, with the deformation per pass controlled between 15% and 20%. During the drawing process, a drawing lubricant is evenly applied to the wire surface. The lubricant is a water-soluble copper drawing lubricant with a concentration of 12%, and the lubricant temperature is controlled at 40℃ to ensure effective lubrication and reduce the risk of die wear and wire surface scratches. Two intermediate annealing treatments are performed during the drawing process. The first intermediate annealing is carried out after the 6th drawing pass, at which point the wire diameter is 2.0mm. A bright annealing furnace is used, with a high-purity nitrogen atmosphere of 99.999% purity. The annealing temperature is set at 550℃, and the holding time is 90 minutes. After holding, the wire is cooled to room temperature in the furnace before being removed from the furnace. The second intermediate annealing is carried out after the 10th drawing pass, at which point the wire diameter is 0.2mm. The annealing temperature is set at 480℃, and the holding time is 60 minutes. The annealing atmosphere and cooling method are the same as the first intermediate annealing. After the intermediate annealing, subsequent drawing passes are performed, ultimately yielding a recycled copper alloy monofilament with a diameter of 0.08mm. The prepared recycled copper alloy monofilament has a smooth surface free of burrs, oxidation, and scratches. The diameter deviation of the monofilament is controlled within ±0.001 mm. Testing shows that the monofilament has an electrical conductivity of 102.8% IACS, a tensile strength of 245 MPa, and an elongation at break of 18.5%, meeting the performance requirements. Multi-pass gradient deformation cold drawing can match the work hardening characteristics of copper alloy wire. By progressively decreasing deformation per pass, wire breakage caused by large deformation is avoided, ensuring the yield of ultra-fine monofilaments. Polycrystalline diamond drawing dies ensure the dimensional accuracy and surface finish of the monofilament, reducing the impact of surface defects on the mechanical and electrical properties of the monofilament. Specialized drawing lubricant forms a uniform lubricating film during the drawing process, reducing the coefficient of friction between the wire and the die, minimizing die wear, and preventing scratches and burrs on the wire surface. Intermediate annealing can eliminate work hardening generated during drawing, restore the plasticity of the wire, provide sufficient deformation capacity for subsequent drawing passes, and at the same time, it can regulate the internal grain structure of the wire to achieve synergistic optimization of single filament strength and plasticity.Matching the temperature and time of the two intermediate annealing processes to the wire diameter and work hardening degree can eliminate internal stress while avoiding the decrease in strength caused by excessive grain growth, thus ensuring the final comprehensive performance of the monofilament.

[0028] Specifically, in the S5 stranding process, 49 recycled copper alloy monofilaments prepared above are selected and stranded using a concentric stranding device to create a stranded core layer. In this embodiment, the stranding pitch ratio is set to 15, and the stranding direction is left-handed. During stranding, the tension of the monofilaments is uniformly controlled at 12 cN, with a tension deviation within ±5%, avoiding defects such as stranding and skipping caused by uneven tension. After stranding, the outer diameter of the stranded core is inspected online, and the outer diameter is controlled within 0.72 mm ± 0.02 mm, resulting in a uniformly structured, tightly packed, and regular stranded core. The concentric stranding structure ensures the structural stability and flexibility of the stranded core, while also ensuring uniform stress on the monofilaments inside the core, improving the bending fatigue resistance of the filament. A pitch ratio of 15 ensures a tight, non-loose core wire structure while balancing flexibility and conductivity. This avoids excessive stiffness and reduced flexibility due to a too-small pitch ratio, while preventing a loose core wire structure and uneven stress on individual filaments due to a too-large pitch ratio. Uniform and stable filament tension control guarantees the roundness and structural consistency of the stranded core wire, preventing filament protrusion or breakage and improving the overall performance stability of the core wire.

