Preparation method of rhenium powder with micro-nano particle size

Abstract

The invention relates to the technical field of rhenium powder preparation, in particular to a preparation method of rhenium powder with micro-nano granularity. The method comprises the following steps: mixing a crude ammonium rhenate raw material with deionized water in proportion, and heating and dissolving the mixture on a heating table to form an unsaturated solution; subsequently, introducing the ammonium rhenate solution into a peristaltic pump, and introducing the ammonium rhenate solution into centrifugal spray drying equipment in cooperation with an auxiliary heater to obtain ultrafine-grained ammonium rhenate powder; then low-temperature hydrogen introduction reduction is conducted through a pusher reduction furnace, and rhenium oxide powder is obtained; and then carrying out high-temperature hydrogen introduction reduction through a pusher reduction furnace, and finally obtaining the superfine rhenium powder within 10 microns. The rhenium powder prepared through the method is in the micro-nano particle size, the technological process is short, large-scale continuous production can be achieved, impurity pollution is extremely little, and the product can be widely applied to rhenium element doping strengthening.

Description

Technical Field

[0001] The invention relates to the technical field of rhenium powder preparation, and in particular to a method for preparing micro-nano particle size rhenium powder. Background Art

[0002] Rhenium plays an indispensable role in the field of high-temperature alloys. Adding rhenium to metal matrices such as tungsten and molybdenum can significantly exert the "rhenium effect", thereby enhancing their processing plasticity and high-temperature mechanical properties. At the same time, rhenium powder, as the basic raw material for rhenium products, has many product forms, including conventional rhenium powder, ultrafine rhenium powder, spherical rhenium powder and ultra-high purity rhenium powder, etc., while rhenium powder with micro-nano scale (i.e., particle size <10μm) and public preparation technology are very rare. The main application of rhenium powder with micro-nano particles is element doping, such as doping and modification of cemented carbide for special tools, pumps and valves, shafts, transmission parts, and wear-resistant parts for equipment, and doping for smelting, powder metallurgy and compound preparation.

[0003] Since the ammonium rhenate particles obtained from copper ore and molybdenum concentrate are usually extremely coarse, they need to be refined. At present, the commonly used methods are ball milling, grinding, ultrasonic crushing, and powder milling for refinement. However, it is difficult to refine ammonium rhenate or intermediate products to the micro-nano scale by the above methods, and impurity elements are easily introduced after contact with grinding media and utensils. Furthermore, fine-grained rhenium is easily oxidized in the air due to its large surface area, and even spontaneously combusts. Through short-process treatment, hydrogenation throughout the process, and controlled reduction process, the particle size of the powder can be effectively maintained, and it is loose and not compacted. Summary of the invention

[0004] The invention discloses a method for producing micro-nano particle size rhenium powder to solve the problems of large particle size and low purity in the prior art.

[0005] In order to achieve the above object, the technical solution provided by the present invention is: a method for preparing micro-nano particle size rhenium powder, the preparation method specifically comprising the following steps:

[0006] S1) mixing crude ammonium rhenate and deionized water in proportion, placing on a heating table and heating to dissolve to form an unsaturated solution;

[0007] S2) connecting the ammonium rhenate solution obtained in S1) to a peristaltic pump, and passing it into a centrifugal spray drying device with an auxiliary heater to obtain an ultrafine ammonium rhenate powder;

[0008] S3) putting the ammonium rhenate powder obtained in S2) into a boat, and performing low-temperature hydrogen reduction in a push-boat reduction furnace to obtain rhenium oxide powder;

[0009] S4) crushing and sieving the powder obtained in S3), and then reducing it with high temperature hydrogen in a push boat reduction furnace to finally obtain rhenium powder with a particle size of less than 10 μm.

[0010] Furthermore, the purity of the ammonium rhenate in S1) is ≥99%; the ratio of ammonium rhenate to deionized water is 1 g / L-250 g / L.

[0011] Furthermore, the temperature of the heating table in S1) is 100-300° C., the heating method is a water bath or an oil bath, and the material of the container for the ammonium rhenate solution is glass.

[0012] Furthermore, the peristaltic pump speed in S2) is 10-50 rpm; the auxiliary heating temperature is 70-100°C; the atomizing pump speed is 15000-30000rpm; the air inlet temperature is 150-200°C, and the cavity and the pipeline in contact with the material are all sprayed with polytetrafluoroethylene or highly chlorinated polyethylene coating.

