A method for processing copper-nickel alloy return material

Abstract

The present invention provides a method for processing copper-nickel alloy return materials, which belongs to the technical field of non-ferrous metal processing. The processing method comprises the following steps: step S1. classifying and processing the return materials of the same grade according to shape and size, and performing pretreatment; step S2. performing shot blasting on the return materials; step S3. adding the return materials to the pickling solution for pickling, removing the oxide scale and rust on the surface of the return materials, and then rinsing; step S4. drying the return materials; step S5. heating the return materials under a vacuum environment to melt the return materials into a molten liquid, then adding a deoxidizer and a desulfurizer to the molten liquid, blowing argon gas into the molten liquid for degassing, then pouring the molten liquid into a mold for cooling, and finally performing chemical composition detection. The processing method for copper-nickel alloy return materials of the present invention is through classification, pretreatment, shot blasting, pickling, rinsing, drying, vacuum degassing and smelting, and the return materials after treatment have low impurity content and small component fluctuation.

Description

Technical Field

[0001] The invention relates to the technical field of nonferrous metal processing, and in particular to a method for processing copper-nickel alloy return materials. Background Art

[0002] With the continuous development of industrial production, the amount of returned copper-nickel alloy materials generated in the production process is increasing. If these returned materials are directly discarded, it will not only waste resources but also may cause environmental pollution. Therefore, it is particularly important to develop an efficient and environmentally friendly method for processing returned copper-nickel alloy materials.

[0003] There are some technical difficulties in the recycling process of copper-nickel alloy return materials, mainly including the following aspects: high impurity content: the return materials often contain high impurity elements, such as sulfur, phosphorus, etc. These impurity elements will seriously affect the performance and processing performance of copper-nickel alloy; large composition fluctuations: due to the complex source of the return materials, their composition fluctuates greatly, and it is difficult to ensure the quality and stability of the recycled products; complex recycling process: traditional recycling processes are often cumbersome, energy-intensive, and inefficient, and it is difficult to meet the needs of modern industrial production. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a method for processing copper-nickel alloy return materials to solve the problems of high impurity content, large component fluctuations and complex recycling process of return materials in conventional processes.

[0005] The technical solution adopted by the present invention is: A method for processing copper-nickel alloy return material, comprising the following steps: Step S1. Classify the returned materials of the same brand according to shape and size, and perform pretreatment; Step S2. Shot blasting the returned material after pretreatment in step S1; Step S3. adding the return material after the shot blasting treatment in step S2 into the pickling solution for pickling to remove the oxide scale and rust on the surface of the return material, and then rinsing to remove the residual pickling solution on the surface of the return material; Step S4. Drying the returned material after the acid washing in step S3; Step S5. Add the return material dried in step S4 into a crucible, and place the crucible in a smelting furnace and heat it under vacuum to melt the return material into a molten liquid. Then, add a deoxidizer and a desulfurizer to the molten liquid, and blow argon gas into the molten liquid for degassing. Then, pour the molten liquid into a mold to cool it, and finally perform a chemical composition test.

[0006] Preferably, in the method for processing copper-nickel alloy return materials, the return materials of the same grade in step S1 include pipes, scraps and plates.

[0007] Preferably, the processing method of the copper-nickel alloy return material, wherein: the pipes are classified and processed according to the outer diameter size, and the classified pipe return materials include three categories: outer diameter <16mm, 16mm < outer diameter <35mm and outer diameter >35mm, and the pretreatment of the pipe return materials is specifically: the pipes are sawed, and the pipes with an outer diameter <16mm are sawed to a length of 5-8cm, the pipes with an outer diameter of 16mm <outer diameter <35mm are sawed to a length of 8-15cm, and the pipes with an outer diameter >35mm are sawed to a length of 15-20cm.

[0008] Preferably, the method for processing the copper-nickel alloy return material, wherein: the plates are classified and processed according to their length, and the plate return materials after classification include two categories: maximum length <20cm and maximum length >20cm, and the pretreatment of the plate return materials is specifically: the plate return materials with a maximum length >20cm are sheared by a shearing machine into plate-shaped or block-shaped plates with a maximum length <20cm.

[0009] Preferably, the method for processing the copper-nickel alloy return material, wherein: the number of shot blasting treatments in step S2 is 2 to 4 times, the single shot blasting time is 5 to 8 minutes, when the Ni content of the return material is greater than 20%, the shot blasting speed is 50 to 80 m / s; when the Ni content of the return material is less than 20%, the shot blasting speed is 30 to 50 m / s.

