Process for purifying scrap copper to produce high-purity phosphorus copper rod with high conductivity

Abstract

The present application relates to a kind of high conductivity high purity phosphor copper pole preparation process of waste copper purification, belong to non-ferrous metal processing technical field.Waste copper is broken, magnetic separation, pickling, drying, then input into medium-frequency induction furnace melting, add composite refining agent, stirring, standing slag removal;The melt is transferred to refining furnace, nitrogen is passed, add phosphor copper intermediate alloy, and refining is carried out;Rare earth element yttrium, phosphor copper intermediate alloy is added to the melt after refining, and stirring is uniform;The melt is cooled, using upper guide continuous casting process, and casting is carried out;Phosphor copper pole after casting is cooled by ketone hydrazine condensation cooling liquid, and high purity phosphor copper pole is obtained;Ketone hydrazine condensation cooling liquid is prepared by acetone, tetrahydrothiophene-3-ketone, isopropyl hydrazine phosphate, lanthanum isopropyl alcohol, acetic acid, propylene glycol, deionized water, boron nitride nanosheet;The present application realizes the efficient purification of waste copper, and the prepared phosphor copper pole has the advantages of high conductivity, low oxygen content and the like, and is suitable for high-end electrical material field.

Description

Technical Field

[0001] This invention relates to the field of non-ferrous metal processing technology, and in particular to a process for purifying waste copper to prepare high-conductivity, high-purity phosphorus copper rods. Background Technology

[0002] Scrap copper is an important renewable resource, but traditional processing techniques have problems such as incomplete removal of impurities and unstable control of phosphorus content, resulting in low electrical conductivity and poor mechanical properties of copper rods.

[0003] Chinese Patent CN106001477A discloses a method for preparing phosphorus copper alloy rods, which involves continuous melting, alloying, heat preservation and storage, continuous casting, and continuous rolling to produce phosphorus copper alloy rods with a phosphorus content of 400-650 PPM and an oxygen content of 10-50 PPM.

[0004] Chinese Patent CN103966442B: A method for preparing high-purity copper by electrowinning of waste copper, characterized by placing waste copper in a CuCl2-NH3-NH4Cl solution containing copper, dissolving it, filtering to obtain a filtrate; adding extractant Kelex 100, isooctanol, sulfonated kerosene and co-extractant P204 for extraction; adjusting the copper content of the raffinate with NH3-NH4Cl solution; adding HEDP or ethylenediamine to the raffinate as an electrolyte, and electrowinning for 24 hours at a current density of 220-250 A / m2 and a cell voltage of 1.9-2.2 V using an anion exchange membrane as a diaphragm to obtain electrowinning copper on the cathode plate.

[0005] In existing technologies, pyrometallurgical refining is difficult to effectively remove impurities such as lead and tin, while electrolytic refining is costly and time-consuming. Furthermore, excessive phosphorus, as a deoxidizer, significantly reduces conductivity, and existing processes lack precise control methods. Summary of the Invention

[0006] To address the aforementioned problems, this invention provides a process for purifying waste copper to prepare high-conductivity, high-purity phosphor bronze rods, the operation steps of which are as follows:

[0007] S1 Pretreatment: The waste copper is crushed to a particle size of 5-20mm, ferromagnetic impurities are removed by magnetic separation, and then surface oil and oxides are removed by acid washing and drying.

[0008] S2 smelting: 60-90 parts by weight of pretreated scrap copper are put into a medium frequency induction furnace, fueled by natural gas, and heated to 1150-1200℃ to melt. 0.1-0.5 parts by weight of composite refining agent are added, stirred for 10-15 minutes, and allowed to stand to remove slag.

[0009] S3 Refining: Transfer the melt to a refining furnace, introduce nitrogen gas and stir, while adding 0.07-0.2 parts by mass of phosphorus copper master alloy. The refining temperature is 1180-1220℃ and the refining time is 20-30 minutes.

