JPH06171949A - Production of lanthanum manganite powder - Google Patents
Production of lanthanum manganite powderInfo
- Publication number
- JPH06171949A JPH06171949A JP34992992A JP34992992A JPH06171949A JP H06171949 A JPH06171949 A JP H06171949A JP 34992992 A JP34992992 A JP 34992992A JP 34992992 A JP34992992 A JP 34992992A JP H06171949 A JPH06171949 A JP H06171949A
- Authority
- JP
- Japan
- Prior art keywords
- lanthanum manganite
- powder
- manganite powder
- lanthanum
- repose
- 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.)
- Pending
Links
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、触媒、電極材料として
有用なランタンマンガナイト粉末の製造方法に関するも
のである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a lanthanum manganite powder useful as a catalyst or an electrode material.
【０００２】[0002]
【従来の技術】一般に、ストロンチウム置換ランタンマ
ンガナイト粉末は、酸化ランタン、炭酸マンガン、およ
び炭酸ストロンチウムの粉末を所定量秤り取り、乾式お
よび／または湿式で混合した後、1,200 ℃以上の高温で
焼成することにより製造されている。しかしながら、上
記方法により得られたものは、未反応物が存在した粉末
となり、また、未反応物を減少させるために、さらに高
温で長時間焼成を行っても、未反応物が残存する。この
粉末を原料に焼結体を製造した場合、残存する酸化ラン
タンにより焼結体の強度が著しく低下したり、或は電気
的特性が著しく低下してしまう。また、高温で焼成して
いる為、粗大粒子が生成し、粉砕が必要になり、製造コ
ストが高くなる。また粉末のまま使用する場合にも同等
の問題が生じるという欠点がある。2. Description of the Related Art Generally, a strontium-substituted lanthanum manganite powder is prepared by weighing out a predetermined amount of lanthanum oxide, manganese carbonate, and strontium carbonate powder, mixing them dry and / or wet, and then baking them at a high temperature of 1,200 ° C. or higher. It is manufactured by However, the product obtained by the above method becomes a powder in which an unreacted substance is present, and the unreacted substance remains even if the unreacted substance is reduced to reduce the amount of the unreacted substance and is baked at a higher temperature for a long time. When a sintered body is manufactured using this powder as a raw material, the remaining lanthanum oxide causes a marked decrease in the strength of the sintered body or a marked decrease in the electrical characteristics. In addition, since the particles are fired at a high temperature, coarse particles are generated and pulverization is required, which increases the manufacturing cost. Further, there is a drawback that the same problem occurs when the powder is used as it is.
【０００３】[0003]
【発明が解決しようとする課題】これらの問題の解決策
として特開平 4-74721号ではLa、SrおよびMnの水溶液に
炭酸アンモニウム溶液を加えて沈殿物を生成させた後、
熱処理してランタンマンガナイト粉末を製造することが
提案されている。しかし該方法では流動性の良い粉末は
得られず、熔射用材料としては適さない。本発明は従来
技術の問題点を解決した、流動性が良く、未反応物が無
い均一組成のランタンマンガナイト粉末の製造方法を提
供しようとするものである。As a solution to these problems, in JP-A-4-74721, an ammonium carbonate solution is added to an aqueous solution of La, Sr and Mn to form a precipitate,
It has been proposed to heat treat to produce lanthanum manganite powder. However, a powder having good fluidity cannot be obtained by this method, and it is not suitable as a material for spraying. The present invention is intended to provide a method for producing a lanthanum manganite powder having a good fluidity and a uniform composition with no unreacted matter, which solves the problems of the prior art.
