JPH11209126A - Production of small lithium zirconate sintered granule - Google Patents
Production of small lithium zirconate sintered granuleInfo
- Publication number
- JPH11209126A JPH11209126A JP2159698A JP2159698A JPH11209126A JP H11209126 A JPH11209126 A JP H11209126A JP 2159698 A JP2159698 A JP 2159698A JP 2159698 A JP2159698 A JP 2159698A JP H11209126 A JPH11209126 A JP H11209126A
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- JP
- Japan
- Prior art keywords
- zro
- particles
- sintered
- granules
- powder
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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- Inorganic Compounds Of Heavy Metals (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、リチウムジルコネ
ート(Li2ZrO3) 微小焼結粒の製造方法に関するものであ
る。The present invention relates to a method for producing lithium zirconate (Li 2 ZrO 3 ) fine sintered particles.
【０００２】[0002]
【従来の技術】従来より、Li2ZrO3 の焼結粒を製造する
方法としては、転動造粒法が知られている。この転動造
粒法は、回転ドラム内にLi2ZrO3 の原料粉末を入れ、回
転ドラムの回転によって粒状にし、これを焼結してLi2Z
rO3 の微小焼結粒を得る方法である。 2. Description of the Related Art Conventionally, a rolling granulation method has been known as a method for producing sintered particles of Li 2 ZrO 3 . In this tumbling granulation method, a raw material powder of Li 2 ZrO 3 is put in a rotating drum, and the powder is granulated by rotation of the rotating drum, and this is sintered to form a Li 2 Z
This is a method for obtaining fine sintered particles of rO 3 .
【０００３】図３は、転動造粒法の工程を簡単に示した
説明図である。以下、簡単に説明する。まず、Li2ZrO3
の原料粉末を回動するドラム内に搬入し、粒状にする
（図３ａ）。この時、造粒を容易にするため、ポリビニ
ルアルコール（ＰＶＡ）等の増粘剤を添加する場合もあ
る。粒状になったLi2ZrO3 を取り出し、空気中、約650
℃で仮焼し（図３ｂ）、その後、空気中、約1600℃で焼
結してLi2ZrO3 焼結粒を得る（図３ｃ）。[0003] FIG. 3 is an explanatory diagram simply showing the steps of the rolling granulation method. Hereinafter, a brief description will be given. First, Li 2 ZrO 3
The raw material powder is carried into a rotating drum and granulated (FIG. 3a). At this time, a thickener such as polyvinyl alcohol (PVA) may be added in order to facilitate granulation. Take out the granular Li 2 ZrO 3 and in air, about 650
Calcined at ° C. (FIG. 3b), then in air to obtain a Li 2 ZrO 3 sintered particles sintered at about 1600 ° C. (FIG. 3c).
【０００４】また、近年では、ポリビニルアルコール水
溶液に原料粉末(Li2ZrO3) を分散させ、この液をアセト
ン中に滴下してポリビニルアルコールをゲル化させるこ
とにより得られたゲル粒体を焼結することにより微小焼
結粒を得るゲル沈殿法も提案されている。In recent years, a raw material powder (Li 2 ZrO 3 ) has been dispersed in an aqueous solution of polyvinyl alcohol, and the resulting solution has been dropped into acetone to gel the polyvinyl alcohol. There is also proposed a gel precipitation method in which fine sintered particles are obtained by performing the method.
【０００５】[0005]
【発明が解決しようとする課題】しかしながら、上述し
た転動造粒法ではドラムの回動によってLi2ZrO3 の原料
粉末を粒状化しているため、真球度の高いLi2ZrO3 焼結
粒を得ることが困難である。それだけでなく、満足なLi
2ZrO3 焼結粒を効率よく得ることはできない。加えて、
粒径を自由に制御する点に関しても非常に困難である。However, in the above-described rolling granulation method, since the raw powder of Li 2 ZrO 3 is granulated by rotating the drum, the sintered particles of Li 2 ZrO 3 having high sphericity are obtained. Is difficult to obtain. Not only that, Li
2 ZrO 3 sintered particles cannot be obtained efficiently. in addition,
It is also very difficult to freely control the particle size.
【０００６】このように、従来のLi2ZrO3 焼結粒の製造
法は、真球度の高いLi2ZrO3 焼結粒を得ることが困難で
あるだけでなく、微小なサイズのLi2ZrO3 焼結粒を得る
こともまた困難である。さらには、個々のLi2ZrO3 焼結
粒の粒径を一律に揃えるのも難しいという難点もある。[0006] Thus, the conventional Li 2 ZrO 3 sintered grain production methods, not only it is difficult to obtain a high Li 2 ZrO 3 sintered particle sphericity, a small size Li 2 Obtaining ZrO 3 sintered grains is also difficult. Furthermore, it is difficult to make uniform the particle size of each Li 2 ZrO 3 sintered particle.
