A preparation method for synthesizing cuprous chloride by using pure copper powder and chlorine

Abstract

The present invention relates to the field of metal powder production, and in particular to a preparation method of cuprous chloride synthesized from pure copper powder and chlorine, comprising the following steps: (1) smelting copper metal to obtain copper liquid, and adopting a high-pressure water mist method to prepare primary copper powder; (2) placing primary copper powder, deionized water, formaldehyde solution and alkaline solution into a high-pressure reactor, taking out the copper powder after hydrothermal treatment, and repeatedly washing it with de-distilled water, and drying to obtain prefabricated copper powder; (3) immersing the prefabricated copper powder in a coating liquid, heat-insulating and film-forming, taking it out, then washing the prefabricated copper powder after film formation with an organic solvent, centrifugally separating and drying, and then obtaining pure copper powder. The present invention hydrothermally treats the primary copper powder prepared by the water mist method, and in a reducing atmosphere of sodium hydroxide and formaldehyde, reduces copper ions to metallic copper, further reduces the oxygen content in the primary copper powder, thereby increasing the purity of the copper powder and improving the overall quality of the copper powder.

Description

Technical Field

[0001] The invention relates to the technical field of metal powder production, and in particular to a preparation method for synthesizing cuprous chloride by using pure copper powder and chlorine. Background Art

[0002] As one of the important raw materials for powder metallurgy products, copper powder plays an irreplaceable role in industrial production and is mainly used in powder metallurgy machinery parts, friction materials, electric carbon products, diamond tools and other industries. Atomized copper powder is a type of copper-based powder, which is manufactured by gas atomization or water atomization.

[0003] The water atomization method uses high-pressure water to impact the copper liquid, which is rapidly broken into small droplets and quickly cooled to form copper powder. However, water reacts with metallic copper at high temperatures, and the oxygen content of the prepared copper powder is high, which affects the purity of the copper powder. In addition, the copper powder prepared by the water atomization method has a relatively general antioxidant property, which is not conducive to the storage of copper powder. To this end, we proposed a preparation method for synthesizing cuprous chloride by using pure copper powder and chlorine gas. Summary of the invention

[0004] (I) In view of the shortcomings of the prior art, the present invention provides a method for preparing cuprous chloride by synthesizing pure copper powder and chlorine gas, which overcomes the problem of high oxygen content in copper powder prepared by water atomization in the prior art, improves the purity of copper powder, and improves the overall quality of copper powder.

[0005] (II) To achieve the above objectives, the present invention is implemented by the following technical scheme: a method for preparing pure copper powder, the preparation method specifically comprising the following steps:

[0006] (1) After smelting metallic copper, molten copper is obtained, and primary copper powder is prepared by high-pressure water mist method.

[0007] (2) placing primary copper powder, deionized water, formaldehyde solution and alkaline solution into a high pressure reactor; after the hydrothermal treatment, taking out the copper powder and repeatedly washing it with deionized water; and drying it to obtain prefabricated copper powder.

[0008] (3) The prefabricated copper powder is immersed in the coating liquid, and the film is formed by heat preservation, and then the prefabricated copper powder after the film is washed with an organic solvent, and the prefabricated copper powder is centrifuged and dried to obtain pure copper powder.

[0009] Preferably, in step (1), the temperature of the copper liquid is 1150-1200° C., the atomization water pressure is 14-16 MPa, and the nozzle aperture is 4-4.5 mm.

[0010] Preferably, in step (2), the alkaline solution is a 1 mol / L sodium hydroxide solution, and the pH value is adjusted to 9-10; the mass fraction of the formaldehyde solution is 50-55%, and the volume ratio of the formaldehyde solution to deionized water is 1:(100-150); the hydrothermal temperature is 230-240°C, and the hydrothermal reaction time is 3.5-5.5h.

