A production device and a production method for mass production of magnesium hydride

Abstract

The application discloses a production device and a production method for large-scale preparation of magnesium hydride, and the production device comprises a reaction separation bin, a crushing bin, a raw material bin, a heater, a hydrogen compressor, a cooler, a heat exchanger, a steam drum, a filter, a product bin and a product separator. The fluidization operation of the application uses reaction gas as a carrier gas, which not only solves the material transfer, but also makes the heat and mass transfer between the gas and the solid more sufficient and efficient, solves the problems of uneven material reaction, poor solid heat transfer performance, large temperature gradient and local temperature runaway caused by too fast reaction, and the high-speed flow can increase the collision and friction between the material particles. In combination with the use of a high-speed mill, the magnesium hydride layer on the surface of the magnesium powder particles is timely broken, the hydrogen gas is more easily contacted with the surface of the fresh magnesium powder particles, and the reaction rate is accelerated. The steam drum in the application can effectively recover the reaction heat, and reduce the energy consumption of the device.

Description

TECHNICAL FIELD

[0001] The application relates to a production device and a production method for large-scale preparation of magnesium hydride, and belongs to the technical field of chemical industry. BACKGROUND

[0002] At present, China is facing two challenges of energy security and carbon emission, and must adjust the current energy structure which excessively depends on fossil energy and develop in the direction of low carbon and cleanness.

[0003] Incorporating hydrogen energy into the whole energy system of China helps to improve the high-carbon energy structure of China and ensure energy security. The application of hydrogen energy not only includes hydrogen energy vehicles, but also includes energy storage, power generation and other industrial applications.

[0004] In the whole hydrogen energy supply chain, high-density safe hydrogen storage and transportation is the main bottleneck. The use of solid-state hydrogen storage can greatly improve the volume hydrogen storage density and improve the safety of hydrogen storage and transportation, providing an important solution for the development of hydrogen energy industry.

[0005] Magnesium hydride (MgH2), also known as magnesium dihydride, is an inorganic compound with a gray-white crystalline powder appearance, a density of 1.45 g / cm 3 , a high volume hydrogen storage density (110 g / L) and a mass hydrogen storage density (7.6%), high purity of released hydrogen, and high stability at room temperature and normal pressure, and is an important solid hydrogen storage material.

[0006] Common preparation methods include using alkyl magnesium thermal decomposition to prepare magnesium hydride, magnesium powder catalytic decomposition under normal pressure, and magnesium powder heated and pressurized to prepare magnesium hydride. The existing preparation technology has the problems of long hydrogenation time, large size of magnesium hydride, uneven particles, inability to produce in large scale and continuously, high price, and limitation of large-scale popularization and use of magnesium hydride as a hydrogen storage material.

[0007] After information retrieval, there are currently disclosed technologies, 1) Patent No. CN109795987A discloses a device for preparing magnesium hydride powder and a method for preparing magnesium hydride powder. The device includes a heating chamber for heating magnesium metal material to produce metal droplets; a powder preparation chamber, the powder preparation chamber includes an atomization device for atomizing the metal droplets and then cooling to form metal powder; a collection chamber for collecting and screening the metal powder; and a reaction chamber for carrying out hydrogenation reaction on the metal powder to form magnesium hydride powder. The device of the invention is an integrated structure, and the structure is simple and convenient to operate; the whole process of preparing magnesium hydride powder can be completed in one device, and automation control can be realized. The method is simple and easy to operate, and the product obtained has moderate size, uniform particles and excellent performance. The integrated structure does not have a crushing facility, which cannot timely strip the magnesium hydride shell formed on the surface of the magnesium particles, affecting the contact between hydrogen and the surface of fresh magnesium particles, and the hydrogenation efficiency is low and the time is long; there is no cooling facility, and the heat generated by hydrogenation of magnesium powder cannot be timely transferred, and local high temperature points will be generated when the reaction intensity is high; the heating relies on external heat source, the material is unevenly heated, and the temperature gradient is large; it cannot be produced continuously; the preparation scale is limited, and large-scale production is difficult; raw material feeding and product transfer are not convenient, and it is difficult to realize automatic operation, etc.