[0013] Furthermore, the boat pushing speed in S3) is 30-60 min / time, the boat loading amount is 0.3-1 kg, the reduction temperature is controlled at 280-350 ° C, and the hydrogen flow rate is controlled at 3-5 m 3 / h.

[0014] Furthermore, the boat pushing speed in S4) is 20-40 min / time, the boat loading amount is 0.3-1 kg, the reduction temperature is controlled at 900-1000 ° C, and the hydrogen flow rate is controlled at 2-6 m 3 / h.

[0015] Furthermore, the material of the crushing rod in S4) is corundum, and the mesh number of the sieve is ≥40 meshes.

[0016] Furthermore, the pressure inside the furnace during production of the equipment in S3) and S4) is slightly positive.

[0017] Furthermore, the value of the slight positive pressure is ≥ atmospheric pressure + 0.5 Kpa.

[0018] A rhenium powder with micro-nano particle size is prepared by the above method.

[0019] The beneficial effects of the present invention are:

[0020] (1) The present invention makes full use of the advantages of ultra-high speed centrifugal spray drying and explores a specific speed range to allow the ammonium rhenate solution to quickly precipitate into a specific particle size. At the same time, by relying on the mechanism of reverse hydrogen flow in the push-boat reduction furnace equipment, the particle size of the prepared rhenium powder is less than 10 μm, and even includes a scale of hundreds of nanometers.

[0021] (2) The present invention controls the material of the heating and grinding vessels, reduces the process steps, and sprays customized anti-corrosion polytetrafluoroethylene or highly chlorinated polyethylene coatings on the spray chamber and the contact points between the pipes and the materials, thereby effectively avoiding the introduction of Fe elements and other equipment corrosion products such as Cu, Cr, Ni, etc. due to the introduction of impurities in the contact materials and the corrosion of the hot solution of ammonium rhenate and the stainless steel in the chamber.

[0022] (3) The process of preparing micro-nano particle size rhenium powder of the present invention is short and can be mass-produced. The technical route only involves spray drying and reduction steps, and both can be continuously produced using industrial equipment, and the cost per kilogram of product is relatively low. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a FESEM morphology image of ammonium rhenate prepared by the preparation method Example 1 of the present invention.

[0024] Figure 2 This is a laser particle size distribution diagram of rhenium powder prepared by Example 2 of the preparation method of the present invention.

[0025] Figure 3 This is a FESEM morphology image of rhenium powder prepared in Example 3 of the preparation method of the present invention. DETAILED DESCRIPTION

[0026] The present invention will be further described below in conjunction with specific embodiments.

[0027] The present invention provides a method for preparing rhenium powder with micro-nano particle size, and the method specifically comprises the following steps:

[0028] S1) mixing the crude ammonium rhenate raw material and deionized water in proportion, placing the mixture on a heating table and heating to dissolve the mixture to form an unsaturated solution;

[0029] S2) connecting the obtained ammonium rhenate solution to a peristaltic pump, and passing it into a centrifugal spray drying device with an auxiliary heater to obtain an ultrafine ammonium rhenate powder;

[0030] S3) loading the obtained ammonium rhenate powder into a boat, and performing low-temperature hydrogen reduction in a push-boat reduction furnace to obtain rhenium oxide powder;

[0031] S4) The obtained powder is appropriately crushed and sieved, and then reduced with high temperature hydrogen in a push boat reduction furnace to finally obtain rhenium powder with micro-nano particle size.

[0032] Furthermore, the purity of the ammonium rhenate in S1) is ≥99%, and the particle size is not limited; the ratio of ammonium rhenate to deionized water is 1g / L-250g / L.

[0033] Furthermore, the temperature of the heating table in S1) is 100-300° C., the heating method is a water bath or an oil bath, and the material of the container for the ammonium rhenate solution is glass.

[0034] Furthermore, the peristaltic pump speed in S2) is 10-50 rpm; the auxiliary heating temperature is 70-100°C; the atomizing pump speed is 15000-30000rpm; the air inlet temperature is 150-200°C, and the cavity and the pipeline in contact with the material are all sprayed with polytetrafluoroethylene or highly chlorinated polyethylene coating.

[0035] Furthermore, the boat pushing speed in S3) is 30-60 min / time, the boat loading amount is 0.3-1 kg, the reduction temperature is controlled at 280-350 ° C, and the hydrogen flow rate is controlled at 3-5 m 3 / h.

[0036] Furthermore, the material of the crushing rod in S4) is corundum, and the mesh number of the sieve is ≥40 meshes.

[0037] Furthermore, the pressure in the furnace during production of the equipment in S3) and S4) is slightly positive pressure (≥ atmospheric pressure + 0.5 Kpa).