[0011] Preferably, in step (3), the preparation method of the coating solution is as follows: add benzotriazole to a 75% ethanol solution by mass, stir evenly until the benzotriazole is completely dissolved to obtain a mixed solution; then add a silane coupling agent to the mixed solution, and mix well to obtain a coating solution. The benzotriazole accounts for 2.5% of the total mass of the ethanol solution; the mass ratio of the silane coupling agent to the benzotriazole is 1:3. The insulation time is 2.5-3h; and the organic solvent is acetone.

[0012] The present invention provides a method for preparing cuprous chloride, which specifically comprises the following steps:

[0013] S1: Prefabricated copper powder is put into a No. 1 reactor, heated and melted to obtain copper water, during which an excess of dry chlorine gas is introduced to react and generate copper chloride which is discharged into a No. 2 reactor;

[0014] S2: Then, an excess of prefabricated copper powder is added to the second reactor to react with the cupric chloride to form cuprous chloride.

[0015] Preferably, in step S1, the flow rate of the chlorine gas is 0.62 m / s. The temperature of the molten copper is 1100-1200°C.

[0016] (III) The present invention provides a method for preparing cuprous chloride by synthesizing pure copper powder and chlorine gas, which has the following characteristics:

[0017] Beneficial effects:

[0018] 1. The present invention hydrothermally treats the primary copper powder prepared by the water mist method, and reduces the copper ions to metallic copper in a reducing atmosphere of sodium hydroxide and formaldehyde, thereby further reducing the oxygen content in the primary copper powder, thereby increasing the purity of the copper powder and improving the overall quality of the copper powder.

[0019] 2. In the present invention, by adding a coating liquid, benzotriazole will coat a layer of complex film on the surface of the copper particles, but the complex film will dissolve to form holes in an environment with high humidity, and water vapor and oxygen will still pass through the holes to corrode the metal copper inside. For this reason, a silane coupling agent is added, and benzotriazole and the silane coupling agent jointly construct a thin film on the surface of the copper particles. The introduction of silane improves the hydrophobicity of the film, can better reduce the micro-dissolution of benzotriazole by water vapor, improves the stability of the film, and further improves the antioxidant property of the pure copper powder.

[0020] 3. The copper powder prepared by the method of the present invention has a bulk density of 2.08 g·cm -3 The oxygen content is also low, which meets the actual processing requirements; and when the mass ratio of silane coupling agent to benzotriazole is 1:3, the oxidation resistance of copper powder is better.

[0021] 4. In the production process of cuprous chloride, the present invention uses prefabricated copper powder to replace the traditional copper plate or copper wire, which can react quickly with chlorine, thereby increasing the reaction speed and reducing the cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The figure is a relationship diagram between the mass ratio of the silane coupling agent and benzotriazole and the weight gain rate in the present invention. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0024] Example 1

[0025] A method for preparing a coating liquid is as follows: adding benzotriazole to a 75% by mass ethanol solution, stirring evenly until the benzotriazole is completely dissolved to obtain a mixed solution; then adding a silane coupling agent to the mixed solution, mixing evenly to obtain the coating liquid.

[0026] Specifically, benzotriazole accounts for 2.5% of the total mass of the ethanol solution; the mass ratio of the silane coupling agent to benzotriazole is 1:3.

[0027] Example 2

[0028] A method for preparing pure copper powder, the preparation method specifically comprising the following steps:

[0029] (1) After smelting copper metal, copper liquid is obtained, and primary copper powder is prepared by high-pressure water mist method, wherein the temperature of the copper liquid is 1150°C, the atomization water pressure is 16 MPa, and the nozzle aperture is 4 mm.

[0030] (2) Put the primary copper powder, deionized water, formaldehyde solution and alkaline solution into a high-pressure reactor. After the hydrothermal treatment, take out the copper powder and rinse it repeatedly with deionized water, and then dry it to obtain the prefabricated copper powder. Among them, the alkaline solution is a 1 mol / L sodium hydroxide solution, and the pH value is adjusted to 10; the mass fraction of the formaldehyde solution is 50%, and the volume ratio of the formaldehyde solution to deionized water is 1:150. The hydrothermal temperature is 230°C and the hydrothermal reaction time is 5.5h.

