JP2000297305A - Method and equipment for manufacturing fluorinated hydrogen storage alloy powder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently manufacture a fluorinated hydrogen storage alloy powder under an inert atmosphere. SOLUTION: This equipment is provided with a mixer 4 and a pulverizing device 5 in an inert atmosphere holding vessel 1A and also with a product powder separating device 6 and a product powder packing device 7 in an inert atmosphere holding vessel 1B, respectively. Further, a hydrogen storage alloy 2 is mixed with a fluoride 3 in the mixer 4, a mixture 4a is pulverized in the pulverizing device 5 by a roller mill 19 and crushed fine powders 23 are floated by means of inert gas 9 and conveyed via a classifier 24 through a feed pipe 25. The product powder separating device 6 is connected to the feed pipe 25 so as to separate product powders 28, 31, and the product powders 28, 31 separated in the product powder separating device 6 are hermetically sealed by the product powder packing device 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method and an apparatus for producing a hydrogen fluoride storage alloy powder.

[0002]

2. Description of the Related Art In general, a hydrogen storage alloy is used as a negative electrode material of a nickel-metal hydride battery which is a kind of a secondary battery (a battery which performs charging and discharging). This negative electrode material is obtained by integrating a hydrogen storage alloy powder with a porous core material such as a punched metal. In order to improve the performance of the battery, the hydrogen storage alloy is made finer and the specific surface area of the powder is increased. There is a need.

[0003] A hydrogen storage alloy is an alloy that can convert molecular hydrogen into atoms and coordinate them in a metal lattice interval to form a metal hydride.

[0004]

Embedded image

Conventionally, in order to produce a hydrogen storage alloy powder, the hydrogen storage alloy is isolated from the atmosphere using a medium (water, organic solvent) by a wet grinding device such as a wet ball mill or a wet stirring mill. Was crushed.

By the way, the hydrogen storage alloy is a highly ignitable material. Therefore, in order to secure the safety and to improve the performance of the battery such as an increase in the charge capacity, the hydrogen storage alloy is stored under the condition of being isolated from the atmosphere. It is necessary to treat the alloy so as not to be oxidized.

[0007] Further, as the amount of the hydrogen storage alloy used increases with the spread of secondary batteries, it has been required to improve the productivity of the hydrogen storage alloy powder.

[0008]

However, the hydrogen storage alloy has an activity not only for hydrogen but also for oxygen and water in the air, so that oxides and hydroxides can be easily deposited on the particle surface. Formed. In addition, as the storage and release of hydrogen are repeated, the particles are cracked and the ability to store hydrogen gradually decreases.

In recent years, various treatment methods have been proposed to cope with such a problem, such as pulverizing a hydrogen storage alloy to produce a hydrogen storage alloy powder and then fluorinating the particle surface of the hydrogen storage alloy powder. However, all of them are wet treatments and have a problem of low productivity.

The pulverized hydrogen-absorbing alloy powder is once packed in a sealed manner so as to prevent formation of oxides and the like on the surface, and then the pack is opened to perform fluorination treatment. I was sick.

The present invention has been made to solve the above-mentioned conventional problems, and efficiently manufactures a fluorinated hydrogen storage alloy powder by pulverizing a hydrogen storage alloy together with a fluorinated product in a dry manner. It is an object of the present invention to provide a method and an apparatus for producing a hydrogen fluoride storage alloy powder that can be used.

[0012]

According to the present invention, a hydrogen storage alloy and a fluorinated product are mixed in an inert atmosphere, and the mixture is pulverized by a roller mill to form a powder of the hydrogen storage alloy on the surface of the powder of the hydrogen storage alloy. A method for producing a hydrogen fluoride storage alloy powder, characterized in that the thin film is formed into fine powder, the fine powder is guided to a mill separation device to separate the mill, and the obtained mill is sealed in a sealed container. is there.

According to the present invention, there is provided a mixer for mixing a hydrogen storage alloy and a fluorinated substance in an inert atmosphere holding container, a mixture obtained by pulverizing the mixture with a roller mill and suspending the pulverized fine powder with an inert gas through a classifier. Fluorine, comprising: a crusher that is conveyed by a feed pipe, a flour separator that is connected to the feed pipe to separate flour, and a flour pack that seals the flour separated by the flour separator. An apparatus for producing a hydrogen fluoride storage alloy powder.

In the above means, the inert atmosphere holding container is a first inert atmosphere holding container containing a mixer and a crusher, and a second inert atmosphere holding container containing a milling separation device and a milling pack device.
An inert atmosphere holding container, and a plurality of second inert atmosphere holding containers.

