Cleaning method, cleaning agent and cleaning device for oxygen-free copper for superconducting material

Abstract

The invention discloses a cleaning method, a cleaning agent and a cleaning device for oxygen-free copper for a superconducting material, and belongs to the technical field of superconducting wire raw material pretreatment. According to the cleaning method, gas-phase steam generated by volatilization of a cleaning agent acts on the surface of an oxygen-free copper material, oil removal is achieved, and the volume percentage ratio of dimethyl carbonate to isopropanol in the cleaning agent is (75-80): (20-25). The gas-phase steam of the cleaning agent has high emulsibility and permeability, a good cleaning effect can be achieved on materials which are complex in structure and cannot be cleaned manually, and the cleaned oxygen-free copper materials are stable in quality and good in effect. The cleaning agent disclosed by the invention is combined with a gas-phase steam cleaning process, so that a relatively excellent oil removal effect is achieved, and the problems that an existing cleaning technology is relatively high in dependence on a mechanical wiping technology and an ultrasonic technology and the consistency of oil removal quality is insufficient are solved.

Description

Technical Field

[0001] The invention belongs to the technical field of superconducting wire raw material pretreatment, and relates to a cleaning method, a cleaning agent and a cleaning device for oxygen-free copper used for superconducting materials. Background Art

[0002] Oxygen-free copper is a high-purity copper material with an extremely low oxygen content, usually not exceeding 0.003%, and a low total impurity content. This high-purity property makes oxygen-free copper have good electrical and thermal conductivity, and is often used as an important component of superconducting wires, especially as a substrate or coating material for superconducting materials. The surface quality of oxygen-free copper has a great influence on the performance of superconducting wires. Any small pollution or defect may affect the superconducting performance of superconducting wires. Therefore, the surface quality requirements of oxygen-free copper before assembly are high. It is usually required that its surface presents the natural color of oxygen-free copper pink, bright and uniform. Thorough degreasing of oxygen-free copper before assembly is a necessary condition to ensure the stability of superconducting material processing, bonding and stretching process.

[0003] At present, the commonly used oxygen-free copper degreasing methods include: soaking in metal cleaning agents or organic solvents, and assisted by mechanical wiping or ultrasonic cleaning. However, since the oxygen-free copper material itself is easy to bend and damage, the strong vibration caused by traditional mechanical wiping or ultrasonic action and the blasting of ultrasonic waves in the solution are easy to damage the surface of the material, and for oxygen-free copper materials with complex structures, there are problems such as difficulty in manual operation, low efficiency, and inability to ensure the consistency of surface quality. Existing cleaning agents often contain acidic or alkaline components. These components will corrode the surface of oxygen-free copper if used for a long time or at too high a concentration, resulting in white spots or other forms of damage on the surface of the copper tube, or the chemical reaction and emulsification properties of the cleaning agent are poor, resulting in insufficient degreasing effect, residual cleaning agent and tiny oil droplets are retained on the surface of the material, and then enter the pickling solution, reducing the quality of the pickling solution, increasing the viscosity of the pickling solution, affecting the solubility of the pickling solution, and affecting the cleaning process and cleaning quality. Therefore, it is of great significance to provide a degreasing process that avoids material damage, has good degreasing effect, and has uniform material surface quality, as well as a cleaning agent with better cleaning quality for the application of oxygen-free copper in superconducting materials. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a cleaning method, cleaning agent and cleaning device for oxygen-free copper for superconducting materials. The above cleaning method allows the gas phase steam generated by the volatilization of the cleaning agent to act on the surface of the oxygen-free copper material to achieve oil removal. The volume percentage of dimethyl carbonate and isopropanol in the cleaning agent is 75~80:20~25. The gas phase steam of the cleaning agent of the present invention has strong emulsification and permeability, and can produce a good cleaning effect on materials with complex structures that cannot be cleaned manually. The oxygen-free copper material after cleaning has a good quality stability effect. The cleaning agent of the present invention has a better oil removal effect in combination with the gas phase steam cleaning process, which solves the problem that the existing cleaning technology relies heavily on mechanical wiping and ultrasonic technology and the oil removal quality consistency is insufficient.

