Spherical copper oxide powder, copper powder and preparation method

Abstract

The invention provides a preparation method of spherical copper oxide powder, a preparation method of spherical copper powder, the spherical copper oxide powder and the spherical copper powder, and relates to the technical field of powder materials. The preparation method of the spherical copper oxide powder comprises the following steps: preparing a copper salt aqueous solution and a weak base aqueous solution; wherein the copper salt aqueous solution contains a dispersing agent; converting the copper salt aqueous solution into copper salt aerosol, and adding the copper salt aerosol into a weak base aqueous solution to obtain a suspension containing a copper compound; performing homogeneous hydrothermal reaction on the suspension containing the copper compound to obtain a copper precursor suspension; and carrying out solid-liquid separation on the copper precursor suspension, and drying the obtained solid substance to obtain the spherical copper oxide powder. The preparation cost of the spherical copper oxide powder and the copper powder can be reduced.

Description

Technical Field

[0001] The present disclosure relates to the technical field of powder materials, and in particular to a method for preparing spherical copper oxide powder, a method for preparing spherical copper powder, spherical copper oxide powder and spherical copper powder. Background Art

[0002] Copper oxide is a brown-black metal oxide powder, soluble in dilute acid, insoluble in water and ethanol. It has the characteristics of large specific surface area, high chemical activity, high electron mobility, high thermal conductivity, strong adsorption capacity, strong selectivity, and special electrical, optical, catalytic and other properties. It is widely used in catalytic reactions such as oxidation, reduction, and hydrogenation, and is suitable for lithium-ion batteries, energetic materials, gas sensors, printing and dyeing, glass, ceramics, and medicine.

[0003] Copper powder is a purple-brown or brown powder, which is mostly used in the production of microelectronic devices and the manufacture of terminals for multilayer ceramic capacitors. It can also be used as a catalyst in the reaction process of synthesizing methanol from carbon dioxide and hydrogen, as well as in petroleum lubricants and the pharmaceutical, electroplating, and coating industries.

[0004] Currently, the preparation of copper oxide powder and copper powder generally has the problem of high cost.

[0005] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0006] The purpose of the present disclosure is to provide a method for preparing spherical copper oxide powder, a method for preparing spherical copper powder, spherical copper oxide powder and spherical copper powder, thereby overcoming the problem of high preparation cost of copper oxide powder and copper powder at least to a certain extent.

[0007] According to a first aspect of the present disclosure, a method for preparing spherical copper oxide powder is provided, comprising: preparing a copper salt aqueous solution and a weak alkali aqueous solution; wherein the copper salt aqueous solution contains a dispersant; converting the copper salt aqueous solution into a copper salt aerosol, and adding the copper salt aerosol to the weak alkali aqueous solution to obtain a suspension containing a copper compound; subjecting the suspension containing the copper compound to a homogeneous hydrothermal reaction to obtain a copper precursor suspension; subjecting the copper precursor suspension to solid-liquid separation, and drying the obtained solid matter to obtain spherical copper oxide powder.

[0008] Optionally, the copper salt in the copper salt aqueous solution is copper acetate or copper chloride, and the copper ion concentration in the copper salt aqueous solution is 40g / L to 70g / L; the dispersant is a mixture of one or more of hexadecyltrimethylammonium bromide, polyethylene glycol, polyvinyl alcohol, polyvinyl pyrrolidone, and sodium dodecylbenzene sulfonate, and the mass fraction of the dispersant is 1% to 5%; the weak base in the weak base aqueous solution is sodium carbonate or ammonium bicarbonate, and the alkali concentration in the weak base aqueous solution is 50g / L to 100g / L.

[0009] Optionally, converting the copper salt aqueous solution into a copper salt aerosol comprises: converting the copper salt aqueous solution into a copper salt aerosol using an atomizing device; wherein the liquid inlet amount of the copper salt aqueous solution in the atomizing device is set to 110 mL / h to 350 mL / h, and the air flow rate of the atomizing device is set to 5 L / min to 20 L / min.

