Method and device for directly preparing high-purity rhenium powder from high-purity ammonium rhenate

Abstract

The present application relates to the technical field of high-purity metal material preparation, and discloses a method and device for directly preparing high-purity rhenium powder from high-purity ammonium rhenium acid, wherein the device comprises a reaction furnace, a microwave device is arranged on the top of the inside of the reaction furnace, an ultrasonic device is arranged on the bottom of the inside of the reaction furnace, a plurality of layers of storage racks are arranged in the middle of the inside of the reaction furnace in a spaced-apart manner, and a plurality of pure molybdenum material trays with upward openings are arranged on each layer of the storage racks; the method is simple, has strong adaptability to raw materials, and can directly use high-purity ammonium rhenium acid with a moisture content purity of 99.99% after extraction or ion exchange and evaporation crystallization as raw materials, dry the raw materials by using microwave heating, uniformly disperse the materials under the action of ultrasonic waves, make the materials fully contact with hydrogen under high-temperature conditions after drying of the materials, and reduce the materials to generate high-purity superfine rhenium powder, the purity of the rhenium powder is greater than 99.99%, the particle size of the rhenium powder is less than 100 microns, the overall preparation efficiency is improved, the production cost is reduced, and the purity and particle size of the product are fully guaranteed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high-purity metal material preparation, and particularly relates to a method and device for directly preparing high-purity rhenium powder from high-purity ammonium rhenium. BACKGROUND

[0002] Metal rhenium and its alloys have a series of excellent characteristics, and are therefore widely used in the petroleum chemical industry, aerospace industry and electronic industry, and particularly play an irreplaceable role in some high-tech fields related to national security and national development strategy.

[0003] At present, the methods for preparing high-purity rhenium powder mainly include electrolysis, hydrogen reduction and gas deposition, among which the hydrogen reduction method is the most commonly used method in industry. The general practice is to evaporate and crystallize high-purity ammonium rhenium solution prepared by ion exchange or extraction, and then to dry the material in a vacuum. The dried material is then ball milled to a certain particle size and screened, and then loaded into a hydrogen reduction furnace for multi-stage reduction to prepare high-purity rhenium powder. However, this method is greatly affected by the properties of the raw material, and the prepared rhenium powder has uneven particle distribution, and has a series of shortcomings such as serious caking, poor flowability and low tap density. Moreover, the process is long, and the material needs to be treated by ball milling and screening, which not only consumes a lot of time and effort, but also consumes a large amount of high-purity hydrogen. Moreover, the material is easily contaminated during the operation process due to contact with the outside world, thereby reducing the purity of the product and greatly affecting the performance of the related products prepared from the high-purity rhenium metal. SUMMARY

[0004] The present application provides a method and device for directly preparing high-purity rhenium powder from high-purity ammonium rhenium, which overcomes the shortcomings of the prior art and effectively solves the problems of long process flow, long-term exposure of the product to air, resulting in reduced product purity, and uneven particle size of the prepared high-purity rhenium powder.

[0005] To solve the above problems, one of the technical solutions of the present application is achieved by the following method: a method for directly preparing high-purity rhenium powder from high-purity ammonium rhenium, comprising the following steps:

[0006] Step 1: placing the high-purity ammonium rhenium solution containing water obtained by evaporating and crystallizing high-purity ammonium rhenium solution in a pure molybdenum tray of a reaction furnace; wherein the high-purity ammonium rhenium solution is prepared by extraction or ion exchange;

[0007] Step 2: introducing high-purity nitrogen into the reaction furnace, starting microwave heating, and drying the high-purity ammonium rhenium containing water at a temperature of 200 DEG C;

[0008] Step 3: during the drying process, the ultrasonic function is turned on to disperse the dried high-purity ammonium rhenium containing water into small particles;

[0009] Fourth step: after the high-purity ammonium rhenate containing moisture is fully dried, the temperature of the reaction furnace is increased to 300 DEG C, and hydrogen is introduced to reduce the high-purity ammonium rhenate;

[0010] Fifth step: after the temperature in the reaction furnace is increased to 800 DEG C, the temperature is kept constant;

[0011] Sixth step: after the temperature keeping is finished, nitrogen is introduced to reduce the temperature, and high-purity rhenium powder is obtained.

