JP2000096160A - Material for vanadium series hydrogen storage alloy and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow an alloy to exhibit excellent hydrogen occluding characteristics at the time of mixing an alloy raw material contg. vanadium oxides with an Al series reducing material and executing the reduction and alloying of the vanadium oxides, by controlling the content of Al in the produced vanadium series alloy to a specified value. SOLUTION: In a thermite process in which an alloy raw material contg. vanadium oxides is mixed with an Al series reducing agent, and the reduction and alloying of vanadium oxides are executed, the content of Al in the vanadium series alloy is controlled to <=1 wt.%, and Al by the content of 85 to 99% of Al theoretical quantity required for reducing all oxides in the alloy raw material is used as the reducing agent. As the vanadium oxides, V2O5, V2O, V2O2, V2O3, V2O4 or the like is given, the content thereof is controlled to about >=50 wt.% and at least one kind among Ni, Fe, Cu, Co, Mn and Cr may moreover be incorporated into the alloy raw material. As the Al reducing material, Al or an Al series alloy composed of Al and at least one kind among Cr, Cu, Ni, Co, Mn and Ti is used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a material for a vanadium-based hydrogen storage alloy and a method for producing the same.

[0002]

2. Description of the Related Art Thermite process (thermit reduction method) has been conventionally used for the production of vanadium (V) metal. In this method, a reducing agent is mixed with a powder of vanadium oxide such as V ₂ O ₅ , and the mixture is heated in a refractory crucible to start a reduction reaction, and the reaction proceeds by utilizing self-heating generated by the reaction. . Aluminum is often used as a reducing agent. In this case, reduction of vanadium oxide mainly proceeds according to the following reaction formula.

The oxide (Al ₂ O ₃ ) by-produced by the reduction reaction of 10Al + 3V ₂ O ₅ → 5Al ₂ O ₃ + 6V floats on the upper part of the refractory crucible due to its low specific gravity. The generated metal vanadium (hereinafter simply referred to as “vanadium”) is deposited on the bottom of the refractory crucible. The bottom vanadium is recovered from these products.

In this regard, not only metal vanadium,
A method using a thermite process has also been proposed for the production of vanadium-based alloys and the like (for example, Japanese Patent Application Laid-Open No. Sho 60-3).
No. 6632, JP-A-60-50129, JP-A-1-1-1
No. 65731).

[0005]

By the way, among vanadium alloys, those having a hydrogen storage capacity such as V-Ti alloys are known, and these are used as a negative electrode active material of an alkaline secondary battery. Attempts have been made to use it. For this reason, the demand for vanadium alloys as hydrogen storage alloys is also increasing.

However, even if vanadium or a vanadium-based alloy obtained by a conventional thermite process is used as a hydrogen storage alloy, it is not practical to use it as it is because the amount of hydrogen storage is insufficient. It is possible.

Accordingly, an object of the present invention is to produce a vanadium-based alloy suitable for a hydrogen storage alloy by a thermite process.

[0008]

Means for Solving the Problems The present inventor has conducted intensive studies in view of the problems of the prior art, and as a result, found that a vanadium-based alloy controlled to have a specific composition can achieve the above object. The present invention has been completed.

That is, the present invention relates to the following material for a vanadium-based hydrogen storage alloy and a method for producing the same.

[0010] 1. In a thermite process in which an Al-based reducing material is mixed with an alloy raw material containing a vanadium oxide to reduce and alloy the vanadium oxide, the Al content in the resulting vanadium-based alloy is reduced to 1% by weight or less. A method for producing a material for a vanadium-based hydrogen storage alloy.

2. A vanadium-based hydrogen storage alloy material having an Al content of 1% by weight or less.

3. 2. A material for a vanadium-based hydrogen storage alloy, which is an alloy obtained by the production method according to the above item 1 and has an Al content of 1% by weight or less.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION A method for producing a material for a vanadium-based hydrogen storage alloy according to the present invention comprises a thermite for reducing and alloying a vanadium oxide by mixing an aluminum-based reducing material with an alloy raw material containing a vanadium oxide. The process is characterized in that the Al content in the obtained vanadium-based alloy is set to 1% by weight or less.

In the production method of the present invention, the Al content in the obtained vanadium alloy is usually 1% by weight or less, preferably 0.5% by weight or less. By setting within this range, excellent characteristics can be exhibited for a hydrogen storage alloy.