Further, the milling and separating apparatus may be provided with a cyclone classifier, a bag filter, or both a cyclone classifier and a bag filter. A gas supply pipe may be connected.

Further, the inert atmosphere holding container may be provided with a lock chamber for charging raw materials and a lock chamber for extracting powder.

According to the above embodiment, the following operation is performed.

In the present invention, the hydrogen storage alloy and the fluorinated compound are mixed in an inert atmosphere holding vessel, and the mixture is pulverized by a roller mill to form a fluorinated thin film on the surface of the powder particles of the hydrogen storage alloy. Fine powder,
This fine powder was guided to a flour separation device to separate the flour, and the obtained flour was sealed in a sealed container.Therefore, in an inert atmosphere, the flourization of the hydrogen fluoride storage alloy powder was continuously and efficiently performed. Can be manufactured.

Further, when a first inert atmosphere holding container accommodating the mixer and the pulverizing device and a second inert atmosphere holding container accommodating the flour separation device and the flour packing device are separately provided, the pulverizing device and the pulverizing device are separated. If any of the separation devices fail, open and inspect only the necessary inert atmosphere holding container.
Repair can be performed, and therefore, the amount of inert gas used when the apparatus is restarted can be reduced, and the time required for replacing the inert gas with the inert gas and restarting the operation can be shortened. Further, when a plurality of the second inert atmosphere holding containers are provided, operations such as back washing of the bag filter and replacement of the filter can be performed while the separation of the flour is continued, and the productivity can be improved.

If the flour separation apparatus is provided with a cyclone classifier, a bag filter or both, the flour can be continuously classified and the particle size of the flour can be arbitrarily adjusted by a roller mill and a flour separation apparatus.

By providing the milling and packing apparatus in the milling and separating apparatus, the oxidation of the milling can be prevented.

By providing the lock chamber for charging the raw material and the lock chamber for taking out the flour in the inert atmosphere holding container, the inert atmosphere in the inert atmosphere holding container can be reliably held.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the method for producing a hydrogen fluoride storage alloy powder of the present invention.

In FIG. 1, reference numeral 1 denotes a vessel for forming an inert atmosphere. A hydrogen storage alloy 2 and a fluorinated substance 3 are supplied into the inert atmosphere holding vessel 1, and the hydrogen storage alloy 2 is supplied in an inert atmosphere. A first step (I) of mixing the fluorinated product with the fluorinated product 3 is performed, and then the mixture is pulverized by a roller mill to obtain fine powder having a thin film of the fluorinated product formed on the surfaces of the powder particles of the hydrogen storage alloy. The second step (II) is carried out, and then the third step (III) is carried out in which the fine powder is introduced into a flour separation apparatus to separate the flour of the hydrogen fluoride storage alloy powder, and then the separated flour is sealed in a sealed container. Fourth step (IV)
Is carried out to take out the sealed powder from the inert atmosphere holding container 1 to the outside.

FIG. 2 is a schematic flow chart showing an embodiment of an apparatus for carrying out the method for producing the above-mentioned hydrogen fluoride storage alloy powder.

In FIG. 2, the above-mentioned inert atmosphere holding container 1 is constituted by a first inert atmosphere holding container 1A and a second inert atmosphere holding container 1B. 1A is provided with a mixer 4 for mixing the hydrogen storage alloy 2 and the fluorinated substance 3 and a pulverizer 5 by a roller mill 19, and a pulverizer / separator 6 and a pulverizer in a second inert atmosphere holding container 1B. It is configured to include a packing device 7.

An inert gas 9 such as a nitrogen gas or an argon gas from an inert gas supply source 8 is supplied to the first inert atmosphere holding container 1A via a flow control valve 10. Further, an oxygen concentration controller 11 for sampling the inert gas 9 in the first inert atmosphere holding container 1A and detecting the oxygen concentration is provided, and the oxygen concentration controller 11 controls the first inert atmosphere holding container 1A. The supply amount of the inert gas 9 is adjusted by adjusting the flow control valve 10 so that the oxygen concentration in the inside is maintained at a predetermined value.

The inert gas 9 from the air blower 12 provided in the first inert atmosphere holding container 1A is supplied to the pressure control valve 13
After being guided to the atmospheric backflow prevention tank 14 via the, and further guided to the oxygen removing device 15 to remove oxygen, the oxygen is circulated in the first inert atmosphere holding container 1A,
The pressure control valve 16 detects the pressure in the first inert atmosphere holding container 1A so that the pressure in the first inert atmosphere holding container 1A becomes a predetermined positive pressure.
3 is controlled. Reference numeral 17 denotes a check valve provided in the atmospheric check tank 14.