[0031] (3) The prefabricated copper powder is immersed in the coating liquid, and the film is formed by heat preservation, then the prefabricated copper powder after film formation is washed with an organic solvent, and then centrifuged and dried to obtain pure copper powder. The heat preservation time is 2.5 hours, and the organic solvent is acetone.

[0032] The coating solution in this example was prepared by the method in Example 1.

[0033] Example 3

[0034] A method for preparing pure copper powder, the preparation method specifically comprising the following steps:

[0035] (1) After smelting copper metal, copper liquid is obtained, and primary copper powder is prepared by high-pressure water mist method, wherein the temperature of the copper liquid is 1200°C, the atomization water pressure is 14 MPa, and the nozzle aperture is 4.5 mm.

[0036] (2) Put the primary copper powder, deionized water, formaldehyde solution and alkaline solution into a high-pressure reactor. After the hydrothermal treatment, take out the copper powder and rinse it repeatedly with deionized water, and then dry it to obtain the prefabricated copper powder. Among them, the alkaline solution is a 1 mol / L sodium hydroxide solution, and the pH value is adjusted to 9; the mass fraction of the formaldehyde solution is 55%, and the volume ratio of the formaldehyde solution to deionized water is 1:100. The hydrothermal temperature is 240°C and the hydrothermal reaction time is 3.5h.

[0037] (3) The prefabricated copper powder is immersed in the coating liquid, and the film is formed by heat preservation. Then, the prefabricated copper powder after film formation is washed with an organic solvent, and the prefabricated copper powder is centrifuged and dried to obtain pure copper powder. The heat preservation time is 3 hours, and the organic solvent is acetone.

[0038] The coating solution in this example was prepared by the method in Example 1.

[0039] Example 4

[0040] A method for preparing pure copper powder, the preparation method specifically comprising the following steps:

[0041] (1) After smelting copper metal, copper liquid is obtained, and primary copper powder is prepared by high-pressure water mist method, wherein the temperature of the copper liquid is 1150°C, the atomization water pressure is 15 MPa, and the nozzle aperture is 4.5 mm.

[0042] (2) Put the primary copper powder, deionized water, formaldehyde solution and alkaline solution into a high-pressure reactor. After the hydrothermal treatment, take out the copper powder and rinse it repeatedly with deionized water, and then dry it to obtain the prefabricated copper powder. Among them, the alkaline solution is a 1 mol / L sodium hydroxide solution, and the pH value is adjusted to 10; the mass fraction of the formaldehyde solution is 55%, and the volume ratio of the formaldehyde solution to deionized water is 1:120. The hydrothermal temperature is 235°C and the hydrothermal reaction time is 4 hours.

[0043] (3) The prefabricated copper powder is immersed in the coating liquid, and the film is formed by heat preservation. Then, the prefabricated copper powder after film formation is washed with an organic solvent, and the prefabricated copper powder is centrifuged and dried to obtain pure copper powder. The heat preservation time is 3 hours, and the organic solvent is acetone.

[0044] The coating solution in this example was prepared by the method in Example 1.

[0045] Example 5

[0046] A method for preparing cuprous chloride, characterized in that the method specifically comprises the following steps:

[0047] S1: Prefabricated copper powder is put into the No. 1 reactor, heated and melted to obtain copper water, during which excessive dry chlorine gas is introduced to react and generate copper chloride which is discharged into the No. 2 reactor. The flow rate of chlorine gas is 0.62 m / s; the temperature of the copper water is 1100°C.

[0048] S2: Then, an excess of prefabricated copper powder is added to the second reactor to react with the cupric chloride to form cuprous chloride.

[0049] The prefabricated copper powder in this embodiment is prepared according to the method in Example 2.

[0050] Example 6

[0051] A method for preparing cuprous chloride, characterized in that the method specifically comprises the following steps:

[0052] S1: Prefabricated copper powder is put into the No. 1 reactor, heated and melted to obtain copper water, during which excessive dry chlorine gas is introduced to react and generate copper chloride which is discharged into the No. 2 reactor. The flow rate of chlorine gas is 0.62 m / s; the temperature of the copper water is 1200°C.