[0029] Specifically, in the S6 coating and finished product annealing process, the prepared stranded core wire is fed into an extrusion coating unit for extrusion coating of a high-temperature resistant insulating coating layer. In this embodiment, the coating material is modified polyurethane, the coating thickness is set to 0.03 mm, and the temperatures of each section of the extruder are as follows: feeding section 170°C, plasticizing section 190°C, melting section 205°C, and die head section 200°C. The extrusion traction speed is set to 60 m / min. During the coating process, the coating thickness is monitored online using laser technology, and the thickness deviation is controlled within ±0.002 mm to ensure the uniformity and consistency of the coating layer. After coating, the core wire with the insulating coating layer is sent to a protective atmosphere annealing furnace for finished product annealing. The annealing atmosphere is a mixture of high-purity nitrogen and hydrogen with a purity of 99.999%, of which hydrogen accounts for 5% by volume. The annealing temperature is set at 420℃, and the holding time is 40 minutes. After holding, the wire is cooled to below 100℃ in the furnace and then air-cooled to room temperature, finally obtaining the copper alloy nylon wire based on recycled copper in this embodiment. In the preparation process of this embodiment, the total carbon emission of steps S2 to S4 is calculated to be 0.98 kg CO2e / kg finished product, which is only 26% of the carbon emission of the same specification nylon wire preparation process using virgin copper, meeting the technical requirements for low emissions. The extrusion coating process can achieve a tight bond between the insulation layer and the stranded core wire, ensuring the adhesion and uniformity of the coating layer, avoiding defects such as coating eccentricity and missing coating, and improving the insulation performance and environmental resistance of the nylon wire. Modified polyurethane material possesses excellent high-temperature resistance, insulation properties, and flexibility, making it suitable for the use of nylon wire in high-frequency and high-temperature conditions. Finished product annealing eliminates internal stress generated during stranding and wrapping, further optimizing the flexibility and bending fatigue resistance of the nylon wire, while also stabilizing the conductivity of the monofilaments and preventing performance degradation during use. Protective atmosphere annealing prevents oxidation of the copper alloy core wire during high-temperature annealing, ensuring the long-term stability of the nylon wire.

[0030] This embodiment fully implements the product scheme and preparation method of copper alloy filament wire based on recycled copper. Through the precise design of the silver-zirconium binary composite alloy system, matched with a low-emission preparation process throughout the entire process, it fully covers all the core technical characteristics of product structure, raw material composition, performance indicators, and preparation process. The copper alloy filament wire prepared in this embodiment meets the design requirements for single filament conductivity, tensile strength, and elongation at break. The carbon emissions throughout the process are significantly lower than those of the same specification product made from virgin copper. At the same time, it has excellent flexibility and insulation properties, and can be directly applied to precision electronic components, high-frequency signal transmission, and other scenarios. The process parameters of this embodiment are clear and controllable, and the operation steps are complete and clear, which can directly guide the implementation of industrial production, fully verifying the feasibility and technical effectiveness of this technical solution.

[0031] Example 2 This embodiment provides a copper alloy filament wire based on recycled copper and its preparation method. Specifically, it employs a ternary composite alloy system with optimized matching process, using high-purity recycled cathode copper as the matrix. Through multi-element synergistic alloying and refined process control throughout the entire process, a copper alloy filament wire with high conductivity, high strength, high elongation, and excellent high-temperature resistance is obtained, while significantly reducing carbon emissions throughout the entire process. This embodiment fully covers the core technical features of product structure, raw material composition, and preparation method, presenting a complete and directly implementable technical solution.

[0032] The base material used in this embodiment is high-purity recycled cathode copper. Specifically, the copper purity of this high-purity recycled cathode copper is 99.992%, the conductivity is 100.8% IACS, and the carbon footprint emission value per unit mass of copper is 1.05 kg CO2e / kg, which meets the core performance requirements of the raw material. The composite alloying elements used in this embodiment are a ternary combination of silver, tin, and zirconium. By mass percentage, the composition of the recycled copper alloy monofilament includes 99.92% high-purity recycled cathode copper and 0.08% composite alloying elements. Among the composite alloying elements, the mass percentage of silver is 52% of the total mass of the composite alloying elements, the mass percentage of zirconium is 18% of the total mass of the composite alloying elements, the mass percentage of tin is 30% of the total mass of the composite alloying elements, and the balance is unavoidable impurities, with the total mass percentage of unavoidable impurities being 0.0041%. The mass percentage of each individual element, lead, arsenic, and bismuth, does not exceed 0.0004%, which meets the impurity control requirements.

[0033] The preparation method of this embodiment includes the following steps: S1 Pretreatment of recycled copper raw materials. Specifically, high-purity recycled cathode copper that meets the requirements is selected as raw material. First, the surface is mechanically polished. 320-mesh silicon carbide sandpaper is used to uniformly polish the surface of the cathode copper plate to remove the oxide scale and attached solid impurities. After polishing, the copper plate is cut into blocks of 120mm×60mm×12mm. Then, the blocks are ultrasonically degreased and cleaned. The raw material is completely immersed in a neutral degreasing agent aqueous solution at a temperature of 60℃. The mass concentration of the neutral degreasing agent is 10%. The ultrasonic power is set to 350W, and the ultrasonic treatment time is 20min to completely remove the oil and residual impurities attached to the surface of the raw material. After ultrasonic degreasing, the raw material is rinsed four times countercurrently with deionized water. Each rinse lasts for no less than 2min to completely remove the residual degreasing agent from the surface of the raw material. After rinsing, the raw material is placed in a hot air circulating drying oven for drying. The drying temperature is set at 130℃ and the drying time is 70 minutes. After drying, the raw material is cooled to room temperature in the oven to obtain pretreated recycled copper raw material.

