CN116477568A - A kind of hydrogenation metal powder dehydrogenation method - Google Patents

Abstract

The invention discloses a hydrogenated metal powder dehydrogenation method, which relates to the field of metal powder preparation. The process steps are as follows: A. Put hydrogenated metal powder into a special dehydrogenation device, and design a stirring powder device; B. Vacuum the furnace, and start to slowly heat up to 100°C, and start stirring at the same time, and dry the powder material; C. After the materials are dried, continue to raise the furnace temperature to 300°C, and then the dehydrogenation reaction begins to slowly occur; D. Continue to raise the furnace temperature to 600°C for 4 hours, and then start to release a large amount of hydrogen ; E Finally, raise the temperature of the furnace to 850°C, keep it warm for 2 hours, and then start to cool down until it drops to room temperature to complete the dehydrogenation process. Compared with the prior art, the method of the present application changes the existing dehydrogenation process of metal powder flat and fixed during the dehydrogenation treatment, and changes it to a stirring motion type dehydrogenation, which not only has high furnace volume utilization rate, enhanced production capacity, dehydrogenation treatment speed and dehydrogenation effect are also extremely superior, the hydrogen content of the obtained metal powder is reduced to <0.003%, and the dehydrogenation efficiency is increased by 30%.

Description

A kind of hydrogenation metal powder dehydrogenation method

technical field

The invention relates to the field of metal powder preparation, in particular to a method for preparing metal powder by dehydrogenating metal powder.

Background technique

Metal powder refers to a group of metal particles whose size is less than 1 mm. Including single metal powder, alloy powder and some insoluble compound powder with metal properties, it is the main raw material of powder metallurgy. Metal powder preparation methods include reduction method, atomization method, electrolysis method, mechanical pulverization method, hydroxyl method, etc. Mechanical pulverization method is the simplest, but most metals have ductility and hardness, which brings difficulties to mechanical pulverization. Therefore, in the process, the properties of metals are changed to make them brittle and then mechanical pulverization. The most common method is hydrogenation method. Get the required metal powder.

The traditional hydrodehydrogenation process generally puts hydrogenated metal powder into the material tray, the thickness of the material is not more than 10cm, and then carries out vacuum high-temperature dehydrogenation in the vacuum dehydrogenation furnace. In this process, because the material is fixed to a certain thickness, the dehydrogenated hydrogen is not easy to diffuse quickly, resulting in a reduction in the dehydrogenation effect and efficiency. In addition, due to the limited thickness of the metal powder material, the effective use volume of the furnace body is reduced and the production capacity is reduced.

Contents of the invention

Aiming at the deficiencies in the prior art, the present invention provides a hydrogenation metal powder dehydrogenation method. This method changes the existing dehydrogenation process of the metal powder in flat and fixed dehydrogenation during the dehydrogenation treatment, and changes it to a stirring motion type dehydrogenation. Not only the furnace volume utilization rate is high, the production capacity is enhanced, the dehydrogenation treatment speed and dehydrogenation effect are also extremely superior, the hydrogen content is <0.003%, and the dehydrogenation efficiency is increased by 30%, which solves the problem of low dehydrogenation efficiency in the prior art.

In order to solve the above-mentioned technical problems, the present invention is solved by the following technical proposal: a method for dehydrogenating metal hydrogenation powder, comprising the following steps: Step A: loading metal hydrogenation powder with a particle size of less than 1mm into a vacuum dehydrogenation device; Step B: vacuuming the furnace to less than 7×10^-4Pa, and start to slowly raise the temperature to 100°C, keep it warm for 1 hour, and dry the powder material; Step C: After the material is dried, continue to raise the furnace temperature to 250°C-350°C and keep it warm for 1-6h. ℃ for at least 1h, until the dehydrogenation process is completed at room temperature.

Preferably, in the above technical solution, in step A, a stirring device is provided in the vacuum dehydrogenation device.

Preferably, in the above technical solution, in step B, stirring is started during dehydrogenation, and the stirring speed is less than 100 rpm.

Preferably, in the above technical solution, the stirring device is rake stirring, and the stirring rate is 10-100 revolutions/min.

Preferably, in the above technical solution, in step A, the vacuum degree in the vacuum dehydrogenation device is less than 10 ^-4 Pa.

Preferably, in the above technical solution, in step A, a 316L stainless steel filter with a pore size of less than 50 microns is installed at the vacuum port of the vacuum dehydrogenation device.