[0012] In the fourth step, the equation of the reduction reaction of the high-purity ammonium rhenate and hydrogen is as follows:

[0013] 2NH4ReO4+ H2→ Re2O7+ 4H2O + 2NH3.

[0014] In the fifth step, the temperature increasing speed is controlled to be 5-10 DEG C / min during the temperature increasing process, and the temperature keeping time is 2-3 h.

[0015] In the sixth step, after the temperature keeping is finished, when the temperature in the reaction furnace is reduced to 300 DEG C, nitrogen is introduced to reduce the temperature, and the high-purity rhenium powder is taken out after the temperature is less than or equal to 50 DEG C.

[0016] The second technical scheme of the application is realized by the following device for directly preparing high-purity rhenium powder from high-purity ammonium rhenate, which comprises a reaction furnace, a microwave device arranged on the inner top of the reaction furnace, an ultrasonic device arranged on the inner bottom of the reaction furnace, a plurality of layers of shelves arranged on the inner middle of the reaction furnace, a plurality of pure molybdenum trays with openings upward arranged on each layer of the shelves, a plurality of air holes penetrating through the upper and lower shelves arranged on the upper side of the shelves corresponding to the positions of the outer sides of the pure molybdenum trays, a gas inlet penetrating through the inside and outside of the reaction furnace arranged on the lower side of the outside of the reaction furnace, a gas outlet penetrating through the inside and outside of the reaction furnace arranged on the upper side of the outside of the reaction furnace, a temperature measuring device arranged in the middle of the reaction furnace, a gas flow meter arranged on the bottom of the reaction furnace, and a control device arranged on the bottom of the reaction furnace and connected with the microwave device and the ultrasonic device.

[0017] The control device comprises an ultrasonic control end and a microwave control end, the ultrasonic control end is connected with the ultrasonic device, and the microwave control end is connected with the microwave device.

[0018] The temperature measuring device is a thermocouple.

[0019] The method is simple, the raw material is adaptable, the high-purity ammonium rhenate with a moisture content of 99.99% after extraction or ion exchange and evaporation crystallization can be directly used as the raw material, the raw material is dried by microwave heating, the material is uniformly dispersed under the action of ultrasonic waves, the material is fully contacted with hydrogen under high temperature conditions after drying, high-purity superfine rhenium powder is generated, the purity of the rhenium powder is greater than 99.99%, and the particle size is less than 100 mu m, the conventional vacuum drying and ball milling process are avoided, the overall preparation efficiency is improved, the production cost is reduced, and the purity and particle size of the product are fully guaranteed.BRIEF DESCRIPTION OF DRAWINGS BRIEF DESCRIPTION OF DRAWINGS

[0020] The specific embodiments of the present application will be further described in detail below with reference to the accompanying drawings.

[0021] Figure 1 The schematic diagram of the device structure of the embodiment 2 of the present application.

[0022] Figure 2 The top view of the shelf in the embodiment 2 of the present application.

[0023] In the figure: 1-reaction furnace, 2-microwave device, 3-ultrasonic device, 4-shelf, 5-pure molybdenum tray, 6-vent hole, 7-gas inlet, 8-gas outlet, 9-temperature measuring device, 10-gas flow meter, 11-ultrasonic control end, 12-microwave control end. DETAILED DESCRIPTION

[0024] The present application is not limited by the following embodiments, and the specific embodiments can be determined according to the technical solutions of the present application and the actual situation.

[0025] Embodiment 1: The embodiment of the present application discloses a method for directly preparing high-purity rhenium powder from high-purity ammonium rhenate, which comprises the following steps:

[0026] First step: the high-purity ammonium rhenate solution obtained by evaporation and crystallization is placed in the pure molybdenum tray 5 of the reaction furnace 1; wherein the high-purity ammonium rhenate solution is prepared by extraction or ion exchange method.