[0053] S2: Then, an excess of prefabricated copper powder is added to the second reactor to react with the cupric chloride to form cuprous chloride.

[0054] The prefabricated copper powder in this embodiment is prepared according to the method in Example 2.

[0055] Comparative Example 1

[0056] A method for preparing pure copper powder, the preparation method specifically comprising the following steps:

[0057] (1) After smelting copper metal, copper liquid is obtained, and primary copper powder is prepared by high-pressure water mist method, wherein the temperature of the copper liquid is 1150°C, the atomization water pressure is 16 MPa, and the nozzle aperture is 4 mm.

[0058] (2) Put the primary copper powder, deionized water, formaldehyde solution and alkaline solution into a high-pressure reactor. After the hydrothermal treatment, take out the copper powder and rinse it repeatedly with deionized water, and then dry it to obtain pure copper powder. Among them, the alkaline solution is a 1 mol / L sodium hydroxide solution, and the pH value is adjusted to 10; the mass fraction of the formaldehyde solution is 50%, and the volume ratio of the formaldehyde solution to deionized water is 1:150. The hydrothermal temperature is 230°C and the hydrothermal reaction time is 5.5h.

[0059] Comparative Example 2

[0060] A method for preparing pure copper powder, the preparation method specifically comprising the following steps:

[0061] (1) After smelting copper metal, copper liquid is obtained, and primary copper powder is prepared by high-pressure water mist method, wherein the temperature of the copper liquid is 1150°C, the atomization water pressure is 16 MPa, and the nozzle aperture is 4 mm.

[0062] (2) Put the primary copper powder, deionized water, formaldehyde solution and alkaline solution into a high-pressure reactor. After the hydrothermal treatment, take out the copper powder and rinse it repeatedly with deionized water, and then dry it to obtain the prefabricated copper powder. Among them, the alkaline solution is a 1 mol / L sodium hydroxide solution, and the pH value is adjusted to 10; the mass fraction of the formaldehyde solution is 50%, and the volume ratio of the formaldehyde solution to deionized water is 1:150. The hydrothermal temperature is 230°C and the hydrothermal reaction time is 5.5h.

[0063] (3) The prefabricated copper powder is immersed in the coating liquid, and the film is formed by heat preservation, then the prefabricated copper powder after film formation is washed with an organic solvent, and then centrifuged and dried to obtain pure copper powder. The heat preservation time is 2.5 hours, and the organic solvent is acetone.

[0064] The coating solution preparation method in this embodiment is as follows: add benzotriazole to a 75% ethanol solution by mass, stir evenly until the benzotriazole is completely dissolved, and obtain the coating solution. The benzotriazole accounts for 2.5% of the total mass of the ethanol solution; the mass ratio of the silane coupling agent to the benzotriazole is 1:3.

[0065] Performance Characterization

[0066] 1. Use ON-1000 oxygen and nitrogen analyzer to analyze the oxygen mass fraction of the prefabricated copper powder; use HY-100 powder density tester to measure the bulk density and flowability of the prefabricated copper powder. Test objects: prefabricated copper powders in Examples 2-4 and Comparative Example 2, primary copper powder in Example 2, and pure copper powder in Comparative Example 1. The specific test results are shown in the following table.

[0067] Table 1 Copper powder properties

[0068] Group Oxygen content / % <![CDATA[Bulk density / g·cm -3 > <![CDATA[Liquidity / s·(50 g) -1 > Embodiment 2 (prefabricated copper powder) 0.0105 2.08 14.95 Embodiment 3 (prefabricated copper powder) 0.0112 2.11 14.16 Embodiment 4 (prefabricated copper powder) 0.0108 2.12 14.74 Comparative Example 1 (pure copper powder) 0.0110 2.13 14.86 Comparative Example 2 (prefabricated copper powder) 0.0109 2.12 14.81 Example 2 (primary copper powder) 0.0641 2.47 13.62

[0069] 2. Antioxidation: Take a certain amount of pure copper powder and oxidize it at a humidity of 90% and a temperature of 65°C for 100 hours. The oxidation weight gain rate is used to detect the oxidation resistance of the pure copper powder, and the calculation method is as follows:

[0070] P=(W-W0) / W0×100%

[0071] Where: P——weight gain rate;

[0072] W——the weight of pure copper powder after oxidation;

[0073] W0——initial mass of pure copper powder.