A raw material charging lock chamber 18 is provided outside the first inert atmosphere holding container 1A, and the hydrogen storage alloy 2 and the fluoride 3
After charging, the inert gas 9 is charged into the raw material charging lock chamber 18, and the hydrogen storage alloy 2 and the fluorinated substance 3 are introduced from the raw material charging lock chamber 18 into the first inert atmosphere holding container 1A. The hydrogen storage alloy 2 and the fluorinated substance 3 can be supplied into the first inert atmosphere holding container 1A while maintaining airtightness.

The hydrogen storage alloy 2 and the fluorinated substance 3 supplied from the raw material charging lock chamber 18 into the first inert atmosphere holding container 1A are first supplied to the mixer 4 to be uniformly mixed.

The mixture 4a mixed by the mixer 4 is supplied to a pulverizer 5 by a roller mill 19 by a raw material feeder 20.

The roller mill 19 is configured to pulverize the mixture 4a supplied on the rotary table 21 by a roller 22 which rotates while being pressed from above, and the pulverized fine powder 23 is held in an inert atmosphere. The coarse powder is blown up by the inert gas 9 introduced from the inlet 19a, and separated by the classifier 24 provided at the upper part thereof.
1 and only the fine powder 23 is transported by the feed pipe 25. In the figure, reference numeral 26 denotes a compressor for supplying a classifying auxiliary gas to the classifier 24, and reference numeral 27 denotes an air conditioner for adjusting the temperature in the first inert atmosphere holding container 1A.

In the second inert atmosphere holding vessel 1B, there is provided a cyclone classifier 29 connected to the feed pipe 25 to separate the flour 28. At this time, an on-off valve 30 is provided between the first inert atmosphere holding container 1A and the second inert atmosphere holding container 1B in the feed pipe 25.
Is provided.

At the gas outlet of the cyclone classifier 29, a bag filter 32 for separating the flour 31 is provided.
The gas outlet of the bag filter 32 is connected to a suction pipe 33, and the suction pipe 33 is connected to a suction port of the exhaust fan 12.

The flour separation apparatus 6 may be provided with only the cyclone classifier 29, or may be provided with only the bag filter 32. As shown in FIG. Both may be provided. The bag filter 32 is connected to an inert gas supply pipe 34 for backwashing.

Further, to the suction pipe 33 connected to the bag filter 32, a control pipe 36 which is opened in the second inert atmosphere holding container 1B and is provided with a pressure control valve 35 on the way is connected. The pressure regulator 37 for detecting the pressure in the second inert atmosphere holding vessel 1B controls the pressure regulating valve 35 so that the pressure in the second inert atmosphere holding vessel 1B becomes a predetermined pressure. I have.

In the second inert atmosphere holding container 1B, there is provided a milling and packing device 7 for packing and sealing the milling materials 28 and 31 separated by the milling and separating device 6.

Further, outside the second inert atmosphere holding container 1B, the packed powder is taken out from the second inert atmosphere holding container 1B while the airtightness is maintained by the supply of the inert gas 9. A flour take-out lock chamber 38 is provided.

In FIG. 2, one crushing device 5 has one
Although the case where two flour separation devices 6 are connected by the feed pipe 25 is illustrated, a plurality of flour separation devices 6 may be connected to the feed pipe 25 and provided. Further, a plurality of crushing devices 5 can be provided.

The operation of the above embodiment will be described below.

In order to operate the apparatus shown in FIG. 2, first, an inert gas supply source 8 supplies an inert gas 9 into the first inert atmosphere holding vessel 1A, and further, an oxygen concentration controller 11 supplies the first inert gas. The flow control valve 10 is controlled so that the oxygen concentration in the active atmosphere holding container 1A becomes equal to or lower than a predetermined value.

On the other hand, the exhaust fan 12 is driven to
, The gas outlet of the bag filter 32 is sucked, and the inert gas 9 is circulated in the first inert atmosphere holding container 1A via the atmospheric backflow prevention tank 14 and the oxygen removing device 15.
At this time, the pressure in the first inert atmosphere holding container 1A is adjusted to a predetermined positive pressure by adjusting the pressure adjusting valve 13 by the pressure adjuster 16, and the pressure adjusting valve 35 is adjusted by the pressure adjuster 37. By adjusting the pressure, the pressure in the second inert atmosphere holding container 1B is adjusted to a predetermined pressure.