[0010] S4 Phosphorus Addition and Rare Earth Modification: Add 0.005-0.01 parts by weight of rare earth element yttrium and 0.03-0.1 parts by weight of phosphorus copper master alloy to the refined melt, control the phosphorus content to be 0.0045-0.006 wt%, and stir evenly;

[0011] S5 casting: The melt temperature is reduced to 1100-1120℃, and the upward continuous casting process is adopted;

[0012] S6 Cooling: The cast phosphor bronze rod is cooled by ketone-hydrazine condensation coolant to obtain a high-purity phosphor bronze rod.

[0013] As a preferred embodiment of the present invention, the acid washing of S1 uses a sulfuric acid solution with a mass percentage of 5-10%.

[0014] As a preferred embodiment of the present invention, the composite refining agent is composed of 30wt% quartz sand, 25wt% sodium carbonate, 20wt% fluorite, 15wt% rare earth elements, and 10wt% titanium boride.

[0015] As a preferred embodiment of the present invention, the rare earth element in the composite refining agent is a mixture of lanthanum and cerium in a mass ratio of 1:1.

[0016] As a preferred embodiment of the present invention, the nitrogen flow rate of the S3 refining is 5-10 L / min.

[0017] As a preferred embodiment of the present invention, the phosphorus content in the S3 phosphorus copper master alloy is 15-20 wt%.

[0018] As a preferred embodiment of the present invention, the S5 casting speed is 0.8-1.2 m / min.

[0019] As a preferred embodiment of the present invention, the cast phosphor bronze rod needs to undergo online eddy current testing to remove surface defects.

[0020] As a preferred embodiment of the present invention, the method for preparing the ketone-hydrazine condensation coolant is as follows:

[0021] According to the mass fraction, 15-27 parts of acetone, 0.05-0.7 parts of tetrahydrothiophene-3-one, 0.2-2 parts of isopropyl phosphate, and 0.2-0.6 parts of lanthanum isopropoxide are mixed, and 0.1-0.3 parts of acetic acid are added. The mixture is reacted at 50-60℃ for 1-3 hours, and then 22-26 parts of propylene glycol, 130-160 parts of deionized water, and 0.8-1.2 parts of boron nitride nanosheets are added. The mixture is ultrasonically dispersed for 25-50 minutes to obtain a ketone-hydrazine condensation cooling liquid.

[0022] Reaction mechanism:

[0023] The ketone group of acetone and the hydrazine group of isopronicotinamide phosphate undergo a condensation reaction under acetic acid catalysis. At the same time, the ketone group of tetrahydrothiophene-3-one also participates in the condensation reaction, jointly generating hydrazone derivatives containing phosphorus and sulfur. The polar groups (such as phosphoryl groups and sulfur heterocycles) in these derivative molecules enhance their adsorption capacity on the copper surface.

[0024] Lanthanum isopropoxide dissociates into lanthanum ions in the system, which form coordination compounds with hydrazone derivatives. These compounds are deposited on the copper surface to form a composite protective film. The lanthanum ions can fill the micropores of the protective film, further isolating it from oxidizing media such as oxygen and moisture. The sulfur heterocycle introduced by tetrahydrothiophene-3-one can enhance the chemical stability of the protective film.

[0025] Technical effects:

[0026] The present invention provides a process for purifying waste copper to prepare high-conductivity, high-purity phosphor bronze rods. Compared with the prior art, the present invention has the following significant advantages:

[0027] 1. The composite protective film formed by phosphorus and sulfur-containing hydrazone derivatives and lanthanum ions has strong adhesion to the copper surface, effectively preventing the oxidation reaction of copper, avoiding the formation of black spots, maintaining the good condition of the copper rod surface, and ensuring the stability of its electrical conductivity, thermal conductivity and signal transmission performance.

[0028] 2. The boron nitride nanosheets are uniformly dispersed in the system and work synergistically with the composite protective film mentioned above. They do not affect the heat transfer during the cooling process, and can improve the cooling efficiency through their high thermal conductivity. This ensures that the copper rod is dimensionally stable after cooling and meets the precision requirements of subsequent processing.