[0010] Optionally, a suspension of a copper compound is subjected to a homogeneous hydrothermal reaction to obtain a copper precursor suspension, comprising: placing the suspension of the copper compound in a sealed reaction kettle, and conducting a homogeneous hydrothermal reaction at a temperature of 60° C. to 100° C. for a reaction time of 4 h to 10 h to obtain a copper precursor suspension.

[0011] Optionally, the copper precursor suspension is subjected to solid-liquid separation, and the obtained solid matter is dried to obtain spherical copper oxide powder, including: solid-liquid separation of the copper precursor suspension by suction filtration or centrifugation; and vacuum drying or freeze drying is used to dry the obtained solid matter to obtain spherical copper oxide powder.

[0012] According to a second aspect of the present disclosure, a method for preparing spherical copper oxide powder is provided, comprising: preparing a copper salt aqueous solution and a weak base aqueous solution; wherein the copper salt aqueous solution contains a dispersant; converting the weak base aqueous solution into a weak base aerosol, and adding the weak base aerosol to the copper salt aqueous solution to obtain a suspension containing a copper compound; subjecting the suspension containing the copper compound to a homogeneous hydrothermal reaction to obtain a copper precursor suspension; performing solid-liquid separation on the copper precursor suspension, and drying the obtained solid matter to obtain spherical copper oxide powder.

[0013] Optionally, the copper salt in the copper salt aqueous solution is copper acetate or copper chloride, and the copper ion concentration in the copper salt aqueous solution is 40g / L to 70g / L; the dispersant is a mixture of one or more of hexadecyltrimethylammonium bromide, polyethylene glycol, polyvinyl alcohol, polyvinyl pyrrolidone, and sodium dodecylbenzene sulfonate, and the mass fraction of the dispersant is 1% to 5%; the weak base in the weak base aqueous solution is sodium carbonate or ammonium bicarbonate, and the alkali concentration in the weak base aqueous solution is 50g / L to 100g / L.

[0014] Optionally, converting the weak alkali aqueous solution into a weak alkali aerosol includes: converting the weak alkali aqueous solution into a weak alkali aerosol using an atomizing device; wherein the liquid inlet amount of the weak alkali aqueous solution in the atomizing device is set to 110 mL / h to 350 mL / h, and the air flow rate of the atomizing device is set to 5 L / min to 20 L / min.

[0015] Optionally, a suspension of a copper compound is subjected to a homogeneous hydrothermal reaction to obtain a copper precursor suspension, comprising: placing the suspension of the copper compound in a sealed reaction kettle, and conducting a homogeneous hydrothermal reaction at a temperature of 60° C. to 100° C. for a reaction time of 4 h to 10 h to obtain a copper precursor suspension.

[0016] Optionally, the copper precursor suspension is subjected to solid-liquid separation, and the obtained solid matter is dried to obtain spherical copper oxide powder, including: solid-liquid separation of the copper precursor suspension by suction filtration or centrifugation; and vacuum drying or freeze drying is used to dry the obtained solid matter to obtain spherical copper oxide powder.

[0017] According to a third aspect of the present disclosure, a method for preparing spherical copper powder is provided, comprising: preparing spherical copper oxide powder by adopting any of the above-mentioned methods for preparing spherical copper oxide powder; and performing hydrogen reduction treatment on the spherical copper oxide powder to obtain spherical copper powder.

[0018] Optionally, the spherical copper oxide powder is subjected to hydrogen reduction treatment by heating the temperature to 180° C. to 300° C. at a heating rate of 5° C. / min to 10° C. / min, and the temperature is kept for 30 min to 2 h to obtain spherical copper powder.

[0019] According to a fourth aspect of the present disclosure, a spherical copper oxide powder is provided, which is prepared by any of the above-mentioned methods for preparing spherical copper oxide powder.

[0020] According to a fifth aspect of the present disclosure, a spherical copper powder is provided, which is prepared by any of the above-mentioned methods for preparing spherical copper powder.