【０００４】[0004]
【課題を解決するための手段】本発明者等は、上記課題
を解決するためにこの共沈反応を鋭意検討した結果、L
a、SrおよびMnの鉱酸塩混合水溶液に蓚酸アンモニウム
を固体粒状で添加することにより、固体表面で沈殿反応
が局所的に進行して、組成の均一な沈殿が生成し、しか
もこの沈殿が微小結晶の凝集した粒子からなるため濾過
性が著しく向上し、これを焼成すると流動性の良いペロ
ブスカイト単一相のランタンマンガナイト粉末が得られ
ることを見出し、この共沈反応の条件を厳密に特定して
本発明を完成したもので、その要旨とするところは、L
a、SrおよびMnまたはLa、Mnの鉱酸塩の混合水溶液に固
体粒状蓚酸アンモニウムを投入して攪拌反応させ、生成
した沈殿を分離、焼成することを特徴とするランタンマ
ンガナイト粉末の製造方法、および焼成して得られるラ
ンタンマンガナイト粉末の組成が(La1-xSrx)yMnOz(ここ
に、０≦ｘ≦0.5、 0.8≦ｙ≦１、ｚ≦３）であり、流動
性が良く安息角が45度以下であることを特徴とするもの
である。Means for Solving the Problems As a result of diligent examination of the coprecipitation reaction in order to solve the above problems, the present inventors have found that L
By adding ammonium oxalate in the form of solid particles to a mixed aqueous solution of a, Sr, and Mn mineral salts, the precipitation reaction locally proceeds on the solid surface, and a precipitate with a uniform composition is produced. Since it is composed of aggregated particles of crystals, the filterability is remarkably improved, and it was found that a perovskite single-phase lanthanum manganite powder with good fluidity can be obtained by firing it, and the conditions of this coprecipitation reaction were rigorously specified. The present invention has been completed by
a, Sr and Mn or La, Mn is a mixed aqueous solution of a mineral acid salt of solid particulate ammonium oxalate and stirred to react, the resulting precipitate is separated, a method for producing a lanthanum manganite powder, which is characterized by firing. And the composition of the lanthanum manganite powder obtained by firing is (La 1-x Sr x ) y MnO z (where 0 ≦ x ≦ 0.5, 0.8 ≦ y ≦ 1, z ≦ 3) and the fluidity is It is well characterized in that the angle of repose is 45 degrees or less.
【０００５】以下、本発明を詳細に説明する。先ず、L
a、SrおよびMnの各元素の酸化物、水酸化物および炭酸
塩等を所定量鉱酸に溶解する。鉱酸は硝酸がよく、溶解
後の金属元素濃度は三者合計で0.01〜３モル／L 、好ま
しくは 0.5〜 1.0モル／L が良い。また反応前に稀アン
モニア水でpHを６〜８に調整しておくのが好ましい。The present invention will be described in detail below. First, L
A predetermined amount of oxides, hydroxides, carbonates, etc. of the elements a, Sr, and Mn are dissolved in mineral acid. The mineral acid is preferably nitric acid, and the metal element concentration after dissolution is 0.01 to 3 mol / L, preferably 0.5 to 1.0 mol / L in total of the three. It is also preferable to adjust the pH to 6 to 8 with dilute aqueous ammonia before the reaction.
【０００６】次いでこの溶液に固体粒状蓚酸アンモニウ
ムを添加し、攪拌しつつ常温で反応させ沈殿を生成させ
る。ここで蓚酸アンモニウムの代わりに蓚酸を用いても
良いが、アンモニアを同時に添加する必要がある。添加
する固体粒状蓚酸アンモニウムの平均粒度は１μｍ以
上、好ましくは10〜 100μｍが良い。粒子形状は球状に
近い程良いが、扁平な板状以外の角型は使用できる。こ
の固体粒状蓚酸アンモニウムの調整は市販品を粉砕し、
所定粒度に篩分けすれば良い。添加量は蓚酸として過剰
率（＝実添加量／理論量） 0.7〜 1.5倍量、好ましくは
1.0± 0.1倍量が良い。 0.7倍量未満および 1.5倍量を
越えるとMnの収率が低下し、好ましくない。反応時の添
加方法は原料元素水溶液を攪拌しながら少しづつ分割し
て投入するのが良いが、一度に全量を投入してもかまわ
ない。反応時アンモニア水を同時に添加し、沈殿物の生
成が完了し分離するまでpHを６〜９、好ましくは 6.5〜
８に維持する必要がある。pH６以下では沈殿生成が充分
でなく、また単一粒子が大きくなり好ましくなく、９を
越えると濾過が困難になってしまう。この反応は均一溶
液反応と異なり粒状蓚酸アンモニウムの表面で局部的に
進行し、微細な結晶が凝集して球状沈殿粒子を生成する
と考えられる。Next, solid granular ammonium oxalate is added to this solution and reacted at room temperature with stirring to form a precipitate. Here, oxalic acid may be used instead of ammonium oxalate, but it is necessary to add ammonia at the same time. The solid granular ammonium oxalate to be added has an average particle size of 1 μm or more, preferably 10 to 100 μm. The closer the particle shape is to the spherical shape, the better, but square shapes other than the flat plate shape can be used. The adjustment of this solid granular ammonium oxalate crushes a commercial product,
It may be sieved to a predetermined particle size. The addition amount of oxalic acid is an excess ratio (= actual addition amount / theoretical amount) 0.7 to 1.5 times, preferably
1.0 ± 0.1 times the amount is good. If the amount is less than 0.7 times or more than 1.5 times, the yield of Mn decreases, which is not preferable. Regarding the method of addition during the reaction, it is preferable to add the raw material element aqueous solution in small portions while stirring, but it is also possible to add the entire amount at once. Ammonia water is added at the same time during the reaction, and the pH is kept at 6-9, preferably 6.5-until the precipitation is completed and separated.