In this state, the material input lock chamber 18
Then, the hydrogen storage alloy 2 and the fluorinated substance 3 are introduced into the first inert atmosphere holding container 1A while maintaining the inert atmosphere, and further supplied to the mixer 4 to be uniformly mixed.

Subsequently, the mixture 4a of the hydrogen storage alloy 2 and the fluorinated substance 3 mixed in the mixer 4 is supplied to the rotary table 21 of the roller mill 19 via the raw material feeder 20, and the rotary table 21 is driven to rotate. .

Then, the mixture 4a is pulverized by the pressure rotation of the roller 22, and the pulverized fine powder 23 is kept in an inert atmosphere and is supplied with an inert gas 9 introduced through the inlet 19a.
The coarse powder is separated by a classifier 24 provided above and returned to the rotary table 21 to remove the fine powder.
3 alone is conveyed to the cyclone classifier 29 of the flour separation device 6 by the feed pipe 25, and the flour 28 is separated. Furthermore,
The powder 31 is separated by the bag filter 32. At this time, the flour 31 separated by the bag filter 32 has a smaller particle size than the flour 28 separated by the cyclone classifier 29, and thus has a different particle size.
Different types of milling 28, 31 can be obtained.

When the thus obtained hydrogen fluoride storage alloy powder is used as a negative electrode material for a secondary battery, if the particle diameter is too large, the surface area is small, the hydrogen storage amount is small, and the hydrogen storage capacity is low. -There is a problem that cracks are easily generated by the release, and the internal resistance increases. On the other hand, when the particle diameter is small, the hydrogen storage capacity is large because the surface area is large. On the other hand, when the particle diameter is too small, the surface area is too large and oxidation or reaction with other elements is apt to occur, and the durability is reduced. There's a problem.

Accordingly, the particle size of the hydrogen fluoride storage alloy powder has an optimum particle size. However, when the powder is used as a negative electrode material of a secondary battery, the particle size is about tens to tens of microns. Is preferred.

In order to adjust the particle size of the hydrogen fluoride storage alloy powder, the upper limit of the particle size is specified by the classifier 24 of the roller mill 19 and the lower limit is specified by the cyclone classifier 29 of the mill separation device 6. It can be easily adjusted.

At this time, in the bag filter 32, flour having a small particle size smaller than the lower limit is separated. The bag filter 32 is easily clogged, but if clogged, the classification function can be restored by supplying an inert gas from the backwashing inert gas supply pipe 34 and backwashing.

Cyclone classifier 29 and bag filter 3
The flours 28 and 31 separated in 2 are packed by the flour packing device 7 and taken out of the flour take-out lock chamber 38 in a state where they are processed so as not to come into contact with the outside air.

According to the above-mentioned apparatus, it is possible to continuously produce a hydrogen fluorinated alloy powder while simultaneously performing a surface fluorination treatment without oxidizing a hydrogen occluding alloy having a high particle surface activity.

A typical hydrogen storage alloy, LaNi _4.7
When a mixture obtained by adding KF (potassium fluoride) to Al _0.3 to a few percent is treated, L
It is possible to obtain a hydrogen fluoride storage alloy powder in which an extremely thin film of aF ₃ is formed in a matrix.

The hydrogen fluorinated alloy powder thus obtained can enhance the performance of the hydrogen storage alloy (repetitive hydrogen storage capacity, increase in hydrogen storage amount, etc.).

Further, the particle size of the powders 28 and 31 of the hydrogen fluoride storage alloy powder can be freely and continuously adjusted by the cyclone classifier 29 and the bag filter 32 of the powder separation device 6. By the adjustment, the performance of the hydrogen storage alloy can be further enhanced.

In the apparatus shown in FIG. 2, a plurality of milling / separating devices 6 are provided for the pulverizing device 5. Since the flour can be collected by the flour separation device 6, the flour can be continuously produced without stopping the operation of the device, and the flour can be continuously produced when the filter provided in the bag filter 32 is replaced. Thus, milling can be manufactured, and thus productivity can be greatly improved.

It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that various changes can be made without departing from the spirit of the present invention.

[0058]

According to the present invention, the hydrogen-absorbing alloy and the fluorinated compound are mixed in an inert atmosphere holding vessel, and the mixture is pulverized by a roller mill. Into a fine powder having a thin film formed thereon, and the fine powder is guided to a flour separation device to separate the flour,
Since the obtained milling is sealed in a sealed container, there is an effect that the milling of the hydrogen fluoride storage alloy powder can be continuously and efficiently manufactured in an inert atmosphere.