[0034] Specifically, in S2 vacuum melting and precision alloying, pre-treated recycled copper raw materials are placed into a graphite crucible in a high-vacuum medium-frequency melting furnace. After the furnace is closed, the vacuum system is activated to evacuate the furnace until the vacuum level reaches 3×10⁻⁶. -3 Pa was then applied, followed by activation of the medium-frequency heating system to heat the raw material at a heating rate of 12℃ / min until it was completely melted, with the melting temperature controlled at 1190℃. After complete melting, the material was held at this temperature for 25 minutes to homogenize the melt temperature and promote the escape of residual gaseous impurities. After holding, high-purity silver granules, high-purity tin granules, and high-purity zirconium granules were added to the melt according to a pre-set composition ratio, with each metal raw material having a purity of 99.99%. After adding the materials, the melt was held at 1190℃ for another 20 minutes to ensure that the alloying elements were completely dissolved in the copper matrix. After the heat treatment is completed, high-purity argon gas (99.999% purity) is introduced into the furnace until the furnace pressure returns to atmospheric pressure. Then, a graphite stirring device is activated to stir the alloy melt at a speed of 100 r / min for 8 minutes. This ensures uniform dispersion of alloying elements in the melt and promotes the escape of dissolved hydrogen and other gaseous impurities with the argon gas bubbles, completing the degassing process. After degassing, the alloy melt is introduced into an online impurity removal and filtration system. The online filtration uses two-stage ceramic filter plates in series. The first-stage filter plate has a filtration accuracy of 50 μm, and the second-stage filter plate has a filtration accuracy of 20 μm. This two-stage filtration completely removes residual non-metallic inclusions and incompletely dissolved alloy particles from the melt, resulting in an alloy melt with uniform composition and meeting purity standards.

[0035] Specifically, in S3 continuous casting, the filtered alloy melt is introduced into the holding furnace of the upward drawing continuous casting unit through a sealed guide pipe. The melt temperature in the holding furnace is controlled at 1170℃, and high-purity argon gas is continuously introduced into the furnace for atmosphere protection to prevent oxidation of the melt. The upward drawing continuous casting unit uses a graphite crystallizer with an inner diameter of 12mm. The upward drawing speed is set to 220mm / min, and the drawing mode is intermittent, specifically drawing for 2 seconds and pausing for 0.5 seconds. Continuous drawing produces recycled copper alloy casting rods with a diameter of 12mm. During the drawing process, the cooling water inlet temperature of the crystallizer is controlled at 22℃, and the temperature difference between the inlet and outlet water is controlled within 4℃ to ensure stable cooling intensity of the crystallizer and achieve directional solidification and grain refinement of the casting rod. The resulting recycled copper alloy casting rod has no oxidation, cracks, porosity, slag inclusions, or other defects on its surface, and its internal structure is uniform and dense, providing qualified billets for subsequent cold drawing processes.