[0008] 2) Patent No. CN114436213A discloses a magnesium hydride preparation device and a magnesium hydride preparation method. The magnesium hydride preparation device includes a transition bin including a feeding port; a heating chamber connected to the transition bin through a first valve; a heater with an open upper end and capable of moving between the transition bin and the heating chamber through the first valve, the heater being used to heat the magnesium raw material placed therein in the heating chamber; a collection chamber connected to the heating chamber through a conduit to collect magnesium powder; and a reaction chamber connected to the collection chamber through a second valve to receive magnesium powder, and the reaction chamber is connected to an external hydrogen source to receive hydrogen. The magnesium hydride preparation device combines magnesium powder preparation and hydrogenation reaction into one device, and the magnesium hydride preparation method using the device has simple steps, and the particle size of the prepared magnesium hydride particles can be controlled in the range of 1-60 μm by controlling the temperature, pressure and other conditions. The integrated device for large-scale preparation of magnesium hydride powder solves part of the problem of large-scale production, but still cannot solve the problem of continuous and automatic production, the raw material and product cannot be completely fluidized, the pneumatic conveying is difficult, the feeding and discharging cannot be continuous, the pneumatic crushing strength is small, and the raw material cannot be efficiently crushed.

[0009] The existing hydrogenated magnesium preparation technology is difficult to realize scale, continuity and automation, and mainly has the following problems: 1) the preparation process is a gas-solid reaction, the existing static high temperature and high pressure hydrogenation process, the mass transfer of hydrogen to the surface of fresh magnesium is difficult, which affects the production efficiency, the heat transfer is difficult, the uneven heat transfer in the hydrogenation starting heating process will cause local high temperature, the heat generated in the hydrogenation process cannot be transferred in time, which also causes local high temperature, and even the temperature will rise rapidly, the high temperature will cause the magnesium powder to melt, weld and become large particles, and the hydrogenation is incomplete; 2) there is no effective method for breaking the magnesium particle surface hydrogenated magnesium shell, and the hydrogenation efficiency is low; 3) the feeding, discharging, internal conveying and transfer in the preparation process cannot realize automation and continuity, and can only be produced in batches; 4) a large amount of heat energy generated in the magnesium powder hydrogenation process cannot be recycled, causing energy waste. SUMMARY

[0010] In view of the technical problems that the existing hydrogenated magnesium preparation technology is difficult to realize scale, continuity and automation, the application provides a hydrogenated magnesium preparation device and a preparation method which can simultaneously meet the requirements of scale, fluidization, continuity, automation, efficient hydrogenation, accurate temperature control and energy recovery.

[0011] According to one aspect of the application, a production device for preparing hydrogenated magnesium on a large scale is provided, and the production device comprises a reaction separation bin, a crushing bin, a raw material bin, a heater, a hydrogen compressor, a cooler, a heat exchanger, a steam drum, a filter, a product bin, a product separator, a heat exchanger cross-line valve, a cooler cross-line valve, a heater cross-line valve and a main valve.

[0012] The upper end of the reaction separation bin is connected with the filter, the heat exchanger, the cooler, the hydrogen compressor, the heater and the crushing bin in sequence through a circulating hydrogen pipeline.

[0013] The raw material bin is arranged between the crushing bin and the heater.

[0014] One side of the circulating hydrogen pipeline entering the reaction separation bin is provided with the product separator, and the product separator is connected with the product bin.

[0015] The heat exchanger is connected with the steam drum and the heat exchanger cross-line valve.

[0016] The cooler is connected with the cooler cross-line valve, and the heater is connected with the heater cross-line valve.

[0017] A product separation gas return valve is arranged between the product separator and the reaction separation bin.

[0018] The main valve is arranged on the pipeline of the circulating hydrogen pipeline entering the reaction separation bin.

[0019] The bottom of the reaction separation bin is provided with a reaction separation bin bottom valve, the bottom of the crushing bin is provided with a crushing bin bottom valve, and the bottom of the raw material bin is provided with a raw material bin bottom valve.

[0020] Optionally, a multi-stage cyclone separator and a reaction separation bin gas outlet line are arranged in the reaction separation bin.

[0021] Optionally, the multi-stage cyclone separator is arranged at an upper portion in the cavity of the reaction separation bin.

