JPH0360772B2 - - Google Patents

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Publication number
JPH0360772B2
JPH0360772B2 JP7144585A JP7144585A JPH0360772B2 JP H0360772 B2 JPH0360772 B2 JP H0360772B2 JP 7144585 A JP7144585 A JP 7144585A JP 7144585 A JP7144585 A JP 7144585A JP H0360772 B2 JPH0360772 B2 JP H0360772B2
Authority
JP
Japan
Prior art keywords
lithium carbonate
lithium
crystallization
weight
aqueous solution
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.)
Expired
Application number
JP7144585A
Other languages
Japanese (ja)
Other versions
JPS61232205A (en
Inventor
Kenji Niwa
Ichiro Ichikawa
Yutaka Suzuki
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sumitomo Chemical Co Ltd
Original Assignee
Sumitomo Chemical Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Sumitomo Chemical Co Ltd filed Critical Sumitomo Chemical Co Ltd
Priority to JP7144585A priority Critical patent/JPS61232205A/en
Publication of JPS61232205A publication Critical patent/JPS61232205A/en
Publication of JPH0360772B2 publication Critical patent/JPH0360772B2/ja
Granted legal-status Critical Current

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Description

【発明の詳細な説明】[Detailed description of the invention]

〈産業上の利用分野〉 本発明は高純度炭酸リチウム粉末の製造方法に
関するものである。 さらに詳しくは加熱減量成分の少ない高純度炭
酸リチウム粉末の製造方法に関するものである。 最近の電子工業の発展は目覚ましく、新しい原
理に基づく機能性素子、ニユーセラミツクスがつ
ぎつぎと開発されている。これにともない使用さ
れる原料である素材もよりいつそう高純度高品質
であることが要求されている。 炭酸リチウムは近年表面弾性波フイルター、温
度湿度センサー、オプトエレクトロエクス素子等
の構成部材であるタンタル酸リチウム、ニオブ酸
リチウム等の単結晶あるいは薄膜の原料として注
目されているものであり、より一層、高純度・高
品質であることが望まれている。 この目的に供される炭酸リチウムはアルカリ金
属、アルカリ土類金属、遷移金属等の金属不純
物、塩素、硫酸根等の陰イオン不純物の含有量が
少ないこととともに加熱減量成分が少ないことが
重要である。すなわち炭酸リチウムと五酸化タン
タルあるいは五酸化ニオブとを原料とし白金製の
ルツボを用いチヨクラルスキー法でタンタル酸リ
チウム、ニオブ酸リチウム等の単結晶を製造する
場合、炭酸リチウムと他の成分の重量比をコング
ルエントメルト組成として知られる特定の比率に
厳密に制御する必要があり、この比率よりずれる
と得られる製品の特性の変動、結晶のクラツクの
発生による収率の低下をもたらすため加熱減量成
分の少ない炭酸リチウムが望まれている。 しかしながら、従来炭酸リチウムには炭酸リチ
ウムの融点以下の温度、たとえば300〜550℃の温
度範囲で消失減量する炭酸リチウム以外の成分が
0.5%から数%存在し、かつその量が原料ロツト
間、原料の使用部分によつて変動し、炭酸リチウ
ム仕込量の誤差の原因となり、前述の組成比の制
御を困難にし、性能、収率の低下をもたらしてい
た。 〈従来の技術および発明が解決しようとする問題
点〉 粗リチウム化合物、一般には粗炭酸リチウムよ
り高純度の炭酸リチウムを得る方法として再結晶
法、再沈殿法、隔膜電解法等が知られている。 再結晶法の例としては炭酸リチウム水溶液を蒸
発濃縮し炭酸リチウムを析出させるとともに不純
物を除去する方法が知られている。再沈殿法の例
