Preparation method and application of up-drawing continuous casting oxygen-free copper rod antioxidant

Abstract

The invention discloses a preparation method of an up-drawing continuous casting oxygen-free copper rod antioxidant, which comprises the following steps: S1, mixing nano copper powder with acetylacetone, heating, preserving heat and stirring to obtain a solution 1; s2, mixing alcohol, benzotriazole, aniline nitrate, methacrylate and ammonium sulfate, heating, preserving heat and stirring to obtain a solution 2; and S3, mixing the solution 1, the solution 2 and water according to a preset proportion, and stirring for a preset time to obtain the antioxidant for the up-drawing continuous casting oxygen-free copper rod. The invention further discloses application of the up-drawing continuous casting oxygen-free copper rod antioxidant. According to the antioxidant provided by the invention, copper oxide and cuprous oxide are prevented from being formed on the surface of the oxygen-free copper rod due to air oxidation in the production and preparation process, so that the processing performance and the electrical performance of subsequent extruded products are not influenced. Meanwhile, the oxygen-free copper rod is mainly composed of organic compounds, after the temperature of the oxygen-free copper rod is reduced to the room temperature, the oxygen-free copper rod is normally volatilized, residues are not caused, and subsequent products are not affected.

Description

Technical Field

[0001] The invention belongs to the field of metal smelting and casting, and specifically relates to a preparation method and application of an upward continuous casting oxygen-free copper rod antioxidant. Background Art

[0002] Oxygen-free copper rod is pure copper that does not contain oxygen or any deoxidizer residue. But in fact, it still contains very trace oxygen and some impurities. According to the standard, the oxygen content is not more than 20ppm, the total impurity content is not more than 0.05%, and the purity of copper is greater than 99.95%. The copper busbar prepared by continuous extrusion of oxygen-free copper rod is widely used in electrical cabinets, switch cabinets, electrical connectors and other fields. However, due to the cooling degree during the continuous casting process of copper water, the residual temperature of the copper rod can reach 40-100℃. The warm copper rod is easily oxidized in the air, forming copper oxide, cuprous oxide and other substances on the surface. These impurities will enter the copper busbar during the subsequent extrusion process, causing problems such as bending and cracking during processing, decreased conductivity, and affecting the quality of the product. Therefore, during the casting process of the copper rod, a layer of antioxidant needs to be coated on its surface to prevent the copper rod from oxidizing. At present, the commonly used antioxidant is a mixture of alcohol and water, which is applied to the surface of the copper rod with a towel. The main problems of this method are: 1. The mixture is not evenly coated and fails to protect the entire copper rod; 2. As the use time increases, the remaining amount of the mixture gradually decreases and needs to be added regularly; 3. The mixture contains water. If more is applied, the water cannot be completely dried, which will aggravate subsequent oxidation. Therefore, it is necessary to develop a new type of antioxidant and coating device to evenly cover the surface of the copper rod to prevent oxidation of the copper rod. At the same time, the antioxidant volatilizes normally at room temperature and will not be mixed into the copper busbar during the extrusion process with the copper rod. Summary of the invention

[0003] One of the purposes of the present invention is to provide a method for preparing an antioxidant for upward continuous casting oxygen-free copper rod.

[0004] A second object of the present invention is to provide an application of the antioxidant.

[0005] The present invention provides a method for preparing an antioxidant for an upward continuous casting oxygen-free copper rod, comprising the following steps:

[0006] S1. Mix the nano copper powder with acetylacetone, heat and stir to obtain a solution 1;

[0007] S2. The alcohol, benzotriazole, aniline nitrate, methacrylate, and ammonium sulfate were mixed and heated and stirred to obtain a solution 2;

[0008] S3. Mix solution 1, solution 2 and water in a preset ratio and stir for a preset time to obtain the upward continuous casting oxygen-free copper rod antioxidant.

[0009] In step S1, the diameter of the nano copper powder is 0.5-1.5 nm; the dosage ratio of the nano copper powder to acetylacetone is (10-30 g): (90-110 mL); the heating temperature is 50-70° C., and the stirring time is 4-8 h.

[0010] In step S2, the mass ratio of alcohol, benzotriazole, aniline nitrate, methacrylate and ammonium sulfate is (50-70):(10-30:):(10-20):(2-4):(1-3); the heating temperature is 40-60°C, and the stirring time is 2-6h.

[0011] In step S3, the volume ratio of solution 1, solution 2 and water is (4-6): (10-20): (75-85); and the stirring time is 2-4h.

[0012] The present invention also provides an application of the upward continuous casting oxygen-free copper rod antioxidant.