[0005] To achieve the technical purpose of the present invention, on the one hand, the present invention provides a method for cleaning oxygen-free copper for superconducting materials, which specifically comprises the following steps: S1: slowly add isopropyl alcohol into dimethyl carbonate and stir evenly to obtain a cleaning agent, wherein the volume percentage of dimethyl carbonate and isopropyl alcohol is 75-80:20-25.

[0006] S2: Disperse oxygen-free copper evenly in the cleaning tank, heat the cleaning agent, and volatilize the gas phase steam to remove the oil on the surface of the oxygen-free copper. The heating temperature is 84~88℃, and the gas phase steam cleaning time is 8~12min.

[0007] S3: Wash and dry the oxygen-free copper rod after the S2 vapor phase steam cleaning treatment at a temperature of 55-65°C for a drying time of 120-240 minutes.

[0008] On the other hand, the present invention claims protection for an oxygen-free copper cleaning agent, wherein the effective ingredients are composed of dimethyl carbonate and isopropyl alcohol, and the volume percentage of dimethyl carbonate and isopropyl alcohol in the oxygen-free copper cleaning agent is 75-80:20-25.

[0009] In addition, the present invention seeks protection for a cleaning device for implementing the above-mentioned cleaning method, wherein the cleaning device includes a solvent area, a material area and a condensation area from bottom to top.

[0010] Furthermore, the solvent area is used to store and heat the cleaning agent; the material area is used to discharge the oxygen-free copper material; the condensation area is used to condense and recover the gas phase vapor of the cleaning agent; a condensation device is arranged around the condensation area, and the condensation device is a disc-shaped condenser tube, and the disc-shaped condenser tube is an oxygen-free copper tube with a wall thickness of 1mm, Φ15.0mm, a total length of 45m, and is wound 20 times.

[0011] Furthermore, the size of the cleaning device tank is 800mm (length) × 300mm (width) × 1200mm (height), the solvent area is the area from the bottom of the cleaning device to the 300mm height of the device, the material area is the area from 400 to 700mm height of the cleaning device, and the condensation area is the area from 800 to 1100mm height of the cleaning device.

[0012] Compared with the prior art, the technical solution provided by the present invention has at least the following beneficial effects or advantages: (1) The cleaning agent provided by the present invention has dimethyl carbonate and isopropyl alcohol as active ingredients, and the volume percentage of dimethyl carbonate and isopropyl alcohol is 75~80:20~25. The raw materials of the cleaning agent are all low-toxic chemical solvents, which have the advantages of safety and environmental protection. The cleaning agent has the characteristics of narrow boiling point range, low viscosity, fast evaporation rate, etc. It can be quickly vaporized and evaporated at 84~88℃, and the viscosity of the cleaning agent steam condensate is low and the fluidity is strong. The cleaning agent of the present invention does not chemically react with the copper body material and will not cause changes in the internal organizational structure of the copper.

[0013] (2) The cleaning agent of the present invention has a better degreasing effect in combination with the gas phase steam cleaning process, which solves the problem that the existing cleaning technology relies heavily on mechanical wiping and ultrasonic technology and the degreasing quality is not consistent enough, and will not cause damage to the material surface or structural bending and damage. The gas phase steam of the cleaning agent has strong emulsification and permeability, and reacts strongly with grease. Its strong permeability can produce a better cleaning effect on materials with complex structures that cannot be cleaned manually, thereby ensuring the cleaning quality. The present invention soaked oxygen-free copper in a low-temperature cleaning agent and found that the degreasing effect was not good. The reason can be analyzed as follows: the penetration and emulsification ability of the cleaning agent has high requirements on temperature conditions, and the mixed solvent can greatly improve the emulsification ability under high-temperature gas phase conditions.