【０００７】また、ゲル沈殿法を応用してLi2ZrO3 の原
料粉末を粒状にすることも考えられるが、この場合、Li
2ZrO3 の焼結に最適な温度が1600℃であるため、この温
度では焼結中に大量にリチウム(Li)が蒸発してしまうと
いう難点がある。It is also conceivable that the raw material powder of Li 2 ZrO 3 is granulated by applying a gel precipitation method.
Since the optimal temperature for sintering 2 ZrO 3 is 1600 ° C., there is a disadvantage that a large amount of lithium (Li) evaporates during sintering at this temperature.
【０００８】以上のことから本発明は、粒径の寸法制御
が容易で、容易に微小なサイズの粒状物が大量に得ら
れ、量産化に適したリチウムジルコネート微小焼結粒の
製造方法を提供することを主目的とする。また、高真球
度のLi2ZrO3 焼結粒を得ることのできる方法を提供する
ことも本発明の別の目的である。In view of the above, the present invention provides a method for producing lithium zirconate micro-sintered particles suitable for mass production, which makes it easy to control the size of the particle size, easily obtains a large amount of fine particles having a fine size. The main purpose is to provide. It is another object of the present invention to provide a method by which Li 2 ZrO 3 sintered particles having high sphericity can be obtained.
【０００９】さらに、焼結中にLiが大量に蒸発すること
を抑えてLi2ZrO3 の組成が変化するのを防ぐことがで
き、しかも製造歩留よくLi2ZrO3 焼結粒を得ることので
きる方法を提供することも本発明の別の目的である。Further, it is possible to prevent a large amount of Li from evaporating during sintering and to prevent a change in the composition of Li 2 ZrO 3 , and to obtain Li 2 ZrO 3 sintered grains with a good production yield. It is another object of the present invention to provide a method that can be used.
【００１０】[0010]
【課題を解決するための手段】上記目的を達成すべく、
請求項１による発明は、アセトン中でゲル化する高分子
樹脂化合物の水溶液に原料粉末を分散させて得られる原
液を、アセトン液浴中に滴下してゲル粒体とし、このゲ
ル粒体を仮焼することにより高分子樹脂化合物水溶液の
ゲルを取り除いた仮焼粒体とし、その後この仮焼粒体を
焼結して焼結粒を得るリチウムジルコネート微小焼結粒
の製造方法において、原料粉末として、Li2CO3とZrO2と
の混合粉末を用い、前記仮焼粒体を焼結する際に、空気
中、1300℃以上1500℃以下の温度で４時間以上10時間以
下熱処理することにより、Li2CO3 + ZrO2 → Li2ZrO3 +
CO2↑なる反応を経て焼結粒とすることを特徴としてい
る。In order to achieve the above object,
The invention according to claim 1 is to provide a gel solution by dropping a stock solution obtained by dispersing a raw material powder in an aqueous solution of a polymer resin compound which gels in acetone into an acetone solution bath, and temporarily forming the gel particles. In a method for producing lithium zirconate micro-sintered particles in which the gel of the aqueous solution of the polymer resin compound is removed by baking to obtain calcined particles, and then the calcined particles are sintered to obtain sintered particles. As a mixed powder of Li 2 CO 3 and ZrO 2 , when sintering the calcined granules, in air, by heat treatment at a temperature of 1300 ℃ or more and 1500 ℃ or less for 4 hours or more and 10 hours or less , Li 2 CO 3 + ZrO 2 → Li 2 ZrO 3 +
It is characterized by being converted into sintered particles through a reaction of CO 2 .
【００１１】本発明は、原料粉末として、従来のように
Li2ZrO3 粉末を用いるのではなく、Li2CO3とZrO2との混
合粉末を用い、空気中にて1300℃以上1500℃以下の温度
で４時間以上10時間以下熱処理することによりLi2CO3と
ZrO2とを反応させてLi2ZrO3とCO2↑にし、これにより得
られたLi2ZrO3を焼結してリチウムジルコネート微小焼
結粒を製造するものである。[0011] The present invention relates to a method for preparing a raw material powder,
Li 2 ZrO 3 powder instead of using, Li 2 by Li 2 CO 3 and a mixed powder of ZrO 2, a heat treatment following 10 hours or more 4 hours at a temperature of 1300 ° C. or higher 1500 ° C. or less in the air CO 3 and
Li 2 ZrO 3 is reacted with ZrO 2 to produce Li 2 ZrO 3 and CO 2 、, and the resulting Li 2 ZrO 3 is sintered to produce lithium zirconate fine sintered particles.
【００１２】Li2CO3とZrO2は 800℃〜1000℃程度から反
応をし始めるが、本発明では仮焼粒体の焼結温度を1300
℃以上1500℃以下とし、好ましくは1460℃としている。
これは、焼結温度を1300℃より低くするとLi2ZrO3 の焼
結があまり進まず、1500℃より高くするとLiの蒸発量が
無視できないほど多くなってしまうからである。Although Li 2 CO 3 and ZrO 2 start reacting from about 800 ° C. to 1000 ° C., in the present invention, the sintering temperature of the calcined granules is set to 1300
The temperature is set to not less than 1500 ° C and preferably not more than 1460 ° C.