Preferably, in the above technical solution, in step C, after the materials are dried, continue to raise the furnace temperature to 300°C and keep it warm for 2 hours. At this time, the dehydrogenation reaction begins to slowly occur, and then continue to raise the furnace temperature to 600°C and keep it warm for 4 hours.

Preferably, in the above technical solution, in step D, the temperature of the furnace is raised to 850° C., and the temperature is slowly lowered after keeping the temperature for 2 hours.

Compared with the traditional dehydrogenation method, the method of the present application mainly makes significant improvements in the dehydrogenation process. In the traditional dehydrogenation method, the metal powder needs to be laid flat and fixed in the furnace body. Once the thickness of the metal powder is too thick, the dehydrogenation effect will be greatly reduced. Every time the dehydrogenation process is performed, the space utilization rate in the furnace body is low. Therefore, this application adopts the form of rotary stirring for dehydrogenation, that is, during the dehydrogenation process, the furnace body is continuously stirred to keep the metal powder moving in the furnace body. This setting not only allows the metal powder to be heated evenly, but also allows the hydrogen to be discharged quickly without accumulation. What's more, the method of rotating and stirring can be used to put in more than 3 times the amount of tiles at one time, and the dehydrogenation time in the furnace is much less than the time of tiles for dehydrogenation.

Compared with the existing technology, the method of the present application changes the existing dehydrogenation process of metal powder flat and fixed during dehydrogenation treatment, and changes it to stirring motion dehydrogenation. Not only the furnace volume utilization rate is high, the production capacity is enhanced, the dehydrogenation treatment speed and dehydrogenation effect are also extremely superior. After the metal powder is dehydrogenated, the hydrogen content is <0.003%, and the dehydrogenation efficiency can be increased by 30%, which effectively solves the problem of low dehydrogenation efficiency in the prior art.

Description of drawings

Figure 1 is a schematic diagram of the dehydrogenation device in this application.

Fig. 2 is a flow chart of the method of the present application.

Detailed ways

As shown in Figure 1 and Figure 2.

Example 1: Weigh 1 kg of titanium hydride powder, put it into a special dehydrogenation furnace, start the rake stirring in the furnace, set the stirring rate to 30 rpm, and vacuum the furnace to 7×10^-4Pa, and began to slowly raise the temperature to 100°C, and keep it warm for 1h, continue to raise the temperature in the furnace to 300°C, and keep it warm for 3h, then raise the temperature to 650°C, a large amount of hydrogen gas begins to be precipitated, and the vacuum gauge pressure shows a rise, reaching 10^-3Pa, continue to raise the temperature to 750°C and keep it warm for 3 hours, and finally raise the temperature to 850°C. After holding the heat for 2 hours, start to cool down slowly, and keep it for 1 hour every time the temperature drops by 100°C, until it drops to room temperature to complete the dehydrogenation, release the dehydrogenated titanium powder, and the hydrogen content is 0.0024%.

Example 2: Weigh 3 kg of titanium hydride powder, put it into a special dehydrogenation furnace, start the rake stirring in the furnace, set the stirring rate to 50 rpm, and vacuum the furnace to 8×10^-4Pa, and began to slowly raise the temperature to 100°C, and keep it warm for 1h, continue to raise the temperature in the furnace to 300°C, and keep it warm for 3h, then raise the temperature to 650°C, a large amount of hydrogen gas begins to be precipitated, and the vacuum gauge pressure shows a rise, reaching 10^-1Pa, continue to raise the temperature to 750°C, keep it warm for 3 hours, and finally raise the temperature to 900°C, keep it warm for 2 hours, then start to lower the temperature slowly, and keep it warm for 1 hour every time it drops by 100°C, until it drops to room temperature to complete the dehydrogenation, release the dehydrogenated titanium powder, and the hydrogen content is 0.0021%.

Example 3: Weigh 10 kg of titanium hydride powder, put it into a special dehydrogenation furnace, start the rake stirring in the furnace, set the stirring rate at 60 rpm, and vacuum the furnace to 9×10^-4Pa, and began to slowly raise the temperature to 100°C, and keep it warm for 1h, continue to raise the temperature in the furnace to 300°C, and keep it warm for 3h, then raise the temperature to 650°C, a large amount of hydrogen gas begins to be precipitated, and the vacuum gauge pressure shows a rise, reaching 10^-1Pa, continue to raise the temperature to 750°C, keep it warm for 3 hours, and finally raise the temperature to 900°C. After holding it for 2 hours, start to cool down slowly, and keep it for 1 hour every time it drops by 100°C, until it drops to room temperature to complete the dehydrogenation, release the dehydrogenated titanium powder, and the hydrogen content is 0.0022%.