[0036] Specifically, the S4 multi-pass cold drawing and intermediate annealing process involves subjecting the prepared recycled copper alloy cast rod to multi-pass continuous cold drawing. A high-precision CNC wire drawing machine is used, and polycrystalline diamond dies are employed, with the die aperture decreasing progressively with each drawing pass. In this embodiment, the total number of cold drawing passes is 16, with a total deformation of 99.999%, drawing the 12mm diameter cast rod to a 0.03mm diameter recycled copper alloy single wire. Specifically, the first 7 passes draw the cast rod from 12mm to 1.5mm in diameter, with the deformation per pass controlled between 22% and 28%. The middle 5 passes draw the wire from 1.5mm to 0.15mm in diameter, with the deformation per pass controlled between 18% and 23%. The last 4 passes draw the wire from 0.15mm to 0.03mm in diameter, with the deformation per pass controlled between 12% and 18%. During the drawing process, a drawing lubricant is evenly applied to the wire surface. The lubricant is a water-soluble copper drawing lubricant with a concentration of 15%, and the lubricant temperature is controlled at 38℃ to ensure effective lubrication and reduce the risk of die wear and wire surface scratches. Three intermediate annealing treatments are performed during the drawing process. The first intermediate annealing is carried out after the 7th drawing pass, at which point the wire diameter is 1.5mm. A bright annealing furnace is used, with a 99.999% pure nitrogen atmosphere, an annealing temperature of 560℃, and a holding time of 80 minutes. After holding, the wire is cooled to room temperature in the furnace before being removed from the furnace. The second intermediate annealing is carried out after the 12th drawing pass, at which point the wire diameter is 0.15mm. The annealing temperature is set at 490℃, and the holding time is 50 minutes. The annealing atmosphere and cooling method are the same as the first intermediate annealing. The third intermediate annealing was performed after the 14th drawing pass, at which point the wire diameter was 0.06 mm. The annealing temperature was set at 450℃, and the holding time was 30 minutes. The annealing atmosphere and cooling method were consistent with the previous two intermediate annealing passes. After the intermediate annealing, subsequent drawing passes were performed, ultimately yielding a recycled copper alloy monofilament with a diameter of 0.03 mm. The prepared recycled copper alloy monofilament had a smooth surface free of burrs, oxidation, and scratches. The diameter deviation of the monofilament was controlled within ±0.0005 mm. Testing showed that the monofilament had an electrical conductivity of 102.3% IACS, a tensile strength of 260 MPa, and an elongation at break of 16.2%, meeting the performance requirements.

[0037] Specifically, in the S5 stranding process, 19 recycled copper alloy monofilaments prepared above are selected and stranded using a concentric stranding device to create a stranded core layer. In this embodiment, the stranding pitch ratio is set to 12, and the stranding direction is right-handed. During stranding, the tension of the monofilaments is uniformly controlled at 5 cN, with tension deviation controlled within ±5%, to avoid defects such as stranding and skipping caused by uneven tension. After stranding, the outer diameter of the stranded core is inspected online, and the outer diameter is controlled within 0.15 mm ± 0.01 mm, resulting in a uniformly structured, tightly packed, and regular stranded core.

[0038] Specifically, in the S6 coating and finished product annealing process, the prepared stranded core wire is fed into an extrusion coating unit for extrusion coating of a high-temperature resistant insulating coating layer. In this embodiment, the coating material is polyimide, the coating thickness is set to 0.02 mm, and the temperatures of each section of the extruder are as follows: feeding section 210°C, plasticizing section 260°C, melting section 320°C, and die head section 310°C. The extrusion traction speed is set to 40 m / min. During the coating process, the coating thickness is monitored online using laser technology, and the thickness deviation is controlled within ±0.0015 mm to ensure the uniformity and consistency of the coating layer. After coating, the core wire with the insulating coating layer is sent to a protective atmosphere annealing furnace for finished product annealing. The annealing atmosphere is high-purity nitrogen gas with a purity of 99.999%, the annealing temperature is set to 380°C, and the holding time is 60 min. After holding, the wire is cooled in the furnace to below 100°C and then air-cooled to room temperature, finally obtaining the copper alloy nylon wire based on recycled copper in this embodiment. In the preparation process of this embodiment, the total carbon emissions of steps S2 to S4 are calculated to be 1.08 kg CO2e / kg of finished product, which is only 28% of the carbon emissions of the same specification copper nylon wire preparation process, and meets the technical requirements for low emissions.

[0039] This embodiment fully implements the product scheme and preparation method of copper alloy filament wire based on recycled copper. Through the precise design of the silver-tin-zirconium ternary composite alloy system, matched with the ultra-fine single-filament drawing process and high-temperature resistant coating design, it fully covers all the core technical characteristics of product structure, raw material composition, performance indicators, and preparation process. The copper alloy filament wire prepared in this embodiment meets the design requirements for single-filament conductivity, tensile strength, and elongation at break. The carbon emissions of the entire process are significantly lower than those of the same specification product made from virgin copper. At the same time, it has excellent ultra-fine specification adaptability and high-temperature insulation performance, and can be directly applied to micro-precision electronic components, aerospace precision wire harnesses, and other scenarios. The process parameters of this embodiment are clear and controllable, and the operation steps are complete and clear, which can directly guide the implementation of industrial production, fully verifying the feasibility and technical effectiveness of this technical solution.