[0022] Optionally, one end of the reaction separation bin gas outlet line is arranged in the reaction separation bin, and the other end is connected with an exhaust pipeline of the multi-stage cyclone separator.

[0023] Optionally, a mill is arranged in the crushing bin, and the crushing bin can be provided with one or more mills according to the processing scale of the magnesium hydride.

[0024] Optionally, the power of the mill is 5-11 kW.

[0025] Optionally, a hydrogen feeding line is arranged between the hydrogen compressor and the cooler, and the hydrogen enters the hydrogen compressor through the hydrogen feeding line.

[0026] Optionally, a deionized water line and a by-product steam line are arranged on the steam drum.

[0027] Optionally, a powder fluidization tube bundle is further arranged in the cavity of the reaction separation bin, and the powder fluidization tube bundle is arranged at the bottom in the cavity of the reaction separation bin.

[0028] Optionally, the gas inlet end of the powder fluidization tube bundle is connected with the outlet of the heater.

[0029] Optionally, a safety relief line is arranged at the top of the reaction separation bin, and a safety valve is arranged on the safety relief line.

[0030] According to another aspect of the present application, a production method of the production device for large-scale preparation of magnesium hydride is provided, and the production method comprises the following steps:

[0031] (1) When feeding, all the valves are closed, the hydrogen compressor is started to feed the raw material in the raw material bin to the reaction separation bin through the hydrogen;

[0032] (2) When reacting, the powder fluidization tube bundle is started, the heater cross line valve is closed, the hydrogen compressor and the heater are started, the hydrogen is reacted with the raw material, and the magnesium hydride is obtained;

[0033] (3) When collecting, the main valve is closed, the product line valve and the product separation gas return valve are opened, and the magnesium hydride enters the product bin.

[0034] The raw material is a magnesium-based metal powder material.

[0035] Optionally, in the step (2), the hydrogen is heated by a heater before reacting with the raw material.

[0036] Optionally, in the step (2), the temperature of the reaction of the hydrogen with the raw material is adjusted by a heater, a heat exchanger and a cooler.

[0037] Optionally, in the step (2), the reaction heat generated in the process of obtaining the magnesium hydride is carried into the heat exchanger by the hydrogen to generate steam, which is delivered to the outside by a steam drum.

[0038] Optionally, in the step (2), the pressure of the reaction is 1-5 MPa, and the temperature of the reaction is 250-400℃.

[0039] Optionally, in the step (2), the pressure of the reaction is selected from any value or a range between any two values selected from 1 MPa, 2 MPa, 3 MPa, 4 MPa and 5 MPa.

[0040] Optionally, in the step (2), the temperature of the reaction is selected from any value or a range between any two values selected from 250℃, 300℃, 350℃, 380℃ and 400℃.

[0041] Optionally, the particle size of the magnesium hydride is 0.5-10 μm.

[0042] Optionally, the purity of the magnesium hydride prepared by the pure magnesium and hydrogen is greater than 95%.

[0043] Optionally, the magnesium-based metal powder material is selected from at least one of magnesium, magnesium-nickel alloy, magnesium-aluminum alloy, magnesium-rare earth alloy, magnesium-iron oxide mixture, magnesium-graphite mixture and magnesium-aluminum oxide mixture; wherein the magnesium content in the alloy or mixture is 60-99.99%.

[0044] Optionally, the raw material further contains an auxiliary agent, and the content of the auxiliary agent is 1-10 wt%.

[0045] In the present application, (1) the feeding, discharging, material conveying and reaction process of the material all adopt fluidization, and the fluidized carrier gas adopts hydrogen, so as to avoid the influence of impurity gas on the preparation of magnesium hydride. In the feeding process, the hydrogen carrier gas is used to convey the magnesium powder in the magnesium powder bin to the reaction and separation bin in a fluidized manner, so as to enter the reaction cycle process of magnesium powder hydrogenation; after the hydrogenation is completed, the material in the reaction cycle process is directly conveyed to the product separator through the adjusting valve, and after separation, enters the product bin; in the whole reaction cycle process, the magnesium powder and the reaction product magnesium hydride powder are carried by the hydrogen carrier gas through each unit, and in the cycle process, the hydrogenation, crushing and separation, and heat transfer are completed, and in the initial hydrogenation process, the material is heated by the carrier gas, and in the reaction process, the carrier gas carries away the heat generated in the reaction.

