Molybdenum powder preparation method and molybdenum powder

Abstract

The invention relates to the technical field of nano material preparation, and provides a molybdenum powder preparation method and molybdenum powder.The molybdenum powder preparation method comprises the steps that original molybdenum trioxide is subjected to thermal shock treatment, and treated molybdenum trioxide is obtained; the defect of the treated molybdenum trioxide is higher than that of the original molybdenum trioxide; adding the treated molybdenum trioxide and a water-soluble carbon source into a solvent, and carrying out ultrasonic dispersion and ball milling treatment to obtain mixed slurry; dehydrating and drying the mixed slurry to obtain precursor powder of organic carbon coated molybdenum trioxide; performing inert atmosphere reduction treatment on the precursor powder to obtain molybdenum dioxide; carrying out gas reduction deoxidation treatment on the molybdenum dioxide to obtain molybdenum powder; and the particle size of the molybdenum powder is nanoscale. The method disclosed by the invention can be used for preparing the nano molybdenum powder with narrow particle size distribution.

Description

Technical Field

[0001] The present invention relates to the technical field of nano material preparation, and in particular to a molybdenum powder preparation method and molybdenum powder. Background Art

[0002] Molybdenum powder has the advantages of high melting point, high thermal conductivity and electrical conductivity, high elastic modulus, thermal neutron capture surface, good elongation performance, etc. It is often used to produce molybdenum alloys and molybdenum products, and can be widely used in the steel industry, non-ferrous metal industry, nuclear industry, aerospace industry, chemical industry, electronic industry and other fields. The purity, size, morphology and distribution of molybdenum powder directly affect the final quality and performance of molybdenum and molybdenum alloy products. Therefore, the research on molybdenum powder preparation technology and supporting processes has become a hot spot in the industry.

[0003] Currently, the molybdenum powder prepared by the industrialized molybdenum powder preparation method has a particle size of several microns, which is difficult to meet the needs of industrial development. Therefore, how to simply and efficiently prepare nano-molybdenum powder with a narrow particle size distribution is a technical problem that needs to be solved urgently.

[0004] 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. Summary of the invention

[0005] The purpose of the present disclosure is to provide a molybdenum powder preparation method and molybdenum powder, thereby overcoming the technical problem that nano molybdenum powder cannot be prepared simply and efficiently due to the limitations of related technologies, at least to a certain extent.

[0006] Other features and advantages of the present disclosure will become apparent from the following detailed description, or may be learned in part by the practice of the present disclosure.

[0007] According to a first aspect of the present disclosure, there is provided a method for preparing molybdenum powder, comprising:

[0008] Performing a thermal shock treatment on the original molybdenum trioxide to obtain treated molybdenum trioxide; the defects of the treated molybdenum trioxide are higher than those of the original molybdenum trioxide;

[0009] Adding the treated molybdenum trioxide and water-soluble carbon source into a solvent for ultrasonic dispersion and ball milling to obtain a mixed slurry;

[0010] Dehydrating and drying the mixed slurry to obtain a precursor powder of organic carbon-coated molybdenum trioxide;

[0011] Performing an inert atmosphere reduction treatment on the precursor powder to obtain molybdenum dioxide;

[0012] The molybdenum dioxide is subjected to gas reduction deoxidation treatment to obtain molybdenum powder; the particle size of the molybdenum powder is nanometer level.

[0013] In an exemplary embodiment of the present disclosure, the thermal shock treatment of the original molybdenum trioxide to obtain the treated molybdenum trioxide includes:

[0014] Performing a preset number of thermal shock treatments on the original molybdenum trioxide to obtain treated molybdenum trioxide; the preset number of times is 2 to 8 times;

[0015] Each thermal shock treatment includes heating the original molybdenum trioxide to a specified temperature and keeping it at a preset time, and then cooling it with liquid nitrogen after taking it out;

[0016] The specified temperature is 300° C. to 500° C., and the preset time is 20 min to 120 min.

[0017] In an exemplary embodiment of the present disclosure, the water-soluble carbon source is sucrose or glucose, the duration of the ultrasonic dispersion is 20 min to 100 min, and the ball milling speed used in the ball milling treatment is 100 r / min to 200 r / min.