Among the alloy raw materials containing vanadium oxide, vanadium oxide is not particularly limited, and examples thereof include V ₂ O ₅ , V ₂ O, V ₂ O ₂ , V ₂ O ₃ and V ₂ O ₄ . Either may be included. The content of the vanadium oxide in the alloy raw material may be appropriately determined according to the type of the vanadium oxide, the type of the target hydrogen storage alloy, and the like, but is usually 50% by weight or more.

In the present invention, N is further added as an alloy raw material.
At least one of i, Fe, Cu, Co, Mn and Cr may be contained. These components may be blended in any form of a simple metal, an oxide (including a double oxide), an alloy, an intermetallic compound, or a mixture thereof.
By containing these components, the slag (mainly aluminum oxide (Al ₂ O) produced in the thermite process is mainly reduced by lowering the melting point of the alloy raw material and increasing the fluidity of the melt of the alloy raw material.
₃ )) (floating of non-metallic inclusions such as Al ₂ O ₃ ) can be promoted, so that a high-quality vanadium-based alloy (V-based alloy) can be obtained. The content of the alloy component is not particularly limited as long as such an effect is obtained, but usually, 10 to 3 as a metal in the obtained V-based alloy.
The content may be about 0% by weight, preferably 15 to 25% by weight.

Further, in the present invention, other metal components may be contained in the alloy raw material as required. For example, if Nb, Ta, or the like, which is expensive as a single metal, is added to the alloy raw material in the form of an oxide in advance, an alloy of these metals and vanadium can be manufactured at a relatively low cost. The amounts of these additions vary depending on the type of metal to be added. For example, when at least one oxide of Nb and Ta is added, usually 0.5 to 1 as an oxide in the alloy raw material.
It may be about 0% by weight, preferably 1 to 3% by weight.

Further, in the present invention, if necessary,
At least one of CaO and CaF ₂ may be added to the alloy raw material. By adding these, mainly, the melting point of the slag generated in the thermit process is lowered to increase the fluidity of the slag, and the reaction between the Al-based reducing agent and the vanadium oxide can be promoted, and at the same time, the slag out can be promoted. It becomes possible. The amount of these additions may be appropriately set according to the amount of slag to be generated, but may be usually about 1 to 10% by weight of the alloy raw material.

In the present invention, in addition to the above, components necessary for producing a V-based hydrogen storage alloy may be contained in the alloy raw material. These may be contained in any form such as a simple metal, a compound (such as an oxide), and an alloy.

As the Al-based reducing material in the production method of the present invention, at least one of Al and an Al-based alloy can be used. The type and the like of Al are not particularly limited, and commercial products can be used as they are. Also,
Although the purity of Al is not particularly limited, it is preferable that carbon, which is one of the impurities, is as small as possible as long as the carbon content in the material of the present invention does not finally exceed 1,000 ppm by weight. Al-based alloys include Al and C
An alloy composed of at least one of r, Cu, Ni, Co, Mn, and Ti can be used. For example, Al-
An alloy such as a Ni-based alloy can be used. These Al
Even in the base alloy, the carbon content is finally 1000
It is preferable that the amount is as small as possible within a range not exceeding ppm by weight.

The amount of the Al-based reducing agent used should be such that the amount of Al in the produced V-based alloy does not exceed 1% by weight.
Therefore, in the present invention, usually about 85 to 99% of the theoretical amount of Al required to reduce all oxides in the alloy raw material,
Preferably, an Al amount of 90 to 97% is used as the Al-based reducing material. If an Al content exceeding 99% is used, the Al content in the V-based alloy may exceed 1% by weight. On the other hand, if the Al content is less than 85%, the oxygen content may be too large. Thus, in the present invention, the Al content can be adjusted mainly by the Al reducing agent.

Next, the alloy raw material and the predetermined amount of the Al-based reducing material are mixed. The form of the alloy raw material and the Al-based reducing material at the time of mixing is not particularly limited as long as the progress of a predetermined reaction is not hindered, and may be any of powder, granules, and the like. In particular, in the present invention, the alloy raw material has a particle size of 0.05
It is desirable to use a granular material of ｍｍ5 mm. Also, Al
It is desirable to use a granular material having a particle size of 0.1 to 10 mm as the system reducing agent. As described above, by using the alloy raw material and the like controlled to have a constant particle size, the reaction can proceed more smoothly, and the remaining of unreacted substances and the incorporation of nonmetallic inclusions can be reliably avoided. Can be. As a result, it is possible to increase the yield (yield) of vanadium.