[0040] Example 3 This embodiment provides a copper alloy filament wire based on recycled copper and its preparation method. Specifically, it employs a quaternary composite alloy system with optimized matching process, using high-purity recycled cathode copper as the matrix. Through multi-element synergistic alloying and a low-emission preparation process throughout the entire process, a copper alloy filament wire with high conductivity, high strength, high elongation, excellent high-temperature resistance, and resistance to bending fatigue is obtained, while significantly reducing carbon emissions throughout the entire process. This embodiment fully covers all technical features of the product structure, raw material composition, and preparation method, presenting a complete and directly implementable technical solution.

[0041] The base material used in this embodiment is high-purity recycled cathode copper. Specifically, the high-purity recycled cathode copper has a copper purity of 99.998%, an electrical conductivity of 101.5% IACS, and a carbon footprint emission value of 0.85 kg CO2e / kg per unit mass of copper, meeting the core performance requirements of the raw material. The composite alloying elements used in this embodiment are a quaternary combination of silver, tin, magnesium, and zirconium. By mass percentage, the composition of the recycled copper alloy monofilament includes 99.98% high-purity recycled cathode copper and 0.02% composite alloying elements. Among the composite alloying elements, silver accounts for 45% of the total mass of the composite alloying elements, zirconium accounts for 12%, tin accounts for 28%, magnesium accounts for 15%, and the balance is unavoidable impurities, with a total mass percentage of 0.0028%. The mass percentage of each individual element, lead, arsenic, and bismuth, does not exceed 0.0002%, meeting the impurity control requirements.

[0042] The preparation method of this embodiment includes the following steps: S1 Pretreatment of recycled copper raw materials Specifically, the above-mentioned high-purity recycled cathode copper that meets the requirements is selected as raw material. First, the surface is mechanically polished. The surface of the cathode copper plate is uniformly polished with 200-mesh silicon carbide sandpaper to remove the oxide scale and attached solid impurities generated on the surface. After polishing, the copper plate is cut into blocks of 150mm×80mm×15mm. Then, the blocks are ultrasonically degreased and cleaned. The raw material is completely immersed in a neutral degreasing agent aqueous solution at a temperature of 50℃. The mass concentration of the neutral degreasing agent is 7%. The ultrasonic power is set to 280W and the ultrasonic treatment time is 30min to completely remove the oil and residual impurities attached to the surface of the raw material. After ultrasonic degreasing, the raw material is rinsed three times in countercurrent with deionized water. Each rinse time is not less than 4min to completely remove the degreasing agent remaining on the surface of the raw material. After rinsing, the raw material is placed in a hot air circulating drying oven for drying. The drying temperature is set at 110℃ and the drying time is 120 minutes. After drying, the raw material is cooled to room temperature in the oven to obtain pretreated recycled copper raw material.

[0043] Specifically, in S2 vacuum melting and precision alloying, pre-treated recycled copper raw materials are placed into a graphite crucible in a high-vacuum medium-frequency melting furnace. After the furnace is closed, the vacuum system is activated to evacuate the furnace until the vacuum level reaches 6×10⁻⁶. -3 Pa, then the medium-frequency heating system is turned on, heating the raw material at a heating rate of 18℃ / min until it is completely melted, with the melting temperature controlled at 1200℃. After the raw material is completely melted, it is held at this temperature for 15 minutes to homogenize the melt temperature and promote the escape of residual gaseous impurities inside the melt. After the holding period, high-purity silver granules, high-purity tin granules, high-purity magnesium granules, and high-purity zirconium granules are added to the melt according to the pre-set component ratio, wherein the purity of each metal raw material is 99.99%. After the addition is completed, the temperature is held at 1200℃ for another 10 minutes to allow the alloying elements to completely dissolve in the copper matrix. After the heat preservation process is completed, high-purity argon gas (99.999% purity) is introduced into the furnace until the furnace pressure returns to atmospheric pressure. Then, a graphite stirring device is activated to stir the alloy melt at a speed of 70 r / min for 12 minutes. This ensures uniform dispersion of alloying elements in the melt and promotes the escape of dissolved hydrogen and other gaseous impurities with the argon gas bubbles, completing the degassing process. After degassing, the alloy melt is introduced into an online impurity removal and filtration system. The online filtration uses two-stage ceramic filter plates in series. The first-stage filter plate has a filtration accuracy of 50 μm, and the second-stage filter plate has a filtration accuracy of 20 μm. This two-stage filtration completely removes residual non-metallic inclusions and incompletely dissolved alloy particles from the melt, resulting in an alloy melt with uniform composition and meeting purity standards.