[0018] In an exemplary embodiment of the present disclosure, the dehydration and drying includes spray drying, vacuum drying or freeze drying.

[0019] In an exemplary embodiment of the present disclosure, the inert atmosphere reduction treatment uses argon gas with a purity higher than a first preset purity threshold or nitrogen gas with a purity higher than a second preset purity threshold.

[0020] In an exemplary embodiment of the present disclosure, the reduction temperature used in the inert atmosphere reduction treatment is 500°C to 1000°C, the heating rate is less than 1°C / min to 5°C / min, and the insulation time after reaching the reduction temperature is 2h to 6h.

[0021] In an exemplary embodiment of the present disclosure, the gas reduction deoxidation treatment uses a hydrogen-argon mixed gas, and the dew point of the hydrogen is less than -20°C.

[0022] In an exemplary embodiment of the present disclosure, the reduction temperature used in the gas reduction dehydrogenation treatment is 500°C to 1200°C.

[0023] In an exemplary embodiment of the present disclosure, the reaction time of the gas reduction dehydrogenation treatment is 3 hours to 6 hours.

[0024] According to a second aspect of the present disclosure, there is provided a molybdenum powder, characterized in that it is prepared by the molybdenum powder preparation method described in the first aspect above.

[0025] It can be seen from the above technical solutions that the molybdenum powder preparation method in the exemplary embodiment of the present disclosure has at least the following advantages and positive effects:

[0026] In the technical solutions provided by some embodiments of the present disclosure, on the one hand, by subjecting the original molybdenum trioxide to thermal shock treatment to obtain treated high-defect molybdenum trioxide, a large number of defects, such as dislocations, vacancies, etc., can be introduced, and these defects can enhance the surface activity of the molybdenum trioxide and improve the subsequent reaction rate and efficiency; further, by adding the treated molybdenum trioxide and a water-soluble carbon source to a solvent for ultrasonic dispersion and ball milling treatment to obtain a mixed slurry, agglomeration can be effectively broken, so that the molybdenum trioxide and the carbon source are evenly dispersed in the solvent, ensuring the uniformity of the subsequent reaction, and the ball milling treatment can further refine the particles and reduce the particle size, Increase the surface area and improve the reaction activity; further, the mixed slurry is dehydrated and dried to obtain a precursor powder of organic carbon-coated molybdenum trioxide, which can avoid structural changes caused by water volatilization during subsequent high-temperature treatment, so that the water-soluble carbon source is evenly coated on the surface of molybdenum trioxide during the ball milling process to form an organic carbon-coated complex; on the other hand, the precursor powder is reduced in an inert atmosphere to obtain molybdenum dioxide, and the molybdenum dioxide is gas-reduced and deoxidized to obtain molybdenum powder, and finally molybdenum powder with a nanometer particle size is obtained, which has a high specific surface area and good dispersibility, and is suitable for a variety of high-end applications, such as catalysts, electronic materials, etc.

[0027] 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

[0028] 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.

[0029] Figure 1 A schematic diagram showing a process of preparing molybdenum powder in an embodiment of the present disclosure is shown;

[0030] Figure 2 A schematic diagram showing a specific process of the first molybdenum powder preparation method according to an embodiment of the present disclosure is shown;

[0031] Figure 3 The SEM image of the nano-molybdenum powder prepared in Example 1 of the present disclosure is shown;

[0032] Figure 4 A schematic diagram showing a specific process of a second molybdenum powder preparation method according to an embodiment of the present disclosure is shown;

[0033] Figure 5 A specific schematic diagram showing a method for preparing large-particle molybdenum powder in the related art;

[0034] Figure 6 The SEM image of the large-particle molybdenum powder prepared by the comparative example in the related art is shown. DETAILED DESCRIPTION

[0035] The following is an explanation of the implementation of the present disclosure by means of specific embodiments. People familiar with the art can easily understand other advantages and effects of the present disclosure from the contents disclosed in this specification.