[0021] In the scheme of the exemplary embodiment of the present disclosure, on the one hand, by configuring a combined process of aerosol, homogeneous hydrothermal, etc., the nucleation and growth process can be effectively regulated to obtain three-dimensional spherical copper oxide powder and copper powder, which has low cost, simple process, easy implementation and easy control of process conditions. On the other hand, the scheme of the present disclosure converts the reactant solution into an aerosol and then conducts a gas-liquid phase reaction, thereby effectively regulating the dispersibility of the powder and avoiding the agglomeration of particles. On the other hand, the scheme of the present disclosure has the advantages of low energy consumption and environmentally friendly process, and is suitable for industrial production.

[0022] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the specification are used to explain the principles of the present disclosure. Obviously, the accompanying drawings described below are only some embodiments of the present disclosure, and for ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without creative work.

[0024] Figure 1 The flowchart of the method for preparing spherical copper oxide powder according to the embodiment of the present disclosure is schematically shown.

[0025] Figure 2 A flow chart of a method for preparing spherical copper oxide powder according to another embodiment of the present disclosure is schematically shown.

[0026] Figure 3 The flowchart of the method for preparing spherical copper powder according to the embodiment of the present disclosure is schematically shown.

[0027] Figure 4 The SEM (Scanning Electron Microscope) image of the spherical copper powder prepared in Example 1 of the present disclosure is schematically shown.

[0028] Figure 5 The SEM image of the spherical copper powder prepared in Example 2 of the present disclosure is schematically shown.

[0029] Figure 6 The SEM image of the spherical copper powder prepared in Example 3 of the present disclosure is schematically shown.

[0030] Figure 7 The SEM image of the spherical copper powder prepared in Example 4 of the present disclosure is schematically shown. DETAILED DESCRIPTION

[0031] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as being limited to the examples set forth herein; on the contrary, these embodiments are provided so that the present disclosure will be more comprehensive and complete, and the concepts of the example embodiments are fully conveyed to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present disclosure. However, those skilled in the art will appreciate that the technical solutions of the present disclosure may be practiced while omitting one or more of the specific details, or other methods, processes, steps, etc. may be adopted. In other cases, known technical solutions are not shown or described in detail to avoid obscuring various aspects of the present disclosure.

[0032] In addition, the accompanying drawings are only schematic illustrations of the present disclosure and are not necessarily drawn to scale. The same reference numerals in the figures represent the same or similar parts, and thus their repeated descriptions will be omitted. The flowcharts shown in the accompanying drawings are only exemplary illustrations and do not necessarily include all the steps. For example, some steps can also be decomposed, while some steps can be combined or partially combined, so the actual execution order may change according to the actual situation.

[0033] The preparation methods of copper oxide materials may include solvothermal method, pyrolysis method, microwave method, wet chemical method, magnetron sputtering method and solid-liquid reaction method, etc. However, these preparation methods have high preparation costs and the obtained nanoparticles have irregular morphology.

[0034] In addition, the global production capacity of multi-layer ceramic capacitors (MLCC) is growing rapidly, which are widely used in consumer electronics, communications industry, automobile industry, military equipment and many other fields. Copper, as the terminal electrode material of MLCC, has many excellent properties such as wide source, low price, conductivity similar to silver, and excellent anti-migration. However, copper is very active in chemical properties and is easily oxidized at room temperature in the air. In particular, ultrafine / nano copper powder with a large specific surface area oxidizes faster. The generated copper oxide is not conductive, which will greatly reduce the conductivity of MLCC. Therefore, it is necessary to sinter in nitrogen or a reducing atmosphere, which increases the complexity and cost of the process. In addition, in some schemes, high-temperature sintering (for example, greater than 850°C) copper terminal electrode slurry has problems such as high sintering temperature and high stress. Especially in high-capacity MLCC products, residual stress can easily cause internal cracks, leading to component failure. However, low-temperature sintering (for example, less than 800°C) copper terminal electrode slurry has always had the problem of insufficient density.

[0035] Ultrafine copper powder for MLCC electrodes is mainly prepared by chemical methods. However, most of the preparation methods of ultrafine copper powder are still in the exploratory experimental stage and are not perfect. For example, the raw material gas required for the gas phase evaporation method is expensive, the equipment is complex, the cost is high, and the output is relatively small. The copper powder prepared by the mechanochemical method has a wide particle size distribution and is easy to introduce impurities. These shortcomings limit the application and promotion of related preparation methods.

