阅读说明：本技术 一种气化渣镁镍合金储氢复合材料及其制备方法 (Gasification slag magnesium-nickel alloy hydrogen storage composite material and preparation method thereof ) 是由 蔡小龙 许云华 曹保卫 刘建勃 白靖 郭磊 刘明欣 于 2020-06-12 设计创作，主要内容包括：本发明提供的一种气化渣镁镍合金储氢复合材料的制备方法,通过将镁粉、镍粉和气化渣混合后,利用气化渣本身具有的多孔结构,通过球磨、超声振动等方式将镁粉、镍粉填充到气化渣的孔道中,并混合均匀,通过压片、烧结、冷却,制备出气化渣镁镍合金储氢复合材料,用于储氢时,多孔气化渣作为催化剂分布在镁镍合金基体中能够促进合金氢化和氢化物脱氢,加速合金集氢、放氢速率,降低储氢体系的活化能,细小的镁镍合金颗粒分布在气化渣孔道内,可有效抑制放氢过程中因加热引起的镁镍合金颗粒长大,进而维持复合材料储氢循环稳定性；本发明的制备方法成本低、原料来源广、同时兼备处理固废气化渣及其资源化、高值化利用的效果,优势显著,适宜推广。(The invention provides a preparation method of a magnesium-nickel alloy hydrogen storage composite material of gasification slag, which comprises the steps of mixing magnesium powder, nickel powder and gasification slag, filling the magnesium powder and the nickel powder into pore channels of the gasification slag by ball milling, ultrasonic vibration and other modes by utilizing the porous structure of the gasification slag, uniformly mixing, tabletting, sintering and cooling to prepare the magnesium-nickel alloy hydrogen storage composite material of the gasification slag, wherein when the magnesium-nickel alloy hydrogen storage composite material is used for storing hydrogen, the porous gasification slag is distributed in a magnesium-nickel alloy matrix as a catalyst, so that alloy hydrogenation and hydride dehydrogenation can be promoted, the alloy hydrogen collection and hydrogen discharge rate can be accelerated, the activation energy of a hydrogen storage system can be reduced, and fine magnesium-nickel alloy particles are distributed in the pore channels of the gasification slag, so that the magnesium-nickel alloy particles caused by heating in the hydrogen discharge process can be effectively inhibited from growing, and the hydrogen storage circulation stability of the composite material can; the preparation method has the advantages of low cost, wide raw material source, obvious advantages and suitability for popularization, and has the effects of treating solid waste gas and dissolving slag, and recycling and high-value utilization of the solid waste gas and the slag.)

1. The magnesium-nickel alloy hydrogen storage composite material for the gasified slag is characterized by being of a porous structure, pore channels of the porous structure are provided by the gasified slag, the surface of the gasified slag is coated by magnesium-nickel alloy to form a magnesium-nickel coating layer, magnesium-nickel alloy particles are contained in the pore channels of the gasified slag, the content of the gasified slag is 10% -30%, and the proportion of the content of magnesium to nickel is 17:1-6: 1.

2. The preparation method of the gasification slag magnesium-nickel alloy hydrogen storage composite material is characterized by comprising the following steps of:

(1) taking 100-300 parts of gasification slag, 850 parts of magnesium powder and 50-100 parts of nickel powder, and ball-milling and mixing uniformly to obtain a mixture A;

(2) pressing the mixture A into a block B;

(3) putting the block B into a vacuum sintering furnace, vacuumizing, introducing inert gas, and sintering in an inert gas atmosphere;

(4) and (6) cooling.

3. The method for preparing the gasification slag magnesium-nickel alloy hydrogen storage composite material according to the claim 2, wherein in the step (1), the purity of the gasification slag is more than or equal to 99%, and the average grain size is 80-240 μm.

4. The method for preparing the gasification slag magnesium-nickel alloy hydrogen storage composite material according to the claim 3, wherein in the step (1), the gasification slag has three-dimensional cross-linking pores, the ratio of spherical pores is more than 80%, and the average diameter of the pores is 0.7-7 μm.

5. The method for preparing the gasification slag magnesium-nickel alloy hydrogen storage composite material according to any one of claims 2 to 4, wherein in the step (1), the purity of the magnesium powder and the purity of the nickel powder are both 99.8%, the average particle size of the magnesium powder is 0.5 to 5 μm, and the average particle size of the nickel powder is 0.4 to 4 μm.

6. The preparation method of the gasification slag magnesium-nickel alloy hydrogen storage composite material according to claim 5, wherein in the step (1), the ball milling time is 4-9 h.

7. The preparation method of the gasification slag magnesium-nickel alloy hydrogen storage composite material according to claim 6, characterized in that the step (1) further comprises vibrating the mixture A by using ultrasonic waves for 0.5-2h after the ball milling is finished.

8. The method of claim 7The preparation method of the gasification slag magnesium-nickel alloy hydrogen storage composite material is characterized in that in the step (3), the vacuumizing pressure is 5.0 multiplied by 10^-3-1.0×10^-1Pa, the pressure of inert gas atmosphere is 0.5-2MPa, the sintering temperature is 550-650 ℃, and the sintering time is 1-6 h.

Technical Field

The invention relates to the field of hydrogen storage material preparation, in particular to a gasification slag magnesium-nickel alloy hydrogen storage composite material and a preparation method thereof.

Background

Currently, in the face of the current situations of high environmental pressure, low effective utilization rate of resources, imminent exhaustion of fossil fuels and the like, the energy in China will be developed towards the direction of energy conservation, environmental protection and sustainability in the future. Among various green energy sources, hydrogen is used as a renewable energy source, and has the advantages of being green, environment-friendly, sustainable, various in acquisition ways and the like. However, storage and transport of hydrogen gas is a major bottleneck limiting the development of hydrogen energy. Currently, the main hydrogen storage technologies include high pressure gaseous hydrogen storage, low temperature liquid hydrogen storage, and hydrogen storage with hydrogen storage materials. Among many hydrogen storage technologies, solid-state hydrogen storage of magnesium alloy is a relatively safe and reliable hydrogen storage method.

Magnesium metal as a hydrogen storage material has the advantages of abundant resources, high theoretical hydrogen storage capacity, low cost, hydrogen purification and the like, and is considered to be one of the most promising solid hydrogen storage materials. However, magnesium hydride (MgH), which is a high activation energy when hydrogen molecules are dissociated and hydrogen atoms are diffused into magnesium metal during hydrogen collection₂) Lower reaction rate during nucleation and growth, MgH₂Higher dehydrogenation temperature in the hydrogen discharge process (>300 ℃) and the coarsening of magnesium crystal grains caused by the problems limit the application of magnesium metal for hydrogen storage.

On the basis, researchers provide magnesium alloying hydrogen storage materials, such as magnesium aluminum, magnesium nickel, magnesium palladium and the like, the magnesium alloying hydrogen storage materials are remarkably accelerated in hydrogen absorption and desorption speed and reduced in reaction enthalpy change, and are widely concerned with the unique structure and electronic characteristics, so that the magnesium alloying hydrogen storage materials have potential application values, but the magnesium alloying hydrogen storage materials have the defects that the manufacturing cost is high, the dissociation temperature and the dissociation speed of hydrogen do not have actual vehicle-mounted application conditions and the like.

Disclosure of Invention

In order to solve the above problems, the present invention provides the following technical solutions:

the magnesium-nickel alloy hydrogen storage composite material for the gasification slag is of a porous structure, pore channels of the porous structure are provided by the gasification slag, the surface of the gasification slag is coated by magnesium-nickel alloy to form a magnesium-nickel coating layer, magnesium-nickel alloy particles are contained in the pore channels of the gasification slag, the content of the gasification slag is 10% -30%, and the proportion of the content of magnesium and nickel is 17:1-6: 1.

Further, in order to prepare the gasification slag magnesium-nickel alloy hydrogen storage composite material, the following technical scheme is provided:

a preparation method of a gasification slag magnesium-nickel alloy hydrogen storage composite material is characterized by comprising the following steps:

(1) taking 100-300 parts of gasification slag, 850 parts of magnesium powder and 50-100 parts of nickel powder, and ball-milling and mixing uniformly to obtain a mixture A;

(2) pressing the mixture A into a block B;

(3) and sintering the block B in a vacuum sintering furnace.

Furthermore, in the step (1), the purity of the gasified slag is more than or equal to 99 percent, and the average grain size is 80-240 μm.

Furthermore, in the step (1), the gasification slag has three-dimensional crosslinking pores, the ratio of spherical pores is more than 80%, and the average diameter of the pores is 0.7-7 μm.

Further, in the step (1), the purities of the magnesium powder and the nickel powder are both 99.8%, the average particle size of the magnesium powder is 0.5-5 μm, and the average particle size of the nickel powder is 0.4-4 μm.

Furthermore, in the step (1), the ball milling time is 4-9 h.

Further, the step (1) also comprises vibrating the mixture A by using ultrasonic waves for 0.5 to 2 hours after the ball milling is finished.

Further, in the step (3), the pressure for evacuation is 5.0X 10^-3-1.0×10^-1Pa, the pressure of inert gas atmosphere is 0.5-2MPa, the sintering temperature is 550-650 ℃, and the sintering time is 1-6 h.

The invention has the following beneficial effects:

the porous metal or composite material can improve the hydrogen storage kinetics and the circulation stability of the magnesium alloy material, wherein the porous material plays a leading role, the metal oxide and the carbide are used as additives of the magnesium alloy hydrogen storage material, the catalytic effect is good, the dissociation of hydrogen is more facilitated particularly under the conditions of a porous structure and high specific surface area, and the main components of the gasified slag are the metal oxide and the carbide which are in the porous structure and have high specific surface area and can be used as an efficient catalyst of the magnesium alloy hydrogen storage material; the raw coal is gasified at high temperature and high pressure to form semi-coke, and simultaneously a large amount of gas and solid by-products are produced, and the solid waste gas is used for slag melting, and the chemical composition of the raw coal is oxide SiO₂、Al₂O₃、Fe₂O₃The method mainly uses carbide, has low resource utilization rate and serious environmental pollution problem, needs to be solved urgently, changes waste into valuable by utilizing the gasification slag as solid waste, improves the hydrogen storage performance of the magnesium-nickel alloy, and solves the problem that the solid waste pollutes the environment at the same time, thereby achieving two purposes.

The invention mixes porous gasified slag and magnesium-nickel powder evenly by ball milling, after further refining, under the action of ultrasonic wave, the fine magnesium-nickel powder fills the pore channel of the gasified slag, the mixture of the gasified slag and the magnesium-nickel powder is pressed into prefabricated blocks by cold press molding, then in a vacuum sintering furnace, when the temperature reaches the vicinity of the melting point of the magnesium-nickel alloy, the magnesium-nickel alloy particles are in a molten state or are melted into a liquid state, at the moment, the molten state or the liquid state alloy is fully filled in the pore channel inside the gasified slag by adopting inert gas atmosphere after vacuum pumping,meanwhile, the surface of the gasification slag is coated by the alloy, the pore channels in the porous gasification slag are filled by the magnesium-nickel alloy, and the outer part of the porous gasification slag is coated by the magnesium-nickel alloy to form a core-shell structure. On the one hand, the magnesium-nickel alloy hydrogen storage composite material prepared by the invention has the advantages that the porous gasified slag is distributed in the magnesium-nickel alloy matrix as the catalyst and can promote the hydrogenation and hydride (Mg) of the magnesium-nickel alloy₂NiH₄) Dehydrogenation, namely accelerating the hydrogen collection and release rate of the alloy and reducing the activation energy of a hydrogen storage system; on the other hand, fine magnesium-nickel crystal grains are distributed in the gasification slag pore channel, and the gasification slag can effectively inhibit magnesium-nickel alloy particles from growing up due to heating in the hydrogen discharge process, so that the hydrogen storage cycle stability of the composite material is maintained;

the method comprises the steps of correspondingly selecting magnesium powder and nickel powder suitable for pore channels of the gasified slag through the limitation on the purity, the granularity and the pore channel size of the gasified slag, enabling the magnesium powder and the nickel powder to be uniformly mixed with the gasified slag during ball milling, promoting the magnesium powder and the nickel powder to enter the pore channels of the gasified slag through vibration, and preparing for subsequent tabletting and sintering, wherein the ball milling time and the ultrasonic vibration time are optimized to promote the uniform mixing of the magnesium powder and the nickel powder and promote the magnesium powder and the nickel powder to be fully filled in the pore channels of the gasified slag; the vacuum or inert gas atmosphere condition is to prevent the magnesium-nickel alloy from being deactivated by oxidation.

In addition, the coal chemical industry in the region of elm forest in Shaanxi is developed, 4000 million tons of semi-coke in the year produces a large amount of raw gas, and the raw gas is rich in 25% of hydrogen, so that the hydrogen extraction amount is rich (about 100 million tons/year); the gasified slag of the semi-coke by-product (about 200 ten thousand tons per year) is used as solid waste to be buried in a messy way, so that the water quality and the soil are polluted, and the environmental pollution is serious; furthermore, elm produces magnesium metal (50 million tons/year) in abundance, and annual yield accounts for 60% of the whole country. The resources and conditions enable the elm area to be used as a hydrogen energy development base, have the advantage of being unique, and have practical significance for the invention.

In summary, the magnesium powder, the nickel powder and the gasified slag are mixed, the porous structure of the gasified slag is utilized, the magnesium powder and the nickel powder are filled in the pore channels of the gasified slag in the modes of ball milling, ultrasonic vibration and the like, the mixture is uniformly mixed, and the magnesium-nickel alloy hydrogen storage composite material of the gas-out gasified slag is prepared through tabletting, sintering and coolingThe chemical composition of the gasified slag is SiO oxide₂、Al₂O₃、Fe₂O₃And carbide is taken as the main component, when the magnesium-nickel alloy hydrogen storage composite material of the gasified slag prepared by the method is used for storing hydrogen, the porous gasified slag is taken as a catalyst to be distributed in a magnesium-nickel alloy matrix to promote alloy hydrogenation and Mg₂NiH₄The hydride is dehydrogenated, the alloy hydrogen collection and discharge rate is accelerated, the activation energy of a hydrogen storage system is reduced, fine magnesium-nickel alloy particles are distributed in a gasification slag pore channel, and the gasification slag can effectively inhibit the growth of the magnesium-nickel alloy particles caused by heating in the hydrogen discharge process, so that the hydrogen storage cycle stability of the composite material is maintained; the preparation method of the gasification slag magnesium-nickel alloy hydrogen storage composite material has the advantages of low cost, wide raw material source, obvious advantages and suitability for popularization and application, and has the function of treating solid waste gas for slagging.

Drawings

FIG. 1 is a schematic view of a scanning electron microscope of a porous structure of gasified slag;

FIG. 2 is a schematic structural diagram of a gasification slag magnesium-nickel alloy hydrogen storage composite material;

FIG. 3 is a schematic diagram of a preparation process route of the gasification slag magnesium-nickel alloy hydrogen storage composite material.

In the figure: 1-gasification slag, 2-magnesium-nickel coating, 3-pore canal and 4-magnesium-nickel alloy particles.

Detailed Description

In order to make the technical means, features and functions of the present invention easier to understand, the technical solutions in the embodiments of the present invention are clearly and completely described below with reference to the detailed description and the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments.

All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in fig. 1, a magnesium-nickel alloy hydrogen storage composite material of gasification slag is a porous structure, pore channels 3 of the porous structure are cross-linked pores, the pore channels 3 are provided by gasification slag 1, the surface of the gasification slag 1 is coated by magnesium-nickel alloy to form a magnesium-nickel coating layer 2, and the pore channels 3 of the gasification slag 1 contain magnesium-nickel alloy particles 4; the preparation process of the gasification slag magnesium-nickel alloy hydrogen storage composite material is shown in fig. 3, and the preparation process of the gasification slag magnesium-nickel alloy hydrogen storage composite material is specifically described below with reference to specific embodiments.