This is because if the sintering temperature is lower than 1300 ° C., the sintering of Li 2 ZrO 3 does not proceed very much, and if the sintering temperature is higher than 1500 ° C., the evaporation amount of Li becomes so large that it cannot be ignored.
【００１３】尚、この温度範囲は、Li2ZrO3 粉末を原料
に用いる従来法の焼結温度に比べて低く、焼結中に大量
のLiの蒸発が起きない温度範囲である。従って本発明に
よれば、従来法よりも低い温度でLi2ZrO3 焼結粒が得ら
れるだけでなく、Liの蒸発量も少ないという利点があ
る。This temperature range is lower than the sintering temperature of the conventional method using Li 2 ZrO 3 powder as a raw material, and is a temperature range in which a large amount of Li does not evaporate during sintering. Therefore, according to the present invention, there are advantages that not only Li 2 ZrO 3 sintered particles can be obtained at a lower temperature than the conventional method, but also the amount of Li evaporated is small.
【００１４】さらに、本発明では仮焼粒体の焼結時間を
上記焼結温度で４時間以上10時間以下としている。これ
は、焼結時間が４時間より短いとLi2ZrO3 が充分に焼結
されず、10時間よりも長いとLiの蒸発量が多くなり歩留
りが悪くなるためである。Further, in the present invention, the sintering time of the calcined granules is 4 hours or more and 10 hours or less at the above sintering temperature. This is because if the sintering time is shorter than 4 hours, Li 2 ZrO 3 is not sufficiently sintered, and if the sintering time is longer than 10 hours, the amount of evaporation of Li increases and the yield deteriorates.
【００１５】請求項２による発明は、請求項１のリチウ
ムジルコネート微小焼結粒の製造方法において、前記原
料粉末として、Li2CO3粉末とZrO2粉末とを１対１のモル
比で含む混合粉末を用いることを特徴としている。According to a second aspect of the present invention, there is provided the method for producing fine sintered particles of lithium zirconate according to the first aspect, wherein the raw material powder includes a Li 2 CO 3 powder and a ZrO 2 powder in a molar ratio of 1: 1. It is characterized by using a mixed powder.
【００１６】本発明は、原料粉末としてLi2CO3粉末とZr
O2粉末とを１対１のモル比で含む混合粉末を用いること
により、反応せずに残存するLi2CO3又はZrO2を殆ど無く
し、高純度のLi2ZrO3 微小焼結粒を得るものである。According to the present invention, Li 2 CO 3 powder and Zr
By using a mixed powder containing O 2 powder in a molar ratio of 1: 1, Li 2 CO 3 or ZrO 2 remaining without reacting is almost eliminated, and high purity Li 2 ZrO 3 fine sintered particles are obtained. Things.
【００１７】[0017]
【発明の実施の形態】以下、本発明によるリチウムジル
コネート微小焼結粒の製造方法の実施の形態について説
明する。本発明では、アセトン液浴中でゲル化する高分
子樹脂化合物の水溶液を担体溶液として、この担体溶液
にLi2CO3とZrO2との混合粉末を分散させて原液を得てい
る。DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the method for producing lithium zirconate fine sintered particles according to the present invention will be described below. In the present invention, an aqueous solution of a polymer resin compound that gels in an acetone liquid bath is used as a carrier solution, and a mixed powder of Li 2 CO 3 and ZrO 2 is dispersed in the carrier solution to obtain a stock solution.
【００１８】この高分子樹脂化合物としては、特定の条
件下においてゲル化し、比較的低温度で焼散して取り除
くことができる物質で、ゲル化途中又はゲル化終了後に
おいて、ゲル粒体が形を保持できる充分な強度があるも
のであれば良い。好ましいものとしては、カチオン性セ
ルロース誘導体（例えば、商品名「レオガード」、ライ
オン(株)製）または、ポリビニルアルコール（例えば、
商品名「PVA-124H」、(株)クラレ製）等の水溶性合成ポ
リマー等が挙げられる。The polymer resin compound is a substance that gels under specific conditions and can be removed by burning off at a relatively low temperature. The gel particles are formed during or after gelation. What is necessary is just to have sufficient strength which can hold | maintain. Preferred are cationic cellulose derivatives (for example, trade name “Leogard”, manufactured by Lion Corporation) or polyvinyl alcohol (for example,
And water-soluble synthetic polymers such as “PVA-124H” (trade name, manufactured by Kuraray Co., Ltd.).
【００１９】また、高分子樹脂化合物水溶液は、３〜12
％の濃度の水溶液、好ましくは10％の濃度の水溶液とす
るのがよい。なぜなら、濃度が３％より低いとゲル粒体
の強度が不充分でその形状を維持するのが難しく、12％
より濃度が高いと高分子化合物が純水中に完全溶解しな
いためである。The aqueous solution of the polymer resin compound is 3 to 12
% Aqueous solution, preferably 10% aqueous solution. Because, when the concentration is lower than 3%, the strength of the gel particles is insufficient and it is difficult to maintain the shape, and the concentration is 12%.
If the concentration is higher, the polymer compound is not completely dissolved in pure water.