[0044] Specifically, in S3 continuous casting, the filtered alloy melt is introduced into the holding furnace of the upward drawing continuous casting unit through a sealed guide pipe. The melt temperature in the holding furnace is controlled at 1180℃, and high-purity argon gas is continuously introduced into the furnace for atmosphere protection to prevent oxidation of the melt. The upward drawing continuous casting unit uses a graphite crystallizer with an inner diameter of 20mm. The upward drawing speed is set to 150mm / min, and the drawing mode is intermittent, specifically 4 seconds of drawing followed by a 1-second pause. Continuous drawing produces recycled copper alloy casting rods with a diameter of 20mm. During the drawing process, the cooling water inlet temperature of the crystallizer is controlled at 28℃, and the temperature difference between the inlet and outlet water is controlled within 6℃ to ensure stable cooling intensity of the crystallizer and achieve directional solidification and grain refinement of the casting rod. The resulting recycled copper alloy casting rod has no oxidation, cracks, porosity, slag inclusions, or other defects on its surface, and its internal structure is uniform and dense, providing qualified billets for subsequent cold drawing processes.

[0045] Specifically, the S4 multi-pass cold drawing and intermediate annealing process involves subjecting the prepared recycled copper alloy cast rod to multi-pass continuous cold drawing. A high-precision CNC wire drawing machine is used, and polycrystalline diamond dies are employed, with the die aperture decreasing progressively with each drawing pass. In this embodiment, the total number of cold drawing passes is 11, with a total deformation of 99.99%, drawing the 20mm diameter cast rod to a 0.18mm diameter recycled copper alloy single wire. Specifically, the first 5 passes draw the cast rod from a diameter of 20mm to a diameter of 3.0mm, with the deformation per pass controlled between 28% and 32%. The middle 3 passes draw the wire from a diameter of 3.0mm to a diameter of 0.5mm, with the deformation per pass controlled between 22% and 27%. The last 3 passes draw the wire from a diameter of 0.5mm to a diameter of 0.18mm, with the deformation per pass controlled between 18% and 22%. During the drawing process, a drawing lubricant is evenly applied to the wire surface. The lubricant is a water-soluble copper drawing lubricant with a concentration of 10%, and the lubricant temperature is controlled at 42℃ to ensure effective lubrication and reduce the risk of die wear and wire surface scratches. Three intermediate annealing treatments are performed during the drawing process. The first intermediate annealing is performed after the fifth drawing pass, at which point the wire diameter is 3.0mm. A bright annealing furnace is used, with an annealing atmosphere of 99.999% high-purity nitrogen, a annealing temperature of 540℃, and a holding time of 100 minutes. After holding, the wire is cooled to room temperature in the furnace before being removed from the furnace. The second intermediate annealing is performed after the eighth drawing pass, at which point the wire diameter is 0.5mm. The annealing temperature is set at 470℃, and the holding time is 70 minutes. The annealing atmosphere and cooling method are the same as the first intermediate annealing. The third intermediate annealing was performed after the 10th drawing pass, at which point the wire diameter was 0.25 mm. The annealing temperature was set at 440℃, and the holding time was 40 min. The annealing atmosphere and cooling method were consistent with the previous two intermediate annealing passes. After the intermediate annealing, subsequent drawing passes were performed, ultimately yielding a recycled copper alloy monofilament with a diameter of 0.18 mm. The prepared recycled copper alloy monofilament had a smooth surface free of burrs, oxidation, and scratches. The diameter deviation of the monofilament was controlled within ±0.002 mm. Testing showed that the monofilament had an electrical conductivity of 103.1% IACS, a tensile strength of 228 MPa, and an elongation at break of 21.3%, meeting the performance requirements.

[0046] Specifically, in the S5 stranding process, seven recycled copper alloy monofilaments prepared above are selected and stranded using a concentric stranding device to create a stranded core layer. In this embodiment, the stranding pitch ratio is set to 18, and the stranding direction is right-handed. During stranding, the tension of the monofilaments is uniformly controlled at 25 cN, with a tension deviation within ±5%, to avoid defects such as stranding and skipping caused by uneven tension. After stranding, the outer diameter of the stranded core is inspected online, and the outer diameter is controlled within 0.54 mm ± 0.02 mm, resulting in a uniformly structured, tightly packed, and regular stranded core.