Further, when a first inert atmosphere holding container accommodating the mixer and the pulverizing device and a second inert atmosphere holding container accommodating the flour separation device and the flour packing device are separately provided, the pulverizing device and the pulverizing device are separated. If any of the separation devices fail, open and inspect only the necessary inert atmosphere holding container.
Repair can be performed, and thus the amount of inert gas used when the apparatus is restarted can be reduced, and the time required for replacing the inert gas with the inert gas and restarting the operation can be shortened. Further, when a plurality of the second inert atmosphere holding containers are provided, operations such as back washing of the bag filter and replacement of the filter can be performed while the separation of the flour is continued, and there is an effect that the productivity can be improved.

If the milling / separating device is provided with a cyclone classifier, a bag filter, or both, the milling can be continuously classified, and the particle size of the mill can be arbitrarily adjusted by the roller mill and the milling / separating device. is there.

The provision of the milling pack device in the milling separation device has the effect of preventing the oxidation of the milling.

Since the inert atmosphere holding container is provided with the lock chamber for charging the raw material and the lock chamber for taking out the powder, there is an effect that the inert atmosphere in the inert atmosphere holding container can be surely held.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a method for producing a hydrogen fluoride storage alloy powder of the present invention.

FIG. 2 is a schematic flow chart showing an embodiment of an apparatus for producing a hydrogen fluoride storage alloy powder of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Inert atmosphere holding container 1A 1st inert atmosphere holding container (inert atmosphere holding container) 1B 2nd inert atmosphere holding container (inert atmosphere holding container) 2 Hydrogen storage alloy 3 Fluoride 4 Mixer 4a Mixture 5 Grinding Apparatus 6 Flour Mill Separating Device 7 Flour Mill Packing Device 9 Inert Gas 18 Raw Material Input Lock Chamber 19 Roller Mill 23 Fine Powder 24 Classifier 25 Feed Pipe 28 Flour Mill 29 Cyclone Classifier 31 Flour Mill 32 Bag Filter 34 Backwash Inactive Gas Feed Pipe 38 Flour mill lock chamber

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01M 4/38 H01M 4/38 A F term (Reference) 4D063 EE03 EE12 GA02 GC01 GC12 GC16 GC27 GC32 4D067 EE01 EE14 EE22 EE47 EE50 GA10 4K017 AA04 BA03 BA08 BB01 BB12 BB17 EA03 FA03 4K018 BC28 BD07 5H003 AA02 BA04 BB02 BC04 BC05

Claims (8)

[Claims] In an inert atmosphere, a hydrogen storage alloy and a fluorinated compound are mixed, and the mixture is pulverized by a roller mill to form a fine powder in which a thin film of a fluorinated compound is formed on the surfaces of the powder particles of the hydrogen storage alloy. A method for producing a hydrogen fluoride storage alloy powder, comprising: introducing a fine powder to a flour separation device to separate the flour; and sealing the obtained flour in a sealed container. 2. A mixer for mixing a hydrogen storage alloy and a fluorinated substance in an inert atmosphere holding container, and a mixture milled by a roller mill, and the milled fine powder is suspended by an inert gas and fed through a classifier. Hydrogen fluoride having a crushing device for conveying by a pipe, a flour separation device connected to a feed pipe for separating flour, and a flour packing device for sealing the flour separated by the flour separation device. Equipment for producing occlusion alloy powder. 3. The inert atmosphere holding container includes a first inert atmosphere holding container containing a mixer and a crushing device, and a second inert atmosphere holding container containing a milling separation device and a milling pack device. 3. The apparatus for producing a hydrogen fluoride storage alloy powder according to claim 2, further comprising a plurality of second inert atmosphere holding containers. 4. The apparatus for producing a hydrogen fluoride storage alloy powder according to claim 2, wherein a cyclone classifier is provided in the milling / separating apparatus. 5. The apparatus for producing a hydrogen fluoride storage alloy powder according to claim 2, wherein the milling and separating apparatus is provided with a bag filter. 6. A flour separation apparatus comprising a cyclone classifier and a bag filter.
An apparatus for producing the hydrogen fluoride storage alloy powder according to the above. 7. The apparatus for producing a hydrogen fluoride storage alloy powder according to claim 5, wherein an inert gas supply pipe for backwashing is connected to the bag filter. 8. The hydrogen fluoride according to claim 2, wherein the inert atmosphere holding container is provided with a lock chamber for charging raw material and a lock chamber for extracting powder. Equipment for producing occlusion alloy powder.