The reactor is not particularly limited as long as the thermite process can be carried out, and the same reactor as that used in the known thermite process can be used. In particular, a reaction vessel (crucible) having a known shape and material can be used. For example, an alumina crucible, a water-cooled Cu
A crucible made of, for example, a crucible having a magnesium oxide layer formed on an inner surface thereof can be used. When using the latter crucible having a magnesium oxide layer formed thereon, it is possible to avoid the possibility that Al is mixed into the vanadium-based alloy from the crucible material, and the diffusion of the molten alloy by Mg gas generated by partially reducing magnesium oxide. Can be promoted, which is advantageous in these respects.

A known crucible having a magnesium oxide layer formed on its inner surface can be used. For example, a crucible in which a steel substrate is coated with magnesium oxide can be used. The thickness of the magnesium oxide layer is not particularly limited, and is usually 30 to 50 mm.
Any degree is acceptable.

The reaction may be performed according to a known thermite process. In the present invention, if a mixture of the alloy raw material and the Al-based reducing material is ignited, the reaction proceeds by the heat of reaction between the Al (component) and the vanadium oxide. In this case, the reaction temperature may be usually about 2000 to 2500 ° C. The holding time at this temperature is usually 5 minutes or more, preferably 10 minutes or more. By performing the reaction under such conditions, the reduction reaction can be completed to the end, and the floating removal of non-metallic inclusions such as Al oxide as a by-product can be reliably performed. As a result, the vanadium alloy It can contribute to the reduction of the amount of Al or the amount of Al oxide therein.

When a predetermined holding time cannot be ensured only by the above-mentioned reaction heat, the reaction may be forcibly heated from the outside. The heating method is not particularly limited, and may be performed using a known heating furnace or the like. The reaction atmosphere is not particularly limited.
Any atmosphere such as a vacuum or an inert gas may be used. In addition, since the upper portion of the generated vanadium alloy is generally covered with slag, even if the reaction is carried out in the atmosphere, the mixing of nitrogen can be reduced to 500 ppm by weight or less. Therefore, from the standpoint of effectively preventing the contamination of nitrogen and reducing the nitrogen content to 200% by weight or less, it is desirable to perform the treatment in an atmosphere in which air is shut off.

After the completion of the reaction, the reaction product (alloy lump) is taken out. Also in the present invention, the slag is formed separately at the top and the vanadium-based alloy is formed separately at the bottom, as in the ordinary thermite process. In addition, slag may also adhere to the vicinity of the surface of the vanadium-based alloy separated and recovered. In this case, when the Al oxide is reduced, it is mixed (solid-solved) into the alloy again as Al. Therefore, it is preferable to remove the slag near these surfaces in advance.

As a means for separating and removing the slag, for example, the slag may be separated from the vanadium-based alloy using a Keren hammer or the like, or the slag may be scraped off. Through these treatments, the content of Al oxide in the alloy can be reduced to usually 0.5% by weight or less, preferably 0.2% by weight or less.

The vanadium alloy thus obtained has an Al content of usually 1% by weight or less, preferably 0.5% by weight or less, and can be used as a material for a vanadium-based hydrogen storage alloy of the present invention. . This Al content refers to the amount of Al (s-Al) in solid solution, and therefore does not include the amount of Al present as an Al oxide. Al content is 1
If it exceeds 10% by weight, a decrease in the amount of hydrogen occlusion occurs,
It becomes difficult to put it to practical use as a hydrogen storage alloy.

In the material of the present invention, both the carbon content and the nitrogen content are generally 1000 ppm by weight or less, preferably 500 ppm by weight or less. If carbon and nitrogen are present in large amounts, these atoms are more likely to occupy hydrogen storage sites in the alloy, and the desired hydrogen storage properties may not be obtained. In the production method of the present invention, the carbon content can be appropriately controlled by, for example, selection of alloy raw materials (purity and the like), selection of furnace materials, selection and installation of carbon electrodes, and setting of other production conditions. In the production method of the present invention, the nitrogen content can be appropriately controlled by, for example, selection of alloy raw materials (purity and the like), reaction atmosphere, and setting of other production conditions.