[0027] Second step: high-purity nitrogen is introduced into the reaction furnace 1, and microwave heating is started to dry the high-purity ammonium rhenate containing moisture at a temperature of 200℃; thereby, the air in the reaction furnace 1 is replaced by introducing nitrogen, and the high-purity nitrogen is used to protect the high-purity ammonium rhenate from being contaminated and oxidized, while the air and water vapor in the reaction furnace 1 are discharged, and the flow rate of nitrogen is determined by the volume of the reaction furnace 1; by microwave heating, the high-purity ammonium rhenate containing moisture can be quickly dried with the characteristics of fast heating speed and small heat loss, thereby shortening the process time.

[0028] Third step: during the drying process, the ultrasonic function is turned on to disperse the dried high-purity ammonium rhenate containing moisture into small particles; thereby, in the reaction process, the high-frequency ultrasonic wave disperses the high-purity ammonium rhenate into small particles, realizing efficient and uniform dispersion of the high-purity ammonium rhenate.

[0029] Fourth step: after the high-purity ammonium rhenate containing moisture is fully dried, the temperature of the reaction furnace 1 is increased to 300℃, and hydrogen is introduced to reduce the high-purity ammonium rhenate; wherein the flow rate of hydrogen is determined according to the amount of high-purity ammonium rhenate containing moisture, and due to the effect of ultrasonic, the dispersed high-purity ammonium rhenate is in full contact with hydrogen, thereby accelerating the reaction speed.

[0030] Fifth step: after the temperature in the reaction furnace 1 is raised to 800℃, keep warm; wherein, the temperature rising speed is controlled to be 5-10℃ / min during the temperature rising process; the keeping warm time is 2-3h.

[0031] Sixth step: after the keeping warm is finished, nitrogen is introduced to reduce the temperature, and high-purity rhenium powder is obtained. Wherein, after the keeping warm is finished, when the temperature in the reaction furnace 1 is reduced to 300℃, nitrogen is introduced to reduce the temperature, and after the temperature is less than or equal to 50℃, the prepared high-purity rhenium powder is taken out.

[0032] Wherein, in the fourth step, the equation of the reduction reaction of high-purity ammonium rhenium acid and hydrogen is:

[0033] 2NH4ReO4+ H2→ Re2O7+ 4H2O + 2NH3.

[0034] Example 2: as shown in Figure 1 , 2 The embodiment of the application discloses a device for directly preparing high-purity rhenium powder from high-purity ammonium rhenium acid, which comprises a reaction furnace 1, a microwave device 2 is arranged at the top of the inner side of the reaction furnace 1, an ultrasonic device 3 is arranged at the bottom of the inner side of the reaction furnace 1, a plurality of layers of shelves 4 are arranged at the middle of the inner side of the reaction furnace 1 and are spaced apart from each other, a plurality of pure molybdenum material trays 5 are arranged on each layer of the shelves 4 and are open upward, a plurality of air holes 6 are arranged on the upper side of the shelf 4 corresponding to the position of the outer side of the pure molybdenum material tray 5 and penetrate the shelf 4 from top to bottom; a gas inlet 7 penetrating the reaction furnace 1 from inside to outside is arranged on the lower side of the outer side of the reaction furnace 1, and a gas outlet 8 penetrating the reaction furnace 1 from inside to outside is arranged on the upper side of the outer side of the reaction furnace 1; a temperature measuring device 9 is arranged on the middle of the reaction furnace 1, a gas flow meter 10 is arranged on the bottom of the reaction furnace 1, and a control device is arranged on the bottom of the reaction furnace 1 and is connected with the microwave device 2 and the ultrasonic device 3.

[0035] Wherein, the control device comprises an ultrasonic control end 11 and a microwave control end 12, the ultrasonic control end 11 is connected with the ultrasonic device 3, and the microwave control end 12 is connected with the microwave device 2. The ultrasonic control end 11 and the microwave control end 12 can both be switches, and the opening of the corresponding switch can realize the opening and closing of the microwave device 2 and the ultrasonic device 3.