【００２０】更に、高分子化合物水溶液に分散させるLi
2CO3とZrO2との混合粉末の量は、滴下の際に形成させる
液滴の大きさと、最終的に必要なLi2ZrO3 焼結粒の直径
との兼ね合い及び原液の流動性とにより決定すればよ
い。Further, Li dispersed in an aqueous polymer compound solution
The amount of the mixed powder of 2 CO 3 and ZrO 2 depends on the size of the droplet formed at the time of dropping, the final required diameter of the Li 2 ZrO 3 sintered particles, and the fluidity of the stock solution. You only have to decide.
【００２１】このような原液は、振動ノズルや滴下電極
等のノズル装置を用いてアセトン中に滴下する。尚、振
動ノズルにより液滴を形成する場合、原液の流量をＱ、
液滴の直径をｄ、振動ノズルの振動数をｆとすると、以
下の(１)式が成り立つ。Such a stock solution is dropped into acetone using a nozzle device such as a vibrating nozzle or a dropping electrode. When a droplet is formed by a vibrating nozzle, the flow rate of the stock solution is Q,
Assuming that the diameter of the droplet is d and the frequency of the vibrating nozzle is f, the following equation (1) holds.
【００２２】Ｑ＝（π／６）ｄ3・ｆ ・・・・(１)式Q = (π / 6) d 3 · f (1)
【００２３】従って、液滴の大きさは、原液の流量Ｑと
振動ノズルの振動数ｆとを調節することにより、自由に
制御することが可能である。なお、直径ｄが 0.1mm以上
３mm以下の液滴を形成させる場合は、流量Ｑを任意と
し、振動ノズルの振動数ｆを10Hz以上 500Hz以下の範囲
とすると良い。Accordingly, the size of the droplet can be freely controlled by adjusting the flow rate Q of the stock solution and the frequency f of the vibrating nozzle. When droplets having a diameter d of 0.1 mm or more and 3 mm or less are formed, the flow rate Q may be arbitrarily set, and the frequency f of the vibrating nozzle may be set to a range of 10 Hz to 500 Hz.
【００２４】また、アセトン液浴の温度は、常温、若し
くは常温より低い温度に調整する。好ましくは、25℃以
下−80℃以上とすると良い。なぜならば、25℃よりも高
温であると、Li2ZrO3 焼結粒の真球性、密度等が低下す
るという問題が生じ、逆に、−80℃よりも低温である
と、液滴の浸漬において割れが生じるという問題がある
ためである。The temperature of the acetone liquid bath is adjusted to room temperature or a temperature lower than room temperature. Preferably, the temperature is set to 25 ° C. or lower and −80 ° C. or higher. This is because if the temperature is higher than 25 ° C., the sphericity, density, etc. of the Li 2 ZrO 3 sintered particles decrease, and conversely, if the temperature is lower than −80 ° C., the droplets This is because there is a problem that cracks occur during immersion.
【００２５】また、液滴の浸漬時間は、製造効率の面か
らは短ければ短いほどよいが、浸漬時間が短いと乾燥工
程においてゲル粒体が変形するため、ゲル化が完全に終
了する時間以上とすると良い。ゲル化の反応速度は、液
浴の温度、滴下原液の組成、液滴の大きさ等により決定
されるので、好ましくは、それぞれの場合に応じて最適
な時間を予め求めておくとよい。The immersion time of the droplet is preferably as short as possible from the viewpoint of the production efficiency. However, if the immersion time is short, the gel particles are deformed in the drying step, and the immersion time is equal to or longer than the time when gelation is completely completed. It is good to The gelation reaction rate is determined by the temperature of the liquid bath, the composition of the stock solution to be dropped, the size of the droplets, and the like. Therefore, preferably, an optimal time may be determined in advance in each case.
【００２６】例えば、液浴温度−20℃、7.4 wt％ポリビ
ニルアルコール水溶液中に46.0wt％の原料粉末を分散さ
せた滴下原液から直径 1.7mmの液滴を得、これを焼結し
たときの粒径を 1.0mmとする場合、好ましい液滴の浸漬
時間は１時間である。また、例えば、液浴温度−50℃、
6.4 wt％ポリビニルアルコール水溶液中に53.0wt％の原
料粉末を分散させた滴下原液から直径 1.5mmの液滴を
得、これを焼結したときの粒径を 1.0mmとする場合、好
ましい液滴の浸漬時間は30分である。For example, a droplet having a diameter of 1.7 mm is obtained from a dropping solution obtained by dispersing 46.0% by weight of a raw material powder in a 7.4% by weight aqueous solution of polyvinyl alcohol at a liquid bath temperature of -20 ° C. When the diameter is 1.0 mm, the preferable immersion time of the droplet is 1 hour. Also, for example, a liquid bath temperature of −50 ° C.,
When a droplet having a diameter of 1.5 mm is obtained from a dropping stock solution in which 53.0 wt% of a raw material powder is dispersed in an aqueous solution of 6.4 wt% polyvinyl alcohol, and the particle diameter when this is sintered is set to 1.0 mm, a preferable droplet is Immersion time is 30 minutes.