Further, the oxygen content in the above material is usually about 0.5 to 2% by weight, preferably 1 to 1.5% by weight. By adjusting the oxygen content in this range, mechanical pulverization of the obtained alloy can be easily performed. The oxygen content refers to dissolved oxygen, and does not include oxygen existing as Al ₂ O ₃ or the like. This oxygen content can be controlled mainly by the type and amount of the Al-based reducing material.

In the present invention, the vanadium-based alloy can be re-dissolved before and / or after the slag removing step. By remelting, Al oxide and the like existing inside the vanadium-based alloy are also slagged out near the surface, so that Al or slag can be removed more efficiently.

The method of remelting is not particularly limited, and the produced vanadium-based alloy lump may be melted by a known melting method. For example, a vanadium-based alloy lump may be put into a high-frequency vacuum induction furnace, all of which may be melted, and then cooled by casting. Since Al oxide and the like are slagged out near the surface of the vanadium-based alloy ingot by the remelting, the slag may be removed by performing the same slag removing step as described above after the remelting. In addition, when aluminum is unevenly distributed, uniform dispersion of aluminum can be achieved by re-dissolution.

The content of the Al oxide in the vanadium-based alloy from which the Al oxide has been removed through re-melting is usually 0.1.
It is at most 3% by weight, preferably at most 0.1% by weight. In the present invention, the re-dissolution and the removal of the Al oxide may be repeated once or more as necessary. For example, removing the slag near the surface of the generated vanadium alloy ingot,
After remelting the alloy ingot, the Al oxide can be further removed, then the second remelting can be performed, and the slag-out Al oxide can be removed again.

In the present invention, when redissolving, T
At least one of i, Zr and Hf can be added. These components also act as a deoxidizing agent, so it is not easy to alloy them by a thermite process. However, if they are added at the time of re-melting, they can be alloyed with a vanadium-based alloy. The amount of these additives depends on the alloy composition,
It may be appropriately set according to the purpose of the final product, etc., and usually 10 to 2 parts by weight per 100 parts by weight of the ingot of the vanadium alloy.
About 0 part by weight, preferably 15 to 17 parts by weight may be added. These components can be added as single metals,
It may be added in the form of an intermetallic compound or an alloy.

If necessary, another alloy component is added to the V-based alloy, and a deoxidizing treatment or the like is performed to finally obtain a hydrogen storage alloy. The timing of adding the other alloy components is not particularly limited, and the production stage of the V-based alloy, re-melting,
The deoxidizing step may be performed at any stage such as after the production of the V-based alloy.

The deoxidizing step may be performed according to a known deoxidizing method. In this case, as a deoxidizing agent, rare earth elements such as La and Ce, or alloys or mixtures thereof (Mm)
It is preferable to use Further, it is preferable that the oxygen content of the hydrogen storage alloy obtained by the deoxidizing step be 2,000 ppm by weight or less, particularly 1000 ppm by weight or less.

[0038]

According to the production method of the present invention, a material for a vanadium-based hydrogen storage alloy can be produced by applying a thermite process. Since the above-obtained material, that is, the material of the present invention, has an Al content controlled to a certain amount or less, a hydrogen storage alloy exhibiting excellent hydrogen storage characteristics can be obtained.

The hydrogen storage alloy obtained from the material for a hydrogen storage alloy of the present invention can be used for an electrode (negative electrode) for an alkaline secondary battery such as a nickel-metal hydride battery, etc., as well as for hydrogen storage and hydrogen transport. It can be used in the field.

[0040]

The present invention will be described in more detail with reference to the following examples. In addition, each physical property was measured by the following method, respectively. All samples in the following measurement method were used after removing the slag after thermite reaction (before re-dissolving), pulverizing and homogenizing.

(1) Al content (s-Al content) Particle size 16 to 32 mesh (0.495 to 0.99 mm)
0.5 g of the sample adjusted to 10 ml of concentrated sulfuric acid and 10 ml of concentrated nitric acid.
Dissolve in a mixed solution with water and heat to generate white smoke of sulfuric acid. After cooling, add 50 ml of water, heat again to dissolve the salts, cool, and then make up with a 250 ml measuring cylinder with distilled water. And after collecting 25 ml,
What was measured with a 00 ml measuring cylinder was measured with a polarized Zeeman atomic absorption spectrophotometer (“HITACHI Z-6100” manufactured by Hitachi, Ltd.).