[0046] The fluidization of the material not only realizes the continuous transfer of the material in the preparation process, facilitates the realization of automatic control, but also enhances the mass and heat transfer between hydrogen and the material, and increases the friction and collision between the materials in the flow process, destroys part of the magnesium particle surface magnesium hydride shell, and promotes the hydrogenation reaction.

[0047] (2) A high-speed mill is arranged, and a magnesium hydride shell is produced on the surface of the magnesium powder in the hydrogenation reaction process. The shell affects the mass transfer of hydrogen to the surface of the magnesium powder particles, and reduces the reaction efficiency. By arranging a high-speed mill, the material is continuously conveyed to the high-speed mill head to crush the material and strip off the magnesium hydride shell on the surface of the magnesium particles during the hydrogenation reaction, so that the fresh magnesium surface is exposed, and the magnesium powder hydrogenation process is accelerated.

[0048] (3) Increase the steam drum recovery energy. A large amount of heat is released during the magnesium powder hydrogenation process, and the enthalpy of formation of magnesium hydride is about 76 kJ / mol-H2. The heat is wasted by cooling during the preparation of magnesium hydride. The present application increases the steam drum in the reaction cycle system, which can not only save the heat generated in the reaction process in the form of high-pressure steam by generating steam, but also stabilize the temperature of the hydrogen carrier gas by adjusting the steam pressure.

[0049] (4) Heating or cooling the hydrogen carrier gas, and heating or cooling the material with the hydrogen carrier gas. The conventional heating process at the beginning of the preparation of magnesium hydride is to heat the magnesium powder by means of heat-conducting oil or electric heating, etc. Due to the poor heat conduction capacity of the magnesium powder, the internal and external temperature gradient of the reactor is too large, the heating is uneven, and local temperature may be too high, which may cause the magnesium powder to melt and the particles to become large. The present application heats the hydrogen carrier gas by electric heating or heat-conducting oil, etc., and then heats the magnesium powder by the hydrogen carrier gas. The high-temperature hydrogen gas realizes efficient heat transfer to the magnesium powder by forced convection, and the process is in a fluidized state, so that the magnesium powder is heated more uniformly and efficiently, and the cooling process is the same.

[0050] The a) magnesium powder circulation reaction fluidization system disclosed in the present application. The system comprises a hydrogen compressor, a heater, a cooler, a magnesium powder bin, a crushing bin, a reaction separation bin, a gas fluidization tube bundle, a product separator and a magnesium hydride product bin, etc. The magnesium powder feeding, discharging, reaction and transportation between units are all completed under fluidization.

[0051] b) By setting a high-speed mill to break the magnesium hydride shell on the surface of the magnesium powder particles, the hydrogen gas is in contact with the fresh magnesium surface, and the reaction rate is improved;

[0052] c) By setting a steam drum on the hydrogen circulation pipeline, the heat generated by the hydrogenation of magnesium powder is recovered in the form of high-pressure steam, and at the same time the temperature of hydrogen gas can be controlled by adjusting the steam pressure;

[0053] d) By adjusting the temperature of hydrogen gas through the cooler and heater on the hydrogen circulation system, the magnesium powder is heated to the reaction temperature by heated hydrogen gas, and at the same time the heat generated by the hydrogenation of magnesium powder can be removed by cooled hydrogen gas.

[0054] In the present application, "magnesium powder" is not specific, but refers to magnesium metal materials, including pure magnesium, magnesium-nickel alloy, magnesium-aluminum alloy, magnesium-rare earth alloy, magnesium-iron oxide mixture, magnesium-graphite mixture, magnesium-alumina mixture, etc. One or a combination of more than one, wherein the magnesium content in the alloy or mixture is between 60-99.99%, and the content of other substances is between 0.1-40%.