[0029] 3. This invention achieves efficient purification of waste copper, and the resulting phosphor bronze rod has advantages such as high electrical conductivity and low oxygen content, making it suitable for the field of high-end electrical materials. Detailed Implementation

[0030] To further illustrate the technical means and effects adopted by the present invention to achieve the intended purpose, the following detailed description is provided in conjunction with embodiments and comparative examples:

[0031] 1. Conductivity: Measured using an eddy current conductivity meter in accordance with ASTM B193-20 standard;

[0032] 2. Phosphorus content: Tested using ICP-OES (Inductively Coupled Plasma Optical Emission Spectrometer);

[0033] 3. Oxygen content: Tested using the inert gas melting-infrared absorption method (ASTM E1019).

[0034] Example 1

[0035] A process for purifying waste copper to prepare high-conductivity, high-purity phosphor bronze rods, comprising the following steps:

[0036] S1 Pretreatment: The waste copper is crushed to a particle size of 20mm, ferromagnetic impurities are removed by magnetic separation, and then surface oil and oxides are removed by acid washing and drying.

[0037] S2 Smelting: 60kg of pretreated scrap copper is put into a medium-frequency induction furnace, fueled by natural gas, and heated to 1150℃ to melt. 0.1kg of composite refining agent is added, stirred for 10 minutes, and allowed to stand to remove slag.

[0038] S3 Refining: Transfer the melt to a refining furnace, introduce nitrogen gas and stir, while adding 0.07 kg of phosphorus copper master alloy. The refining temperature is 1180℃ and the refining time is 20 minutes.

[0039] S4 Phosphorus Addition and Rare Earth Modification: Add 0.005 kg of rare earth element yttrium and 0.03 kg of phosphorus copper master alloy to the refined melt, control the phosphorus content to 0.0045 wt%, and stir evenly;

[0040] S5 casting: The melt temperature is reduced to 1100℃, and the upward continuous casting process is adopted;

[0041] S6 Cooling: The cast phosphor bronze rod is cooled by ketone-hydrazine condensation coolant to obtain a high-purity phosphor bronze rod.

[0042] The pickling of S1 uses a sulfuric acid solution with a mass percentage of 5%.

[0043] The composite refining agent is composed of 30 wt% quartz sand, 25 wt% sodium carbonate, 20 wt% fluorite, 15 wt% rare earth elements, and 10 wt% titanium boride.

[0044] The rare earth element in the composite refining agent is a mixture of lanthanum and cerium in a mass ratio of 1:1.

[0045] The nitrogen flow rate for the S3 refining process is 5 L / min.

[0046] The phosphorus content in the S3 phosphorus copper master alloy is 15 wt%.

[0047] The S5 casting speed is 0.8 m / min.

[0048] The cast phosphor bronze rod needs to undergo online eddy current testing to remove surface defects.

[0049] The method for preparing the ketone-hydrazine condensation coolant is as follows:

[0050] Mix 15 kg of acetone, 0.05 kg of tetrahydrothiophene-3-one, 0.2 kg of isopropyl phosphate, and 0.2 kg of lanthanum isopropoxide. Add 0.1 kg of acetic acid and react at 50 °C for 1 hour. Then add 22 kg of propylene glycol, 130 kg of deionized water, and 0.8 kg of boron nitride nanosheets. Disperse the mixture by ultrasonication for 25 minutes to obtain a ketone-hydrazine condensation cooling liquid.

[0051] Example 2

[0052] A process for purifying waste copper to prepare high-conductivity, high-purity phosphor bronze rods, comprising the following steps:

[0053] S1 Pretreatment: The scrap copper is crushed to a particle size of 10mm, ferromagnetic impurities are removed by magnetic separation, and then surface oil and oxides are removed by acid washing and drying.

[0054] S2 Smelting: 70kg of pretreated scrap copper is put into a medium-frequency induction furnace, fueled by natural gas, and heated to 1160℃ to melt. 0.2kg of composite refining agent is added, stirred for 10 minutes, and allowed to stand to remove slag.