(2) Aluminum oxide content The value obtained by subtracting the s-Al content from the total Al content (t-Al content) is defined as i-Al content, and Al ₂ O ₃ equivalent to the i-Al content is obtained.
The amount was determined as the aluminum oxide content.

The amount of t-Al was measured as follows. First, a particle size of 16-32 mesh (0.495-0.
99 g) was mixed with lithium borate (mp = 845 ° C.) and the resulting mixture was
Heat at 50 ° C. for 20 minutes and 1000 ° C. for 30 minutes, then cool. Then, the sample was mixed with 10 ml of concentrated hydrochloric acid and 12 ml of water.
The mixture was added to a mixed solution of 0 ml, and the volume was increased with distilled water using a 250 ml measuring cylinder. This was measured by a multi-element light velocity sequential analysis type ICP (“SPS-1500VR” manufactured by Seiko Denshi).

(3) Carbon content 0.3 g of a sample adjusted to a particle size of 7 to 16 mesh (0.99 to 2.79 mm) was added to a combustion aid (W (1.5 g) + Sn).
(0.3 g)), and the resulting mixture was measured using a C, S infrared absorption analyzer ("HORIBA EMIA-520" manufactured by Horiba, Ltd.).

(4) Nitrogen content In the case of a granular sample, 7 to 16 mesh (0.99 to 2.
79 mm), ultrasonic cleaning in dilute hydrochloric acid for 1 minute, washing with water, ultrasonic cleaning in methanol for 1 minute, drying with warm air, filling 50 mg into Ni capsules, and using an analyzer " LECOTC-436 "(manufactured by LECO).

In the case of a powdery sample, the size was adjusted to 100 to 325 mesh (0.043 to 0.15 mm), and the Ni capsule was filled with 50 mg, and the analyzer "LECO TC-436" (LE
Co., Ltd.).

In the case of a solid sample, the sample is cut out to a size of about 2 to 3 cm by a water-cooled micro cutter, polished with an endless belt (cooled with ethanol), and cut with a clipper.
mg sample, ultrasonic cleaning in dilute hydrochloric acid for 1 minute, water washing, ultrasonic cleaning in methanol for 1 minute, hot air drying, filling 50 mg into Ni capsules, analyzer " LECO TC-436 "(manufactured by LECO).

(5) Oxygen content Measured in the same manner as in the above (4) Measurement of nitrogen content.

Production Example 1 V ₂ O ₅ , Ni and Nb ₂ O ₅ were _converted to V ₄ Ni _0.65 Nb
_0.047 (V: 82.74% by weight, Ni 15.49% by weight, Nb: 1.77% by weight) was weighed, and 95 of the theoretical amount required to reduce oxides in the alloy raw material was obtained.
% Of Al, and a thermite process (in air) was performed. The slag is removed from the obtained reaction product with a kelen hammer to obtain a V ₄ Ni _0.65 Nb _0.047 alloy (V
Based hydrogen storage alloy material).

The V content of this V-based alloy was about 0.33% by weight. Also, the nitrogen content, carbon content and oxygen content are 100 ppm by weight and 100 parts by weight, respectively.
m and 1% by weight. Further, the content of aluminum oxide was 0.24% by weight.

This alloy was redissolved and deoxidized (Mm was used as a deoxidizing agent), and Cr, Ti and Co were added, and finally V ₄ TiNi _0.65 Co _0.025 Nb _0.047 C
r _0.058 alloy (hydrogen storage alloy) was produced.

Example 1 The difference in hydrogen storage characteristics depending on the Al content was examined.

Except that Al was blended so that the Al content in the obtained V-based hydrogen storage alloy material was 0.3% by weight (sample 1a) and 1.08% by weight (sample 1b),
V ₄ N was formed by a thermite process in the same manner as in Production Example 1.
After producing an i _0.65 Nb _0.047 alloy, the alloy was further subjected to re-melting and deoxidizing treatment in the same manner as in Production Example 1 and Cr, Ti
Finally, two kinds of hydrogen storage alloys having different Al contents (V ₄ TiNi _0.65 Co
_0.025 Nb _0.047 Cr _0.058 alloy).