[0036] It should be noted that the process equipment or devices not specifically specified in the following embodiments are all conventional equipment or devices in the art.

[0037] In addition, it should be understood that one or more method steps mentioned in the present disclosure do not exclude the existence of other method steps before or after the combination step or the insertion of other method steps between these explicitly mentioned steps, unless otherwise specified; it should also be understood that the combination connection relationship between one or more devices / apparatuses mentioned in the present disclosure does not exclude the existence of other devices / apparatuses before or after the combination device / apparatus or the insertion of other devices / apparatuses between these explicitly mentioned two devices / apparatuses, unless otherwise specified. Moreover, unless otherwise specified, the numbering of each method step is only a convenient tool for identifying each method step, and is not intended to limit the order of arrangement of each method step or to limit the scope of the present invention. Changes or adjustments in their relative relationships should also be regarded as the scope of the present disclosure without substantially changing the technical content.

[0038] At present, the industrialized method for preparing molybdenum powder is mainly the two-step hydrogen reduction of molybdenum trioxide. This process is to first reduce commercial molybdenum trioxide at 600-700°C to prepare molybdenum dioxide, and then further hydrogen reduce molybdenum dioxide at 850-1100°C to prepare molybdenum powder. This method has a large output and a mature process, but the prepared molybdenum powder has problems such as large particle size, low sintering activity and high sintering temperature. The particle size of the prepared molybdenum material reaches several microns, which restricts the further improvement of the performance of molybdenum products.

[0039] Nano powders have unique advantages such as small particle size, large specific surface area, and high sintering activity. They can significantly change the physical, mechanical and chemical properties of related alloys and products. Compared with traditional molybdenum powders, they can achieve sintering density of related products at a lower temperature, avoid grain coarsening, and improve product performance and added value while reducing energy consumption. With the rapid development of my country's economy and the structural upgrading of the manufacturing industry, the demand for nano molybdenum powder has gradually increased. Traditional processes usually achieve molybdenum powder particle size control by adjusting hydrogen dew point, material layer thickness, air flow field, etc. The control range of molybdenum powder particle size refinement is limited, and it is difficult to meet the needs of industrial development. Therefore, how to simply and efficiently prepare nano molybdenum powder with narrow particle size distribution through molybdenum trioxide is a technical problem that needs to be solved urgently.

[0040] Based on this, the present invention proposes a method for preparing nano-molybdenum powder with a narrow particle size distribution. The method increases the defects of molybdenum trioxide powder by means of cyclic rapid heating and cooling, ultrasonic oscillation and ball milling, and achieves uniform coating of molybdenum trioxide powder by a water-soluble carbon source, thereby improving the binding points and uniformity of the molybdenum source and the carbon source, providing convenience for the nucleation and inhibition of grain growth in the subsequent reduction process, and then preparing nano-molybdenum dioxide and molybdenum powder, solving the problems of abnormal growth, agglomeration and wide particle size distribution of molybdenum powder in the traditional hydrogen reduction process.

[0041] Next, the molybdenum powder preparation method in the embodiment of the present disclosure is specifically described. Specifically, refer to Figure 1 , Figure 1 The schematic flow chart of the method for preparing molybdenum powder in the embodiment of the present disclosure is shown, comprising steps S110 to S150:

[0042] In step S110, the original molybdenum trioxide is subjected to a thermal shock treatment to obtain treated molybdenum trioxide; the defects of the treated molybdenum trioxide are higher than those of the original molybdenum trioxide;

[0043] In step S120, the treated molybdenum trioxide and water-soluble carbon source are added to a solvent for ultrasonic dispersion and ball milling to obtain a mixed slurry;

[0044] In step S130, the mixed slurry is dehydrated and dried to obtain a precursor powder of organic carbon-coated molybdenum trioxide;

[0045] In step S140, the precursor powder is subjected to an inert atmosphere reduction treatment to obtain molybdenum dioxide;

[0046] In step S150, molybdenum dioxide is subjected to gas reduction deoxidation treatment to obtain molybdenum powder; the particle size of the molybdenum powder is nanometer level.