[0055] The present application solves the problems of gas-solid reaction in the preparation process by fluidization operation and heating and cooling of the material with carrier gas. The existing static high temperature and high pressure hydrogenation process has the problems of difficult mass transfer of hydrogen gas to the fresh magnesium surface, affecting production efficiency, difficult heat transfer, uneven heat transfer during hydrogenation start-up heating process, local high temperature, heat generated during hydrogenation process cannot be transferred in time, also causing local high temperature, even temperature runaway, high temperature causing magnesium powder melting, welding, particle size increasing, incomplete hydrogenation, and the problems of non-automation and non-continuity of feeding, discharging, internal transportation and transfer during preparation process. The problem of large amount of heat energy generated during magnesium powder hydrogenation process cannot be recovered, causing energy waste, is solved by setting a steam drum. The problem of low hydrogenation efficiency due to the inability to effectively break the magnesium hydride shell on the surface of magnesium particles is solved by setting a high-speed mill.

[0056] The beneficial effects that can be produced by the present application include:

[0057] 1) The present application adopts a fluidized material conveying process, which can realize the continuity and automation of material conveying, and the carrier gas can also be used as a heating and cooling medium for the material, which is more uniform and reliable than the traditional heating method, and can also achieve partial material crushing effect.

[0058] 2) In the production apparatus for large-scale preparation of magnesium hydride of this application, a high-speed mill is set up to effectively break the surface material of magnesium powder particles, generate fresh magnesium surface, and accelerate the hydrogenation reaction rate.

[0059] 3) In the production equipment for large-scale preparation of magnesium hydride of this application, the heat released by adding hydrogen to magnesium powder can be recovered by setting up a steam drum. Attached Figure Description

[0060] Figure 1 This is a schematic diagram of the process flow for the large-scale preparation of magnesium hydride in this application.

[0061] In the picture:

[0062] 1. Reaction Separation Chamber; 2. Crushing Chamber; 3. Raw Material Chamber; 4. Heater; 5. Hydrogen Compressor; 6. Cooler; 7. Heat Exchanger; 8. Steam Drum; 9. Filter; 10. Multistage Cyclone Separator; 11. Powder Fluidized Bed Tube Bundle; 12. Product Chamber; 13. Product Separator; 14. Product Separation Gas Return Valve; 15. Main Valve; 16. Product Line Valve; 17. Reaction Separation Chamber Outlet Gas Line; 18. Fluidized Material; 19. Hydrogen Feed Line; 20. Deionized Water Line; 21. By-product Steam Line; 22. Safety Relief Line; 23. Circulating Hydrogen Pipeline; 24. Heat Exchanger Crossover Valve; 25. Cooler Crossover Valve; 26. Heater Crossover Valve; 27. Reaction Separation Chamber Bottom Valve; 28. Crushing Chamber Bottom Valve; 29. ​​Raw Material Chamber Bottom Valve. Detailed Implementation

[0063] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0064] Unless otherwise specified, all raw materials used in the embodiments of this application were purchased through commercial channels.

[0065] Example 1

[0066] like Figure 1 The diagram shows a production apparatus for the large-scale preparation of magnesium hydride: a reaction separation chamber 1, a crushing chamber 2, a raw material chamber 3, a heater 4, a hydrogen compressor 5, a cooler 6, a heat exchanger 7, a steam drum 8, a filter 9, a product chamber 12, and a product separator 13. The upper end of the reaction separation chamber 1 is sequentially connected to the filter 9, heat exchanger 7, cooler 6, hydrogen compressor 5, heater 4, and crushing chamber 2 via a circulating hydrogen pipeline 23. The raw material chamber 3 is located between the crushing chamber 2 and the heater 4. The product separator 13 is located on the side where the circulating hydrogen pipeline 23 enters the reaction separation chamber 1, and the product separator 13 is connected to the product chamber 12. The steam drum 8 is located above the heat exchanger 7 and is connected to the heat exchanger 7. The reaction separation chamber 1 contains fluidized material 18.

[0067] The side of the reaction separation bin 1 is provided with a product separation gas return valve 14, which is connected to a product separator 13, below which is a product bin 12, and the side of the product separator 13 is connected to a product line valve 16, which is connected to a circulating hydrogen pipeline 23, and a main valve 15 is installed downstream of the connection point.