[0036] Liquid phase reduction method for preparing ultrafine copper powder has unique advantages, such as simple equipment, short process flow, easy industrial production, etc. The reducing agents used, such as formaldehyde, ascorbic acid, sodium hypophosphite, sodium borohydride, phosphate hydrate, etc., are simple and easy to obtain, but at the same time, these reducing agents are highly toxic, reactive, cost and other factors, so it is necessary to further find more suitable reducing agents and study more ideal reaction systems.

[0037] In view of the above situation, in order to at least solve the problem of high preparation cost, the present disclosure provides a new spherical copper oxide powder and a preparation method of spherical copper powder.

[0038] Figure 1 The flowchart of the method for preparing spherical copper oxide powder according to the embodiment of the present disclosure is schematically shown. Figure 1 The method for preparing the spherical copper oxide powder according to the embodiment of the present disclosure may include the following steps: S12. Prepare a copper salt aqueous solution and a weak base aqueous solution; wherein the copper salt aqueous solution contains a dispersant.

[0039] In an exemplary embodiment of the present disclosure, on one hand, a copper salt, deionized water and a dispersant may be used to prepare a copper salt aqueous solution. On the other hand, a weak base and deionized water may be used to prepare a precipitant aqueous solution.

[0040] Specifically, the copper salt in the copper salt aqueous solution is copper acetate or copper chloride, and the copper ion concentration in the copper salt aqueous solution is 40g / L to 70g / L; the dispersant is a mixture of one or more of hexadecyltrimethylammonium bromide, polyethylene glycol, polyvinyl alcohol, polyvinyl pyrrolidone, and sodium dodecylbenzene sulfonate, and the mass fraction of the dispersant is 1% to 5%; the weak base in the weak base aqueous solution is sodium carbonate or ammonium bicarbonate, and the alkali concentration in the weak base aqueous solution is 50g / L to 100g / L.

[0041] S14. Converting the copper salt aqueous solution into a copper salt aerosol, and adding the copper salt aerosol into a weak base aqueous solution to obtain a suspension containing a copper compound.

[0042] In an exemplary embodiment of the present disclosure, the copper salt aqueous solution can be converted into a copper salt aerosol by means of a high-pressure airflow. Specifically, the copper salt aqueous solution can be converted into a copper salt aerosol by an atomizing device (such as an atomizing spray gun, etc.). The liquid inlet amount of the copper salt aqueous solution in the atomizing device can be set to 110 mL / h to 350 mL / h, and the air flow rate of the atomizing device can be set to 5 L / min to 20 L / min.

[0043] Next, the copper salt aerosol can be added to the weak base aqueous solution to obtain a suspension containing a copper compound.

[0044] S16. Performing a homogeneous hydrothermal reaction on the suspension of the copper compound to obtain a copper precursor suspension.

[0045] In an exemplary embodiment of the present disclosure, a suspension of a copper-containing compound may be placed in a sealed reaction vessel and subjected to a homogeneous hydrothermal reaction at a temperature of 60° C. to 100° C. for a reaction time of 4 to 10 hours to obtain a copper precursor suspension.

[0046] S18. Performing solid-liquid separation on the copper precursor suspension, and drying the obtained solid matter to obtain spherical copper oxide powder.

[0047] Specifically, the copper precursor suspension can be separated into solid and liquid by suction filtration or centrifugation. The obtained solid matter is dried by vacuum drying or freeze drying to obtain spherical copper oxide powder. Taking vacuum drying as an example, the temperature can be set to 60°C to 80°C.

[0048] Figure 2 The flowchart of the method for preparing spherical copper oxide powder according to another embodiment of the present disclosure is schematically shown. Figure 2 , a method for preparing spherical copper oxide powder according to another embodiment of the present disclosure may include the following steps: S22. A copper salt aqueous solution and a weak base aqueous solution are prepared; wherein the copper salt aqueous solution comprises a dispersant; S24. converting the weak base aqueous solution into a weak base aerosol, and adding the weak base aerosol to the copper salt aqueous solution to obtain a suspension containing a copper compound; S26. subjecting the suspension of the copper compound to a homogeneous hydrothermal reaction to obtain a copper precursor suspension; S28. Performing solid-liquid separation on the copper precursor suspension, and drying the obtained solid matter to obtain spherical copper oxide powder.