[0055] S3 Refining: Transfer the melt to a refining furnace, introduce nitrogen gas and stir, while adding 0.1 kg of phosphorus copper master alloy. The refining temperature is 1190℃ and the refining time is 25 minutes.

[0056] S4 Phosphorus Addition and Rare Earth Modification: Add 0.006 kg of rare earth element yttrium and 0.05 kg of phosphorus copper master alloy to the refined melt, control the phosphorus content to 0.005 wt%, and stir evenly;

[0057] S5 casting: The melt temperature is reduced to 1105℃, and the upward continuous casting process is adopted;

[0058] S6 Cooling: The cast phosphor bronze rod is cooled by ketone-hydrazine condensation coolant to obtain high-purity phosphor bronze rod.

[0059] The pickling of S1 uses a sulfuric acid solution with a mass percentage of 6%.

[0060] The composite refining agent is composed of 30 wt% quartz sand, 25 wt% sodium carbonate, 20 wt% fluorite, 15 wt% rare earth elements, and 10 wt% titanium boride.

[0061] The rare earth element in the composite refining agent is a mixture of lanthanum and cerium in a mass ratio of 1:1.

[0062] The nitrogen flow rate for the S3 refining process is 6 L / min.

[0063] The phosphorus content in the S3 phosphorus copper master alloy is 16%.

[0064] The S5 casting speed is 0.9 m / min.

[0065] The cast phosphor bronze rod needs to undergo online eddy current testing to remove surface defects.

[0066] The method for preparing the ketone-hydrazine condensation coolant is as follows:

[0067] 17 kg of acetone, 0.2 kg of tetrahydrothiophene-3-one, 1 kg of isopronicohydrazine phosphate, and 0.3 kg of lanthanum isopropoxide were mixed, and 0.2 kg of acetic acid was added. The mixture was reacted at 55 °C for 2 hours. Then, 24 kg of propylene glycol, 140 kg of deionized water, and 0.9 kg of boron nitride nanosheets were added and the mixture was ultrasonically dispersed for 35 minutes to obtain a ketone-hydrazine condensation cooling solution.

[0068] Example 3

[0069] A process for purifying waste copper to prepare high-conductivity, high-purity phosphor bronze rods, comprising the following steps:

[0070] S1 Pretreatment: The scrap copper is crushed to a particle size of 10mm, ferromagnetic impurities are removed by magnetic separation, and then surface oil and oxides are removed by acid washing and drying.

[0071] S2 Smelting: 80kg of pretreated scrap copper is put into a medium-frequency induction furnace, fueled by natural gas, and heated to 1180℃ to melt. 0.4kg of composite refining agent is added, stirred for 15 minutes, and allowed to stand to remove slag.

[0072] S3 Refining: Transfer the melt to a refining furnace, introduce nitrogen gas and stir, while adding 0.15 kg of phosphorus copper master alloy. The refining temperature is 1210℃ and the refining time is 25 minutes.

[0073] S4 Phosphorus Addition and Rare Earth Modification: Add 0.008 kg of rare earth element yttrium and 0.2 kg of phosphorus copper master alloy to the refined melt, control the phosphorus content to 0.0055 wt%, and stir evenly;

[0074] S5 casting: The melt temperature is reduced to 1115℃, and the upward continuous casting process is adopted;

[0075] S6 Cooling: The cast phosphor bronze rod is cooled by ketone-hydrazine condensation coolant to obtain a high-purity phosphor bronze rod.

[0076] The pickling of S1 uses a sulfuric acid solution with a mass percentage of 8%.

[0077] The composite refining agent is composed of 30 wt% quartz sand, 25 wt% sodium carbonate, 20 wt% fluorite, 15 wt% rare earth elements, and 10 wt% titanium boride.

[0078] The rare earth element in the composite refining agent is a mixture of lanthanum and cerium in a mass ratio of 1:1.

[0079] The nitrogen flow rate for the S3 refining process is 8 L / min.

[0080] The phosphorus content in the S3 phosphorus copper master alloy is 18 wt%.