【００２７】アセトン液浴中においては高分子樹脂化合
物の水溶液がゲル化するため、アセトン中に滴下された
液滴は、Li2CO3とZrO2とが分散されたゲル粒体となる。
このゲル粒体は、Li2CO3とZrO2とが分散した原液を滴下
した際に原液の表面張力で球形になり、液滴が液浴と接
触した際にその高分子樹脂化合物水溶液がゲル化して球
形に固定されるため、真球性の高いものとなっている。Since the aqueous solution of the polymer resin compound gels in the acetone liquid bath, the droplets dropped into acetone become gel particles in which Li 2 CO 3 and ZrO 2 are dispersed.
When the stock solution in which Li 2 CO 3 and ZrO 2 are dispersed is dropped, the gel particles become spherical due to the surface tension of the stock solution, and when the droplet comes into contact with the liquid bath, the aqueous solution of the polymer resin compound becomes a gel. It is fixed to a spherical shape and has a high sphericity.
【００２８】また、滴下により粒を成形しているため、
滴下の際の条件を一度決定したら恒常的に同じ大きさの
粒が形成され、従って同じ大きさの液滴を大量に製造可
能である。Also, since the grains are formed by dropping,
Once the conditions for dropping are determined once, grains of the same size are constantly formed, so that a large number of drops of the same size can be produced.
【００２９】このようにして得られたゲル粒体は、アセ
トン液浴から取り出し、その表面および内部に含まれる
水分を除去するために、例えば、温風式乾燥ドラムなど
を用いて乾燥させる。この際、例えば、ゲル粒体同士が
癒着し易い場合は乾燥前にエタノール等で洗浄してから
乾燥するとよい。The gel particles thus obtained are taken out of the acetone liquid bath and dried using, for example, a hot-air drying drum or the like in order to remove the water contained on the surface and inside. At this time, for example, when the gel particles easily adhere to each other, the gel particles may be washed with ethanol or the like before drying and then dried.
【００３０】乾燥後のゲル粒体は、高分子樹脂化合物の
焼散温度で、さらに、焼散するのに要する時間だけ加熱
する。これにより、高分子樹脂化合物が焼散して取り除
かれるので、Li2CO3とZrO2とが分散された仮焼粒体とな
る。例えば、高分子樹脂化合物がポリビニルアルコール
の場合は、空気中、 400℃以上 800℃以下の温度で６時
間以上12時間以下に亘り仮焼する。尚、この温度範囲
は、仮焼温度が 400℃未満であるとポリビニルアルコー
ルの除去が不十分であり、 800℃を超えると最終的に得
られるLi2ZrO3 微小焼結粒中のLi密度の向上が阻害され
ることに基づいて決定されている。The gel particles after drying are heated at the temperature at which the polymer resin compound is transpired, and for a time required for transpiration. As a result, the polymer resin compound is burned off and removed, resulting in calcined particles in which Li 2 CO 3 and ZrO 2 are dispersed. For example, when the polymer resin compound is polyvinyl alcohol, it is calcined in air at a temperature of 400 ° C. to 800 ° C. for 6 hours to 12 hours. When the calcination temperature is lower than 400 ° C., the removal of polyvinyl alcohol is insufficient. When the calcination temperature is higher than 800 ° C., the Li density in the Li 2 ZrO 3 micro-sintered particles finally obtained is determined. It is determined based on the inhibition of the improvement.
【００３１】その後、この仮焼粒体を、空気中、1300℃
以上1500℃以下の温度で４時間以上10時間以下に亘り熱
処理し、Li2CO3とZrO2とを焼結反応させてLi2ZrO3とCO2
↑にすることでLi2ZrO3 微小焼結粒を得る。Thereafter, the calcined granules are placed in air at 1300 ° C.
Heat treatment at a temperature of not less than 1500 ° C. for not less than 4 hours and not more than 10 hours to cause a sintering reaction of Li 2 CO 3 and ZrO 2 to produce Li 2 ZrO 3 and CO 2
By obtaining ↑, Li 2 ZrO 3 fine sintered particles are obtained.
【００３２】尚、この時の焼結雰囲気は、例えばアルゴ
ンガス等のような精製、混合調整されたガス中としても
よいが、特に精製、混合調整されたガスとする必要はな
く、加熱された大気中、言い換えると酸素を含む雰囲気
中としても構わない。The sintering atmosphere at this time may be in a purified and mixed gas such as argon gas. However, it is not necessary to use a purified and mixed gas. It may be in the atmosphere, in other words, in an atmosphere containing oxygen.
【００３３】[0033]
【実施例】図１は本発明の一実施例を示すフローチャー
ト図である。本実施例では、水溶性高分子樹脂化合物と
してポリビニルアルコール、液浴としてアセトンを用い
ている。勿論、本発明はこの組み合わせに限定されるも
のではない。FIG. 1 is a flow chart showing an embodiment of the present invention. In this embodiment, polyvinyl alcohol is used as the water-soluble polymer resin compound, and acetone is used as the liquid bath. Of course, the present invention is not limited to this combination.
