阅读说明：本技术 一种氢化镁的制备方法 (Preparation method of magnesium hydride ) 是由 刘建勃 李晓慧 白靖 于 2020-12-30 设计创作，主要内容包括：本发明涉及一种氢化镁的制备方法,包括如下工艺步骤：在惰性气体保护下,对金属镁片进行激光刻蚀处理；并对经过激光刻蚀的金属镁片进行粉碎、研磨,得到镁粉；将步骤2中的镁粉送入反应室内,在惰性气体的保护下,向反应室内通入氢气与镁粉进行反应得到氢化镁颗粒；本发明通过以金属镁片为原材料,同时采用激光刻蚀技术对金属镁片表面进行刻蚀改变其表面粗糙度,从而提高了金属镁的比表面积,进而提高了金属镁与氢的反应活性,不仅解决了现有技术中制备氢化镁需要较高温度和较高氢压的技术问题；而且制备的氢化镁颗粒粒径均匀、尺寸适中,纯度较高,同时降低了氢化镁的放氢时所需的温度。(The invention relates to a preparation method of magnesium hydride, which comprises the following process steps: under the protection of inert gas, carrying out laser etching treatment on the metal magnesium sheet; crushing and grinding the metal magnesium sheet subjected to laser etching to obtain magnesium powder; feeding the magnesium powder obtained in the step 2 into a reaction chamber, and introducing hydrogen into the reaction chamber under the protection of inert gas to react with the magnesium powder to obtain magnesium hydride particles; according to the invention, the magnesium sheet is used as a raw material, and the surface roughness of the magnesium sheet is changed by etching the surface of the magnesium sheet by adopting a laser etching technology, so that the specific surface area of magnesium is increased, the reaction activity of magnesium and hydrogen is further improved, and the technical problem that the magnesium hydride preparation in the prior art needs higher temperature and higher hydrogen pressure is solved; the prepared magnesium hydride particles have uniform particle size, moderate size and higher purity, and simultaneously the temperature required by the hydrogen discharge of the magnesium hydride is reduced.)

1. A preparation method of magnesium hydride is characterized in that: the method comprises the following process steps:

step 1: under the protection of inert gas, carrying out laser etching treatment on the metal magnesium sheet;

step 2: under the protection of inert gas, crushing and grinding the metal magnesium sheet subjected to laser etching to obtain magnesium powder;

and step 3: and (3) feeding the magnesium powder obtained in the step (2) into a reaction chamber, and introducing hydrogen into the reaction chamber to react with the magnesium powder under the protection of inert gas to obtain magnesium hydride particles.

2. The method for preparing magnesium hydride according to claim 1, wherein: the thickness of the magnesium metal sheet in the step 1 is 0.02-0.1 mm.

3. The method for preparing magnesium hydride according to claim 2, wherein: the wavelength of the laser in the step 1 is 355 nm.

4. The method for preparing magnesium hydride according to claim 3, wherein: the particle size of the magnesium powder in the step 2 is 30-50 μm.

5. The method for preparing magnesium hydride according to claim 4, wherein: the temperature in the reaction chamber is 200-250 ℃.

6. The method for preparing magnesium hydride according to claim 5, wherein: the pressure in the reaction chamber is 0.1-0.3 MPa.

7. The method for preparing magnesium hydride according to claim 6, wherein: the inert gas is argon or helium.

Technical Field

The invention relates to preparation of magnesium hydride, in particular to a preparation method of magnesium hydride.

Background

Magnesium hydride is also known as magnesium dihydride, formula mgh 2. A white crystalline chemical substance reacts with water to release hydrogen, and is mainly used as a strong reducing agent. Hydrogen is the most abundant element in the universe, and has the potential to replace gasoline, coal gas and other hydrocarbon-based fuels to become a novel clean energy source. The chemical hydrogen storage method comprises metal hydride storage, organic liquid hydride storage, inorganic substance storage and the like, and the initial research finds that magnesium is an ideal metal for storing hydrogen, and MgH2 has hydrogen content as high as 7.65% and has wide potential application.