[0010] Preferably, in the method for processing the copper-nickel alloy return material, the pickling solution in step S3 comprises water, nitric acid and hydrochloric acid in a volume ratio of 20-25:5-7:1, the nitric acid concentration is 60%-70%, and the hydrochloric acid concentration is 30%-50%.

[0011] Preferably, in the method for processing the copper-nickel alloy return material, the pickling temperature in step S3 is 30-55° C. and the pickling time is 60-15 min.

[0012] Preferably, in the method for processing the copper-nickel alloy return material, the vacuum degree in step S5 is 50-100 Pa and the smelting temperature is 1300-1380°C.

[0013] Preferably, in the method for processing the copper-nickel alloy return material, the number of degassing in step S5 is 1 to 3 times, and the time of each degassing is 3 to 5 minutes.

[0014] Advantages of the present invention: The processing method of the copper-nickel alloy return material of the present invention comprises the following steps: firstly, the return material is classified according to brand, shape and size; the return material of the same brand but different shapes and sizes is pretreated to a suitable size; impurities attached to the surface are removed by shot blasting, surface oxides and impurities are further removed by pickling, and the purpose of physical cleaning is achieved after rinsing and drying; finally, vacuum degassing and smelting are adopted to reduce the impurity content, so as to realize high efficiency, recovery and reuse of the copper-nickel alloy return material, obtain pure return material for further copper-nickel alloy smelting, and have the advantages of low impurity content of the return material, small component fluctuation and simple recovery process. DETAILED DESCRIPTION

[0015] The present invention will be further described below in conjunction with specific embodiments.

[0016] Example 1 A method for processing returned BFe10-1-1 copper-nickel alloy pipes with a diameter of 25*2, comprising the following steps: Step S1. Classification: Classify and pre-treat copper-nickel alloy pipes with a specification of φ25*2 and a grade of BFe10-1-1. The pre-treat is as follows: sawing is performed on pipes with a length of more than 20 cm to a length of 15 cm; Step S2. Shot blasting: The return material after the pretreatment in step S1 is shot blasted with ceramic shot, and the return material is hung on the ceramic shot hanger to ensure that the gap between the return materials is suitable for the shot blasting material to pass through. The shot blasting speed is 50 m / s, and the shot blasting is performed twice, and the single shot blasting time is 8 minutes; Step S3. Pickling: Add the return material after the shot blasting treatment in step S2 into the pickling solution for pickling to remove the scale and rust on the surface of the return material; the pickling solution is prepared according to the volume ratio of water: nitric acid: hydrochloric acid of 25:5:1, the nitric acid concentration before adding water is 60%, the hydrochloric acid concentration is 50%, the pickling temperature is 45°C, the pickling time is 20 minutes, and then rinse to clean the surface of the return material and remove the residual pickling solution; Step S4. Drying: drying the returned material after the acid washing in step S3 naturally; Step S5. Vacuum degassing smelting: add the return material after drying in step S4 into a crucible, and put the crucible into a smelting furnace, evacuate to 50 Pa, heat the smelting furnace under a vacuum environment to melt the return material into a molten liquid, then add 0.1% of the mass of the return material as phosphor copper as a deoxidizer and 0.002% of the mass of the return material as a nickel-magnesium alloy as a desulfurizer to the molten liquid, and blow argon into the molten liquid for degassing. The degassing times are 2 times, and the degassing time for each time is 3 minutes. The casting temperature is 1320°C. After the smelting is completed, the molten liquid is poured into a mold for cooling, and finally the chemical composition is detected and classified according to different grades. The chemical composition detection results of Example 1 are shown in Table 1.

[0017] Table 1

[0018] It can be seen from Table 1 above that the φ25*2 copper-nickel alloy pipe return material with a specification of BFe10-1-1 after being treated in Example 1 has uniform chemical composition and low impurity content, which meets the chemical composition requirements of GB / T 5231 for BFe10-1-1.