[0013] The application comprises the following steps:

[0014] S11. The electrolytic copper is added to the upper lead furnace, heated and kept warm, and cast into oxygen-free copper rods by the upper lead;

[0015] S12. Coating the oxygen-free copper rod obtained in step S11 with the antioxidant, and pulling the wire to coil.

[0016] In step S11, the heating temperature is 1140°C to 1160°C; the diameter of the oxygen-free copper rod is 5-30 mm; and the pulling speed is 0.4 to 2.5 m / min.

[0017] Principle of the present invention:

[0018] (1) Using the characteristics of large specific surface area and high activity of nano copper powder, it is evenly distributed on the surface of oxygen-free copper rod, and preferentially reacts with oxygen in the air to form copper oxide. However, nano copper powder is insoluble in water and settles to the bottom. Using the dispersing and suspending effect of acetylacetone, a uniformly dispersed organic solvent is formed with alcohol as the matrix, which is volatilized and distributed in the air, acting on the surface of oxygen-free copper rod;

[0019] (2) Taking advantage of the volatility and anti-oxidation properties of alcohol, highly reducing substances such as benzotriazole, aniline nitrate, acrylate, and ammonium sulfate are evenly dispersed in the alcohol, and the residual heat of the oxygen-free copper rod is used to evaporate into the air, forming an anti-oxidation layer on the surface of the oxygen-free copper rod to prevent the copper rod from oxidizing in the air;

[0020] (3) Design a coating device for oxygen-free copper rod antioxidant, make full use of the residual heat of the oxygen-free copper rod to volatilize the antioxidant, and ensure the effect of uniform coating. At the same time, design the entry and exit chambers to prevent the antioxidant from diffusing into the air and causing waste.

[0021] Beneficial effects of the present invention:

[0022] (1) The antioxidant provided by the present invention is mainly composed of organic compounds. After the temperature of the oxygen-free copper rod is reduced to room temperature, it evaporates normally without causing any residue and having no impact on subsequent products;

[0023] (2) The antioxidant provided by the present invention prevents the oxygen-free copper rod from forming cupric oxide and cuprous oxide on its surface due to air oxidation during the production process, thereby affecting the processing performance and electrical properties of subsequent extruded products. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The discoloration of the oxygen-free copper rod in Example 1 after being placed in air for 15 days (no change);

[0025] Figure 2 The discoloration (coloring) of the oxygen-free copper rod of Comparative Example 1 after being placed in the air for 2 days;

[0026] Figure 3 The discoloration (blackening) of the oxygen-free copper rod in comparative example 1 after being placed in air for 5 days;

[0027] Figure 4 Schematic diagram of the designed antioxidant uniform coating device;

[0028] Figure 5 It is a schematic diagram of the dimensions of the antioxidant uniform coating device used in the examples and comparative examples, wherein the unit of the dimension data is centimeter. DETAILED DESCRIPTION

[0029] Example 1

[0030] Add electrolytic copper to the upper induction furnace, heat to 1150℃ and keep warm, use a 20mm diameter graphite crystallizer and an upper induction speed of 0.6m / min to lead out the oxygen-free copper rod. Mix 1nm diameter nano copper powder and acetylacetone in a ratio of 20g:100ml, heat to 60℃, keep warm and stir for 6h, so that the copper powder is evenly suspended in acetylacetone to obtain solution 1. Mix alcohol, benzotriazole, aniline nitrate, methacrylate, and ammonium sulfate in a mass ratio of 60:20:15:3:2, heat to 50℃, keep warm and stir for 4h, so that the liquid and the particulate solid are fully mixed to obtain solution 2. Mix solution 1, solution 2 and water in a volume ratio of 5:15:80, stir well for 3h, and obtain the final oxygen-free copper rod antioxidant. According to production needs, the oxygen-free copper rod antioxidant is placed in a reagent bin of a special box (such as Figure 5 As shown in the figure, the reagent adding height is 35cm. When the warm oxygen-free copper rod enters the reagent chamber from the entry chamber, the reagent chamber is filled with antioxidant gas due to the volatile antioxidant. The entry chamber and the exit chamber can effectively collect the antioxidant gas to avoid dissipation into the air, causing pollution and waste. The gas adheres to the surface of the oxygen-free copper rod, which can effectively prevent it from being oxidized during subsequent storage and transportation. After the oxygen-free copper rod passes through the special box, it is pulled and reeled into a coil.