[0047] exist Figure 1In the technical solution provided by the illustrated embodiment, on the one hand, by subjecting the original molybdenum trioxide to thermal shock treatment to obtain treated high-defect molybdenum trioxide, a large number of defects, such as dislocations, vacancies, etc., can be introduced, and these defects can enhance the surface activity of molybdenum trioxide, thereby improving the subsequent reaction rate and efficiency; further, by adding the treated molybdenum trioxide and a water-soluble carbon source to a solvent for ultrasonic dispersion and ball milling treatment to obtain a mixed slurry, agglomeration can be effectively broken, so that the molybdenum trioxide and the carbon source are evenly dispersed in the solvent, thereby ensuring the uniformity of the subsequent reaction, and the ball milling treatment can further refine the particles, reduce the particle size, and increase Furthermore, the mixed slurry is dehydrated and dried to obtain a precursor powder of organic carbon-coated molybdenum trioxide, which can avoid structural changes caused by water volatilization during subsequent high-temperature treatment, so that the water-soluble carbon source is evenly coated on the surface of molybdenum trioxide during ball milling to form an organic carbon-coated composite; on the other hand, the precursor powder is reduced in an inert atmosphere to obtain molybdenum dioxide, and the molybdenum dioxide is subjected to gas reduction and deoxidation treatment to obtain molybdenum powder, and finally molybdenum powder with a nanometer particle size is obtained, which has a high specific surface area and good dispersibility and is suitable for a variety of high-end applications, such as catalysts, electronic materials, etc.

[0048] The following Figure 1 The specific implementation process of each step is described in detail:

[0049] In step S110, the original molybdenum trioxide is subjected to a thermal shock treatment to obtain treated molybdenum trioxide.

[0050] In this step, the original molybdenum trioxide can be subjected to a preset number of thermal shock treatments to obtain treated molybdenum trioxide.

[0051] Specifically, each thermal shock treatment may include: placing the original molybdenum trioxide in a crucible and placing it in a high-temperature muffle furnace to heat to a specified temperature, which may be 300°C to 500°C, and keeping it warm for a preset time, which may be 20 minutes to 120 minutes, and then quickly taking it out and quickly cooling it with liquid nitrogen. The thermal shock treatment is performed 2 to 8 times in a cycle to obtain the treated molybdenum trioxide.

[0052] The treated molybdenum trioxide can also be called high-defect molybdenum trioxide. For example, high defects can be reflected in dislocations, vacancies, cracks, grain boundaries, etc. in the internal crystal. Among them, dislocation refers to a linear defect in the crystal, which can be an edge dislocation, a screw dislocation or a mixed dislocation. Vacancy refers to a point defect in the crystal, that is, an atom missing at a lattice position, etc. Cracks refer to linear or planar defects in the material, which may cause the material to break. Grain boundaries refer to the interface between adjacent grains in polycrystalline materials, etc.

[0053] In step S120, the treated molybdenum trioxide and water-soluble carbon source are added to a solvent for ultrasonic dispersion and ball milling to obtain a mixed slurry.

[0054] In this step, the molybdenum trioxide and the water-soluble carbon source treated in step S110 can be added to a solvent for ultrasonic dispersion and ball milling to obtain a mixed slurry of molybdenum trioxide and the organic carbon source.

[0055] Ultrasonic dispersion refers to the process of using the energy of ultrasound to disperse solid particles in a liquid. When ultrasound propagates in a liquid, it produces alternating changes in compression and rarefaction, which causes tiny bubbles to form in the liquid, also known as cavitation. These bubbles grow rapidly and release a large amount of energy when they collapse, which can destroy particles that have gathered together and make them evenly distributed in the liquid medium.

[0056] Ball milling is a physical crushing method. The material is placed in a ball mill together with a certain amount and size of grinding media, such as zirconium balls. During the rotation, the collision and friction between the grinding media and between the grinding media and the container wall will crush and refine the material. Ball milling can not only refine the particle size of the material, but also change the crystal structure of the material and promote chemical reactions. It is one of the important means to prepare high-purity and fine-grained powder materials.