[0036] According to the need, the temperature measuring device 9 is a thermocouple. In use, the thermocouple is connected with an external display instrument, the thermocouple converts the temperature signal measured into an electric signal and then outputs to the display instrument, the display instrument processes and converts the received electric signal, and finally displays the corresponding temperature value.

[0037] Embodiment 3: The embodiment of the application discloses a method for directly preparing high-purity rhenium powder from high-purity ammonium rheniate. The high-purity ammonium rheniate with high water content after extraction or ion exchange evaporation crystallization is placed in a pure molybdenum tray 5 in a reaction furnace 1, about 0.5 kg of ammonium rheniate is evenly distributed in each pure molybdenum tray 5, and the thickness is about 5-6 cm. Close the furnace door, and introduce high-purity nitrogen at a flow rate of 3-4 L / min. After the nitrogen replaces the inside of the furnace, start the microwave heating and ultrasonic functions. When the temperature rises to 200℃, keep the temperature for 30 min. After the high-purity ammonium rheniate with high water content is dried, continue to increase the temperature in the furnace to 300℃, and introduce high-purity hydrogen. The flow rate of the hydrogen is 3-4 L / min, the temperature rising speed is 10℃ / min, and after the temperature rises to 800℃, keep the temperature for 2 h. After the temperature keeping is finished, introduce sufficient nitrogen, and reduce the temperature to below 50℃ to take out the high-purity rhenium powder.

[0038] In summary, the method of the application is simple, and the raw material is highly adaptable. The high-purity ammonium rheniate with a water content of 99.99% after extraction or ion exchange evaporation crystallization is directly used as a raw material. The raw material is dried by microwave heating, and the high-purity ammonium rheniate is uniformly dispersed under the action of ultrasonic waves. After the high-purity ammonium rheniate with high water content is dried, the high-purity ammonium rheniate is fully contacted with hydrogen at high temperature to perform reduction, and high-purity ultrafine rhenium powder is generated. The purity of the rhenium powder is greater than 99.99%, and the particle size is less than 100 μm. The use of conventional vacuum drying and ball milling processes is avoided, the overall preparation efficiency is improved, the production cost is reduced, and the purity and particle size of the product are fully guaranteed.

Claims

1. A method for directly preparing high purity rhenium powder from high purity ammonium rhenate, characterized by, The method comprises the following steps: Step 1: high-purity ammonium rhenate solution is evaporated and crystallized to obtain high-purity ammonium rhenate containing moisture, which is placed in a pure molybdenum material tray of a reaction furnace; wherein the high-purity ammonium rhenate solution is prepared by an extraction method or an ion exchange method; Step 2: high-purity nitrogen is introduced into the reaction furnace, and microwave heating is started, and the high-purity ammonium rhenate containing moisture is dried at a temperature of 200 DEG C; Step 3: during the drying process, the ultrasonic function is started, and the dried high-purity ammonium rhenate containing moisture is dispersed into small particles; Step 4: after the high-purity ammonium rhenate containing moisture is fully dried, the temperature of the reaction furnace is increased to 300 DEG C, and hydrogen is introduced to reduce the high-purity ammonium rhenate; Step 5: after the temperature in the reaction furnace is increased to 800 DEG C, the temperature is kept constant; Step 6: after the temperature keeping is finished, nitrogen is introduced to cool down, and high-purity rhenium powder is obtained; In the fifth step, during the temperature increasing process, the temperature increasing speed is controlled to be 5-10 DEG C / min; and the temperature keeping time is 2-3 h.

2. The method for directly preparing high-purity rhenium powder from high-purity ammonium rhenate according to claim 1, characterized in that, In the sixth step, after the temperature keeping is finished, when the temperature in the reaction furnace is reduced to 300 DEG C, nitrogen is introduced to cool down, and after the temperature is less than or equal to 50 DEG C, the high-purity rhenium powder is taken out.

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