Need to maintain 8. If the pH is 6 or less, the precipitation is not sufficient, and single particles become large, which is not preferable, and if it exceeds 9, the filtration becomes difficult. Unlike the homogeneous solution reaction, this reaction locally proceeds on the surface of the granular ammonium oxalate, and it is considered that fine crystals aggregate to form spherical precipitate particles.
【０００７】得られた沈殿は微結晶の凝集体なので容易
に濾別でき、700℃以上で焼成することにより、流動性が
良く、未反応物が無く、(La1-xSrx)yMnOz(ここに、０≦
ｘ≦0.5、 0.8≦ｙ≦１、ｚ≦３好ましくは 2.5≦ｚ≦
３）の組成を有するペロブスカイト型構造を持つランタ
ンマンガナイトの粉末が得られる。焼成粉末の流動性を
評価する物性として安息角を測定した結果、本発明の粉
末は45度以下の優れた流動性を示した。安息角が45度を
越えると流動性が極端に悪くなり、該粉末を応用製品の
製造工程で取扱う場合、例えば原料ホッパー内でブリッ
ジを形成して排出が困難になるような現象を生ずる。Since the obtained precipitate is an agglomerate of fine crystals, it can be easily separated by filtration, and by calcining at 700 ° C. or higher, it has good fluidity, no unreacted substances, and (La 1-x Sr x ) y MnO z (where 0 ≦
x ≦ 0.5, 0.8 ≦ y ≦ 1, z ≦ 3, preferably 2.5 ≦ z ≦
A lanthanum manganite powder having a perovskite structure having the composition of 3) is obtained. As a result of measuring the angle of repose as a physical property for evaluating the fluidity of the calcined powder, the powder of the present invention showed excellent fluidity of 45 degrees or less. When the angle of repose exceeds 45 degrees, the fluidity becomes extremely poor, and when the powder is handled in the manufacturing process of applied products, for example, a phenomenon occurs in which a bridge is formed in the raw material hopper and discharge becomes difficult.
【０００８】[0008]
【実施例】本発明の具体的実施態様を実施例を挙げて説
明するが、本発明はこれらに限定されるものではない。 （実施例１）2.82ｇの酸化ランタンと2.55ｇの炭酸スト
ロンチウムおよび5.00ｇの炭酸マンガンを16.3ccの濃硝
酸に溶解し、純水で 700ccに希釈後、稀アンモニア水で
pHを7.3に調整した。該溶液に 16.20ｇ、平均粒度50μ
ｍの固体粒状蓚酸アンモニウムを撹拌しながら添加混合
して、沈殿物を得た。これを濾別後、900℃で20時間焼成
した。得られた酸化物はLa0.5Sr0.5MnO2.75 の組成を有
するペロブスカイト単一相のランタンマンガナイト粉末
であり、未反応酸化ランタンはなく、安息角は38.3度で
あった。EXAMPLES Specific embodiments of the present invention will be described with reference to examples, but the present invention is not limited thereto. (Example 1) 2.82 g of lanthanum oxide, 2.55 g of strontium carbonate and 5.00 g of manganese carbonate were dissolved in 16.3 cc concentrated nitric acid, diluted with pure water to 700 cc, and then diluted with diluted ammonia water.
The pH was adjusted to 7.3. 16.20g in this solution, average particle size 50μ
m of solid granular ammonium oxalate was added and mixed with stirring to obtain a precipitate. This was separated by filtration and then baked at 900 ° C. for 20 hours. The obtained oxide was a perovskite single-phase lanthanum manganite powder having a composition of La 0.5 Sr 0.5 MnO 2.75 , no unreacted lanthanum oxide, and a repose angle of 38.3 degrees.