としては炭酸リチウム水溶液と石灰乳を反応させ
水酸化リチウムにし不純物を炭酸塩として除去し
たのち二酸化炭素と反応させ炭酸リチウムを析出
させる方法(米国特許4207297号)が知られてい
る。また隔膜電解法の例としては硫酸リチウム水
溶液を隔膜電解し高純度水酸化リチウムを得て二
酸化炭素と反応させ炭酸リチウムを析出させる方
法(特開昭54−43174号)が知られている。 しかしながらこれらの方法はいずれも炭酸リチ
ウム中の金属不純物、陰イオン不純物を除去する
方法に関するものであり、現在まで前述したチヨ
クラルスキー法でニオブ酸リチウム、タンタル酸
リチウム等の単結晶を製造する際、反応生成物の
組成をくるわし、性能、収率に悪影響を及ぼす加
熱減量成分の少ない高純度炭酸リチウムの製造方
法についてはなんら効果的な提案が成されていな
かつた。やむをえず、高価な装置と費用を費やし
精製した炭酸リチウムを再汚染させながら500〜
600℃の温度で炭酸リチウムを焼成し加熱減量成
分を除去しているのが実情である。 このため加熱減量成分の少ない、少なくとも
0.1重量%以下の高純度炭酸リチウムの提供が望
まれている。 〈問題点を解決するための手段と作用〉 本発明者らは前述した問題点を解消し加熱減量
成分の少ない高純度炭酸リチウムの経済的な製造
方法を開発すべく鋭意検討を重ねた結果、加熱減
量成分はリチウム化合物水溶液より炭酸リチウム
の結晶を析出させる晶析操作中に生成し、その主
要成分が水分であることを見出した。さらに加熱
減量成分は晶析時間の延長、晶析槽内の撹拌の強
化、晶析時の加圧あるいは減圧等の手段によつて
はほとんど減少できないが、リチウム化合物水溶
液の再結晶、再沈殿等により炭酸リチウムの結晶
を析出させる際、 該水溶液の液温を90℃以上に加温し晶析する
ことにより炭酸リチウム中の加熱減量成分を
0.1重量%以下に減少できることを見出した。
(以下第1の方法と称する) さらに晶析時に前以つてリチウム化合物水溶
液に炭酸リチウム粉末を、晶析により新に生成
する炭酸リチウム100重量部あたり5〜100重量
部添加し、且つ該水溶液の液温を70℃以上に加
温し晶析することにより炭酸リチウム中の加熱
減量成分を0.1重量%以下、特に0.02重量%以
下にすら減量できることを見出した。(以下第
2の方法と称する) こられの方法により、高い液温での晶析、炭酸
リチウムの添加という容易な手段により加熱減量
成分の少ない高純度炭酸リチウムが得られるとい
うことは従来知られていなかつたものである。そ
して晶析によりえられた炭酸リチウム粉末に対し
焼成等の処理は不必要であり、単なる乾燥のみで
良く、また晶析時の炭酸リチウムの著しい収率向
上ももたらされる。 以下これらの方法の構成について説明する。 リチウム化合物を含有する水溶液としては、粗
リチウム化合物、一般には粗炭酸リチウムを原料
とする炭酸リチウム水溶液あるいはよく知られた
無機酸、石灰乳等により可溶化したリチウム化合
物を含有する水溶液、これら水溶液をよくしられ
た再結晶法、再沈殿法、イオン交換法等により処
理した精製リチウム化合物水溶液等が用いられ
る。 リチウム化合物を含有する水溶液中のリチウム
化合物の種類は晶析時の反応により炭酸リチウム
に変化し結晶を析出するものであれば種類をとわ
ないが、水酸化リチウム、飽和濃度以下の炭酸リ
チウム、炭酸水素リチウム等が好適である。 水酸化リチウムの場合、第1の方法では、撹拌
機、加熱ジヤケツト、二酸化炭素吹き込み口、炭
酸リチウムスラリー取り出し口を備えた耐圧晶析
槽に5〜10重量%濃度の水酸化リチウム水溶液を
入れ、該水溶液の液温が90℃以上になるまで加温
し、ついで液温を90℃以上に保ちながら水酸化リ
チウムの2分の1当量以上の二酸化炭素を晶析槽
内へ連続的に吹き込み水酸化リチウムを炭酸リチ
ウムに変え結晶として析出させる。得られた炭酸
リチウムスラリーより炭酸リチウムを公知の分離
手段により分離回収し、洗浄後よくしられた乾燥
方法で60℃〜120℃で乾燥する。得られる炭酸リ
チウム中の加熱減量成分は晶析時の水酸化リチウ
ム水溶液の液温により異なり液温が高温であるほ
ど少ない。即ち液温90℃以上では加熱減量成分
0.1重量%以下の、液温120℃以上では加熱減量成
分0.05重量%以下の高純度炭酸リチウムを得るこ
とができる。 なお晶析槽内においては結晶として析出した炭
酸リチウム粉末が槽下部に沈積することなく十分
浮遊分散するように撹拌等の手段により分散させ
る。分散が不十分で炭酸リチウム粉末が沈積する
場合は得られる炭酸リチウム中の加熱減量成分は
増加する。 二酸化炭素の供給速度は晶析時間が少なくとも
1時間以上、好ましくは3時間以上となるよう連
続的に供給する。晶析が1時間以内に完了するよ
う二酸化炭素を急速に供給し炭酸リチウムの結晶
を析出させると得られる炭酸リチウム粉末の加熱
減量成分は増加する。 第2の方法では水酸化リチウムの場合、同じ晶
析槽を用い5〜10重量%の水酸化リチウム水溶液