[0014] (3) The quality of the oxygen-free copper material after cleaning by the cleaning method of the present invention is stable and has good effect. The present invention immerses the cleaned oxygen-free copper material in water, and observes that a layer of water film is continuously distributed on the surface of the material in a short time. The present invention wipes the cleaned oxygen-free copper material with a thick cloth dipped in isopropyl alcohol, and finds that the surface of the material is cleaned without oil stains or foreign matter. The present invention immerses the cleaned oxygen-free copper material in an inorganic acid solution for pickling, and finds that no oil stains float on the surface of the acid solution.

[0015] (4) After cleaning by the cleaning method of the present invention, the surface cleanliness and purity of oxygen-free copper are greatly improved, meeting the use requirements. Before cleaning, there are many types of impurity elements on the surface of the oxygen-free copper rod and the content of impurity elements is high. The weight content of copper is low, which is 20.70%. After cleaning, the surface cleanliness of the oxygen-free copper rod is significantly improved, the types of surface impurity elements are significantly reduced, and only oxygen elements are present, and the content is low. The weight content of copper is high, which is 97.07%.

[0016] (5) The present invention provides a cleaning device in combination with a cleaning method, in which the distance between the condensation area and the bottom is increased, providing sufficient space for the gas phase steam cleaning process, avoiding the negative impact of the condensation area at the top of the device on the formation of high-temperature gas phase steam, and improving the quality and efficiency of material cleaning. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention.

[0018] Figure 1 The structural diagram of the cleaning device is shown in FIG. 1, where 1 is the solvent area, 2 is the material area, and 3 is the condensation area.

[0019] Figure 2 This is a physical picture of the condensation area of ​​the cleaning device.

[0020] Figure 3 This is a physical picture of oxygen-free copper evenly dispersed in the material area.

[0021] Figure 4 This is a physical picture of the oxygen-free copper rod before cleaning.

[0022] Figure 5 This is a physical picture of the oxygen-free copper rod after cleaning. DETAILED DESCRIPTION

[0023] The technical scheme of the present invention is described below in conjunction with the embodiments, but the present invention is not limited to the following embodiments. The experimental methods and detection methods described in each embodiment are conventional methods unless otherwise specified; the reagents and materials described are all commercially available unless otherwise specified.

[0024] Dimethyl carbonate and isopropanol were of analytical grade.

[0025] A method for cleaning oxygen-free copper for superconducting materials comprises the following steps: S1: slowly add isopropyl alcohol into dimethyl carbonate and stir evenly to obtain a cleaning agent, wherein the volume percentage of dimethyl carbonate and isopropyl alcohol is 75-80:20-25.

[0026] S2: Disperse oxygen-free copper evenly in the cleaning tank, heat the cleaning agent, and volatilize the gas phase steam to remove the oil on the surface of the oxygen-free copper. The heating temperature is 84~88℃, and the gas phase steam cleaning time is 8~12min.

[0027] S3: Wash and dry the oxygen-free copper rod after the S2 vapor phase steam cleaning treatment at a temperature of 55-65°C for a drying time of 120-240 minutes.

[0028] Example 1 This embodiment provides a method and a device for cleaning oxygen-free copper for superconducting materials.

[0029] 1. Cleaning device for oxygen-free copper for superconducting materials The structural diagram of the cleaning device is as follows: Figure 1 As shown, the dimensions of the device tank are 800 mm (length) × 300 mm (width) × 1200 mm (height), and the cleaning device includes a solvent area 1, a material area 2 and a condensation area 3.

[0030] Solvent area (from the bottom of the device to the 300mm height area of ​​the device), material area (400~700mm height area of ​​the device) and condensation area (800~1100mm height area of ​​the device). Condensation devices are set around the condensation area. Its main structure is a disc-shaped condenser tube. The condenser tube is an oxygen-free copper tube with a wall thickness of 1mm and Φ15.0mm. The total length is 45m. It is wound 20 times, and each turn is about 2.2m long. The actual picture of the condensation area is as follows Figure 2 shown.

[0031] The condensing device condenses and refluxes the evaporated cleaning agent gas, ensuring the effective recovery of the gas phase solvent and also ensuring the balance of the cleaning agent content at the bottom of the tank.