【０００９】（実施例２）3.60ｇの酸化ランタンと0.81
ｇの炭酸ストロンチウムおよび5.00ｇの炭酸マンガンを
15.5ccの濃硝酸に溶解し、純水で 700ccに希釈後、稀ア
ンモニア水でpHを6.9に調整した。該溶液に 15.42ｇ、
平均粒度50μｍの固体粒状蓚酸アンモニウムを撹拌しな
がら添加混合して、沈殿物を得た。これを濾別後、900℃
で20時間焼成した。得られた酸化物は（La0.8Sr0.2)0.8
MnO2.62 の組成を有するペロブスカイト単一相のランタ
ンマンガナイト粉末であり、未反応酸化ランタンはな
く、安息角は37.8度であった。Example 2 3.60 g of lanthanum oxide and 0.81
g strontium carbonate and 5.00 g manganese carbonate
It was dissolved in 15.5 cc concentrated nitric acid, diluted to 700 cc with pure water, and then adjusted to pH 6.9 with diluted ammonia water. 15.42 g in the solution,
Solid granular ammonium oxalate having an average particle size of 50 μm was added and mixed with stirring to obtain a precipitate. After filtering this off, 900 ° C
It was baked for 20 hours. The resulting oxide is (La 0.8 Sr 0.2 ) 0.8
It was a perovskite single-phase lanthanum manganite powder having a composition of MnO 2.62 , no unreacted lanthanum oxide, and a repose angle of 37.8 degrees.
【００１０】（実施例３）5.62ｇの酸化ランタンと5.00
ｇの炭酸マンガンを17.7ccの濃硝酸に溶解し、純水で 7
00ccに希釈後、稀アンモニア水でpHを 7.4に調整した。
該溶液に 15.65ｇの固体粒状蓚酸を撹拌しながら添加
し、同時に稀アンモニア水も添加し、pHを 6.5〜 7.5に
調整しながら混合して、沈殿物を得た。これを濾別後、9
00℃で20時間焼成した。得られた酸化物はLaMnO3の組成
を有するペロブスカイト単一のランタンマンガナイト粉
末であり、未反応酸化ランタンはなく、安息角は36.9度
であった。(Example 3) 5.62 g of lanthanum oxide and 5.00
g of manganese carbonate is dissolved in 17.7cc of concentrated nitric acid,
After diluted to 00 cc, the pH was adjusted to 7.4 with diluted ammonia water.
15.65 g of solid granular oxalic acid was added to the solution while stirring, and dilute aqueous ammonia was also added at the same time, and the mixture was mixed while adjusting the pH to 6.5 to 7.5 to obtain a precipitate. After filtering this off, 9
It was baked at 00 ° C for 20 hours. The obtained oxide was a single perovskite lanthanum manganite powder having a composition of LaMnO 3 , no unreacted lanthanum oxide, and a repose angle of 36.9 degrees.
【００１１】（比較例１）最終的に得られる組成がLa
0.9Sr0.1MnO2.95 となるように、6.22ｇの酸化ランタン
と0.62ｇの炭酸ストロンチウムおよび4.87ｇの炭酸マン
ガンを秤量し、12ccの水と充分混合し、乾燥後1,200 ℃
で10時間焼成し、ランタンマンガナイト粉末を得た。未
反応酸化ランタンがＸ線回折で検出され、安息角は55.3
度であった。Comparative Example 1 The composition finally obtained is La
Weigh 6.22 g of lanthanum oxide, 0.62 g of strontium carbonate and 4.87 g of manganese carbonate to give 0.9 Sr 0.1 MnO 2.95 , mix well with 12 cc of water, and dry at 1200 ° C.
Then, it was baked for 10 hours to obtain a lanthanum manganite powder. Unreacted lanthanum oxide was detected by X-ray diffraction, and the angle of repose was 55.3.
It was degree.