と二酸化炭素から炭酸リチウムの結晶を析出させ
るに際し、晶析の開始に先立つて該水溶液中に炭
酸リチウム粉末を添加し撹拌分散させ、且つ該水
溶液の液温を70℃以上に加温し、該水溶液中の水
酸化リチウムの2分の1当量以上の二酸化炭素を
吹き込み炭酸リチウムの結晶を析出させる。この
方法では第1の方法に較べより低い液温で加熱減
量成分0.1重量%以下の炭酸リチウム粉末を得る
ことができ、100℃以上の液温では加熱減量成分
0.02重量%以下の極めて加熱減量成分の少ない炭
酸リチウム粉末を得ることができる。 この方法においても晶析槽内の炭酸リチウム粉
末の撹拌分散また晶析時間については第1の方法
と同様におこなわれる。 晶析に先立つて添加する炭酸リチウムは粉末で
あればよいが、平均粒径が80μm以下が好まし
く、50μm以下がさらに好ましい。添加量は新た
に晶析により結晶として析出する炭酸リチウム
100重量部あたり5〜100重量部、好ましくは10〜
50重量部である。5重量部より少ないと晶析に先
立つて炭酸リチウム粉末を添加した効果が小さ
く、100重量部以上添加しても格段の加熱減量成
分の減少は認められない。添加する炭酸リチウム
粉末は第1の方法で晶析した炭酸リチウム粉末あ
るいは市販の高純度炭酸リチウムを550℃の温度
で1時間焼成した炭酸リチウム粉末あるいは別途
第2の方法で晶析した炭酸リチウム粉末等の加熱
減量成分の少ないものを用いる。 これら2つの方法において晶析に供する水溶液
中のリチウム化合物が炭酸リチウム、炭酸水素リ
チウムであつても、加熱減量成分は炭酸リチウム
の析出挙動によるため、水酸化リチウムの場合と
同様の効果が得られる。 例えば、飽和濃度以下の炭酸リチウム水溶液の
場合では、該水溶液を晶析槽に入れ水を減圧除去
し炭酸リチウム濃度を飽和濃度以上に濃縮し、第
1の方法では予め該水溶液の液温を90℃以上に加
温し晶析する。また第2の方法では晶析に先立つ
て該水溶液中に炭酸リチウム粉末を添加し且つ該
水溶液の液温を70℃以上に加温し晶析する。いず
れの方法によつても加熱減量成分が0.1重量%以
下の炭酸リチウム粉末が得られる。 また炭酸水素リチウムの場合では、濃度5〜8
重量%の炭酸水素リチウム水溶液を晶析槽に入れ
減圧あるいは窒素ガスフイードにより二酸化炭素
を脱離させ炭酸リチウムにし炭酸リチウムの結晶
を析出させるに際し、第1の方法では該水溶液の
液温を90℃以上に保ちながら減圧分解させ晶析す
る。第2の方法では晶析に先立つて該水溶液中に
炭酸リチウム粉末を水酸化リチウムの場合と同様
に加え且つ該水溶液の液温を70℃以上に加温し炭
酸水素リチウムを分解し炭酸リチウム結晶を析出
させる。 いずれの方法によつても加熱減量成分0.1重量
%以下の炭酸リチウム粉末を得ることができる。 〈本発明の効果〉 本発明は上述の2つの方法の内、第2の方法で
あり以下に述べる効果を有する。 晶析液の液温制御、炭酸リチウム粉末の添加
という簡単かつ経済的な方法により加熱減量成
分0.1重量%以下さらには0.02重量%以下の高
純度炭酸リチウムが得られる。 炭酸リチウムの水に対する溶解度は高温ほど
減少するため、晶析操作での炭酸リチウムの収
率が大きく改善される。 特別な焼成装置は不要であり、焼成操作に付
随する炭酸リチウムの汚染がなく、製品価値の
高い高純度炭酸リチウムをえることができる。 参考例 1 晶析槽として撹拌機、加熱用スチームジヤケツ
ト、リチウム化合物水溶液フイード口、炭酸リチ
ウム粉末添加口、ガス吹き込み口、排気口、炭酸
リチウムスラリーぬきだし口、圧力ゲージ等を備
えた内容積30の耐圧オートクレープを用いた。 精製した濃度5.2重量%の水酸化リチウム水溶
液を20を水溶液フイード口より晶析槽にいれ回
転数600rpmで十分撹拌しながら約30分かけて液
温を90℃に昇温した。十分撹拌し液温を90℃に保
ちながらガス吹き込み口より二酸化炭素ガスを毎
分2.2の流量で4時間連続的に槽内に供給し、
水酸化リチウムと反応させ炭酸リチウムの結晶を
晶析した。 晶析完了後、炭酸リチウムスラリーを晶析槽よ
り抜き出し遠心分離機により水と分離し、さらに
炭酸リチウムケーキを80℃の温水10で洗浄し該
炭酸リチウムケーキを60℃で12時間真空乾燥し
た。 熱天秤により乾燥炭酸リチウムの加熱重量変化
を測定し550℃までの加熱減少量の全体に占める
割合を加熱減量成分とした。 得られた炭酸リチウム粉末の収率は74.4%、平
均粒径47μm、加熱減量成分は0.092%であつた。 実施例 1 参考例1で用いたのと同じ晶析槽を用い、精製
した濃度5.2重量%の水酸化リチウム水溶液を20
を水溶液フイード口より晶析槽にいれ撹拌しな
がら液温を80℃に昇温した。炭酸リチウム粉末投
入口より平均粒径43μm、加熱減量成分0.073%の
炭酸リチウム粉末を165g加え、十分撹拌し水溶
液中に分散させた。 液温を80℃に保ち十分撹拌しながら二酸化炭素
ガスを毎分2.2の流量で4時間連続的に槽内に