【００３４】１）原液の調整 まず、濃度10wt％のポリビニルアルコール水溶液に、Li
2CO3を50 mol％とZrO2を50 mol％含む混合粉末及び純水
を加え、均一に分散するまで混合撹拌し、これにより４
wt％のポリビニルアルコール水溶液中に46wt％の混合粉
末が均一に分散した混合液を準備し、この混合液を75μ
ｍのメッシュ開口のステンレス製ザルに通過させたもの
を原液とした。1) Preparation of stock solution First, a 10 wt% aqueous solution of polyvinyl alcohol was added to Li
2 A mixed powder containing 50 mol% of CO 3 and 50 mol% of ZrO 2 and pure water are added, and mixed and stirred until uniformly dispersed.
A mixed solution in which 46 wt% of a mixed powder is uniformly dispersed in a wt% aqueous polyvinyl alcohol solution is prepared.
The solution passed through a stainless steel colander having a mesh opening of m was used as a stock solution.
【００３５】２）液滴の形成及び乾燥 前記原液調整工程において作成した原液を振動ノズルに
より滴下した。この振動ノズルには、原液の流量を制御
するためのポンプと、ノズルを振動させる振動機構とが
設けられており、振動機構は、制御系で決定された振動
数で発振する発振器と、この発振器の振動出力を増幅す
るアンプと、アンプにより増幅された振動出力を受け取
ってノズルを機械的に振動させる加振器とを備えてい
る。2) Formation and Drying of Droplets The stock solution prepared in the stock solution adjustment step was dropped by a vibrating nozzle. The vibration nozzle is provided with a pump for controlling the flow rate of the stock solution and a vibration mechanism for vibrating the nozzle. The vibration mechanism includes an oscillator that oscillates at a frequency determined by the control system, And an exciter that receives the vibration output amplified by the amplifier and mechanically vibrates the nozzle.
【００３６】本実施例では、ノズルからの原液の流量を
10 cm3/minとし、発振器の振動数を80Hzとして振動ノズ
ルを振動させ、ノズルから直径1.58mmの液滴を得た。ま
た、別の大きさの液滴を得るために振動数を110 Hzに変
えて振動ノズルを振動させ、直径1.43mmの液滴を得た。In this embodiment, the flow rate of the stock solution from the nozzle is
The vibration nozzle was vibrated at 10 cm 3 / min and the frequency of the oscillator was 80 Hz, and a droplet having a diameter of 1.58 mm was obtained from the nozzle. In addition, in order to obtain a droplet of another size, the vibration frequency was changed to 110 Hz and the vibration nozzle was vibrated to obtain a droplet having a diameter of 1.43 mm.
【００３７】振動ノズルから滴下された液滴は、−20℃
に温度調整したアセトン液浴中に落下させ、ポリビニル
アルコール水溶液をゲル化させてゲル粒体とした。この
時、ゲル粒体をアセトン液浴中に１時間に亘って浸漬し
て熟成させ、中心まで完全にポリビニルアルコール水溶
液がゲル化したゲル粒体とした。The droplet dropped from the vibrating nozzle is at -20.degree.
The solution was dropped into an acetone solution bath whose temperature had been adjusted to a value of 1 to gel the polyvinyl alcohol aqueous solution to obtain gel particles. At this time, the gel particles were immersed in an acetone liquid bath for 1 hour to be aged, thereby obtaining a gel particle in which the aqueous polyvinyl alcohol solution was completely gelled up to the center.
【００３８】熟成を経たゲル粒体を液浴から取り出し、
回転ドラム式温風乾燥装置を用いて80℃にて１時間に亘
り乾燥させた。尚、これに代えて、大気中にて常温（25
℃）で24時間かけて乾燥させてもよい。The aged gel particles are removed from the liquid bath,
It dried at 80 degreeC for 1 hour using the rotating drum type warm air drying apparatus. Instead of this, in the atmosphere at room temperature (25
C) for 24 hours.
【００３９】３）仮焼 乾燥後のゲル粒体を乾熱炉に入れ、炉内の温度を 650℃
に昇温して 650℃で６時間加熱した。このれによりゲル
粒体を構成するポリビニルアルコールが焼散され、ゲル
粒体はLi2CO3とZrO2とが分散された仮焼粒体となった。3) Calcination The dried gel particles are placed in a dry heat oven, and the temperature in the oven is set to 650 ° C.
And heated at 650 ° C. for 6 hours. As a result, the polyvinyl alcohol constituting the gel particles was burned off, and the gel particles became calcined particles in which Li 2 CO 3 and ZrO 2 were dispersed.