[0057] The duration of the ultrasonic dispersion may be 20 min to 100 min, and the ball milling speed used in the ball milling treatment may be 100 r / min to 200 r / min.

[0058] The water-soluble carbon source may be sucrose or glucose, and the solvent may be deionized water.

[0059] In step S130, the mixed slurry is dehydrated and dried to obtain a precursor powder of organic carbon-coated molybdenum trioxide.

[0060] In this step, the mixed slurry obtained in the above step S120 can be dehydrated and dried to obtain the precursor powder of organic carbon-coated molybdenum trioxide. Dehydration and drying is a process for removing water from the material, wherein the dehydration and drying can be carried out by spray drying, vacuum drying or freeze drying.

[0061] Spray drying is a method of rapidly drying liquid materials. It atomizes the liquid material into tiny droplets and directly contacts them with hot air, so that the water evaporates quickly, thereby obtaining a dry powder or granular product. This method is suitable for drying heat-sensitive materials because it can complete the drying process in a short time, reducing the time the material is heated, thereby avoiding the deterioration of the material due to long-term high temperature.

[0062] Vacuum drying is a drying process carried out under reduced pressure. By reducing the ambient pressure, the boiling point of water is reduced, so that the water in the material evaporates at a lower temperature. This method is particularly suitable for materials that are sensitive to temperature or easily oxidized, because effective drying can be achieved at a relatively low temperature.

[0063] Freeze drying, also known as freeze drying, is a method of removing water from materials through a sublimation process under low temperature and low pressure conditions. The material is first frozen and then heated under a vacuum environment, causing the ice to sublime directly into steam and be pumped away.

[0064] In step S140, the precursor powder is subjected to an inert atmosphere reduction treatment to obtain molybdenum dioxide.

[0065] In this step, the precursor powder obtained in the above step S130 can be subjected to an inert atmosphere reduction treatment to obtain molybdenum dioxide.

[0066] Among them, inert atmosphere reduction treatment refers to a process method for preparing a target product by causing a precursor material to undergo a reduction reaction by heating or other means in a gas environment that does not chemically react with the reactants. In this treatment process, the main function of the inert atmosphere is to prevent the precursor material or intermediate product from having unnecessary side reactions with oxygen, water vapor, etc. in the air, and to ensure that the reduction reaction can proceed smoothly. The inert atmosphere reduction treatment may use argon gas with a purity higher than a first preset purity threshold or nitrogen gas with a purity higher than a second preset purity threshold. For example, the first preset purity threshold may be, for example, 99.99%, and the second preset purity threshold may be, for example, 99.999%. Both can be set according to actual needs, and the present disclosure does not make any special restrictions on this.

[0067] In addition, when performing the inert atmosphere reduction treatment, the reduction temperature used is 500°C to 1000°C, the heating rate is less than 1°C / min to 5°C / min, and the insulation time after reaching the reduction temperature is 2h to 6h.

[0068] In step S150, molybdenum dioxide is subjected to gas reduction deoxidation treatment to obtain molybdenum powder; the particle size of the molybdenum powder is nanometer level.

[0069] In this step, the molybdenum dioxide obtained in step S140 can be subjected to gas reduction deoxidation treatment to obtain molybdenum powder, and the particle size of the obtained molybdenum powder is nanometer level. Gas reduction deoxidation treatment refers to the process of removing oxygen elements in the material through chemical reaction in a specific gas environment, thereby reducing it to a metallic state.

[0070] The hydrogen-argon mixed gas used in the gas reduction deoxidation treatment has a dew point of hydrogen <-20°C, a reduction temperature of 500°C to 1200°C, and a reaction time of 3h to 6h.

[0071] The solution of the embodiment of the present disclosure is described in detail below through specific examples.