供給し、炭酸リチウムの結晶を晶析した。 参考例1と同様にして乾燥炭酸リチウム粉末を
得た。 炭酸リチウム粉末の回収率は70.2%、平均粒径
は52μm、加熱減量成分は0.052%であつた。 参考例2、実施例2 参考例1と同じ晶析槽を用い、液温、炭酸リチ
ウム粉末の添加量をかえた以外は参考例1、実施
例1と同様にして晶析、回収をおこなつた。
<Industrial Application Field> The present invention relates to a method for producing high purity lithium carbonate powder. More specifically, the present invention relates to a method for producing high-purity lithium carbonate powder with a small amount of components that lose weight on heating. The recent development of the electronics industry is remarkable, and functional devices based on new principles, such as new ceramics, are being developed one after another. Along with this, the materials used as raw materials are required to be of even higher purity and quality. In recent years, lithium carbonate has been attracting attention as a raw material for single crystals or thin films such as lithium tantalate and lithium niobate, which are components of surface acoustic wave filters, temperature and humidity sensors, optoelectronic devices, etc. High purity and high quality are desired. It is important that the lithium carbonate used for this purpose has a low content of metal impurities such as alkali metals, alkaline earth metals, and transition metals, anionic impurities such as chlorine and sulfuric acid radicals, and has a low content of components lost on heating. . In other words, when producing single crystals of lithium tantalate, lithium niobate, etc. using lithium carbonate and tantalum pentoxide or niobium pentoxide as raw materials using a platinum crucible using the Czyochralski method, the weight of lithium carbonate and other components is The ratio must be strictly controlled to a specific ratio known as the congruent melt composition; any deviation from this ratio will result in variations in the properties of the resulting product and a decrease in yield due to the occurrence of crystal cracks. Lithium carbonate with fewer components is desired. However, conventional lithium carbonate contains components other than lithium carbonate that disappear and lose weight at temperatures below the melting point of lithium carbonate, for example in the temperature range of 300 to 550°C.