[0038] Furthermore, the boat pushing speed in S4) is 20-40 min / time, the boat loading amount is 0.3-1 kg, the reduction temperature is controlled at 900-1000 ° C, and the hydrogen flow rate is controlled at 2-6 m 3 / h.

[0039] Embodiment 1:

[0040] A method for preparing rhenium powder of micro-nano particle size comprises the following steps: step 1: mixing ammonium rhenate raw material with a purity of 99.99% and deionized water at a ratio of 250 g / L in a glass reactor, placing the mixture on a heating table and heating it to 100° C., dissolving the mixture in a water bath or oil bath to form an unsaturated solution; step 2: connecting the obtained ammonium rhenate solution to a peristaltic pump at a speed of 30 revolutions per minute, heating the mixture to 70° C. with an auxiliary heater, and passing the mixture into a centrifugal spray drying device, wherein the cavity and the pipeline are connected to the peristaltic pump; All contact points of the materials are sprayed with polytetrafluoroethylene coating, the speed of the atomizing pump is 20000rpm; the air inlet temperature is 160℃, and ammonium rhenate powder with a particle size of less than 10μm is obtained; Step 3: The obtained ammonium rhenate powder is loaded into a boat, and low-temperature hydrogen reduction is carried out through a push boat reduction furnace. The pressure in the furnace is slightly positive (atmospheric pressure + 0.5Kpa), the push boat speed is 30min / time, the boat loading amount is 1kg, the reduction temperature is controlled at 280℃, and the hydrogen flow rate is controlled at 5m 3 / h, to obtain rhenium oxide powder; Step 4: The obtained powder is appropriately crushed with a corundum rod and sieved through a 40-mesh screen, and then passed through a push boat reduction furnace for high-temperature hydrogen reduction. The pressure in the furnace is slightly positive (atmospheric pressure + 0.6Kpa), the push boat speed is 20min / time, the boat loading is 0.3kg, the reduction temperature is controlled at 900℃, and the hydrogen flow rate is controlled at 2m 3 / h, and finally obtained rhenium powder with a purity of 99.988% and an average particle size of 5.6μm.

[0041] Embodiment 2:

[0042] A method for preparing rhenium powder of micro-nano particle size comprises the following steps: step 1: mixing ammonium rhenate raw material with a purity of 99.998% and deionized water at a ratio of 200 g / L in a glass reactor, placing the mixture on a heating table and heating it to 180°C, dissolving it in an oil bath, and forming an unsaturated solution; step 2: connecting the obtained ammonium rhenate solution to a peristaltic pump at a rate of 50 revolutions per minute, heating it to 100°C with an auxiliary heater, and passing it into a centrifugal spray drying device, wherein the cavity and the pipeline are connected to the peristaltic pump. The contact points of the materials are all sprayed with high chlorinated polyethylene coating, the speed of the atomizing pump is 30000rpm; the air inlet temperature is 200℃, and ultra-fine ammonium rhenate powder is obtained; Step 3: The obtained ammonium rhenate powder is loaded into a boat, and low-temperature hydrogen reduction is carried out through a push boat reduction furnace. The pressure in the furnace is slightly positive (atmospheric pressure + 0.5Kpa), the push boat speed is 50min / time, the boat loading amount is 0.6kg, the reduction temperature is controlled at 350℃, and the hydrogen flow rate is controlled at 3m 3 / h, to obtain rhenium oxide powder; Step 4: The obtained powder is appropriately crushed with a corundum rod and sieved to 100 mesh, and then passed through a push boat reduction furnace for high-temperature hydrogen reduction. The pressure in the furnace is slightly positive (atmospheric pressure + 0.7Kpa), the push boat speed is 40min / time, the boat loading is 0.6kg, the reduction temperature is controlled at 950℃, and the hydrogen flow rate is controlled at 6m 3 / h, and finally obtained rhenium powder with a purity of 99.995% and an average particle size of 3.5μm.