[0047] Specifically, in the S6 coating and finished product annealing process, the prepared stranded core wire is fed into an extrusion coating unit for extrusion coating of a high-temperature resistant insulating coating layer. In this embodiment, the coating material is polyetheretherketone (PEEK), the coating thickness is set to 0.04 mm, and the temperatures of each section of the extruder are as follows: feeding section 300°C, plasticizing section 350°C, melting section 380°C, and die head section 370°C. The extrusion traction speed is set to 30 m / min. During the coating process, the coating thickness is monitored online using laser technology, and the thickness deviation is controlled within ±0.002 mm to ensure the uniformity and consistency of the coating layer. After the insulation coating is completed, the core wire with the insulation coating layer is sent to a protective atmosphere annealing furnace for finished product annealing. The annealing atmosphere is a mixture of high-purity nitrogen and hydrogen gas with a purity of 99.999%, of which hydrogen accounts for 3% by volume. The annealing temperature is set at 450℃, and the holding time is 30 minutes. After the holding time, the wire is cooled to below 100℃ in the furnace and then air-cooled to room temperature, finally obtaining the copper alloy nylon wire based on recycled copper in this embodiment. In the preparation process of this embodiment, the total carbon emission of steps S2 to S4 is calculated to be 0.85 kg CO2e / kg finished product, which is only 22% of the carbon emission of the same specification nylon wire preparation process using primary copper, meeting the technical requirements for low emissions.

[0048] This embodiment fully implements the product scheme and preparation method of copper alloy nylon wire based on recycled copper. Through the precise design of the silver-tin-magnesium-zirconium quaternary composite alloy system, matched with the large-size cast rod drawing process and high-temperature resistant coating design, it fully covers all technical characteristics of product structure, raw material composition, performance indicators and preparation process. The copper alloy nylon wire prepared in this embodiment meets the design requirements for single filament conductivity, tensile strength and elongation at break. The carbon emissions of the whole process are significantly lower than those of the same specification of virgin copper. At the same time, it has excellent high conductivity, high plasticity and resistance to extreme environments, and can be directly applied to new energy vehicle wiring harnesses, industrial automation control cables and other scenarios. The process parameters of this embodiment are clear and controllable, and the operation steps are complete and clear, which can directly guide the implementation of industrial production, fully verifying the feasibility and technical effectiveness of this technical solution.

[0049] Comparative Example This comparative example uses native high-purity cathode copper as the base material, without adding any composite alloying elements. The rest of the preparation process is completely consistent with that of Example 1. It is used to compare and analyze the impact of base material and alloying design on the comprehensive performance and carbon emissions of copper alloy filament wire, and to clarify the technical advantages and innovations of this technical solution.

[0050] The matrix material used in this comparative example is virgin high-purity cathode copper. Specifically, the copper purity of this virgin high-purity cathode copper is 99.995%, the conductivity is 101.0% IACS, and the carbon footprint emission value per unit mass of copper is 3.8 kg CO2e / kg. This comparative example does not add any composite alloying elements; the balance is unavoidable impurities, with the total mass percentage of unavoidable impurities being 0.0035%, of which the mass percentage of lead, arsenic, and bismuth does not exceed 0.0003%.

[0051] The preparation method of this comparative example is completely consistent with that of Example 1, and all process parameters are kept the same as in Example 1. A native copper monofilament with a diameter of 0.08 mm was finally obtained, and copper nylon wire of the same specification was also prepared. Testing showed that the monofilament prepared in this comparative example had an electrical conductivity of 101.5% IACS, a tensile strength of 195 MPa, and an elongation at break of 14.2%. The total carbon emissions from steps S2 to S4 were calculated to be 3.62 kg CO2e / kg of finished product.

[0052] This comparative example uses a native copper matrix without alloying. The resulting copper alloy wire exhibits lower conductivity, tensile strength, and elongation at break compared to the product in the embodiment of this invention. Simultaneously, the overall carbon emissions are significantly higher than those of the product in the embodiment of this invention. This comparison clearly demonstrates that the high-purity recycled cathode copper matrix and composite alloying design employed in this invention can significantly reduce overall carbon emissions while simultaneously improving the conductivity and mechanical properties of the copper alloy copper alloy wire, fully validating the innovation and effectiveness of this technical solution.

[0053] To clearly and intuitively compare the core components, process parameters, and overall performance of each embodiment and comparative example, the core information of the above three embodiments and one comparative example is summarized in the table below.

[0054]

[0055] As can be seen from the summarized data above, the copper alloy filaments based on recycled copper prepared in the three embodiments of this invention all meet the design requirements in terms of performance indicators. Their electrical conductivity, tensile strength, and elongation at break are all superior to the virgin copper filaments in the comparative example. Simultaneously, the carbon emissions of the entire process are only within 30% of those of the virgin copper filaments of the same specifications, achieving a synergistic optimization of environmental protection, low carbon emissions, and performance improvement. Each embodiment, through different alloy systems and process parameter matching, has achieved stable implementation of the technical solution, fully verifying the universality, feasibility, and technical effectiveness of this technical solution, and providing sufficient basis for the implementation of the scope of protection of the claims of this invention.