It exists from 0.5% to several percent, and its amount varies between raw material lots and depending on the part of the raw material used, causing errors in the amount of lithium carbonate charged, making it difficult to control the composition ratio mentioned above, and reducing performance and yield. was causing a decline in <Prior art and problems to be solved by the invention> Recrystallization methods, reprecipitation methods, diaphragm electrolysis methods, etc. are known as methods for obtaining crude lithium compounds, generally lithium carbonate with higher purity than crude lithium carbonate. . As an example of a recrystallization method, a method is known in which an aqueous lithium carbonate solution is evaporated and concentrated to precipitate lithium carbonate and remove impurities. As an example of the reprecipitation method, a method is known in which an aqueous lithium carbonate solution and milk of lime are reacted to form lithium hydroxide, impurities are removed as carbonate, and then reacted with carbon dioxide to precipitate lithium carbonate (US Pat. No. 4,207,297). . Further, as an example of the diaphragm electrolysis method, a method is known in which a lithium sulfate aqueous solution is electrolyzed through a diaphragm to obtain high-purity lithium hydroxide, which is then reacted with carbon dioxide to precipitate lithium carbonate (Japanese Patent Application Laid-open No. 43174/1983). However, all of these methods are related to methods for removing metal impurities and anion impurities in lithium carbonate, and until now, when producing single crystals of lithium niobate, lithium tantalate, etc. using the Czyochralski method described above, However, considering the composition of the reaction product, no effective proposal has been made regarding a method for producing high-purity lithium carbonate with few components that lose heat on heating and have a negative effect on performance and yield. Unavoidably, 500~
The reality is that lithium carbonate is fired at a temperature of 600°C to remove components that lose weight on heating. For this reason, the amount of components lost by heating is small, at least
It is desired to provide high purity lithium carbonate of 0.1% by weight or less. <Means and effects for solving the problems> As a result of intensive studies by the present inventors to solve the above-mentioned problems and develop an economical method for producing high-purity lithium carbonate with a small amount of heat loss components, It was found that the heating loss component is generated during the crystallization operation of precipitating lithium carbonate crystals from an aqueous lithium compound solution, and its main component is water. Furthermore, the components lost on heating cannot be reduced by extending the crystallization time, strengthening the stirring in the crystallization tank, increasing or decreasing pressure during crystallization, etc., but recrystallization of the aqueous lithium compound solution, reprecipitation, etc. When crystals of lithium carbonate are precipitated by heating the aqueous solution to a temperature of 90°C or higher and crystallizing, the components lost on heating in the lithium carbonate are removed.
It has been found that the amount can be reduced to 0.1% by weight or less.
(Hereinafter referred to as the first method) Furthermore, 5 to 100 parts by weight of lithium carbonate powder is added to the lithium compound aqueous solution in advance during crystallization per 100 parts by weight of lithium carbonate newly produced by crystallization, and It has been found that by heating the liquid temperature to 70°C or higher and crystallizing it, it is possible to reduce the amount of components lost on heating in lithium carbonate to 0.1% by weight or less, particularly 0.02% by weight or less. (Hereinafter referred to as the second method) It is conventionally known that by this method, high purity lithium carbonate with a small amount of components lost on heating can be obtained by simple means such as crystallization at a high liquid temperature and addition of lithium carbonate. It's something that didn't exist before. The lithium carbonate powder obtained by crystallization does not require any treatment such as calcination, and only simple drying is required, and the yield of lithium carbonate during crystallization is significantly improved. The configurations of these methods will be explained below. Examples of aqueous solutions containing lithium compounds include crude lithium compounds, generally aqueous lithium carbonate solutions made from crude lithium carbonate, or aqueous solutions containing lithium compounds solubilized with well-known inorganic acids, milk of lime, etc. A purified lithium compound aqueous solution treated by a well-known recrystallization method, reprecipitation method, ion exchange method, etc. is used. The type of lithium compound in the aqueous solution containing the lithium compound is not limited to any type as long as it changes to lithium carbonate and precipitates crystals through the reaction during crystallization, but lithium hydroxide, lithium carbonate below the saturated concentration, Lithium hydrogen carbonate and the like are preferred. In the case of lithium hydroxide, in the first method, a lithium hydroxide aqueous solution with a concentration of 5 to 10% by weight is placed in a pressure-resistant crystallization tank equipped with a stirrer, a heating jacket, a carbon dioxide inlet, and a lithium carbonate slurry outlet. The aqueous solution is heated until the temperature reaches 90°C or higher, and then, while maintaining the liquid temperature at 90°C or higher, carbon dioxide equivalent to 1/2 or more of lithium hydroxide is continuously blown into the crystallization tank. Converts lithium oxide to lithium carbonate and precipitates it as crystals. Lithium carbonate is separated and recovered from the obtained lithium carbonate slurry by a known separation means, washed and then dried at 60°C to 120°C by a well-known drying method. The amount of components lost on heating in the obtained lithium carbonate varies depending on the temperature of the lithium hydroxide aqueous solution at the time of crystallization, and the higher the liquid temperature, the smaller the amount. In other words, when the liquid temperature is 90°C or higher, the components lose weight on heating.