[0049] Among them, step S22, step S26 and step S28 correspond to the above-mentioned step S12, step S16 and step S18 respectively, and will not be repeated here.

[0050] For step S24, the weak base aqueous solution can also be converted into a weak base aerosol by means of a high-pressure airflow. Specifically, the weak base aqueous solution can be converted into a weak base aerosol by an atomizing device (such as an atomizing spray gun, etc.). Among them, the liquid inlet amount of the weak base aqueous solution in the atomizing device can be set to 110mL / h to 350mL / h, and the air flow rate of the atomizing device can be set to 5L / min to 20L / min. Next, the weak base aerosol can be added to the copper salt aqueous solution to obtain a suspension of the copper compound.

[0051] According to the test, the primary particle size of the spherical copper oxide prepared by the above preparation process of the present disclosure is 20nm to 30nm, and the secondary particle size is 200nm to 500nm.

[0052] Based on the above preparation process, further, the embodiment of the present disclosure also provides a method for preparing spherical copper powder.

[0053] Figure 3 The flowchart of the method for preparing spherical copper powder according to an exemplary embodiment of the present disclosure is schematically shown. Figure 3 The method for preparing the spherical copper powder according to the embodiment of the present disclosure may include the following steps: S32. Preparation of spherical copper oxide powder.

[0054] Specifically, the spherical copper oxide powder can be prepared by using the preparation method of steps S12 to S18 or steps S22 to S28.

[0055] S34. The spherical copper oxide powder is subjected to hydrogen reduction treatment to obtain spherical copper powder.

[0056] For the hydrogen reduction treatment process, specifically, the temperature can be raised to 180° C. to 300° C. at a heating rate of 5° C. / min to 10° C. / min and kept warm for 30 min to 2 h to obtain spherical copper powder from spherical copper oxide powder.

[0057] The copper powder obtained in the embodiment of the present disclosure is spherical ultrafine copper powder, and the thickness of the powder layer is 5 mm to 20 mm. In addition, the size of the prepared spherical ultrafine copper powder is 150 nm to 400 nm.

[0058] The disclosed solution adopts an atomization method to effectively control the irregular agglomeration phenomenon of the copper precursor during the nucleation and growth process. At the same time, during the low-temperature hydrothermal process, the copper precursor is in situ decomposed into highly dispersed spherical copper oxide particles, which simplifies the process flow while ensuring the sphericity, dispersion and uniformity of the particles.

[0059] The preparation scheme based on the present disclosure is conducive to the uniformity of the size and shape of copper grains, controllable particle size, dispersibility and sphericity. The present disclosure first converts the reactant solution into an aerosol before the hydrothermal process, and performs a gas-liquid phase reaction in a limited area. Compared with directly adding or dripping the solution, the aerosol is easier to diffuse and has a smaller average particle size and a higher specific surface area, which greatly accelerates the transmission rate of the copper salt and the precipitation phase during the reaction, effectively improves the reaction rate and increases the number of nucleations; at the same time, the gas-liquid phase reaction in a limited area can inhibit the aggregation and growth of copper-containing compounds, thereby effectively regulating the sphericity and dispersibility of the copper precursor particles and avoiding the agglomeration of particles. The present disclosure can decompose the copper precursor particles in situ into highly dispersed spherical copper oxide ultrafine powders during the hydrothermal process. The synthesis method of the present disclosure for obtaining three-dimensional spherical ultrafine copper powder is low in cost, simple in process, low in energy consumption, can be operated continuously, and the process conditions are easy to control.

[0060] The three-dimensional spherical ultrafine copper powder prepared by the present invention has high purity, good crystallinity, good sphericity, uniform morphology, and good dispersibility, and can obtain a series of three-dimensional spherical copper particles formed by self-assembly of nanoparticles with controllable particle size, with a particle size range of 30nm to 1μm. The present invention effectively obtains high-sphericity copper particles under low-cost and low-energy consumption conditions, and at the same time meets the ultrafine copper powder particle size, uniformity and fluidity required for the terminal electrode slurry for MLCC, which is conducive to the preparation of high-performance MLCC terminal electrode slurry.