Example 4: Weigh 1 kg of titanium hydride powder, put it into a special dehydrogenation furnace, start the rake stirring in the furnace, set the stirring rate to 50 rpm, and vacuum the furnace to 7×10^-4Pa, and began to slowly raise the temperature to 120°C, and keep it warm for 1h, continue to raise the temperature in the furnace to 300°C, and keep it warm for 2.5h, then raise the temperature to 700°C, a large amount of hydrogen gas begins to be precipitated, and the vacuum gauge pressure shows a rise, reaching 10^-3Pa, continue to raise the temperature to 800°C, keep it warm for 2 hours, and finally raise the temperature to 900°C, keep it warm for 1.5 hours, then start to cool down slowly, and keep it warm for 1 hour every time it drops by 100°C, until it drops to room temperature to complete the dehydrogenation, release the dehydrogenated titanium powder, and the hydrogen content is 0.0026%.

Example 5: Weigh 1 kg of titanium hydride powder, put it into a special dehydrogenation furnace, start the rake stirring in the furnace, set the stirring rate to 40 rpm, and vacuum the furnace to 7×10^-4Pa, and began to slowly raise the temperature to 100°C, and keep it warm for 1.5h, continue to raise the temperature in the furnace to 300°C, and keep it warm for 2.5h, then raise the temperature to 700°C, a large amount of hydrogen gas begins to be precipitated, and the vacuum gauge pressure shows a rise, reaching 10^-3Pa, continue to raise the temperature to 800°C, keep it warm for 1.5h, and finally raise the temperature to 900°C, keep it warm for 2h, then start to cool down slowly, and keep it warm for 1h every time it drops by 100°C, until it drops to room temperature to complete the dehydrogenation, release the dehydrogenated titanium powder, and the hydrogen content is 0.0027%.

Claims (8)

1. The dehydrogenation method of the hydrogenated metal powder is characterized by comprising the following steps of:

step A: loading hydrogenated metal powder with the particle size smaller than 1mm into a vacuum dehydrogenation device;

and (B) step (B): vacuum in the furnace to less than 7X10 ^-4 Pa, starting to slowly heat up to 100 ℃, preserving heat for 1h, and drying the powder material;

step C: after the materials are dried, continuously heating the furnace to 250-350 ℃, preserving heat for 1-6 hours, at the moment, starting to slowly perform dehydrogenation reaction, then continuously heating the furnace to 500-700 ℃ and preserving heat for 1-6 hours, at the moment, starting to release a large amount of hydrogen;

step D: and finally, raising the furnace temperature to above 800 ℃, keeping the temperature for 1-6 hours, then starting to slowly cool, keeping the temperature for at least 1 hour when the temperature is lowered by 100 ℃, and finishing the dehydrogenation process until the temperature is lowered to normal temperature.

2. The method for dehydrogenating a hydrogenated metal powder according to claim 1, wherein in the step A, a stirring device is provided in the vacuum dehydrogenating device.

3. The method for dehydrogenating a hydrogenated metal powder according to claim 2, wherein in the step B, stirring is started at a stirring speed of less than 100 rpm.

4. A method for dehydrogenating a hydrogenated metal powder according to claim 2 or 3, wherein the stirring means is a rake stirring at a stirring rate of 10 to 100 rpm.

5. The method for dehydrogenating a hydrogenated metal powder according to claim 1, wherein in the step A, the vacuum degree in the vacuum dehydrogenating apparatus is less than 10 ^-4 Pa。

6. The method for dehydrogenating metal hydride powder as claimed in claim 1, wherein in the step A, a 316L stainless steel filter screen with a pore size of less than 50 μm is installed at the vacuum port of the vacuum dehydrogenation unit.

7. The method for dehydrogenating metal hydride powder according to claim 1, wherein in the step C, after the material is dried, the furnace temperature is continuously raised to 300 ℃ for 2 hours, at which time the dehydrogenation reaction is slowly started, and then the furnace temperature is continuously raised to 600 ℃ for 4 hours.

8. The method for dehydrogenating a hydrogenated metal powder according to claim 1, wherein in the step D, the furnace temperature is raised to 850℃and the temperature is kept for 2 hours and then the temperature is slowly lowered.