[0032] 2. The cleaning method of oxygen-free copper for superconducting materials specifically includes the following steps: S1: Clean the solvent area tank, add dimethyl carbonate, then slowly add isopropyl alcohol and slowly stir evenly, the volume percentage of dimethyl carbonate and isopropyl alcohol is 75:25.

[0033] S2: Distribute H30×500mm oxygen-free copper rods evenly in the cleaning tank in the material area ( Figure 3 ), the cleaning agent is heated, and the volatilized gaseous vapor acts on the oil stains on the surface of oxygen-free copper to achieve degreasing. The heating temperature is 84°C, and the gas phase steam cleaning time is 12 minutes.

[0034] S3: The oxygen-free copper rod treated by S2 vapor phase steam cleaning is washed with water and dried at a drying temperature of 55°C for 240 minutes.

[0035] The actual picture of oxygen-free copper rod before cleaning is as follows Figure 4 As shown, the actual picture of the oxygen-free copper rod after cleaning by the cleaning method of the present invention is as follows Figure 5As shown, the scanning electron microscope energy spectrum detection data of the surface of the oxygen-free copper rod before cleaning is shown in Table 1, and the scanning electron microscope energy spectrum detection data of the surface of the oxygen-free copper rod after cleaning by the cleaning method of the present invention is shown in Table 2.

[0036] Table 1: Scanning electron microscope energy spectrum test data of oxygen-free copper rod surface before cleaning

[0037] Table 2: Scanning electron microscope energy spectrum test data of oxygen-free copper rod surface after cleaning

[0038] Depend on Figure 5 It can be seen that the cleaning quality of the cleaning method of the present invention is good. The surface of the oxygen-free copper rod after cleaning is bright, uniform, and natural, without acid marks or water marks, and meets the requirements of superconducting materials for the surface state of oxygen-free copper. The surface protection ability of the oxygen-free copper material after cleaning by the cleaning method of the present invention is strong, and the quality stability effect is good. The present invention immerses the cleaned oxygen-free copper material in water, and observes that a layer of water film will be continuously distributed on the surface of the material in a short time. The present invention wipes the cleaned oxygen-free copper material with a thick cloth dipped in isopropanol, and finds that the surface of the material is cleaned without oil or foreign matter. The present invention immerses the cleaned oxygen-free copper material in an inorganic acid solution (25~30% nitric acid solution, inorganic acid and oil are insoluble) for pickling, and finds that no oil floats on the surface of the acid solution.

[0039] It can be seen from Tables 1 and 2 that before cleaning, there are many types of impurity elements on the surface of the oxygen-free copper rod and the content of impurity elements is high, the weight content of copper is low, which is 20.70%. After cleaning, the cleanliness of the surface of the oxygen-free copper rod is significantly improved, and the types of surface impurity elements are significantly reduced. There is only oxygen element, and the content is low. The weight content of copper is high, which is 97.07%, indicating that the surface cleanliness of oxygen-free copper and the purity of oxygen-free copper are greatly improved after cleaning by the cleaning method of the present invention, which meets the use requirements.

[0040] Example 2 This embodiment provides a method for cleaning oxygen-free copper for superconducting materials, which specifically includes the following steps: S1: Clean the solvent area tank, add dimethyl carbonate, then slowly add isopropyl alcohol and slowly stir evenly, the volume percentage of dimethyl carbonate and isopropyl alcohol is 80:20.

[0041] S2: Distribute H30×500mm oxygen-free copper rods evenly in the cleaning tank in the material area ( Figure 3 ), the cleaning agent is heated, and the volatilized gaseous vapor acts on the oil stain on the surface of oxygen-free copper to achieve degreasing. The heating temperature is 86℃, and the gas phase steam cleaning time is 10 minutes.

[0042] S3: The oxygen-free copper rod treated by S2 gas phase steam cleaning is washed with water and dried at a drying temperature of 60°C and a drying time of 180 minutes.

[0043] The cleaning method of this embodiment has good cleaning quality. The surface of the oxygen-free copper rod after cleaning is bright, uniform, and natural in color, without acid marks or water marks, and meets the requirements of superconducting materials for the surface state of oxygen-free copper.