[0061] The copper powder preparation process disclosed in the present invention is described below by way of examples.

[0062] Example 1 First, copper salt and weak base were prepared into copper salt aqueous solution and weak base aqueous solution with concentrations of 70 g / L and 100 g / L, respectively, wherein 1% polyethylene glycol was added to the copper salt aqueous solution as a dispersant.

[0063] Next, the prepared weak base aqueous solution was converted into a weak base aerosol, and the weak base aerosol was added to the copper salt aqueous solution at a liquid inlet of 200 mL / h and a gas flow rate of 15 L / min, and a suspension containing copper compounds was collected.

[0064] Subsequently, the obtained suspension was transferred to a sealed high-pressure reactor for a homogeneous hydrothermal reaction at a temperature of 70°C for a reaction time of 6 hours to obtain a copper precursor suspension. After the reactor was cooled to room temperature, the copper precursor suspension obtained after the reaction was subjected to solid-liquid separation and washing, and the filter cake was placed in a vacuum drying oven for drying at a temperature of 60°C to obtain a dark brown copper oxide powder.

[0065] Then, the dried dark brown copper oxide powder was hydrogen reduced with a heating rate of 5°C / min, a reaction temperature of 220°C, and a heat preservation time of 1.5h. The powder layer thickness was 20mm, and three-dimensional spherical ultrafine copper powder was obtained.

[0066] In this embodiment, the atomization method is used to effectively control the irregular agglomeration phenomenon of the copper precursor during the nucleation and growth process. At the same time, during the low-temperature hydrothermal process, the copper precursor is in situ decomposed into highly dispersed spherical copper oxide particles. While ensuring the sphericity, dispersion and uniformity of the particles, the energy consumption caused by the calcination of the copper precursor is effectively reduced, and the process flow is simplified.

[0067] Figure 4 The SEM image of the spherical copper powder prepared in Example 1 of the present disclosure is schematically shown. Figure 4 It can be seen that the copper powder prepared in Example 1 of the present disclosure has good sphericity, good dispersibility, a particle size of 200nm to 500nm, and no obvious agglomeration phenomenon.

[0068] Example 2 First, copper salt and weak base were prepared into copper salt aqueous solution and weak base aqueous solution with concentrations of 70 g / L and 100 g / L, respectively, wherein 5% polyethylene glycol was added to the copper salt aqueous solution as a dispersant.

[0069] Next, the prepared weak base aqueous solution was converted into a weak base aerosol, and the weak base aerosol was added to the copper salt aqueous solution at a liquid inlet of 110 mL / h and a gas flow rate of 5 L / min, and a suspension containing copper compounds was collected.

[0070] Subsequently, the obtained suspension was transferred to a sealed high-pressure reactor for a homogeneous hydrothermal reaction at a temperature of 60°C for a reaction time of 4 hours to obtain a copper precursor suspension. After the reactor was cooled to room temperature, the copper precursor suspension obtained after the reaction was subjected to solid-liquid separation and washing, and the filter cake was placed in a vacuum drying oven for drying at a temperature of 80°C to obtain a dark brown copper oxide powder.

[0071] Then, the dried dark brown copper oxide powder was hydrogen reduced with a heating rate of 5°C / min, a reaction temperature of 200°C, and insulation for 1h. The powder layer thickness was 20mm, and three-dimensional spherical ultrafine copper powder was obtained.

[0072] Figure 5 The SEM image of the spherical copper powder prepared in Example 2 of the present disclosure is schematically shown. Figure 5 It can be seen that the copper powder prepared in Example 2 of the present disclosure has good sphericity, good dispersibility, uniform particle size, and a particle size of about 120 nm, without obvious agglomeration.

[0073] Example 3 First, copper salt and weak base were prepared into copper salt aqueous solution and weak base aqueous solution with concentrations of 40 g / L and 50 g / L, respectively. Among them, 5% hexadecyltrimethylammonium bromide was added to the copper salt aqueous solution as a dispersant.