[0043] Embodiment 3:

[0044] A method for preparing rhenium powder with micro-nano particle size comprises the following steps: step 1: mixing ammonium rhenate raw material with a purity of 99.5% and deionized water at a ratio of 50 g / L in a glass reactor, placing the mixture on a heating table and heating it to 300° C., dissolving the mixture in an oil bath, and forming an unsaturated solution; step 2: connecting the obtained ammonium rhenate solution to a peristaltic pump at a rate of 10 rpm, heating the mixture to 80° C. with an auxiliary heater, and passing the mixture into a centrifugal spray drying device, spraying polytetrafluoroethylene coatings on the cavity and the pipes at contact with the material, and the speed of the atomizing pump is 20000 rpm; the air inlet temperature is 180° C., and ultrafine ammonium rhenate powder is obtained; step 3: loading the obtained ammonium rhenate powder into a boat, and performing low-temperature hydrogen reduction in a boat-pushing reduction furnace, wherein the pressure in the furnace is a slightly positive pressure (atmospheric pressure+0.6 Kpa), the boat-pushing speed is 60 min / time, the boat loading amount is 0.3 kg, the reduction temperature is controlled at 300° C., and the hydrogen flow rate is controlled at 3 m 3 / h, to obtain rhenium oxide powder; Step 4: The obtained powder is appropriately crushed with a corundum rod and sieved through 80 mesh, and then passed through a push boat reduction furnace for high-temperature hydrogen reduction. The pressure in the furnace is slightly positive (atmospheric pressure + 1Kpa), the push boat speed is 40min / time, the boat loading is 0.3kg, the reduction temperature is controlled at 1000℃, and the hydrogen flow rate is controlled at 4m 3 / h, and finally obtained rhenium powder with a purity of 99.503% and an average particle size of 4.8μm.

[0045] Embodiment 4:

[0046] A method for preparing rhenium powder with micro-nano particle size comprises the following steps: step 1: mixing ammonium rhenate raw material with a purity of 99% and deionized water at a ratio of 1g / L in a glass reactor, placing the mixture on a heating table and heating it to 100°C, dissolving the mixture in a water bath, and forming an unsaturated solution; step 2: connecting the obtained ammonium rhenate solution to a peristaltic pump at a rate of 40 rpm, heating the mixture to 90°C with an auxiliary heater, and passing the mixture into a centrifugal spray drying device, spraying a high-chlorinated polyethylene coating on the cavity and the pipes in contact with the material, and the speed of the atomizing pump is 15000rpm; the air inlet temperature is 150°C, and ultra-fine ammonium rhenate powder is obtained; step 3: loading the obtained ammonium rhenate powder into a boat, and performing low-temperature hydrogen reduction in a boat-pushing reduction furnace, wherein the pressure in the furnace is a slightly positive pressure (atmospheric pressure+0.8Kpa), the boat-pushing speed is 30min / time, the boat loading amount is 0.3kg, the reduction temperature is controlled at 290°C, and the hydrogen flow rate is controlled at 5m 3 / h, to obtain rhenium oxide powder; Step 4: The obtained powder is appropriately crushed with a corundum rod and sieved to 200 mesh, and then passed through a push boat reduction furnace for high-temperature hydrogen reduction. The pressure in the furnace is slightly positive (atmospheric pressure + 0.8Kpa), the push boat speed is 20min / time, the boat loading is 0.3kg, the reduction temperature is controlled at 900℃, and the hydrogen flow rate is controlled at 2m 3 / h, and finally obtained rhenium powder with a purity of 99.004% and an average particle size of 7.2μm.

[0047] Test example:

[0048] 1. Powder morphology characterization: In this experiment, a field emission scanning electron microscope (SEM) from JEOL was used to observe the microscopic morphology of rhenium powder.

[0049] 2. Determination of chemical composition purity of powder: This test adopts glow discharge mass spectrometry (GDMS) method, referring to the non-ferrous metal industry standard YS / T 1017-2015, to detect the 30 impurity elements involved, so as to obtain the purity of the main element Re.

[0050] 3. Powder particle size determination: This test uses a laser particle size distribution analyzer to test the powder particle size of the powder obtained in the preparation process. The test method is a wet method.

[0051] First, from Figure 1 It can be seen that after spray drying, Example 1 can produce extremely fine ammonium rhenate. From the SEM morphology measurement, almost all the particle sizes are less than 5 μm, and a few particle sizes are 700-900 nm. This also proves that the present invention has the raw material conditions for preparing micro-nanoscale rhenium powder.

[0052] Figure 2 It shows that Example 2 further illustrates that through the preparation method described in the present invention, rhenium powder with a particle size of less than 10 μm can be obtained, the laser particle size is bimodal distribution, the average particle size is 4.52 μm, and a small part of the particles have a particle size distribution within 100-1000 nm, which proves that the present invention successfully produces micro-nano scale rhenium powder.

[0053] Figure 3 It is further confirmed from the SEM morphology that the particle size of the rhenium powder obtained in Example 3 is about 5 μm, and a few powder particles have a particle size of several hundred nanometers and are in an agglomerated state.