[0031] Example 2

[0032] Add electrolytic copper to the upper induction furnace, heat to 1150℃ and keep warm, use a 20mm diameter graphite crystallizer and an upper induction speed of 0.6m / min to lead out the oxygen-free copper rod. Mix 1.2nm diameter nano copper powder and acetylacetone in a ratio of 25g:100ml, heat to 60℃, keep warm and stir for 6h, so that the copper powder is evenly suspended in acetylacetone to obtain solution 1. Mix alcohol, benzotriazole, aniline nitrate, methacrylate, and ammonium sulfate in a mass ratio of 55:23:17:3:2, heat to 50℃, keep warm and stir for 4h, so that the liquid and the particulate solid are fully mixed to obtain solution 2. Mix solution 1, solution 2 and water in a volume ratio of 5:15:80, stir well for 3h, and obtain the final oxygen-free copper rod antioxidant. According to production needs, the oxygen-free copper rod antioxidant is placed in a reagent bin of a special box (such as Figure 5 As shown in the figure, the reagent adding height is 35cm. When the warm oxygen-free copper rod enters the reagent chamber from the entry chamber, the reagent chamber is filled with antioxidant gas due to the volatile antioxidant. The entry chamber and the exit chamber can effectively collect the antioxidant gas to avoid dissipation into the air, causing pollution and waste. The gas adheres to the surface of the oxygen-free copper rod, which can effectively prevent it from being oxidized during subsequent storage and transportation. After the oxygen-free copper rod passes through the special box, it is pulled and reeled into a coil.

[0033] Example 3

[0034] Compared with Example 1, the ratio of nano copper powder to acetylacetone is 10 mg:100 ml, and the other steps are exactly the same.

[0035] Example 4

[0036] Compared with Example 1, the mass ratio of alcohol, benzotriazole, aniline nitrate, methacrylate and ammonium sulfate is 50:28:17:3:2, and the other steps are exactly the same.

[0037] Example 5

[0038] Compared with Example 1, the mass ratio of alcohol, benzotriazole, aniline nitrate, methacrylate and ammonium sulfate is 70:13:12:3:2, and the other steps are exactly the same.

[0039] Example 6

[0040] Compared with Example 1, the volume ratio of solution 1, solution 2 and water is 4:10:86, and the other steps are exactly the same.

[0041] Example 7

[0042] Compared with Example 1, the volume ratio of solution 1, solution 2 and water is 6:20:74, and the other steps are exactly the same.

[0043] Comparative Example 1

[0044] Compared with Example 1, the oxygen-free copper rod does not pass through the special box and is not protected by an antioxidant, and the other steps are exactly the same.

[0045] Comparative Example 2

[0046] Compared with Example 1, the volume ratio of solution 1, solution 2 and water is 0:15:80, and the other steps are exactly the same.

[0047] Comparative Example 3

[0048] Compared with Example 1, the volume ratio of solution 1, solution 2 and water is 5:0:80, and the other steps are exactly the same.

[0049] Comparative Example 4

[0050] Compared with Example 1, Solution 2 only contains alcohol, and does not contain benzotriazole, aniline nitrate, methacrylate, and ammonium sulfate. The other steps are exactly the same.

[0051] Comparative Example 5

[0052] Compared with Example 1, Solution 2 contains alcohol and benzotriazole, but does not contain aniline nitrate, methacrylate, and ammonium sulfate, and the other steps are exactly the same.

[0053] Comparative Example 6

[0054] Compared with Example 1, Solution 2 contains alcohol, benzotriazole, and aniline nitrate, but does not contain methacrylate and ammonium sulfate, and the other steps are exactly the same.

[0055] Comparative Example 7

[0056] Compared with Example 1, Solution 2 contains alcohol, methacrylate, and ammonium sulfate, but does not contain benzotriazole and aniline nitrate, and the other steps are exactly the same.

[0057] Table 1 shows the content of antioxidant components in each embodiment.

[0058]

[0059]

[0060] Table 2 shows the discoloration and oxidation of oxygen-free copper rods in air in various embodiments.

[0061] serial number 1D 2D 3D 5D 7D 9D 12D 15D Example 1 No color change No color change No color change No color change No color change No color change No color change No color change Example 2 No color change No color change No color change No color change No color change No color change No color change No color change Example 3 No color change No color change No color change No color change No color change No color change No color change Hair Color Example 4 No color change No color change No color change No color change No color change No color change No color change No color change Example 5 No color change No color change No color change No color change No color change No color change Hair Color Hair Color Example 6 No color change No color change No color change No color change No color change No color change Hair Color Hair Color Example 7 No color change No color change No color change No color change No color change No color change No color change No color change Comparative Example 1 No color change Hair Color Black Black Black Black Black Black Comparative Example 2 No color change No color change No color change No color change No color change Hair Color Hair Color Hair Color Comparative Example 3 No color change No color change Hair Color Hair Color Hair Color Black Black Black Comparative Example 4 No color change No color change No color change Hair Color Hair Color Hair Color Black Black Comparative Example 5 No color change No color change No color change No color change No color change No color change Hair Color Hair Color Comparative Example 6 No color change No color change No color change No color change No color change No color change No color change Hair Color Comparative Example 7 No color change No color change No color change No color change No color change Hair Color Black Black