[0074] Next, the prepared weak base aqueous solution was converted into a weak base aerosol, and the weak base aerosol was added to the copper salt aqueous solution at a liquid inlet of 350 mL / h and a gas flow rate of 20 L / min, and a suspension containing copper compounds was collected.

[0075] Subsequently, the obtained suspension was transferred to a sealed high-pressure reactor for a homogeneous hydrothermal reaction at a temperature of 100°C for 10 hours to obtain a copper precursor suspension. After the reactor was cooled to room temperature, the copper precursor suspension obtained after the reaction was subjected to solid-liquid separation and washing, and the filter cake was placed in a vacuum drying oven for drying at a temperature of 80°C to obtain a dark brown copper oxide powder.

[0076] Then, the dried dark brown copper oxide powder was hydrogen reduced with a heating rate of 10°C / min, a reaction temperature of 180°C, and a heat preservation time of 2h. The powder layer thickness was 15mm, and three-dimensional spherical ultrafine copper powder was obtained.

[0077] Figure 6 The SEM image of the spherical copper powder prepared in Example 3 of the present disclosure is schematically shown. Figure 6 It can be seen that the copper powder prepared in Example 3 of the present disclosure has good sphericity, good dispersibility, uniform particle size, and a particle size of about 200 nm, without obvious agglomeration.

[0078] Example 4 First, copper salt and weak base were prepared into copper salt aqueous solution and weak base aqueous solution with concentrations of 50 g / L and 80 g / L, respectively. Among them, 5% sodium dodecylbenzene sulfonate was added to the copper salt aqueous solution as a dispersant.

[0079] Next, the prepared copper salt aqueous solution was converted into copper salt aerosol, and the copper salt aerosol was added into the weak alkaline aqueous solution with a liquid inlet of 350 mL / h and a gas flow rate of 20 L / min, and a suspension containing copper compounds was collected.

[0080] Subsequently, the obtained suspension was transferred to a sealed high-pressure reactor for a homogeneous hydrothermal reaction at a temperature of 75°C for a reaction time of 6 hours to obtain a copper precursor suspension. After the reactor was cooled to room temperature, the copper precursor suspension obtained after the reaction was subjected to solid-liquid separation and washing, and the filter cake was placed in a vacuum drying oven for drying at a temperature of 60°C to obtain a dark brown copper oxide powder.

[0081] Then, the dried dark brown copper oxide powder was hydrogen reduced with a heating rate of 5°C / min, a reaction temperature of 300°C, and a heat preservation time of 30min. The powder layer thickness was 20mm, and three-dimensional spherical ultrafine copper powder was obtained.

[0082] Figure 7 The SEM image of the spherical copper powder prepared in Example 4 of the present disclosure is schematically shown. Figure 7 It can be seen that the copper powder prepared in Example 4 of the present disclosure has good sphericity, good dispersibility, uniform particle size, a particle size of about 300 nm, and no obvious agglomeration phenomenon.

[0083] Furthermore, the embodiment of the present disclosure also provides a spherical copper oxide powder, which is prepared using the above-mentioned method for preparing the spherical copper oxide powder.

[0084] Furthermore, the embodiment of the present disclosure also provides a spherical copper powder, which is prepared using the above-mentioned method for preparing the spherical copper powder.

[0085] It should be noted that although the steps of the method in the present disclosure are described in a specific order in the drawings, this does not require or imply that the steps must be performed in this specific order, or that all the steps shown must be performed to achieve the desired results. Additionally or alternatively, some steps may be omitted, multiple steps may be combined into one step, and / or one step may be decomposed into multiple steps, etc.

[0086] In addition, the above-mentioned figures are only schematic illustrations of the processes included in the method according to the exemplary embodiments of the present disclosure, and are not intended to be limiting. It is easy to understand that the processes shown in the above-mentioned figures do not indicate or limit the time sequence of these processes. In addition, it is also easy to understand that these processes can be performed synchronously or asynchronously, for example, in multiple modules.