After charging about 1 g (average particle size: 40 μm) of each alloy in the measurement reaction vessel, an initial activation treatment was performed, and then the hydrogen storage properties (PCT properties) of the hydrogen storage property at a temperature of 20 ° C. and 2 MPa in a hydrogen atmosphere were measured. A measurement was made. From this, the hydrogen storage amount of each alloy was measured.
/ Formula weight, whereas Sample b having an Al content of more than 1% by weight showed a low value of 0.4H / formula weight.

Example 2 The difference in the amount of aluminum oxide due to the blending of Ni was examined.

A V ₈₀ Ni ₂₀ alloy was produced by a thermit process in the same manner as in Example 1, except that V ₂ O ₅ and Ni were weighed to obtain V ₈₀ Ni ₂₀ (sample 2a). The Al oxide content in this alloy was 0.35% by weight.

Similarly, using only V ₂ O _5, V ₁₀₀ (sample 2) was obtained by a thermite process in the same manner as in Example 1.
b) was prepared and its Al oxide content was measured to be 2.2% by weight.

Example 3 The difference in hydrogen storage characteristics depending on the carbon content was examined.

Thermite process was performed in the same manner as in Example 1 except that the carbon content of the obtained V-based hydrogen storage alloy material was adjusted to 150 ppm by weight (sample 3a) and 1200 ppm by weight (sample 3b). Was carried out. Furthermore, by performing re-dissolving and deoxidizing treatment in the same manner as in Example 1, and adding Cr, Ti and Co, two kinds of hydrogen storage alloys V ₄ TiN having different carbon contents are finally obtained.
An i _0.65 Co _0.025 Nb _0.047 Cr _0.058 alloy was produced.
Next, the amount of hydrogen occlusion was determined in the same manner as in Example 1, and as a result, the result was 0.7 H / formula amount in Sample 3a. In contrast, in Sample 3b, the amount was 0.2 H / formula.

Example 4 The vanadium yield based on the particle size of the vanadium oxide was examined.

A V ₄ Ni _0.65 Nb _0.047 alloy (sample 4a) was produced by a thermite process in the same manner as in Example 1 except that the particle size of V ₂ O ₅ was adjusted to a range of 0.05 to ₅ mm. On the other hand, except that the particle size of V ₂ O ₅ was 10 mm,
V ₄ N was formed by a thermite process in the same manner as in Example 1.
An i _0.65 Nb _0.047 alloy (sample 4b) was produced.

The vanadium yield in sample a was 90 to 9
Sample b had only 80% compared to 5%.

Example 5 The vanadium yield based on the particle size of the Al-based reducing agent was examined.

A V ₄ Ni _0.65 Nb _0.047 alloy (sample a) was produced by a thermite process in the same manner as in Example 1 except that the particle size of Al was adjusted to the range of 0.1 to 10 mm. On the other hand, V ₄ Ni _0.65 was formed by a thermit process in the same manner as in Example 1 except that the particle size of Al was set to 20 mm.
An Nb _0.047 alloy (sample b) was manufactured.

The vanadium yield in sample a was 90 to 9
Sample b had only 80% compared to 5%.

Example 6 The effect of adding CaO was examined.

V ₂ O ₅ , Ni and Nb ₂ O ₅ were _converted to V ₄ Ni _0.65
Nb _0.047 (V: 82.74% by weight, Ni 15.49% by weight, Nb: 1.77% by weight) is weighed, and 95% of the theoretical amount necessary for reducing the oxide in the alloy raw material is weighed.
Of Al and 1% by weight of CaO (sample 6).
a) 5% by weight (sample 6b) and 10% by weight (sample 6b)
c) was added, and a V ₄ Ni _0.65 Nb _0.047 alloy was produced by a thermite process in the same manner as in Example 1. The V content and Al oxide content in the slag of each alloy were measured.

Regarding the V content, in sample 6a, 6.3
%, Whereas in Samples 6b and 6c, they decreased to 4.9% and 2.8%, respectively.

The content of Al oxide in sample 6a was 2.8% by weight, while that in sample 6b and sample 6a was 2.8% by weight.
In the case of c, the content was reduced to 2.1% by weight and 1.6% by weight respectively.