[0081] The S5 casting speed is 1.1 m / min.

[0082] The cast phosphor bronze rod needs to undergo online eddy current testing to remove surface defects.

[0083] The method for preparing the ketone-hydrazine condensation coolant is as follows:

[0084] Mix 25 kg of acetone, 0.5 kg of tetrahydrothiophene-3-one, 1.5 kg of isopropyl phosphate, and 0.5 kg of lanthanum isopropoxide. Add 0.2 kg of acetic acid and react at 55 °C for 2 hours. Then add 25 kg of propylene glycol, 150 kg of deionized water, and 1.1 kg of boron nitride nanosheets. Disperse the mixture by ultrasonication for 45 minutes to obtain a ketone-hydrazine condensation cooling liquid.

[0085] Example 4

[0086] A process for purifying waste copper to prepare high-conductivity, high-purity phosphor bronze rods, comprising the following steps:

[0087] S1 Pretreatment: The waste copper is crushed to a particle size of 5mm, ferromagnetic impurities are removed by magnetic separation, and then surface oil and oxides are removed by acid washing and drying.

[0088] S2 Smelting: 90kg of pretreated scrap copper is put into a medium-frequency induction furnace, fueled by natural gas, and heated to 1200℃ to melt. 0.5kg of composite refining agent is added, stirred for 15 minutes, and allowed to stand to remove slag.

[0089] S3 Refining: Transfer the melt to a refining furnace, introduce nitrogen gas and stir, while adding 0.2 kg of phosphorus copper master alloy. The refining temperature is 1220℃ and the refining time is 30 minutes.

[0090] S4 Phosphorus Addition and Rare Earth Modification: Add 0.01 kg of rare earth element yttrium and 0.1 kg of phosphorus copper master alloy to the refined melt, control the phosphorus content to 0.006 wt%, and stir evenly;

[0091] S5 casting: The melt temperature is reduced to 1120℃, and the upward continuous casting process is adopted;

[0092] S6 Cooling: The cast phosphor bronze rod is cooled by ketone-hydrazine condensation coolant to obtain a high-purity phosphor bronze rod.

[0093] The pickling of S1 uses a sulfuric acid solution with a mass percentage of 10%.

[0094] The composite refining agent is composed of 30 wt% quartz sand, 25 wt% sodium carbonate, 20 wt% fluorite, 15 wt% rare earth elements, and 10 wt% titanium boride.

[0095] The rare earth element in the composite refining agent is a mixture of lanthanum and cerium in a mass ratio of 1:1.

[0096] The nitrogen flow rate for the S3 refining process is 10 L / min.

[0097] The phosphorus content in the S3 phosphorus copper master alloy is 20 wt%.

[0098] The S5 casting speed is 1.2 m / min.

[0099] The cast phosphor bronze rod needs to undergo online eddy current testing to remove surface defects.

[0100] The method for preparing the ketone-hydrazine condensation coolant is as follows:

[0101] 27 kg of acetone, 0.7 kg of tetrahydrothiophene-3-one, 2 kg of isopronicohydrazine phosphate, and 0.6 kg of lanthanum isopropoxide were mixed and 0.3 kg of acetic acid was added. The mixture was reacted at 60 °C for 3 hours. Then, 26 kg of propylene glycol, 160 kg of deionized water, and 1.2 kg of boron nitride nanosheets were added and the mixture was ultrasonically dispersed for 50 minutes to obtain a ketone-hydrazine condensation cooling liquid.

[0102] Comparative Example 1

[0103] A process for purifying waste copper to prepare high-conductivity, high-purity phosphor bronze rods, comprising the following steps:

[0104] S1 Pretreatment: The waste copper is crushed to a particle size of 20mm, ferromagnetic impurities are removed by magnetic separation, and then surface oil and oxides are removed by acid washing and drying.

[0105] S2 Smelting: 60kg of pretreated scrap copper is put into a medium-frequency induction furnace, fueled by natural gas, and heated to 1150℃ to melt. 0.1kg of composite refining agent is added, stirred for 10 minutes, and allowed to stand to remove slag.