At present, there are two main ways for preparing magnesium hydride, one is to directly use magnesium powder to obtain the magnesium hydride with hydrogen under the conditions of heating and pressurizing, the preparation method has higher requirements on reaction conditions, and the conversion rate of the magnesium powder is low; the other method is that the magnesium block is heated by heat energy to generate magnesium vapor, the magnesium vapor is cooled to obtain magnesium powder, and finally the magnesium powder is reacted with hydrogen.

Therefore, there is a need to provide a new technical solution to overcome the above-mentioned drawbacks.

Disclosure of Invention

The invention aims to provide a preparation method of magnesium hydride, which can effectively solve the technical problems.

In order to achieve the purpose of the invention, the following technical scheme is adopted:

a preparation method of magnesium hydride comprises the following process steps:

step 1: under the protection of inert gas, carrying out laser etching treatment on the metal magnesium sheet;

step 2: under the protection of inert gas, crushing and grinding the metal magnesium sheet subjected to laser etching to obtain magnesium powder;

and step 3: and (3) feeding the magnesium powder obtained in the step (2) into a reaction chamber, and introducing hydrogen into the reaction chamber to react with the magnesium powder under the protection of inert gas to obtain magnesium hydride particles.

Preferably, the thickness of the metal magnesium sheet in the step 1 is 0.02-0.1 mm.

Preferably, the wavelength of the laser in the step 1 is 355 nm.

Preferably, the particle size of the magnesium powder in the step 2 is 30-50 μm.

Preferably, the temperature in the reaction chamber is 200-250 ℃.

Preferably, the pressure in the reaction chamber is 0.1-0.3 MPa.

Preferably, the inert gas is argon or helium.

Compared with the prior art, the invention has the following beneficial effects:

according to the invention, the metal magnesium sheet is used as a raw material, and the surface roughness of the metal magnesium sheet is changed by etching the surface of the metal magnesium sheet by adopting a laser etching technology, so that the specific surface area of the metal magnesium is improved, the reaction activity of the metal magnesium and hydrogen is improved, the technical problem that the preparation of magnesium hydride in the prior art needs higher temperature and higher hydrogen pressure is solved, meanwhile, the heat energy consumption in the whole process is less, the environment is protected, and the production cost is reduced; in addition, the magnesium hydride particles prepared by the method have uniform particle size, moderate size and higher purity, and the temperature required during hydrogen release is lower than that of the magnesium hydride particles prepared by the conventional method.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention, and it is obvious that the described embodiments are some embodiments of the present invention, but not all embodiments.

Example 1

The invention provides a preparation method of magnesium hydride, which comprises the following process steps:

step 1: under the protection of inert gas, carrying out laser etching treatment on the metal magnesium sheet;

step 2: under the protection of inert gas, sequentially conveying the metal magnesium sheets subjected to laser etching to a crushing chamber and a grinding chamber for crushing and grinding to obtain magnesium powder;

and step 3: and (3) feeding the magnesium powder obtained in the step (2) into a reaction chamber, and introducing hydrogen into the reaction chamber to react with the magnesium powder under the protection of inert gas to obtain magnesium hydride particles, wherein the reaction time is 30 hours.

Specifically, the thickness of the magnesium metal sheet in the step 1 is 0.02 mm.

The wavelength of the laser in the step 1 is 355 nm.

The particle size of the magnesium powder in the step 2 is 30 microns.

The temperature in the reaction chamber was 200 ℃.

The pressure in the reaction chamber is 0.1 MPa.

The inert gas is argon or helium.

The magnesium hydride particles prepared in the example are subjected to an XRD test and a nanometer particle size test, and the results show that the magnesium hydride particles prepared in the example have a high magnesium hydride (MgH2) content of 95.2 percent and an average particle size of 11.35 mu m; the sample was heated from room temperature to 400 ℃ at 3 ℃/min and the degassing curve of the sample during heating was analyzed using a mass spectrometer, which showed that the sample had a peak hydrogen evolution temperature of 350 ℃.