[0072] Example 1

[0073] refer to Figure 2 , Figure 2 The specific process diagram of the first molybdenum powder preparation method in the embodiment of the present disclosure is shown, which includes the following steps S201-S205:

[0074] In step S201, 50 g of molybdenum trioxide is placed in a crucible and placed in a 500° C. high-temperature muffle furnace for heating and heat preservation for 100 min, and then quickly taken out and quickly cooled with liquid nitrogen, and the cycle is repeated twice to obtain high-defect molybdenum trioxide;

[0075] In step S202, the high-defect molybdenum trioxide obtained in step S201 and glucose in a mass ratio of 1:0.2 are placed in 80° C. deionized water for ultrasonic dispersion for 30 minutes, and then ball-milled at a speed of 100 r / min for 2 hours to obtain a mixed slurry of molybdenum trioxide and glucose;

[0076] In step S203, the mixed slurry obtained in step S202 is spray-dried at 210° C. to obtain an organic carbon-coated molybdenum trioxide precursor powder;

[0077] In step S204, the precursor powder obtained in step S203 is placed in a tube furnace for reduction in a nitrogen atmosphere for 2 hours at a reduction temperature of 500°C;

[0078] In step S205, the molybdenum dioxide obtained in step S204 is further reduced with a hydrogen-argon mixed gas at 1000° C. for 4 hours to obtain nano-molybdenum powder with a narrow particle size distribution.

[0079] refer to Figure 3 , Figure 3 The SEM (Scanning Electron Microscopy) image of the nano-molybdenum powder prepared by Example 1 in the present disclosure is shown, and the scale of the image is 500nm. The nano-molybdenum powder has a narrow particle size uniform distribution (it means that the prepared molybdenum powder particles have a smaller particle size, and the size distribution of these particles is very concentrated without obvious size differences).

[0080] Example 2

[0081] refer to Figure 4 , Figure 4 The specific flow chart of the second molybdenum powder preparation method in the embodiment of the present disclosure is shown, which includes the following steps S401-S405:

[0082] In step S401, 50 g of molybdenum trioxide is placed in a crucible and placed in a 500° C. high-temperature muffle furnace for heating and heat preservation for 100 min, and then quickly taken out and quickly cooled with liquid nitrogen, and the cycle is repeated twice to obtain high-defect molybdenum trioxide;

[0083] In step S402, the high-defect molybdenum trioxide obtained in step S401 and glucose in a mass ratio of 1:0.2 are placed in 90° C. deionized water for ultrasonic dispersion for 20 minutes, and then ball-milled at a speed of 120 r / min for 3 hours to obtain a mixed slurry of molybdenum trioxide and glucose;

[0084] In step S403, the mixed slurry obtained in step S402 is spray-dried at 230° C. to obtain an organic carbon-coated molybdenum trioxide precursor powder;

[0085] In step S404, the precursor powder obtained in step S403 is placed in a tube furnace for reduction in a nitrogen atmosphere for 3 hours at a reduction temperature of 550°C;

[0086] In step S405, the molybdenum dioxide obtained in step S404 is further reduced with a hydrogen-argon mixed gas at 980°C for 4 hours to obtain nano-molybdenum powder with a narrow particle size distribution.

[0087] Comparative Example

[0088] refer to Figure 5 , Figure 5 A specific flow chart of a method for preparing large-particle molybdenum powder in the related art is shown, which includes the following steps S501-S502:

[0089] In step S501, 50 g of molybdenum trioxide is placed in a crucible and placed in a tube furnace, and hydrogen reduction is performed at 580° C. for 120 min to obtain molybdenum dioxide;

[0090] In step S502, the molybdenum dioxide in step S501 is crushed and sieved and then placed in a tubular furnace for further hydrogen reduction at a reduction temperature of 1100° C. for a reduction time of 4 hours to obtain large-particle molybdenum powder.

[0091] refer to Figure 6 , Figure 6 The SEM (Scanning Electron Microscopy) image of the large-particle molybdenum powder prepared by the comparative example in the related art is shown. The scale of the image is 5 microns. The particle size of the large-particle molybdenum powder is in the micron level and is unevenly distributed.