[0106] S3 Refining: Transfer the melt to a refining furnace, introduce nitrogen gas and stir, while adding 0.07 kg of phosphorus copper master alloy. The refining temperature is 1180℃ and the refining time is 20 minutes.

[0107] S4 Phosphorus Addition and Rare Earth Modification: Add 0.005 kg of rare earth element yttrium and 0.03 kg of phosphorus copper master alloy to the refined melt, control the phosphorus content to 0.0045 wt%, and stir evenly;

[0108] S5 casting: The melt temperature is reduced to 1100℃, and the upward continuous casting process is adopted;

[0109] S6 Cooling: The cast phosphor bronze rod is cooled by ketone-hydrazine condensation coolant to obtain a high-purity phosphor bronze rod.

[0110] The pickling of S1 uses a sulfuric acid solution with a mass percentage of 5%.

[0111] The composite refining agent is composed of 30 wt% quartz sand, 25 wt% sodium carbonate, 20 wt% fluorite, 15 wt% rare earth elements, and 10 wt% titanium boride.

[0112] The rare earth element in the composite refining agent is a mixture of lanthanum and cerium in a mass ratio of 1:1.

[0113] The nitrogen flow rate for the S3 refining process is 5 L / min.

[0114] The phosphorus content in the S3 phosphorus copper master alloy is 15 wt%.

[0115] The S5 casting speed is 0.8 m / min.

[0116] The cast phosphor bronze rod needs to undergo online eddy current testing to remove surface defects.

[0117] The method for preparing the ketone-hydrazine condensation coolant is as follows:

[0118] Mix 15 kg of acetone and 0.2 kg of isopropyl phosphate, add 0.1 kg of acetic acid, react at 50 °C for 1 hour, then add 22 kg of propylene glycol, 130 kg of deionized water and 0.8 kg of boron nitride nanosheets, and ultrasonically disperse for 25 minutes to obtain a ketone-hydrazine condensation cooling liquid.

[0119] Comparative Example 2

[0120] A process for purifying waste copper to prepare high-conductivity, high-purity phosphor bronze rods, comprising the following steps:

[0121] S1 Pretreatment: The waste copper is crushed to a particle size of 20mm, ferromagnetic impurities are removed by magnetic separation, and then surface oil and oxides are removed by acid washing and drying.

[0122] S2 Smelting: 60kg of pretreated scrap copper is put into a medium-frequency induction furnace, fueled by natural gas, and heated to 1150℃ to melt. 0.1kg of composite refining agent is added, stirred for 10 minutes, and allowed to stand to remove slag.

[0123] S3 Refining: Transfer the melt to a refining furnace, introduce nitrogen gas and stir, while adding 0.07 kg of phosphorus copper master alloy. The refining temperature is 1180℃ and the refining time is 20 minutes.

[0124] S4 Phosphorus Addition and Rare Earth Modification: Add 0.005 kg of rare earth element yttrium and 0.03 kg of phosphorus copper master alloy to the refined melt, control the phosphorus content to 0.0045 wt%, and stir evenly;

[0125] S5 casting: The melt temperature is reduced to 1100℃, and the upward continuous casting process is adopted;

[0126] S6 Cooling: The cast phosphor bronze rod is cooled by ketone-hydrazine condensation coolant to obtain a high-purity phosphor bronze rod.

[0127] The pickling of S1 uses a sulfuric acid solution with a mass percentage of 5%.

[0128] The composite refining agent is composed of 30 wt% quartz sand, 25 wt% sodium carbonate, 20 wt% fluorite, 15 wt% rare earth elements, and 10 wt% titanium boride.

[0129] The rare earth element in the composite refining agent is a mixture of lanthanum and cerium in a mass ratio of 1:1.

[0130] The nitrogen flow rate for the S3 refining process is 5 L / min.

[0131] The phosphorus content in the S3 phosphorus copper master alloy is 15 wt%.

[0132] The S5 casting speed is 0.8 m / min.