High purity lithium carbonate can be obtained with a heating loss component of 0.1% by weight or less and 0.05% by weight or less when the liquid temperature is 120°C or higher. In the crystallization tank, the lithium carbonate powder precipitated as crystals is dispersed by means such as stirring so that it is sufficiently suspended and dispersed without being deposited at the bottom of the tank. If the lithium carbonate powder is deposited due to insufficient dispersion, the amount of components lost on heating in the obtained lithium carbonate increases. Carbon dioxide is supplied continuously so that the crystallization time is at least 1 hour, preferably 3 hours or more. When carbon dioxide is rapidly supplied to precipitate lithium carbonate crystals so that the crystallization is completed within one hour, the amount of loss on heating of the resulting lithium carbonate powder increases. In the case of lithium hydroxide, in the second method, when crystals of lithium carbonate are precipitated from a 5 to 10% by weight aqueous solution of lithium hydroxide and carbon dioxide using the same crystallization tank, the crystallization of lithium carbonate is performed in the aqueous solution prior to the start of crystallization. Lithium carbonate powder is added to the solution, stirred and dispersed, and the temperature of the aqueous solution is heated to 70°C or higher, and carbon dioxide equivalent to one-half or more of the lithium hydroxide in the aqueous solution is blown into the solution to form crystals of lithium carbonate. Let it precipitate. With this method, it is possible to obtain lithium carbonate powder containing less than 0.1% by weight of components that lose weight on heating at a lower liquid temperature than with the first method, and at a liquid temperature of 100°C or higher, the components that lose weight on heating can be obtained.
It is possible to obtain lithium carbonate powder with extremely low heating loss components of 0.02% by weight or less. In this method as well, stirring and dispersion of the lithium carbonate powder in the crystallization tank and crystallization time are carried out in the same manner as in the first method. The lithium carbonate added prior to crystallization may be in the form of powder, but the average particle size is preferably 80 μm or less, more preferably 50 μm or less. The amount added is lithium carbonate, which is newly precipitated as crystals by crystallization.
5 to 100 parts by weight per 100 parts by weight, preferably 10 to 100 parts by weight
50 parts by weight. When the amount is less than 5 parts by weight, the effect of adding lithium carbonate powder prior to crystallization is small, and even when 100 parts by weight or more is added, no significant reduction in the component lost on heating is observed. The lithium carbonate powder to be added is lithium carbonate powder crystallized by the first method, lithium carbonate powder obtained by calcining commercially available high-purity lithium carbonate at a temperature of 550°C for 1 hour, or lithium carbonate powder separately crystallized by the second method. Use a material with a small amount of components that lose weight on heating, such as In these two methods, even if the lithium compound in the aqueous solution used for crystallization is lithium carbonate or lithium hydrogen carbonate, the component lost on heating depends on the precipitation behavior of lithium carbonate, so the same effect as in the case of lithium hydroxide can be obtained. . For example, in the case of a lithium carbonate aqueous solution with a saturated concentration or less, the aqueous solution is placed in a crystallization tank and the water is removed under reduced pressure to concentrate the lithium carbonate concentration to a saturated concentration or higher. Crystallize by heating above ℃. In the second method, prior to crystallization, lithium carbonate powder is added to the aqueous solution and the temperature of the aqueous solution is heated to 70° C. or higher to perform crystallization. By either method, lithium carbonate powder having a heating loss component of 0.1% by weight or less can be obtained. In the case of lithium hydrogen carbonate, the concentration is 5 to 8.