[0092] By comparing the above-mentioned Example 1 / Example 2 with the comparative example, it can be seen that the present disclosure has at least the following advantages compared with the prior art:

[0093] First, the present invention increases the internal stress of the particles, improves the internal defects and external cracks of the molybdenum trioxide by rapidly heating and cooling, ultrasonic oscillation, etc., to the highly dispersed molybdenum trioxide, thereby facilitating the improvement of the uniformity of the subsequent mixing and increasing the reaction activity of the molybdenum trioxide, and providing a basis for the subsequent preparation of nano molybdenum powder;

[0094] Second, the present disclosure adopts a water-soluble organic carbon source to make the organic carbon source infiltrate into the defects of the molybdenum source, thereby improving the mixing uniformity and coating of the molybdenum source and the carbon source, providing more binding sites and nucleation sites for the subsequent inert atmosphere reduction stage, improving the reaction efficiency, and inhibiting the abnormal growth of molybdenum trioxide in the reduction stage to molybdenum dioxide;

[0095] Third, the present disclosure uses a hydrogen-argon mixed gas to reduce molybdenum dioxide, which effectively reduces the reaction rate and the amount of water vapor generated, and inhibits grain growth and agglomeration;

[0096] Fourth, the raw materials used in the present invention are common commercial molybdenum trioxide and organic carbon, which have a wide range of sources, low cost, easy promotion, and high industrial application prospects.

[0097] It should be noted that the above embodiments are only illustrative of the principles and effects of the present disclosure, and are not intended to limit the present disclosure. Anyone familiar with the technology may modify or change the above embodiments without violating the spirit and scope of the present disclosure. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed in the present disclosure should still be covered by the claims of the present disclosure.

Claims

1. A method for preparing molybdenum powder, characterized in that: include: Performing a thermal shock treatment on the original molybdenum trioxide to obtain treated molybdenum trioxide; the defects of the treated molybdenum trioxide are higher than those of the original molybdenum trioxide; Adding the treated molybdenum trioxide and water-soluble carbon source into a solvent for ultrasonic dispersion and ball milling to obtain a mixed slurry; Dehydrating and drying the mixed slurry to obtain a precursor powder of organic carbon-coated molybdenum trioxide; Performing an inert atmosphere reduction treatment on the precursor powder to obtain molybdenum dioxide; The molybdenum dioxide is subjected to gas reduction deoxidation treatment to obtain molybdenum powder; the particle size of the molybdenum powder is nanometer level.

2. The method according to claim 1, characterized in that The method of subjecting the original molybdenum trioxide to thermal shock treatment to obtain treated molybdenum trioxide comprises: Performing a preset number of thermal shock treatments on the original molybdenum trioxide to obtain treated molybdenum trioxide; the preset number of times is 2 to 8 times; Each thermal shock treatment includes heating the original molybdenum trioxide to a specified temperature and keeping it at a preset time, and then cooling it with liquid nitrogen after taking it out; The specified temperature is 300° C. to 500° C., and the preset time is 20 min to 120 min.

3. The method according to claim 1, characterized in that The water-soluble carbon source is sucrose or glucose, the duration of the ultrasonic dispersion is 20 minutes to 100 minutes, and the ball milling speed used in the ball milling treatment is 100 r / min to 200 r / min.

4. The method according to claim 1, characterized in that The dehydration drying includes spray drying, vacuum drying or freeze drying.

5. The method according to claim 1, characterized in that The inert atmosphere reduction treatment uses argon gas with a purity higher than a first preset purity threshold or nitrogen gas with a purity higher than a second preset purity threshold.

6. The method according to claim 5, characterized in that The reduction temperature used in the inert atmosphere reduction treatment is 500° C. to 1000° C., the heating rate is less than 1° C. / min to 5° C. / min, and the insulation time after reaching the reduction temperature is 2h to 6h.

7. The method according to claim 1, characterized in that The gas reduction deoxidation treatment uses a hydrogen-argon mixed gas, and the dew point of the hydrogen is less than -20°C.

8. The method according to claim 7, characterized in that The reduction temperature used in the gas reduction dehydrogenation treatment is 500°C to 1200°C.

9. The method according to claim 8, characterized in that The reaction time of the gas reduction dehydrogenation treatment is 3h to 6h.

10. A molybdenum powder, characterized in that: The molybdenum powder is prepared according to the method for preparing the molybdenum powder according to any one of claims 1 to 9.

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