[0068] The reaction separation bin 1 is connected to a safety relief line 22, which contains a safety valve, and the exhaust line of the multi-stage cyclone separator 10 is connected to the inlet of the filter 9, the outlet line is connected to the tube side inlet of the heat exchanger 7, the tube side outlet is connected to the inlet of the cooler 6, the hydrogen feed line 19 is connected to the secondary inlet line, the outlet of the cooler 6 is connected to the inlet of the hydrogen compressor 5, the outlet of the compressor is connected to the heater 4, the outlet of the heater 4 is connected to the circulating hydrogen pipeline 23, which is connected to the raw material bin 3, the crushing bin 2, and finally connected to the reaction separation bin 1 through the main valve 15, and the raw material bin 3 is provided with a raw material bin bottom valve 29 on the circulating hydrogen pipeline 23.

[0069] The heat exchanger 7 is connected to a steam drum 8, which is connected to a deionized water line 20 and a byproduct steam line 21. The heat exchanger 7, the cooler 6 and the heater 4 are each provided with a cross line, and the valves on the cross lines are respectively a heat exchanger cross line valve 24, a cooler cross line valve 25 and a heater cross line valve 26.

[0070] The reaction separation bin 1 is connected to the inlet of the crushing bin 2 below, and the connecting line has a reaction separation bin bottom valve 27, the bottom outlet of the crushing bin 2 is connected to the circulating hydrogen pipeline 23, and the connecting line is provided with a crushing bin bottom valve 28.

[0071] The powder fluidization tube bundle 11 is installed at the bottom of the inside of the reaction separation bin 1, and the inlet end is connected to the downstream line of the heater 4, the multi-stage cyclone separator 10 is installed at the upper part of the cavity of the reaction separation bin 1, the reaction separation bin outlet line 17 is installed at the top of the cavity of the reaction separation bin 1, and is connected to the exhaust line of the multi-stage cyclone separator 10 in front of the filter 9; the crushing bin 2 is composed of an outer shell and an internal high-speed grinding mechanism.

[0072] Example 2

[0073] Feed process: First make sure all the valves are closed, make sure the raw material bin 3 has enough raw material, make sure the production device (system) for large-scale production of magnesium hydride has been purged clean, and the system is in a vacuum state except for the raw material bin 3, product separator 13, product bin 12, heat exchanger 7, steam drum 8 and their connecting lines. The shell side of the steam drum 8 and the heat exchanger 7 is injected with an appropriate amount of deionized water, and the steam drum exhaust pressure is set to 4 MPa (G). Adjust the heat exchanger cross-line valve 24, the cooler cross-line valve 25, the heater cross-line valve 26 and the main valve 15 to ensure that the material bypasses the heat exchanger 7, the cooler 6 and the heater 4. Then inject 3 MPa hydrogen into the system through the hydrogen feed line 19 and stop. Start the hydrogen compressor 5 to circulate the hydrogen in the system, open the raw material bin bottom valve 29, and deliver the magnesium powder to the reaction separation bin 1. In the reaction separation bin 1, the hydrogen carrier gas and the magnesium powder material are separated by multiple cyclone separators, the magnesium powder material falls into the reaction separation bin 1, and the hydrogen enters the filter 9. The filtered gas enters the heat exchanger cross-line valve 24, then passes through the cooler cross-line valve 25 and then returns to the compressor inlet. When the magnesium powder material is delivered to the predetermined amount, close the raw material bin bottom valve 29.

[0074] Reaction process: Start the powder fluidization tube bundle 11, close the heater cross-line valve 26, let the hydrogen enter the heater 4, start the heater 4, and raise the hydrogen temperature to 300°C. When the magnesium powder material in the reaction separation bin 1 reaches a temperature of 250°C, start the mill of the crushing bin 2, open the reaction separation bin bottom valve 27 and the crushing bin bottom valve 28 in sequence, and close the heat exchanger cross-line valve 24 and the cooler cross-line valve 25. When the temperature rises to 300°C, close the heater 4. At this time, the hydrogenation reaction has started, and the reaction process will consume hydrogen. When the hydrogen pressure in the system is lower than 3 MPa (G), it will automatically be supplemented. The heat generated by the reaction is carried by hydrogen to the heat exchanger 7, which heats the water and produces steam. The steam is supplied to the outside through the steam drum, and the hydrogen temperature after passing through the heat exchanger is controlled within 270°C. If the temperature is too high, it will be cooled by the cooler 6. The magnesium powder material and hydrogen react to produce magnesium hydride. The material enters the crushing bin 2 from the bottom of the reaction separation bin 1, and the magnesium powder material is extruded and collided by the high-speed mill. The hydrogen hydride shell generated on the surface of the magnesium powder particles is destroyed and falls off due to its brittle nature, and then enters the circulating hydrogen pipeline 23 through the crushing bin bottom valve 28. The particles containing magnesium powder and magnesium hydride are carried by the hydrogen carrier gas into the reaction separation bin 1 and separated by the multiple cyclone separators 10, so that the magnesium powder and magnesium hydride particles fall into the reaction separation bin 1, respectively. The carrier gas hydrogen reenters the filter 9 and enters the next cycle.