【００４０】４）焼結 乾熱炉内の温度をさらに1460℃にまで昇温し、仮焼粒体
を1460℃で４時間加熱した。これによりLi2CO3とZrO2と
が反応してLi2ZrO3とCO2↑となり、Li2ZrO3 微小焼結粒
が得られた。尚、本実施例において直径1.58mmの液滴か
らは直径0.8mmのLi2ZrO3 焼結粒が得られ、また直径1.4
3mmの液滴からは直径0.7mmのLi2ZrO3焼結粒が得られ
た。この時の仮焼及び焼結条件（炉内の温度変化）を図
２にグラフ化して示す。4) Sintering The temperature in the dry heating furnace was further raised to 1460 ° C., and the calcined granules were heated at 1460 ° C. for 4 hours. As a result, Li 2 CO 3 and ZrO 2 reacted to form Li 2 ZrO 3 and CO 2 、, and Li 2 ZrO 3 fine sintered particles were obtained. In this example, Li 2 ZrO 3 sintered particles having a diameter of 0.8 mm were obtained from a droplet having a diameter of 1.58 mm, and a droplet having a diameter of 1.4 mm was obtained.
Li 2 ZrO 3 sintered particles having a diameter of 0.7 mm were obtained from the 3 mm droplets. FIG. 2 is a graph showing the calcination and sintering conditions (temperature change in the furnace) at this time.
【００４１】この様にして得られたLi2ZrO3 焼結粒の10
00粒について、それぞれの直径分布と真球度とを測定し
た。直径分布は、Li2ZrO3 焼結粒の平均直径が 0.8mmの
とき標準偏差は48μｍ、平均直径が 0.7mmのとき標準偏
差は42μｍ（即ち、６％の標準偏差）となった。これ
は、標準偏差が小さく直径が均一であることを示してお
り、均一なサイズのLi2ZrO3 焼結粒の大量製造を実証で
きるものである。The Li 2 ZrO 3 sintered particles thus obtained are
The diameter distribution and sphericity of each of the 00 grains were measured. In the diameter distribution, when the average diameter of the Li 2 ZrO 3 sintered grains was 0.8 mm, the standard deviation was 48 μm, and when the average diameter was 0.7 mm, the standard deviation was 42 μm (that is, 6% standard deviation). This shows that the standard deviation is small and the diameter is uniform, which can demonstrate mass production of sintered particles of Li 2 ZrO 3 having a uniform size.
【００４２】真球度は、Li2ZrO3 焼結粒の1000粒につい
て個々の長径と短径とを測定し、長径／短径の比の平均
値で評価した。本実施例では、Li2ZrO3 焼結粒の平均直
径が0.8 mmのとき長径／短径の比の平均値は1.05とな
り、平均直径が 0.7mmのとき比の平均値は1.04となっ
た。これは、どのような大きさの粒でも真球度が高いこ
とを示している。The sphericity was determined by measuring the major axis and minor axis of each of 1000 Li 2 ZrO 3 sintered grains and evaluating the average value of the ratio of major axis / minor axis. In this example, when the average diameter of the Li 2 ZrO 3 sintered particles was 0.8 mm, the average ratio of the major axis / minor axis was 1.05, and when the average diameter was 0.7 mm, the average ratio was 1.04. This indicates that the sphericity is high for grains of any size.
【００４３】[0043]
【発明の効果】以上に述べたように、本発明によれば、
粒径の寸法制御が容易で、所望サイズのLi2ZrO3 焼結粒
を得ることが可能である。また、本発明による方法で
は、得られるLi2ZrO3 焼結粒は滴下により形成されるも
のであるため真球度が高く、粒径が均一な粒を大量に得
ることができるので、量産化に適しているという利点も
享受可能である。勿論、滴下による造粒方式を採用して
いるために原液の無駄がなく、製造歩留も良好である。As described above, according to the present invention,
It is easy to control the size of the particle size, and it is possible to obtain Li 2 ZrO 3 sintered particles of a desired size. Further, in the method according to the present invention, since the obtained Li 2 ZrO 3 sintered particles are formed by dropping, the sphericity is high, and a large number of particles having a uniform particle size can be obtained. It is also possible to enjoy the advantage of being suitable. Of course, since the granulation method by dropping is adopted, the stock solution is not wasted and the production yield is good.
【００４４】また、Li2ZrO3 粉末を出発原料とする従来
法に比べて焼結温度をかなり低く抑えることができるた
め、焼結中のリチウム蒸発量を大幅に少なくすることが
できる。In addition, since the sintering temperature can be considerably reduced as compared with the conventional method using Li 2 ZrO 3 powder as a starting material, the amount of lithium evaporated during sintering can be greatly reduced.
【００４５】従って、核融合炉のトリチウム増殖材の候
補材としてLi2ZrO3 焼結粒を安定して製造することが可
能である。Therefore, it is possible to stably produce Li 2 ZrO 3 sintered particles as a candidate material of a tritium breeding material for a nuclear fusion reactor.
【００４６】また、核融合炉などの密閉容器内での利用
に際しても、直径が 0.1mm〜１mmの微小なLi2ZrO3 焼結
粒を供給できるので、使用中にLi2ZrO3 焼結粒に応力割
れが起きにくいという利点が得られるだけでなく、複雑
な形状の容器でも速やかに充填できるという利点も得る
ことができる。[0046] Also, when utilized in a sealed container, such as a nuclear fusion reactor, the diameter can supply small Li 2 ZrO 3 sintered grains of 0.1 mm to 1 mm, Li 2 ZrO 3 during use Shoyuitsubu In addition to the advantage that stress cracking hardly occurs, the advantage that even a container having a complicated shape can be quickly filled can be obtained.