[0133] The cast phosphor bronze rod needs to undergo online eddy current testing to remove surface defects.

[0134] The method for preparing the ketone-hydrazine condensation coolant is as follows:

[0135] Mix 15 kg of acetone, 0.2 kg of isopropyl phosphate, and 0.2 kg of lanthanum isopropoxide, add 0.1 kg of acetic acid, react at 50 °C for 1 hour, then add 22 kg of propylene glycol, 130 kg of deionized water, and 0.8 kg of boron nitride nanosheets, and ultrasonically disperse for 25 minutes to obtain a ketone-hydrazine condensation cooling liquid.

[0136] Comparative Example 3

[0137] A process for purifying waste copper to prepare high-conductivity, high-purity phosphor bronze rods, comprising the following steps:

[0138] S1 Pretreatment: The waste copper is crushed to a particle size of 20mm, ferromagnetic impurities are removed by magnetic separation, and then surface oil and oxides are removed by acid washing and drying.

[0139] S2 Smelting: 60kg of pretreated scrap copper is put into a medium-frequency induction furnace, fueled by natural gas, and heated to 1150℃ to melt. 0.1kg of composite refining agent is added, stirred for 10 minutes, and allowed to stand to remove slag.

[0140] S3 Refining: Transfer the melt to a refining furnace, introduce nitrogen gas and stir, while adding 0.07 kg of phosphorus copper master alloy. The refining temperature is 1180℃ and the refining time is 20 minutes.

[0141] S4 Phosphorus Addition and Rare Earth Modification: Add 0.005 kg of rare earth element yttrium and 0.03 kg of phosphorus copper master alloy to the refined melt, control the phosphorus content to 0.0045 wt%, and stir evenly;

[0142] S5 casting: The melt temperature is reduced to 1100℃, and the upward continuous casting process is adopted;

[0143] S6 Cooling: The cast phosphor bronze rod is cooled by ketone-hydrazine condensation coolant to obtain a high-purity phosphor bronze rod.

[0144] The pickling of S1 uses a sulfuric acid solution with a mass percentage of 5%.

[0145] The composite refining agent is composed of 30 wt% quartz sand, 25 wt% sodium carbonate, 20 wt% fluorite, 15 wt% rare earth elements, and 10 wt% titanium boride.

[0146] The rare earth element in the composite refining agent is a mixture of lanthanum and cerium in a mass ratio of 1:1.

[0147] The nitrogen flow rate for the S3 refining process is 5 L / min.

[0148] The phosphorus content in the S3 phosphorus copper master alloy is 15 wt%.

[0149] The S5 casting speed is 0.8 m / min.

[0150] The cast phosphor bronze rod needs to undergo online eddy current testing to remove surface defects.

[0151] The method for preparing the ketone-hydrazine condensation coolant is as follows:

[0152] Mix 15 kg of acetone, 0.05 kg of tetrahydrothiophene-3-one, and 0.2 kg of isopropyl phosphate, add 0.1 kg of acetic acid, react at 50 °C for 1 hour, then add 22 kg of propylene glycol, 130 kg of deionized water, and 0.8 kg of boron nitride nanosheets, and ultrasonically disperse for 25 minutes to obtain a ketone-hydrazine condensation cooling solution.

[0153] The test results of the examples and comparative examples are shown in Table 1.

[0154] Table 1

[0155] Electrical conductivity (%IACS) Phosphorus content (%) Oxygen content (ppm) Example 1 98.5 0.0060 9 Example 2 98.6 0.0056 8 Example 3 98.9 0.0049 6 Example 4 99.0 0.0045 5 Comparative Example 1 88.3 0.0286 25 Comparative Example 2 95.5 0.0153 17 Comparative Example 3 96.1 0.0137 14

[0156] Through data analysis of the above embodiments and comparative examples, the present invention achieves efficient purification of waste copper. The prepared phosphor bronze rod has advantages such as high electrical conductivity and low oxygen content, and is suitable for the field of high-end electrical materials.