[0075] The material collecting process: after several hours of circulation (different size magnesium powder particle feed reaction time is different), the magnesium powder in the system is all converted into magnesium hydride powder, the temperature of the heat exchanger 7 gradually decreases, when the inlet temperature is less than 290 DEG C, the flow is switched to the heat exchanger 7 cross line, and the steam drum stops steaming. The temperature in the reaction separation bin gradually decreases to normal temperature, the main valve 15 is closed, the product line valve 16 and the product separation gas return valve 14 are opened, and the material enters the product separator 13. In the product separator 13, the magnesium hydride powder product is separated by cyclone and enters the product bin 12 from the bottom, and the hydrogen carrier gas enters the reaction separation bin 1, and a reaction cycle is completed. Among them, 0.28mm size magnesium powder particle feed reaction time is 4-12h, and the magnesium hydride with a particle size of 0.5-10um is obtained.

[0076] The fluidization operation of the application using hydrogen reaction gas as the carrier gas not only solves the material transfer, but also makes the heat and mass transfer between gas and solid more sufficient and efficient, solves the problems of uneven material reaction, poor solid heat transfer performance and local overtemperature caused by too fast reaction, and the high-speed flow increases the collision and friction between material particles, timely breaks the magnesium hydride layer on the surface of magnesium powder particles, and makes hydrogen more easily contact the surface of fresh magnesium powder particles, and accelerates the reaction rate.

[0077] The application adopts the steam drum as one of the temperature adjusting means of the reaction system, which can not only stabilize the reaction temperature, but also recycle the heat generated in the reaction in the form of high-temperature and high-pressure steam.

[0078] The application adopts the high-speed mill as a crushing means, which can timely and efficiently break the magnesium hydride layer generated on the surface of magnesium powder, and can continuously crush the magnesium hydride particles to obtain smaller product.

[0079] The above is only a few embodiments of the application, and does not limit the application in any form. Although the application discloses the above preferred embodiments, it does not limit the application. Any skilled person in the art can make some changes or modifications to the above disclosed technical content without departing from the scope of the technical solution of the application, which is equivalent to the equivalent embodiment, and belongs to the scope of the technical solution.

Claims

1. A production apparatus for mass production of magnesium hydride, characterized by comprising: The production device comprises a reaction separation bin (1), a crushing bin (2), a raw material bin (3), a heater (4), a hydrogen compressor (5), a cooler (6), a heat exchanger (7), a steam drum (8), a filter (9), a product bin (12), a product separator (13), a heat exchanger cross-line valve (24), a cooler cross-line valve (25), a heater cross-line valve (26), a main valve (15); The upper end of the reaction separation bin (1) is connected with the filter (9), the heat exchanger (7), the cooler (6), the hydrogen compressor (5), the heater (4) and the crushing bin (2) in sequence through a circulating hydrogen pipeline (23); The raw material bin (3) is arranged between the crushing bin (2) and the heater (4); The outlet of the heater (4) is connected with the circulating hydrogen pipeline (23), the circulating hydrogen pipeline (23) is connected with the raw material bin (3) and the crushing bin (2); the bottom outlet of the crushing bin (2) is connected with the circulating hydrogen pipeline (23), and the bottom of the raw material bin (3) is connected with the circulating hydrogen pipeline (23); The lower end of the reaction separation bin (1) is connected with the inlet of the crushing bin (2); The side, where the circulating hydrogen pipeline (23) enters the reaction separation bin (1), is provided with the product separator (13), and the product separator (13) is connected with the product bin (12); The heat exchanger (7) is connected with the steam drum (8) and the heat exchanger cross-line valve (24); The cooler (6) is connected with the cooler cross-line valve (25), and the heater (4) is connected with the heater cross-line valve (26); The product separator (13) is provided with a product separation gas return valve (14) between the product separator (13) and the reaction separation bin (1); The side of the product separator (13) is connected with a product line valve (16), and the product line valve (16) is connected with the circulating hydrogen pipeline (23); The main valve (15) is arranged on the pipeline, where the circulating hydrogen pipeline (23) enters the reaction separation bin (1); The bottom of the reaction separation bin (1) is provided with a reaction separation bin bottom valve (27), the bottom of the crushing bin (2) is provided with a crushing bin bottom valve (28), and the bottom of the raw material bin is provided with a raw material bin bottom valve (29); The cavity of the reaction separation bin (1) is further provided with a powder flow state pipe bundle (11), and the powder flow state pipe bundle (11) is arranged at the bottom of the cavity of the reaction separation bin (1).