【００１２】（比較例２）最終的に得られる組成が（La
0.8Sr0.2)0.8MnO2.62 となるように、3.60ｇの酸化ラン
タンと0.81ｇの炭酸ストロンチウムおよび5.00ｇの炭酸
マンガンを秤量し、12ccの水と充分混合し、乾燥後1,20
0 ℃で10時間焼成し、ランタンマンガナイト粉末を得
た。未反応酸化ランタンがＸ線回折で検出され、安息角
は流動性が悪く測定不能であった。(Comparative Example 2) The composition finally obtained is (La
0.8 Sr 0.2 ) 0.8 MnO 2.62 Weigh 3.60 g of lanthanum oxide, 0.81 g of strontium carbonate and 5.00 g of manganese carbonate, mix well with 12 cc of water, and dry for 1,20
Firing was performed at 0 ° C. for 10 hours to obtain a lanthanum manganite powder. Unreacted lanthanum oxide was detected by X-ray diffraction, and the angle of repose was poor in fluidity and could not be measured.
【００１３】[0013]
【発明の効果】本発明によれば、流動性が良く未反応物
が無いペロブスカイト単一相のランタンマンガナイト粉
末を容易且つ工業的に製造することができ、産業上その
利用価値は極めて高い。Industrial Applicability According to the present invention, a perovskite single-phase lanthanum manganite powder having good fluidity and no unreacted substances can be easily and industrially produced, and its utility value is extremely high in industry.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 酒井 茂 福井県武生市北府２丁目１番５号 信越化 学工業株式会社磁性材料研究所内 (72)発明者 吉田 紀史 福井県武生市北府２丁目１番５号 信越化 学工業株式会社磁性材料研究所内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shigeru Sakai 2-1, 5 Kitafu, Takefu City, Fukui Prefecture Shin-Etsu Kagaku Kogyo Co., Ltd. Magnetic Materials Laboratory (72) Inventor Noriyoshi Yoshida 2-chome Kitafu, Takefu City, Fukui Prefecture No. 5 Inside Shin-Etsu Chemical Co., Ltd. Magnetic Materials Research Center
Claims (4)
合水溶液に固体粒状蓚酸アンモニウムを投入して攪拌反
応させ、生成した沈殿を分離、焼成することを特徴とす
るランタンマンガナイト粉末の製造方法。1. A lanthanum manganite characterized in that solid granular ammonium oxalate is added to a mixed aqueous solution of La, Sr and Mn or La, Mn mineral acid salt to cause a stirring reaction, and the generated precipitate is separated and calcined. Powder manufacturing method.
末の組成が(La1-xSrx)yMnOz(ここに、０≦ｘ≦0.5、 0.8
≦ｙ≦１、ｚ≦３）である請求項１に記載のランタンマ
ンガナイト粉末の製造方法。2. The composition of the lanthanum manganite powder obtained by firing is (La 1-x Sr x ) y MnO z (where 0 ≦ x ≦ 0.5, 0.8
The method for producing a lanthanum manganite powder according to claim 1, wherein ≦ y ≦ 1, z ≦ 3).
合水溶液のpHを反応前予め６〜８とする請求項１または
２に記載のランタンマンガナイト粉末の製造方法。3. The method for producing a lanthanum manganite powder according to claim 1, wherein the pH of a mixed aqueous solution of La, Sr and Mn or a mineral salt of La, Mn is set to 6 to 8 before the reaction.
末の安息角が45度以下であることを特徴とする請求項１
〜３に記載のランタンマンガナイト粉末の製造方法。4. The angle of repose of the lanthanum manganite powder obtained by firing is 45 degrees or less.
The manufacturing method of the lanthanum manganite powder as described in any one of 1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP34992992A JPH06171949A (en) | 1992-12-02 | 1992-12-02 | Production of lanthanum manganite powder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP34992992A JPH06171949A (en) | 1992-12-02 | 1992-12-02 | Production of lanthanum manganite powder |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH06171949A true JPH06171949A (en) | 1994-06-21 |
Family
ID=18407068
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP34992992A Pending JPH06171949A (en) | 1992-12-02 | 1992-12-02 | Production of lanthanum manganite powder |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH06171949A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2016506032A (en) * | 2013-10-31 | 2016-02-25 | エルジー・ケム・リミテッド | Positive electrode active material, method for producing the same, and lithium secondary battery including the same |
-
1992
- 1992-12-02 JP JP34992992A patent/JPH06171949A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2016506032A (en) * | 2013-10-31 | 2016-02-25 | エルジー・ケム・リミテッド | Positive electrode active material, method for producing the same, and lithium secondary battery including the same |
| US9960418B2 (en) | 2013-10-31 | 2018-05-01 | Lg Chem, Ltd. | Cathode active material, preparation method thereof, and lithium secondary battery comprising the same |
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