【００４７】尚、例えば直径が１mmのLi2ZrO3 焼結粒と
0.1mmのLi2ZrO3焼結粒のように、粒径の異なるものを組
み合わせることにより、密閉容器内に高密度に充填可能
な焼結粒として提供することもできる。For example, Li 2 ZrO 3 sintered particles having a diameter of 1 mm
By combining particles having different particle sizes, such as 0.1 mm Li 2 ZrO 3 sintered particles, the particles can be provided as sintered particles that can be filled in a closed container at high density.
【図１】本発明の一実施例を示すフローチャート図であ
る。FIG. 1 is a flowchart illustrating an embodiment of the present invention.
【図２】仮焼及び焼結条件（炉内の温度変化）を示した
線図である。FIG. 2 is a diagram showing calcination and sintering conditions (temperature change in a furnace).
【図３】従来の転動造粒法の工程を簡単に示した説明図
である。FIG. 3 is an explanatory diagram simply showing steps of a conventional rolling granulation method.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 大橋 準平 茨城県ひたちなか市勝田本町18−12−102 (72)発明者 淵之上 克宏 茨城県那珂郡東海村村松1220−496 (72)発明者 澤田 博司 茨城県那珂郡東海村村松1220−496 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Junpei Ohashi 18-12-102 Katsuta Honcho, Hitachinaka City, Ibaraki Pref. Hiroshi Ibaraki Prefecture Naka-gun Tokai-mura Muramatsu 1220-496
Claims (2)
物の水溶液に原料粉末を分散させて得られる原液を、ア
セトン液浴中に滴下してゲル粒体とし、このゲル粒体を
仮焼することにより高分子樹脂化合物水溶液のゲルを取
り除いた仮焼粒体とし、その後この仮焼粒体を焼結して
焼結粒を得るリチウムジルコネート微小焼結粒の製造方
法において、 原料粉末として、Li2CO3とZrO2との混合粉末を用い、 前記仮焼粒体を焼結する際に、空気中、1300℃以上1500
℃以下の温度で４時間以上10時間以下熱処理することに
より、 Li2CO3 + ZrO2 → Li2ZrO3 + CO2↑なる反応を経てLi2Z
rO3 焼結粒とすることを特徴とするリチウムジルコネー
ト微小焼結粒の製造方法。An undiluted solution obtained by dispersing a raw material powder in an aqueous solution of a polymer resin compound that gels in acetone is dropped into an acetone liquid bath to form gel particles, and the gel particles are calcined. In the method for producing lithium zirconate micro-sintered particles by removing the gel of the aqueous solution of the polymer resin compound to remove the gel and then sintering the calcined particles to obtain sintered particles, Using a mixed powder of Li 2 CO 3 and ZrO 2 , when sintering the calcined granules, in air, 1300 ℃ or more 1500
℃ by heat treatment for 4 hours or more 10 hours or less at a temperature below, through the Li 2 CO 3 + ZrO 2 → Li 2 ZrO 3 + CO 2 ↑ comprising reacting Li 2 Z
A method for producing lithium zirconate micro-sintered particles, characterized by using rO 3 sintered particles.
粉末とを１対１のモル比で含む混合粉末を用いることを
特徴とする請求項１に記載のリチウムジルコネート微小
焼結粒の製造方法。2. The method according to claim 1, wherein the raw material powder is Li 2 CO 3 powder and ZrO 2
The method according to claim 1, wherein a mixed powder containing the powder and the powder in a molar ratio of 1 to 1 is used.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP02159698A JP4017229B2 (en) | 1998-01-20 | 1998-01-20 | Method for producing fine sintered particles of lithium zirconate |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP02159698A JP4017229B2 (en) | 1998-01-20 | 1998-01-20 | Method for producing fine sintered particles of lithium zirconate |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH11209126A true JPH11209126A (en) | 1999-08-03 |
| JP4017229B2 JP4017229B2 (en) | 2007-12-05 |
Family
ID=12059428
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100703465B1 (en) | 2005-08-09 | 2007-04-03 | 한춘 | Production method of Lithium containing reagent and for reducing gases in syngas produced from the gasification of waste plastics |
| CN101857442A (en) * | 2010-05-28 | 2010-10-13 | 北京科技大学 | Preparation method of lithium-based ceramic microsphere |
-
1998
- 1998-01-20 JP JP02159698A patent/JP4017229B2/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100703465B1 (en) | 2005-08-09 | 2007-04-03 | 한춘 | Production method of Lithium containing reagent and for reducing gases in syngas produced from the gasification of waste plastics |
| CN101857442A (en) * | 2010-05-28 | 2010-10-13 | 北京科技大学 | Preparation method of lithium-based ceramic microsphere |
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|---|---|
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