2. The production apparatus according to claim 1, characterized by The reaction separation bin (1) is provided with a multi-stage cyclone separator (10) and a reaction separation bin gas outlet line (17).

3. The production apparatus according to claim 2, characterized by The multi-stage cyclone separator (10) is arranged at the upper portion of the cavity of the reaction separation bin (1).

4. The production apparatus according to claim 2, characterized by One end of the reaction separation bin gas outlet line (17) is connected with the filter (9), and the other end is connected with the exhaust pipeline of the multi-stage cyclone separator (10).

5. The production apparatus according to claim 1, wherein The crushing bin (2) is provided with a mill.

6. The production apparatus according to claim 5, characterized by The power of the mill is 5-11kw.

7. The production apparatus according to claim 1, wherein The hydrogen gas compressor (5) and the cooler (6) are provided with a hydrogen feeding line (19), and the hydrogen gas enters the hydrogen gas compressor (5) through the hydrogen feeding line (19).

8. The production apparatus according to claim 1, wherein The steam drum (8) is provided with a deionized water line (20) and a by-product steam line (21).

9. The production apparatus according to claim 1, wherein, The gas inlet end of the powder fluidization tube bundle (11) is connected with the outlet of the heater (4).

10. The production method of the production apparatus for mass-producing magnesium hydride according to any one of claims 1 to 9, characterized by, The production method comprises the following steps: (1) When feeding, all valves are closed, the hydrogen compressor (5) is started to deliver the raw material in the raw material bin (3) to the reaction and separation bin (1) through hydrogen; (2) When reacting, the powder fluidization tube bundle (11) is started, the heater cross-line valve (26) is closed, the hydrogen compressor (5) and the heater (4) are started, hydrogen reacts with the raw material to obtain magnesium hydride; (3) When collecting, the main valve (15) is closed, the product line valve (16) and the product separation gas return valve (14) are opened, and the magnesium hydride enters the product bin; The raw material is a magnesium-based metal powder material.

11. The production method according to claim 10, characterized by, In the step (2), when the hydrogen reacts with the raw material, the hydrogen is heated by the heater (4) before reacting with the raw material.

12. The production method according to claim 10, characterized by, In the step (2), the temperature of the reaction of the hydrogen with the raw material is adjusted by the heater (4), the heat exchanger (7) and the cooler (6).

13. The production method according to claim 10, characterized by, In the step (2), the reaction heat generated in the process of obtaining magnesium hydride is carried into the heat exchanger (7) by hydrogen to generate steam, which is delivered externally through the steam drum (8).

14. The production method according to claim 10, characterized by, In the step (2), the pressure of the reaction is 1-5 MPa, and the temperature of the reaction is 250-400℃.

15. The production method according to claim 10, characterized by, The particle size of the magnesium hydride is 0.5-10 μm.

16. The production method according to claim 10, characterized by, The magnesium-based metal powder material is selected from at least one of magnesium, magnesium-nickel alloy, magnesium-aluminum alloy, magnesium-rare earth alloy, magnesium-iron oxide mixture, magnesium-graphite mixture, and magnesium-aluminum oxide mixture; wherein the magnesium content in the alloy or mixture is 60-99.99%.

17. The production method according to claim 10, characterized by, The raw material further contains an auxiliary agent, and the content of the auxiliary agent is 1-10 wt%. The raw material further contains an auxiliary agent, and the content of the auxiliary agent is 1-10 wt%.

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