[0054] Figure 4:

[0055]

[0056] Graph 4 shows the GDMS purity of the rhenium powder prepared in Examples 1-4. From the purity results, it can be seen that the present invention effectively retains the purity of the material by controlling the material in contact with the material and the spraying chamber and pipeline for spraying treatment, and basically eliminates the possibility of introducing impurity elements to reduce the purity of the rhenium powder.

[0057] The above is a detailed introduction to the preparation method of micro-nano particle size rhenium powder provided in the embodiment of the present application. The description of the above embodiment is only used to help understand the method and core idea of ​​the present application; at the same time, for ordinary technicians in this field, according to the idea of ​​the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as limiting the present application.

[0058] For example, certain words are used in the specification and claims to refer to specific components. Those skilled in the art should understand that hardware manufacturers may use different nouns to refer to the same component. This specification and claims do not use differences in names as a way to distinguish components, but use differences in the functions of components as the criteria for distinction. As mentioned throughout the specification and claims, "including" and "comprising" are open-ended terms, so they should be interpreted as "including / including but not limited to". "Approximately" means that within an acceptable error range, those skilled in the art can solve the technical problem within a certain error range and basically achieve the technical effect. The subsequent description of the specification is a preferred embodiment of the present application, but the description is for the purpose of illustrating the general principles of the present application, and is not used to limit the scope of the present application. The scope of protection of the present application shall be determined by the definition of the attached claims.

[0059] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a product or system including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such a product or system. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the product or system including the elements.

[0060] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0061] The above description shows and describes several preferred embodiments of the present application, but as mentioned above, it should be understood that the present application is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the application concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art do not deviate from the spirit and scope of the present application, and should be within the scope of protection of the claims attached to the present application.

Claims

1. A method for preparing micro-nano particle size rhenium powder, characterized in that: The preparation method specifically comprises the following steps: S1) mixing crude ammonium rhenate and deionized water in proportion, placing on a heating table and heating to dissolve to form an unsaturated solution; S2) connecting the ammonium rhenate solution obtained in S1) to a peristaltic pump, and passing it into a centrifugal spray drying device with an auxiliary heater to obtain an ultrafine ammonium rhenate powder; S3) putting the ammonium rhenate powder obtained in S2) into a boat, and performing low-temperature hydrogen reduction in a push-boat reduction furnace to obtain rhenium oxide powder; S4) crushing and sieving the powder obtained in S3), and then reducing it with high temperature hydrogen in a push boat reduction furnace to finally obtain rhenium powder with a particle size of less than 10 μm.

2. The preparation method according to claim 1, characterized in that: The purity of the ammonium rhenate in S1) is ≥99%; the ratio of ammonium rhenate to deionized water is 1 g / L-250 g / L.

3. The preparation method according to claim 1, characterized in that: The temperature of the heating table in S1) is 100-300° C., the heating method is a water bath or an oil bath, and the container for the ammonium rhenate solution is made of glass.

4. The preparation method according to claim 1, characterized in that: The peristaltic pump speed in S2) is 10-50 rpm; the auxiliary heating temperature is 70-100°C; the atomizing pump speed is 15000-30000rpm; the air inlet temperature is 150-200°C, and the cavity and the pipeline contacting the material are all sprayed with polytetrafluoroethylene or highly chlorinated polyethylene coating.

5. The preparation method according to claim 1, characterized in that: The boat pushing speed in S3) is 30-60 min / time, the boat loading amount is 0.3-1 kg, the reduction temperature is controlled at 280-350° C., and the hydrogen flow rate is controlled at 3-5 m 3 / h.

6. The preparation method according to claim 1, characterized in that: The boat pushing speed in S4) is 20-40 min / time, the boat loading amount is 0.3-1 kg, the reduction temperature is controlled at 900-1000° C., and the hydrogen flow rate is controlled at 2-6 m 3 / h.

7. The preparation method according to claim 1, characterized in that: The material of the crushing rod in S4) is corundum, and the mesh number of the sieve is ≥40 meshes.

8. The preparation method according to claim 1, characterized in that: During production of the equipment in S3) and S4), the pressure inside the furnace is slightly positive.

9. The preparation method according to claim 8, characterized in that: The value of the micro-positive pressure is ≥ atmospheric pressure + 0.5 Kpa.

10. A micro-nano particle size rhenium powder, characterized in that: The micro-nano particle size rhenium powder is prepared by the preparation method according to any one of claims 1 to 9.

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