[0056] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A copper alloy filament wire based on recycled copper, characterized in that, Made from the following raw materials in parts by weight: The stranded core layer is composed of several recycled copper alloy monofilaments concentrically stranded together. The recycled copper alloy monofilaments are based on high-purity recycled cathode copper and also contain composite alloying elements. The total mass percentage of unavoidable impurities in the recycled copper alloy monofilaments is ≤0.005%. The composite alloying elements are selected from at least two of silver, tin, magnesium, and zirconium.

2. The copper alloy filament wire based on recycled copper according to claim 1, characterized in that, The high-purity recycled cathode copper has a copper purity of ≥99.99%, an electrical conductivity of ≥100% IACS, and a carbon footprint emission value of ≤1.1kgCO2e / kg per unit mass of copper.

3. The copper alloy filament wire based on recycled copper according to claim 1, characterized in that, The recycled copper alloy monofilament is composed of the following components by mass percentage: 99.90%~99.99% high-purity recycled cathode copper and 0.01%~0.10% composite alloying elements.

4. The copper alloy filament wire based on recycled copper according to claim 1, characterized in that, In the composite alloy elements, the mass percentage of silver is 40% to 60% of the total mass of the composite alloy elements, and the mass percentage of zirconium is 10% to 20% of the total mass of the composite alloy elements.

5. The copper alloy filament wire based on recycled copper according to claim 1, characterized in that, Of the unavoidable impurities, the mass percentage of each of lead, arsenic, and bismuth is ≤0.0005%.

6. The copper alloy filament wire based on recycled copper according to claim 1, characterized in that, The recycled copper alloy monofilament has a diameter of 0.02mm to 0.20mm, an electrical conductivity ≥102%IACS, a tensile strength ≥220MPa, and an elongation at break ≥15%.

7. The copper alloy filament wire based on recycled copper according to claim 1, characterized in that, The stranded core wire layer has a stranding pitch ratio of 12 to 18 times, and the stranding direction is either left or right.

8. The copper alloy filament wire based on recycled copper according to claim 1, characterized in that, The outer covering layer is a high-temperature resistant insulating covering layer, and its material is any one of modified polyurethane, polyimide or polyetheretherketone, and the thickness of the covering layer is 0.01mm~0.05mm.

9. A method for preparing copper alloy filament wire based on recycled copper, used to prepare the copper alloy filament wire based on recycled copper as described in any one of claims 1-8, characterized in that, Includes the following steps: S1. Pretreatment of recycled copper raw materials: High-purity recycled cathode copper is selected as raw material. After surface cleaning and drying, oil, oxide layer and impurities on the surface of the raw material are removed to obtain pretreated recycled copper raw materials. S2. Vacuum melting and precision alloying: The pretreated recycled copper raw material is put into a vacuum melting furnace, heated and melted in a vacuum environment, and after holding at the temperature, composite alloying elements are added according to the ratio. The temperature is held and high-purity argon gas is introduced for stirring and degassing. After online impurity removal and filtration, the alloy melt is obtained. S3. Continuous casting: The alloy melt is introduced into the upper continuous casting unit to prepare recycled copper alloy rods. S4. Multi-pass cold drawing and intermediate annealing: The recycled copper alloy casting rod is subjected to multi-pass continuous cold drawing, and 2-3 intermediate annealings are performed during the drawing process to obtain recycled copper alloy monofilament. S5. Stranding: Multiple recycled copper alloy monofilaments are concentrically stranded according to a set pitch ratio and stranding direction to obtain a stranded core wire. S6. Coating and Finished Annealing: The stranded core wire is extruded and coated with a high-temperature resistant insulation layer. After the coating is completed, the finished product is annealed under a protective atmosphere and cooled to obtain the copper alloy nylon wire based on recycled copper.

10. A copper alloy filament wire based on recycled copper according to claim 9, characterized in that, The total carbon emissions of steps S2-S4 are ≤1.2kgCO2e / kg finished product, which is less than 30% of the carbon emissions of the same specification copper nylon wire preparation process. The online impurity removal filtration in step S2 adopts a two-stage ceramic filter plate filtration, with the first stage filtration accuracy of 50μm and the second stage filtration accuracy of 20μm.

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