Example 7 The difference in the amount of oxygen due to the difference in the furnace building materials was examined.

A V ₄ Ni _0.65 Nb _0.047 alloy was produced in the same manner as in Example 1 by a thermite process. In this thermit process, the oxygen content of an alloy manufactured using a furnace whose furnace material (inner surface) was made of alumina (sample 7a) and an alloy manufactured using a furnace whose furnace material was made of magnesia (sample 7b) were used. The amount and Al content were examined.

The oxygen content of sample 7a was 3.6% by weight,
l content was 1.6% by weight. On the other hand, sample 7b
Has an oxygen content of 3.1% by weight and an Al content of 0.5% by weight
Met.

Example 8 The effect of removing aluminum oxide by re-dissolution was examined.

In the same manner as in Example 1, a V ₄ Ni _0.65 Nb _0.047 alloy was produced by a thermite process. In this case, the Al oxide content (after removing the slag) was 0.5% by weight. Next, this was redissolved in a high-frequency induction furnace, and the generated surface slag was removed to remove A in the V-based alloy.
The oxide content could be reduced to 0.1% by weight.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Hiroyuki Takeshita 1-8-31 Midorigaoka, Ikeda-shi, Osaka, Japan Inside the Osaka Institute of Technology (72) Inventor Akio Kawabata Akihito, Nakahiroji, Ako-shi, Hyogo 1603-1 Taiyo Mining Co., Ltd. 1603-1, Higashi-oki, Taiyo Mining Co., Ltd.

Claims (19)

[Claims] 1. An alloy raw material containing vanadium oxide contains A
In a thermite process for reducing and alloying vanadium oxide by mixing an l-based reducing material, the content of Al in the resulting vanadium-based alloy is set to 1% by weight or less, for a vanadium-based hydrogen storage alloy. Material manufacturing method. 2. The method according to claim 1, wherein an Al amount of 85 to 99% of a stoichiometric amount of Al required for reducing all oxides in the alloy raw material is used as the Al-based reducing material. 3. The method according to claim 1, wherein at least one of Al and an Al-based alloy is used as the Al-based reducing material. 4. An Al-based alloy comprising Cr, Cu, Ni, Co,
4. The method according to claim 3, wherein the alloy is an alloy of at least one of Mn and Ti and Al. 5. Ni, Fe, C as an alloy raw material.
The method according to claim 1, comprising at least one of u, Co, Mn, and Cr. 6. The method according to claim 1, wherein the alloy material further contains at least one oxide of Nb and Ta. 7. The method according to claim 1, wherein the oxygen content in the produced vanadium alloy is 0.5 to 2% by weight. 8. The method according to claim 1, wherein both the carbon content and the nitrogen content in the resulting vanadium alloy are 1,000 ppm by weight or less. 9. The method according to claim 1, wherein a granular material having a particle size in the range of 0.05 to 5 mm is used as the alloy raw material, and a granular material having a particle size in the range of 0.1 to 10 mm is used as the Al-based reducing material.
9. The production method according to any one of the above items 8. 10. The method according to claim 1, further comprising adding at least one of CaO and CaF ₂ to the alloy raw material. 11. The production method according to claim 1, wherein the reaction between the alloy raw material and the Al-based reducing material is performed in a crucible having a magnesium oxide layer formed on the inner surface. 12. The method according to claim 1, wherein the temperature is maintained at 2000 to 2500 ° C. for 5 minutes or more. 13. The method according to claim 1, wherein the produced vanadium alloy is remelted. 14. When re-dissolving, Ti, Zr and H
14. The method according to claim 13, wherein at least one of f is added. 15. A material for a vanadium-based hydrogen storage alloy having an Al content of 1% by weight or less. 16. A vanadium-based hydrogen storage alloy material having an Al content of 1% by weight or less, which is an alloy obtained by the method of any one of claims 1 to 14. 17. Both of the carbon content and the nitrogen content are 1
17. The material for a vanadium-based hydrogen storage alloy according to claim 15, wherein the content is not more than 000 ppm by weight. 18. The material for a vanadium-based hydrogen storage alloy according to claim 15, wherein the content of the aluminum oxide is 0.5% by weight or less. 19. The material for a vanadium-based hydrogen storage alloy according to claim 15, wherein the oxygen content is 0.5 to 2% by weight.