[0074] Test object: pure copper powder in Examples 2-4 and Comparative Examples 1-2. Specific test results are shown in the following table.

[0075] Table 2 Weight gain rate

[0076]

[0077]

[0078] It can be seen from Table 2 that the weight gain rate of the embodiment is significantly lower than that of the comparative example 1, indicating that the oxidation resistance of the pure copper powder treated with the coating liquid is greatly improved; the weight gain rate in the comparative example 2 is greater than the weight gain rate in the embodiment, but less than the weight gain rate in the comparative example 1, indicating that the addition of the silane coupling agent can indeed improve the hydrophobicity of the coating and reduce the erosion of water vapor on the pure copper powder.

[0079] The embodiments of the present invention disclose preferred embodiments, but are not limited thereto. A person skilled in the art can easily understand the spirit of the present invention based on the above embodiments and make different extensions and changes. However, as long as they do not deviate from the spirit of the present invention, they are all within the protection scope of the present invention.

Claims

1. A method for preparing pure copper powder, characterized in that: The preparation method specifically comprises the following steps: (1) After smelting metallic copper, copper liquid is obtained, and primary copper powder is prepared by high-pressure water mist method; (2) placing primary copper powder, deionized water, formaldehyde solution and alkaline solution into a high-pressure reactor. After the hydrothermal treatment, taking out the copper powder and repeatedly rinsing it with distilled water, and drying it to obtain prefabricated copper powder; (3) immersing the prefabricated copper powder in the coating solution, keeping the temperature to form a film, taking it out, then washing the prefabricated copper powder after the film is formed with an organic solvent, centrifuging and drying it, and then obtaining pure copper powder; In step (2), the alkaline solution is a 1 mol / L sodium hydroxide solution, and the pH value is adjusted to 9-10; the mass fraction of the formaldehyde solution is 50-55%, and the volume ratio of the formaldehyde solution to deionized water is 1:(100-150); In step (3), the coating solution is prepared by: adding benzotriazole to a 75% by mass ethanol solution, stirring evenly until the benzotriazole is completely dissolved to obtain a mixed solution; then adding a silane coupling agent to the mixed solution, and mixing evenly to obtain a coating solution; The benzotriazole accounts for 2.5% of the total mass of the ethanol solution; the mass ratio of the silane coupling agent to the benzotriazole is 1:

3.

2. The method for preparing pure copper powder according to claim 1, characterized in that: In step (1), the temperature of the copper liquid is 1150-1200° C., the atomization water pressure is 14-16 MPa, and the nozzle aperture is 4-4.5 mm.

3. The method for preparing pure copper powder according to claim 1, characterized in that: In step (2), the hydrothermal temperature is 230-240° C. and the hydrothermal reaction time is 3.5-5.5 h.

4. The method for preparing pure copper powder according to claim 1, characterized in that: In step (3), the insulation time is 2.5-3 hours; and the organic solvent is acetone.

5. A method for preparing cuprous chloride, using the pure copper powder obtained by any one of the preparation methods of claims 1 to 4 as prefabricated copper powder, characterized in that: The specific steps include: S1: putting the prefabricated copper powder into the first reactor, heating and melting to obtain copper water, during which an excess of dry chlorine gas is introduced to react and generate copper chloride which is discharged into the second reactor; S2: Then, an excess of prefabricated copper powder is added to the second reactor to react with the cupric chloride to generate cuprous chloride.

6. A method for preparing cuprous chloride as claimed in claim 5, characterized in that: In step S1, the flow rate of the chlorine gas is 0.62 m / s.

7. A method for preparing cuprous chloride as claimed in claim 5, characterized in that: In step S1, the temperature of the molten copper is 1100-1200°C.

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