[0087] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing what is disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary technical means in the art that are not disclosed in the present disclosure. The specification and embodiments are to be considered merely as exemplary, and the true scope and spirit of the present disclosure are indicated by the claims.

[0088] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A method for preparing spherical copper oxide powder, characterized in that: include: A copper salt aqueous solution and a weak base aqueous solution are prepared; wherein the copper salt aqueous solution contains a dispersant; converting the copper salt aqueous solution into a copper salt aerosol, and adding the copper salt aerosol into the weak base aqueous solution to obtain a suspension containing a copper compound; Performing a homogeneous hydrothermal reaction on the suspension of the copper compound to obtain a copper precursor suspension; The copper precursor suspension is subjected to solid-liquid separation, and the obtained solid matter is dried to obtain spherical copper oxide powder.

2. The preparation method according to claim 1, characterized in that: The copper salt in the copper salt aqueous solution is copper acetate or copper chloride, and the copper ion concentration in the copper salt aqueous solution is 40 g / L to 70 g / L; The dispersant is a mixture of one or more of cetyltrimethylammonium bromide, polyethylene glycol, polyvinyl alcohol, polyvinyl pyrrolidone, and sodium dodecylbenzene sulfonate, and the mass fraction of the dispersant is 1% to 5%; The weak base in the weak base aqueous solution is sodium carbonate or ammonium bicarbonate, and the alkali concentration in the weak base aqueous solution is 50 g / L to 100 g / L.

3. The preparation method according to claim 1, characterized in that: Converting the copper salt aqueous solution into a copper salt aerosol comprises: converting the copper salt aqueous solution into a copper salt aerosol by using an atomizing device; Wherein, the liquid inlet amount of the copper salt aqueous solution in the atomizing device is set to 110 mL / h to 350 mL / h, and the gas flow rate of the atomizing device is set to 5 L / min to 20 L / min.

4. The preparation method according to claim 1, characterized in that: The copper-containing compound suspension is subjected to a homogeneous hydrothermal reaction to obtain a copper precursor suspension, comprising: The suspension of the copper compound is placed in a sealed reaction kettle, and subjected to a homogeneous hydrothermal reaction at a temperature of 60° C. to 100° C. for a reaction time of 4 h to 10 h to obtain a copper precursor suspension.

5. The preparation method according to claim 1, characterized in that: The copper precursor suspension is subjected to solid-liquid separation, and the obtained solid matter is dried to obtain spherical copper oxide powder, comprising: The copper precursor suspension is subjected to solid-liquid separation by suction filtration or centrifugation; The obtained solid material is dried by vacuum drying or freeze drying to obtain spherical copper oxide powder.

6. A method for preparing spherical copper oxide powder, characterized in that: include: A copper salt aqueous solution and a weak base aqueous solution are prepared; wherein the copper salt aqueous solution contains a dispersant; converting the weak base aqueous solution into a weak base aerosol, and adding the weak base aerosol into the copper salt aqueous solution to obtain a suspension containing a copper compound; Performing a homogeneous hydrothermal reaction on the suspension of the copper compound to obtain a copper precursor suspension; The copper precursor suspension is subjected to solid-liquid separation, and the obtained solid matter is dried to obtain spherical copper oxide powder.

7. A method for preparing spherical copper powder, characterized in that: include: Spherical copper oxide powder is prepared by the method for preparing spherical copper oxide powder according to any one of claims 1 to 6; The spherical copper oxide powder is subjected to hydrogen reduction treatment to obtain spherical copper powder.

8. The preparation method according to claim 7, characterized in that: The spherical copper oxide powder is subjected to hydrogen reduction treatment to obtain spherical copper powder, comprising: The temperature is raised to 180° C. to 300° C. at a heating rate of 5° C. / min to 10° C. / min, the spherical copper oxide powder is subjected to hydrogen reduction treatment, and the temperature is kept for 30 minutes to 2 hours to obtain spherical copper powder.

9. A spherical copper oxide powder, characterized in that: The spherical copper oxide powder is prepared by the preparation method of any one of claims 1 to 6.

10. A spherical copper powder, characterized in that: The spherical copper powder is prepared by the preparation method of claim 7 or 8.

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