[0157] 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 process for purifying waste copper to prepare high-conductivity, high-purity phosphor bronze rods, characterized in that: The operating steps are as follows: S1 Pretreatment: The scrap copper is crushed to a particle size of 5-20mm, ferromagnetic impurities are removed by magnetic separation, and then surface oil and oxides are removed by acid washing and drying. S2 smelting: 60-90 parts by weight of pretreated scrap copper are put into a medium frequency induction furnace, fueled by natural gas, and heated to 1150-1200℃ to melt. 0.1-0.5 parts by weight of composite refining agent are added, stirred for 10-15 minutes, and allowed to stand to remove slag. S3 Refining: Transfer the melt to a refining furnace, introduce nitrogen gas and stir, while adding 0.07-0.2 parts by mass of phosphorus copper master alloy. The refining temperature is 1180-1220℃ and the refining time is 20-30 minutes. S4 Phosphorus Addition and Rare Earth Modification: Add 0.005-0.01 parts by weight of rare earth element yttrium and 0.03-0.1 parts by weight of phosphorus copper master alloy to the refined melt, control the phosphorus content to be 0.0045-0.006 wt%, and stir evenly; S5 casting: The melt temperature is reduced to 1100-1120℃, and the upward continuous casting process is adopted; S6 Cooling: The cast phosphor bronze rod is cooled by ketone-hydrazine condensation coolant to obtain high-purity phosphor bronze rod; The ketone-hydrazine condensation coolant is prepared by reacting acetone, tetrahydrothiophene-3-one, isopropanenic acid hydrazine, lanthanum isopropoxide, acetic acid, propylene glycol, and boron nitride nanosheets.

2. The process for purifying waste copper to prepare high-conductivity, high-purity phosphor bronze rods according to claim 1, characterized in that: The pickling of S1 uses a sulfuric acid solution with a mass percentage of 5-10%.

3. The process for purifying waste copper to prepare high-conductivity, high-purity phosphor bronze rods according to claim 1, characterized in that: The composite refining agent is composed of 30 wt% quartz sand, 25 wt% sodium carbonate, 20 wt% fluorite, 15 wt% rare earth elements, and 10 wt% titanium boride.

4. The process for purifying waste copper to prepare high-conductivity, high-purity phosphor bronze rods according to claim 3, characterized in that: The rare earth element in the composite refining agent is a mixture of lanthanum and cerium in a mass ratio of 1:

1.

5. The process for purifying waste copper to prepare high-conductivity, high-purity phosphor bronze rods according to claim 1, characterized in that: The flow rate of nitrogen gas used in the S3 refining process is 5-10 L / min.

6. The process for purifying waste copper to prepare high-conductivity, high-purity phosphor bronze rods according to claim 1, characterized in that: The phosphorus content in the S3 phosphorus copper master alloy is 15-20 wt%.

7. The process for purifying waste copper to prepare high-conductivity, high-purity phosphor bronze rods according to claim 1, characterized in that: The S5 casting speed is 0.8-1.2 m / min.

8. The process for purifying waste copper to prepare high-conductivity, high-purity phosphor bronze rods according to claim 1, characterized in that: The cast phosphor bronze rod needs to undergo online eddy current testing to remove surface defects.

9. The process for purifying waste copper to prepare high-conductivity, high-purity phosphor bronze rods according to claim 1, characterized in that: The method for preparing the ketone-hydrazine condensation coolant is as follows: According to the mass fraction, 15-27 parts of acetone, 0.05-0.7 parts of tetrahydrothiophene-3-one, 0.2-2 parts of isopropyl phosphate, and 0.2-0.6 parts of lanthanum isopropoxide are mixed, and 0.1-0.3 parts of acetic acid are added. The mixture is reacted at 50-60℃ for 1-3 hours, and then 22-26 parts of propylene glycol, 130-160 parts of deionized water, and 0.8-1.2 parts of boron nitride nanosheets are added. The mixture is ultrasonically dispersed for 25-50 minutes to obtain a ketone-hydrazine condensation cooling liquid.