[0044] Example 2 This embodiment provides a method for cleaning oxygen-free copper for superconducting materials, which specifically includes the following steps: S1: Clean the solvent area tank, add dimethyl carbonate, then slowly add isopropyl alcohol and slowly stir evenly, the volume percentage of dimethyl carbonate and isopropyl alcohol is 78:22.

[0045] S2: Distribute H30×500mm oxygen-free copper rods evenly in the cleaning tank in the material area ( Figure 3 ), the cleaning agent is heated, and the volatilized gas phase steam acts on the oil stains on the surface of oxygen-free copper to achieve degreasing. The heating temperature is 88℃, and the gas phase steam cleaning time is 8 minutes.

[0046] S3: The oxygen-free copper rod treated by S2 gas phase steam cleaning is washed with water and dried at a drying temperature of 65°C and a drying time of 120 minutes.

[0047] The cleaning method of this embodiment has good cleaning quality. The surface of the oxygen-free copper rod after cleaning is bright, uniform, and natural in color, without acid marks or water marks, and meets the requirements of superconducting materials for the surface state of oxygen-free copper.

[0048] Comparative Example 1 The cleaning agent of Example 1 was prepared, and an oxygen-free copper rod of H30×500 mm was immersed in the cleaning agent solution at 20-25° C. for 20 minutes. It was found that the oil stain on the surface of the oxygen-free copper rod did not change significantly or dissolve.

[0049] Comparative Example 2 The cleaning agent of Example 1 was prepared, and a H30×500mm oxygen-free copper rod was immersed in the cleaning agent solution at 60-65°C for 20 minutes. It was found that the oil stains on the surface of the oxygen-free copper rod were dissolved to a certain extent, but the oil removal was still not thorough.

[0050] The embodiments described above are part of the embodiments of the present invention, but not all of them. The detailed description of the embodiments of the present invention is not intended to limit the scope of the invention claimed for protection, but only represents selected embodiments of the present invention. All other embodiments obtained without creative work and related deductions and substitutions made by ordinary technicians in the field under the conditions of the concept of the present invention belong to the scope of protection of the present invention.

Claims

1. A method for cleaning oxygen-free copper, characterized in that: include: A cleaning agent is prepared using dimethyl carbonate and isopropyl alcohol as raw materials; The oxygen-free copper is cleaned and degreased using the gas phase steam of the cleaning agent.

2. The cleaning method according to claim 1, characterized in that: The volume percentage of dimethyl carbonate and isopropyl alcohol in the cleaning agent is 75-80:20-25.

3. The cleaning method according to claim 1, characterized in that: The gas phase vapor of the cleaning agent is obtained by heating the cleaning agent to 84-88°C.

4. The cleaning method according to claim 1, characterized in that: The cleaning and degreasing time is 8 to 12 minutes.

5. The cleaning method according to claim 1, characterized in that: After the cleaning and degreasing, water washing and drying are also performed.

6. The cleaning method according to claim 5, characterized in that: The drying temperature is 55-65° C., and the drying time is 120-240 min.

7. An oxygen-free copper cleaning agent, characterized in that: The oxygen-free copper cleaning agent removes oil on the surface of oxygen-free copper; the effective ingredients of the oxygen-free copper cleaning agent are composed of dimethyl carbonate and isopropyl alcohol.

8. The oxygen-free copper cleaning agent according to claim 7, characterized in that: The volume percentage of dimethyl carbonate and isopropyl alcohol in the oxygen-free copper cleaning agent is 75-80:20-25.

9. A cleaning device, characterized in that: Implementing the cleaning method according to any one of claims 1 to 6, the cleaning device comprises, from bottom to top, a solvent area, a material area and a condensation area; The solvent area is used for storing and heating the cleaning agent; The material area is used to discharge oxygen-free copper materials; The condensation area is used to condense and recover the gas phase steam of the cleaning agent; Condensation devices are arranged around the condensation area, and the condensation devices are disc-shaped condensation tubes, and the disc-shaped condensation tubes are oxygen-free copper tubes.

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