[0019] Example 2 A method for processing irregular BFe30-1-1 copper-nickel alloy plate return material, comprising the following steps: Step S1. Classification: Classify and pre-treat the copper-nickel alloy plates with the grade BFe30-1-1. The pre-treating is as follows: Use a shearing machine to cut the copper-nickel alloy plate return material with a maximum length of more than 20 cm into 15 cm blocks; Step S2. Shot blasting: The return material after the pretreatment in step S1 is shot blasted with ceramic shot, and the return material is hung on the ceramic shot hanger to ensure that the gap between the return materials is suitable for the shot blasting material to pass through. The shot blasting speed is 70 m / s, and the shot blasting is performed 4 times. The single shot blasting time is 8 minutes; Step S3. Pickling: Add the return material after the shot blasting treatment in step S2 into the pickling solution for pickling to remove the oxide scale and rust on the surface of the return material; the pickling solution is prepared according to the volume ratio of water: nitric acid: hydrochloric acid of 20:4:1, the nitric acid concentration before adding water is 70%, the hydrochloric acid concentration is 50%, the pickling temperature is 50°C, the pickling time is 60 minutes, and then rinse to clean the surface of the return material and remove the residual pickling solution; Step S4. Drying: drying the returned material after the acid washing in step S3 naturally; Step S5. Vacuum degassing smelting: add the return material after drying in step S4 into a crucible, and place the crucible into a smelting furnace, evacuate to 50 Pa, heat the smelting furnace under a vacuum environment to melt the return material into a molten liquid, then add 0.15% of the mass of the return material as phosphor copper as a deoxidizer and 0.003% of the mass of the return material as a nickel-magnesium alloy as a desulfurizer to the molten liquid, and blow argon into the molten liquid for degassing, the argon blowing times are 3 times, each time for 5 minutes, the casting temperature is 1380°C, after the smelting is completed, the melt is poured into a mold to cool, and finally the chemical composition is detected and classified according to different grades. The chemical composition detection results of Example 2 are shown in Table 2.

[0020] Table 2

[0021] It can be seen from Table 2 above that the irregular BFe30-1-1 copper-nickel alloy plate returned after the treatment in Example 2 has uniform chemical composition and low impurity content, which meets the requirements of GB / T 5231 for the chemical composition of BFe30-1-1.

[0022] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A method for processing copper-nickel alloy return material, characterized in that: The following steps are involved: Step S1. Classify the returned materials of the same brand according to shape and size, and perform pretreatment; Step S2. Shot blasting the returned material after pretreatment in step S1; Step S3. adding the return material after the shot blasting treatment in step S2 into the pickling solution for pickling to remove the oxide scale and rust on the surface of the return material, and then rinsing to remove the residual pickling solution on the surface of the return material; Step S4. Drying the returned material after the acid washing in step S3; Step S5. Add the return material dried in step S4 into a crucible, and place the crucible in a smelting furnace and heat it under vacuum to melt the return material into a molten liquid, then add a deoxidizer and a desulfurizer into the molten liquid, and blow argon gas into the molten liquid for degassing, then pour the molten liquid into a mold for cooling, and finally perform a chemical composition test; In step S5, the vacuum degree is 50-100 Pa, the melting temperature is 1300-1380° C., the degassing times are 1-3 times, and the degassing time for each time is 3-5 minutes.

2. The method for processing copper-nickel alloy return material according to claim 1, characterized in that: The returned materials of the same grade in step S1 include pipes, scraps and plates.

3. The method for processing copper-nickel alloy return material according to claim 2, characterized in that: The pipes are classified and processed according to their outer diameters. After classification, the returned pipes include three categories: outer diameter <16mm, 16mm < outer diameter <35mm and outer diameter >35mm. The pretreatment of the returned pipes is specifically as follows: the pipes are sawed, and the pipes with outer diameter <16mm are sawed to a length of 5-8cm, the pipes with outer diameter 16mm < outer diameter <35mm are sawed to a length of 8-15cm, and the pipes with outer diameter >35mm are sawed to a length of 15-20cm.

4. The method for processing copper-nickel alloy return material according to claim 2, characterized in that: The plates are classified according to their lengths. After classification, the returned plates include two categories: those with a maximum length of less than 20 cm and those with a maximum length of more than 20 cm. The pretreatment of the returned plates is specifically as follows: the returned plates with a maximum length of more than 20 cm are cut into plates or blocks with a maximum length of less than 20 cm by a shearing machine.

5. The method for processing copper-nickel alloy return material according to claim 1, characterized in that: The number of shot blasting treatments in step S2 is 2 to 4 times, and the single shot blasting time is 5 to 8 minutes; when the Ni content of the returned material is greater than 20%, the shot blasting speed is 50 to 80 m / s; when the Ni content of the returned material is less than 20%, the shot blasting speed is 30 to 50 m / s.

6. The method for processing copper-nickel alloy return material according to claim 1, characterized in that: The pickling solution in step S3 includes water, nitric acid and hydrochloric acid in a volume ratio of 20-25:5-7:

1.

7. The method for processing copper-nickel alloy return material according to claim 1, characterized in that: In step S3, the pickling temperature is 30-55° C., and the pickling time is 60-15 min.

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