Example 2

The invention provides a preparation method of magnesium hydride, which comprises the following process steps:

step 1: under the protection of inert gas, carrying out laser etching treatment on the metal magnesium sheet;

step 2: under the protection of inert gas, sequentially conveying the metal magnesium sheets subjected to laser etching to a crushing chamber and a grinding chamber for crushing and grinding to obtain magnesium powder;

and step 3: and (3) feeding the magnesium powder obtained in the step (2) into a reaction chamber, and introducing hydrogen into the reaction chamber to react with the magnesium powder under the protection of inert gas to obtain magnesium hydride particles, wherein the reaction time is 30 hours.

Specifically, the thickness of the magnesium metal sheet in the step 1 is 0.06 mm.

The wavelength of the laser in the step 1 is 355 nm.

The particle size of the magnesium powder in the step 2 is 40 μm.

The temperature in the reaction chamber was 230 ℃.

The pressure in the reaction chamber is 0.2 MPa.

The inert gas is argon or helium.

The magnesium hydride particles prepared in the example are subjected to an XRD test and a nanometer particle size test, and the results show that the magnesium hydride particles prepared in the example have high magnesium hydride (MgH2) content of 97.1 percent and have an average particle size of 8.54 mu m; the sample was heated from room temperature to 400 ℃ at 3 ℃/min and the degassing curve of the sample during heating was analyzed using a mass spectrometer, which showed that the sample had a peak hydrogen evolution temperature of 280 ℃.

Example 3

The invention provides a preparation method of magnesium hydride, which comprises the following process steps:

step 1: under the protection of inert gas, carrying out laser etching treatment on the metal magnesium sheet;

step 2: under the protection of inert gas, sequentially conveying the metal magnesium sheets subjected to laser etching to a crushing chamber and a grinding chamber for crushing and grinding to obtain magnesium powder;

and step 3: and (3) feeding the magnesium powder obtained in the step (2) into a reaction chamber, and introducing hydrogen into the reaction chamber to react with the magnesium powder under the protection of inert gas to obtain magnesium hydride particles, wherein the reaction time is 30 hours.

Specifically, the thickness of the magnesium metal sheet in the step 1 is 0.1 mm.

The wavelength of the laser in the step 1 is 355 nm.

The particle size of the magnesium powder in the step 2 is 50 microns.

The temperature in the reaction chamber was 250 degrees.

The pressure in the reaction chamber is 0.3 MPa.

The inert gas is argon or helium.

The magnesium hydride particles prepared in the example are subjected to an XRD test and a nanometer particle size test, and the results show that the magnesium hydride particles prepared in the example have high magnesium hydride (MgH2) content of 96.4 percent, and the average particle size of the magnesium hydride particles is 12.35 mu m; the sample was heated from room temperature to 400 ℃ at 3 ℃/min and the degassing curve of the sample during heating was analyzed using a mass spectrometer, which showed that the sample had a peak hydrogen evolution temperature of 330 ℃.

Comparative example

The method comprises the steps of selecting metal magnesium powder with the same weight as a metal magnesium sheet in an embodiment, enabling the purity to be 99.99% and the particle size to be 40 microns, placing the magnesium powder in a magnesium alloy box, integrally placing the magnesium powder in a high-temperature high-pressure reaction kettle, slowly introducing hydrogen into the high-temperature high-pressure reaction kettle, slowly discharging the hydrogen, cleaning the hydrogen for a long time, closing an air outlet valve, starting heating and boosting, keeping the temperature and the pressure to be 380 ℃ and 7MPa respectively, and reacting for 30 hours. Then, XRD measurement was performed on the reaction product, and the result showed that the magnesium hydride (MgH2) content of the magnesium hydride particles obtained in this example was 63.2%, the sample was heated from room temperature to 400 ℃ at 3 ℃/min, and the degassing curve of the sample during heating was analyzed using a mass spectrometer, and the result showed that the peak hydrogen evolution temperature of the sample was 440 ℃.

The analysis of the data shows that the magnesium hydride particles prepared by the process have uniform particle size, moderate size, high purity and low requirement on reaction conditions, the reaction can be carried out under normal pressure, and the peak temperature of the prepared magnesium hydride particles during hydrogen release is obviously lower than that of the magnesium hydride particles prepared under the conventional pressurized heating state.

Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention.