Method for preparing titanium-based hydrogen storage alloy in short process

Abstract

The invention discloses a method for preparing a titanium-based hydrogen storage alloy in a short process, and belongs to the technical field of metal alloy preparation. The method comprises the following steps: firstly, carrying out hydrogen plasma reduction smelting on a raw material consisting of ilmenite and iron ore to reduce oxides such as titanium and iron in the raw material and volatilize impurity elements in the form of hydride, and then refining by using argon plasma to remove residual elements such as hydrogen in the smelting process to obtain the titanium-based hydrogen storage alloy. Through the mode, the production thought that a traditional titanium-based hydrogen storage alloy depends on high-purity titanium and iron is broken through, the reduction step of the oxide and the refining step of the alloy are integrated in a hydrogen-argon plasma staged smelting mode, the preparation process of the titanium-based hydrogen storage alloy is shortened, the energy consumption in the production process is reduced, the hydrogen reduction reaction product is water, and the production cost is reduced. Carbon emission and pollution are greatly reduced, and the development trend of global green metallurgy is met.

Description

Technical Field

[0001] This invention relates to the field of metal alloy preparation technology, and in particular to a short-process method for preparing titanium-based hydrogen storage alloys. Background Technology

[0002] The cost of hydrogen storage and transportation typically accounts for 30% of the total cost of hydrogen energy utilization, and in some cases even as high as 40%. Compared to hydrogen production and utilization, hydrogen storage and transportation are the industry's weakest link. Therefore, the development of relevant technologies for hydrogen storage is particularly important. Hydrogen storage alloys, as a type of solid hydrogen storage material, can achieve hydrogen storage and transportation through chemical adsorption. They offer high hydrogen storage density, good safety, and long storage time, making them key to the future development of hydrogen storage technology.

[0003] Ti and Fe are abundant on Earth and relatively inexpensive to obtain. Furthermore, titanium-based hydrogen storage alloys, such as TiFe alloys (atomic molar ratio approximately 1:1), are typical AB-type hydrogen storage alloys, characterized by rapid hydrogen absorption and desorption, reversible hydrogen absorption and desorption processes at room temperature, high theoretical hydrogen storage capacity, and the ability to repeatedly absorb and desorb hydrogen, making them highly promising for large-scale industrial applications. Currently, titanium-based hydrogen storage alloys are mainly prepared by arc melting of high-purity titanium and high-purity iron. The industrial production of raw material titanium primarily relies on the Kroll process (magnesothermic reduction), which consumes 30,000-32,000 kWh of energy per ton of sponge titanium. Meanwhile, the mainstream production process for industrial pure iron is the blast furnace-converter process, emitting approximately 2 tons of CO2 per ton of steel. The enormous energy consumption and environmental burden associated with the production of these two basic metal materials have become significant bottlenecks restricting the sustainable development of related industries. In addition, existing methods for preparing titanium-based hydrogen storage alloys mainly employ carbon-based melting technology, which suffers from long preparation processes and high energy consumption.

[0004] Therefore, it is necessary to design a short-process method for preparing titanium-based hydrogen storage alloys without relying on high-purity titanium and iron raw materials to solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to provide a short-process method for preparing titanium-based hydrogen storage alloys, so as to solve the problems existing in the prior art.

[0006] To achieve the above objectives, the present invention provides the following solution:

[0007] One of the technical solutions of the present invention is a short-process method for preparing titanium-based hydrogen storage alloys, which uses ilmenite and iron ore as raw materials and obtains titanium-based hydrogen storage alloys through hydrogen plasma reduction smelting and argon plasma refining.

[0008] This invention employs hydrogen plasma reduction melting technology to prepare titanium-based hydrogen storage alloys. Compared to traditional carbon-based melting technology, hydrogen plasma can excite, dissociate, and ionize hydrogen particles, converting molecular hydrogen (H2) into more reactive hydrogen particles. These reactive hydrogen particles can significantly reduce the Gibbs free energy and activation energy of metal oxides, thereby achieving and accelerating the oxide reduction process. Hydrogen plasma reduction melting technology also exhibits unique advantages in terms of environmental friendliness and product quality control.

[0009] Hydrogen plasma is a collection of active hydrogen particles obtained through excitation, dissociation, and ionization. Its main components are hydrogen molecules and hydrogen atoms, with a small amount of hydrogen ions. The inventors, based on thermodynamic data (such as...),... Figure 2 As shown in the figure, hydrogen atoms have high reactivity and can reduce oxides in ores, while other non-metallic elements such as P and S will generate hydrides and be discharged during the smelting process.

[0010] This invention is based on hydrogen plasma reduction smelting of raw materials composed of ilmenite and iron ore. This process reduces oxides such as titanium and iron in the raw materials, while impurities volatilize as hydrides. Subsequently, argon plasma refining removes residual hydrogen and other elements from the smelting process, yielding a titanium-based hydrogen storage alloy. This invention breaks away from the traditional production approach of relying on high-purity titanium and iron for titanium-based hydrogen storage alloys. By integrating oxide reduction and alloy refining steps through a staged hydrogen-argon plasma smelting method, the preparation process of titanium-based hydrogen storage alloys is shortened, energy consumption is reduced, and the hydrogen reduction reaction product is water, significantly reducing carbon emissions and pollution, aligning with the global trend of green metallurgy.

[0011] Furthermore, the method specifically includes the following steps:

[0012] The ilmenite and iron ore are crushed, mixed, and pressed into blocks to obtain a blocky mixed ore. The blocky mixed ore is then placed in a plasma melting furnace and evacuated until the vacuum level inside the furnace is ≤5×10⁻⁶. -3 The pressure is increased to 0.05-0.08 MPa, and then argon gas is introduced for washing. After washing, argon gas is continued to be introduced to make the pressure inside the furnace reach 0.05-0.08 MPa. The blocky mixed ore is melted by argon plasma, and then hydrogen-argon mixed gas is introduced for hydrogen plasma reduction smelting. After hydrogen plasma reduction smelting, argon gas is introduced for argon plasma refining. After argon plasma refining, the power is turned off, the gas inside the furnace is discharged, and the furnace is cooled in an argon atmosphere to obtain the titanium-based hydrogen storage alloy.

[0013] Furthermore, the FeTiO3 content in the ilmenite is ≥70wt%.

[0014] Furthermore, the iron ore contains TFe ≥ 50 wt%.

[0015] Furthermore, the atomic ratio of Ti to Fe in the blocky mixed ore is 4:4.5-4:5.5.

[0016] Preferably, the atomic ratio of Ti to Fe in the blocky mixed ore is 4:5.

[0017] Fe atoms will burn off under high-temperature conditions of hydrogen plasma reduction. Therefore, the Fe atom content in the blocky mixed ore is slightly higher than the Ti atom content, so that the molar ratio of Fe atoms to Ti atoms in the final iron-titanium alloy is about 1:1.

[0018] Furthermore, the gas washing is performed a total of 3 times.

[0019] Furthermore, the proportion of hydrogen in the hydrogen-argon mixture is 10-40 vol%. The higher the proportion of hydrogen, the more active hydrogen particles are generated, and the faster the reduction smelting proceeds.

[0020] Furthermore, the hydrogen-argon mixed gas and the argon gas are specifically introduced into the plasma gun, that is, the mixed ore is placed in the plasma melting furnace, the sample is first melted under argon conditions, then 10-40 vol% of hydrogen gas is added for hydrogen plasma reduction melting, and finally the hydrogen supply is stopped and pure argon gas is used for argon plasma refining.

[0021] Furthermore, the parameters for the hydrogen plasma reduction melting include: a current of 100-400A, a cathode distance of 2-6cm from the sample surface, and a melting time of 5-60min.

[0022] By adjusting the process parameters and melting time of the reduction smelting process, oxides such as titanium and iron in the raw materials are reduced, and impurity elements volatilize in the form of hydrides.

[0023] Furthermore, the parameters for melting the blocky mixed ore include: a current of 100-400A and a distance of 2-6cm between the cathode and the sample surface.

[0024] Furthermore, the parameters for the argon plasma refining include: a current of 100-400A, a cathode distance of 2-6cm from the sample surface, and a refining time of 5-60min.

[0025] By adjusting the process parameters and refining time of the refining process, residual elements such as hydrogen in the reduction smelting process are removed to obtain a titanium-based hydrogen storage alloy with the target composition.

[0026] Furthermore, the hydrogen (H2) and argon (Ar) in the argon gas and the hydrogen-argon mixture are both high-purity gases.

[0027] Furthermore, both the hydrogen plasma reduction melting and the argon plasma refining are carried out under a certain pressure, ranging from 0.05 to 0.08 MPa, while keeping the furnace pressure constant when changing the gas composition.

[0028] The second technical solution of the present invention: a titanium-based hydrogen storage alloy prepared according to the above method.

[0029] This invention provides an integrated reduction-smelting-refining single-furnace preparation process. Using ilmenite and iron ore as raw materials, titanium-based hydrogen storage alloys are produced through a short-process, staged smelting process using hydrogen-argon plasma. This solves the problems of energy loss and impurity control caused by multiple process steps. This method can significantly shorten the production process of titanium-based hydrogen storage alloys and reduce energy consumption. Because hydrogen plasma is used as a reducing agent, the reduction temperature of titanium oxides is also lowered, and CO2 emissions during the reaction are greatly reduced, aligning with the global trend of green metallurgy.

[0030] The present invention discloses the following technical effects:

[0031] (1) This invention provides a short-process method for preparing titanium-based hydrogen storage alloys. It uses ilmenite and iron ore as raw materials and achieves the short-process preparation of titanium-based hydrogen storage alloys through hydrogen-argon plasma staged melting. The raw materials used in this invention are ilmenite and iron ore, rather than high-purity titanium and iron, which greatly reduces the cost of raw materials.

[0032] (2) The present invention shortens the production process of traditional titanium-based hydrogen storage alloys. It does not require separate preparation of high-purity titanium and iron. The reduction, smelting and refining processes can be completed in a single furnace, which shortens the production cycle and greatly reduces production energy consumption.

[0033] (3) The present invention uses hydrogen plasma as a reducing agent to replace the traditional carbonaceous reducing agent. The reduction product is H2O, which reduces the large amount of CO2 emissions generated during the carbothermic reduction process. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a process flow diagram of the short-process method for preparing titanium-based hydrogen storage alloys according to the present invention.

[0036] Figure 2 The results are thermodynamic calculations of the main elements in ilmenite and iron ore. Detailed Implementation

[0037] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0038] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0039] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0040] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0041] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0042] It should be noted that any aspects not described in detail in this invention are conventional practices in the field and are not the focus of this invention.

[0043] As a first aspect of the present invention, the present invention provides a short-process method for preparing titanium-based hydrogen storage alloys, using ilmenite and iron ore as raw materials, and obtaining titanium-based hydrogen storage alloys through hydrogen plasma reduction smelting and argon plasma refining.

[0044] As an embodiment of the present invention, the method specifically includes the following steps:

[0045] The ilmenite and iron ore are crushed, mixed, and pressed into blocks to obtain a blocky mixed ore. The blocky mixed ore is placed in a plasma melting furnace, and argon plasma is applied to melt it. Then, hydrogen plasma reduction melting is performed using a hydrogen-argon mixed gas as the plasma source (i.e., hydrogen-argon mixed gas is first introduced into the plasma gun for hydrogen plasma reduction melting), and then argon plasma refining is performed using argon gas as the plasma source (i.e., pure argon gas is introduced for argon plasma refining) to obtain the titanium-based hydrogen storage alloy.

[0046] In a preferred embodiment of the present invention, the method includes the following more specific steps:

[0047] The ilmenite and iron ore are crushed, mixed, and pressed into blocks to obtain a blocky mixed ore. The blocky mixed ore is then placed in a plasma melting furnace and evacuated until the vacuum level inside the furnace is ≤5×10⁻⁶. -3 The pressure is increased to 0.05-0.08 MPa, and then argon gas is introduced for washing. After washing, argon gas is continued to be introduced to make the pressure inside the furnace reach 0.05-0.08 MPa. The blocky mixed ore is melted by argon plasma, and then hydrogen-argon mixed gas is introduced for hydrogen plasma reduction smelting. After hydrogen plasma reduction smelting, argon gas is introduced for argon plasma refining. After argon plasma refining, the power is turned off, the gas inside the furnace is discharged, and the furnace is cooled in an argon atmosphere to obtain the titanium-based hydrogen storage alloy.

[0048] In a preferred embodiment of the present invention, the FeTiO3 content in the ilmenite is ≥70wt%.

[0049] In a preferred embodiment of the present invention, the iron ore contains TFe ≥ 50 wt%.

[0050] In a preferred embodiment of the present invention, the atomic ratio of Ti to Fe in the blocky mixed ore is 4:4.5-4:5.5.

[0051] In a preferred embodiment of the present invention, the atomic ratio of Ti to Fe in the blocky mixed ore is 4:5.

[0052] In a preferred embodiment of the present invention, the proportion of hydrogen in the hydrogen-argon mixture is 10-40 vol%.

[0053] As a preferred embodiment of the present invention, the parameters of the hydrogen plasma reduction melting include: current of 100-400A, cathode distance from sample surface of 2-6cm, and melting time of 5-60min.

[0054] In a preferred embodiment of the present invention, the parameters for argon plasma melting and refining include: current of 100-400A, cathode distance from sample surface of 2-6cm, and refining time of 5-60min.

[0055] In a preferred embodiment of the present invention, the parameters for melting the blocky mixed ore include: a current of 100-400A and a distance of 2-6cm between the cathode and the sample surface.

[0056] In a preferred embodiment of the present invention, both the hydrogen and argon in the argon gas and the hydrogen-argon mixed gas are high-purity gases.

[0057] In a preferred embodiment of the present invention, both the hydrogen plasma reduction melting and the argon plasma refining are carried out under a pressure of 0.05-0.08 MPa.

[0058] The technical solution of the present invention will be further described below with reference to specific embodiments.

[0059] In specific embodiments of the present invention, room temperature or normal temperature refers to 20-30℃.

[0060] Unless otherwise specified, all raw materials used in the specific embodiments of this invention are commercially available products.

[0061] The gases (hydrogen and argon) used in the following examples are all high-purity gases.

[0062] The FeTiO3 content in the ilmenite used in the following examples is 71 wt%, and the TFe content in the iron ore is 52 wt%.

[0063] Example 1

[0064] A short-process method for preparing titanium-based hydrogen storage alloys, comprising the following steps:

[0065] Ilmenite and iron ore were crushed separately using a crusher, passed through a 100-mesh sieve, mixed evenly, and pressed into blocks to obtain a blocky mixed ore (the atomic ratio of Ti to Fe in the final mixed ore is 4:5). The prepared blocky mixed ore was placed in a water-cooled copper crucible in a vacuum plasma melting furnace, and a vacuum was drawn until the vacuum degree inside the furnace was ≤5×10⁻⁶. -3After Pa, the evacuation was stopped, and argon gas was quickly introduced for three purging operations. After purging, a stable flow rate of argon gas (1 L / min) was continued to bring the pressure inside the furnace to 0.05 MPa. Under the condition of argon gas only, electricity was applied to completely melt the blocky mixed ore with argon plasma. The parameters during the melting process included: working current of 150 A and cathode distance of 4 cm from the sample surface. Then, a hydrogen-argon mixture with a hydrogen content of 40 vol% was introduced at a flow rate of 1 L / min (the pressure inside the furnace should be kept constant when changing the gas composition) for hydrogen plasma reduction. In the original smelting process, the operating current during hydrogen plasma reduction smelting was 200A, with the cathode 4cm from the sample surface. This reduced the metal oxides while removing impurity elements. After 30 minutes of reduction smelting, the hydrogen supply was stopped, but argon gas was supplied. Argon plasma was used to refine the smelting product, removing residual hydrogen and other gaseous impurities and homogenizing the alloy composition. The operating current and cathode distance from the sample surface were the same as in the reduction smelting process. After 10 minutes of refining, the power was turned off, and the sample was finally cooled in an argon atmosphere to obtain the titanium-based hydrogen storage alloy. Testing showed that the total content of all impurity elements except Ti and Fe in the final product was 1wt%, with Ti and Fe mass fractions of 46wt% and 53wt%, respectively.

[0066] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A short-process method for preparing titanium-based hydrogen storage alloys, characterized in that, Titanium-based hydrogen storage alloys are prepared by using ilmenite and iron ore as raw materials, through hydrogen plasma reduction smelting and argon plasma refining.

2. The method for preparing titanium-based hydrogen storage alloys via a short process as described in claim 1, characterized in that, The method specifically includes the following steps: The ilmenite and iron ore are crushed, mixed, and pressed into blocks to obtain a blocky mixed ore. The blocky mixed ore is then placed in a plasma melting furnace and evacuated until the vacuum level inside the furnace is ≤5×10⁻⁶. -3 The pressure is increased to 0.05-0.08 MPa, and then argon gas is introduced for washing. After washing, argon gas is continued to be introduced to make the pressure inside the furnace reach 0.05-0.08 MPa. The blocky mixed ore is melted by argon plasma, and then hydrogen-argon mixed gas is introduced for hydrogen plasma reduction smelting. After hydrogen plasma reduction smelting, argon gas is introduced for argon plasma refining. After argon plasma refining, the power is turned off, the gas inside the furnace is discharged, and the furnace is cooled in an argon atmosphere to obtain the titanium-based hydrogen storage alloy.

3. The method for preparing titanium-based hydrogen storage alloys via a short process as described in claim 2, characterized in that, The FeTiO3 content in the ilmenite is ≥70wt%. And / or, the iron ore contains TFe ≥ 50 wt%; And / or, the atomic ratio of Ti to Fe in the blocky mixed ore is 4:4.5-4:5.

5.

4. The method for preparing titanium-based hydrogen storage alloys via a short process as described in claim 2, characterized in that, The hydrogen-argon mixture contains 10-40 vol% hydrogen.

5. The method for preparing titanium-based hydrogen storage alloys via a short process as described in claim 2, characterized in that, The parameters for the hydrogen plasma reduction melting include: current of 100-400A, distance between the cathode and the sample surface of 2-6cm, and melting time of 5-60min.

6. The method for preparing titanium-based hydrogen storage alloys via a short process as described in claim 2, characterized in that, The parameters for melting the blocky mixed ore include: a current of 100-400A and a distance of 2-6cm between the cathode and the sample surface.

7. The method for preparing titanium-based hydrogen storage alloys via a short process as described in claim 2, characterized in that, The parameters for the argon plasma refining include: a current of 100-400A, a cathode distance of 2-6cm from the sample surface, and a melting time of 5-60min.

8. The method for preparing titanium-based hydrogen storage alloys via a short process as described in claim 2, characterized in that, Both the hydrogen and argon in the argon gas and the hydrogen-argon mixture are high-purity gases.

9. A titanium-based hydrogen storage alloy prepared by the method according to any one of claims 1-9.

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