[0062] As can be seen from Table 2, the discoloration and oxidation of oxygen-free copper rods in the air are closely related to the content of antioxidant components. When the oxygen-free copper rod undergoes oxidation reaction in the air, cuprous oxide is preferentially generated, and the copper rod presents a color phenomenon. As the degree of oxidation deepens, copper oxide is gradually generated, and the copper rod presents a black phenomenon. By comparing the discoloration and oxidation conditions, it can be seen that adding solution 1 (nano copper powder + acetylacetone) and solution 2 (alcohol + benzotriazole + aniline nitrate + acrylate + ammonium sulfate) to the antioxidant can effectively prevent the oxidation of the oxygen-free copper rod in the air, and avoid the formation of oxides on the surface during storage and transportation, which has an adverse effect on subsequent processing and use. The nano copper powder of solution 1 is directly added to water, and will sink to the bottom, and will not evaporate into the air with the antioxidant. It is prepared into a suspension with acetylacetone, which can not only make it evenly dispersed in the antioxidant, but also evaporate into the air with the organic solvent. Nano copper powder particles have a large specific surface area and are prone to preferentially react with oxidation to form copper oxides, thereby reducing the preferential reaction level of the oxygen-free copper rod. Solution 2 uses alcohol as a carrier of an organic solvent, adds two strong reducing agents, benzotriazole and aniline nitrate, and utilizes the synergistic effect of acrylate and ammonium sulfate, which is the main source of the antioxidant effect. Alcohol, as a volatile substance, has an antioxidant effect in itself. It carries benzotriazole, aniline nitrate, acrylate, and ammonium sulfate and volatilizes into the air, making them evenly attached to the surface of the oxygen-free copper rod, thereby enhancing the anti-oxidation effect. Therefore, through the preferential oxidation effect of solution 1 and the strong anti-oxidation effect of solution 2, the surface of the oxygen-free copper rod is evenly coated, reducing the oxidation blackening phenomenon during storage and transportation, and avoiding adverse effects on subsequent processing and use.

Claims

1. A method for preparing an antioxidant for upward continuous casting oxygen-free copper rod, characterized in that: The following steps are involved: S1. The nano copper powder was mixed with acetylacetone, heated and stirred to obtain a solution 1; S2. The alcohol, benzotriazole, aniline nitrate, methacrylate, ammonium sulfate were mixed, heated and stirred to obtain a solution 2; S3. Mix solution 1, solution 2 and water in a preset ratio and stir for a preset time to obtain the upward continuous casting oxygen-free copper rod antioxidant.

2. The method for preparing the upward continuous casting oxygen-free copper rod antioxidant according to claim 1, characterized in that: In step S1, the diameter of the nano copper powder is 0.5-1.5 nm; the dosage ratio of the nano copper powder to acetylacetone is (10-30 g): (90-110 mL); the heating temperature is 50-70° C., and the stirring time is 4-8 h.

3. The method for preparing the upward continuous casting oxygen-free copper rod antioxidant according to claim 1, characterized in that: In step S2, the mass ratio of alcohol, benzotriazole, aniline nitrate, methacrylate and ammonium sulfate is (50-70):(10-30:):(10-20):(2-4):(1-3); the heating temperature is 40-60°C, and the stirring time is 2-6h.

4. The method for preparing the upward continuous casting oxygen-free copper rod antioxidant according to claim 1, characterized in that: In step S3, the mass ratio of solution 1, solution 2 and water is (4-6):(10-20):(75-85); and the stirring time is 2-4h.

5. Use of the antioxidant for upward continuous casting oxygen-free copper rod as claimed in any one of claims 1 to 4.

6. The use according to claim 5, characterized in that: The following steps are involved: S11. The electrolytic copper is added to the upper lead furnace, heated and kept warm, and cast into oxygen-free copper rods by the upper lead; S12. Coating the oxygen-free copper rod obtained in step S11 with the antioxidant, and pulling the wire to coil.

7. The use according to claim 6, characterized in that: In step S11, the heating temperature is 1140°C to 1160°C; the diameter of the copper rod is 5 to 30 mm; and the pulling speed is 0.4 to 2.5 m / min.

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