In the first method, a lithium hydrogen carbonate aqueous solution of 1% by weight is placed in a crystallization tank and carbon dioxide is desorbed by reduced pressure or nitrogen gas feed to convert it into lithium carbonate and precipitate lithium carbonate crystals. Decompose under reduced pressure and crystallize while maintaining the temperature. In the second method, prior to crystallization, lithium carbonate powder is added to the aqueous solution in the same manner as in the case of lithium hydroxide, and the temperature of the aqueous solution is heated to 70°C or higher to decompose the lithium hydrogen carbonate and crystallize lithium carbonate. is precipitated. By either method, lithium carbonate powder having a heating loss component of 0.1% by weight or less can be obtained. <Effects of the Present Invention> The present invention is the second method of the above two methods, and has the effects described below. By a simple and economical method of controlling the temperature of the crystallization solution and adding lithium carbonate powder, high-purity lithium carbonate with a heating loss component of 0.1% by weight or less, and even 0.02% by weight or less can be obtained. Since the solubility of lithium carbonate in water decreases as the temperature increases, the yield of lithium carbonate in the crystallization operation is greatly improved. No special firing equipment is required, there is no lithium carbonate contamination associated with the firing operation, and high-purity lithium carbonate with high product value can be obtained. Reference example 1 Crystallization tank with internal volume equipped with a stirrer, heating steam jacket, lithium compound aqueous solution feed port, lithium carbonate powder addition port, gas inlet, exhaust port, lithium carbonate slurry outlet, pressure gauge, etc. 30 pressure autoclave was used. The purified aqueous lithium hydroxide solution having a concentration of 5.2% by weight was poured into a crystallization tank through the aqueous solution feed port, and the liquid temperature was raised to 90°C over about 30 minutes while thoroughly stirring at a rotation speed of 600 rpm. While thoroughly stirring and maintaining the liquid temperature at 90℃, carbon dioxide gas was continuously supplied into the tank from the gas inlet at a flow rate of 2.2 per minute for 4 hours.
Lithium carbonate crystals were crystallized by reacting with lithium hydroxide. After the crystallization was completed, the lithium carbonate slurry was extracted from the crystallization tank and separated from water using a centrifuge, and the lithium carbonate cake was washed with 10 portions of 80°C warm water, and the lithium carbonate cake was vacuum-dried at 60°C for 12 hours. The weight change on heating of dry lithium carbonate was measured using a thermobalance, and the proportion of the weight loss on heating up to 550°C was taken as the weight loss component on heating. The yield of the obtained lithium carbonate powder was 74.4%, the average particle size was 47 μm, and the component lost on heating was 0.092%. Example 1 Using the same crystallization tank as used in Reference Example 1, purified lithium hydroxide aqueous solution with a concentration of 5.2% by weight was mixed with 20%
was poured into the crystallization tank through the aqueous solution feed port and the liquid temperature was raised to 80°C while stirring. 165 g of lithium carbonate powder having an average particle size of 43 μm and a heating loss component of 0.073% was added from the lithium carbonate powder inlet and thoroughly stirred to disperse it in the aqueous solution. While maintaining the liquid temperature at 80°C and stirring thoroughly, carbon dioxide gas was continuously supplied into the tank at a flow rate of 2.2 per minute for 4 hours to crystallize lithium carbonate crystals. Dry lithium carbonate powder was obtained in the same manner as in Reference Example 1. The recovery rate of the lithium carbonate powder was 70.2%, the average particle size was 52 μm, and the component lost on heating was 0.052%. Reference Example 2, Example 2 Crystallization and recovery were performed in the same manner as Reference Example 1 and Example 1, except that the same crystallization tank as in Reference Example 1 was used, and the liquid temperature and the amount of lithium carbonate powder added were changed. Ta.

【表】 参考例 3 参考例1に用いたのと同じ晶析槽を用い、濃度
1.1重量%の炭酸リチウム水溶液を20を水溶液
フイード口より晶析槽にいれ、実施例1で用いた
のと同じ炭酸リチウム粉末63g加え、十分撹拌し
ながら液温を90℃に昇温した。 十分撹拌し液温を90℃に保ちながら排気口より
排気し4時間かけて液量が約10となるまで水分
を蒸発させ炭酸リチウムの析出を行つた。 得られた炭酸リチウムスラリーを80℃の温水4
で洗浄する以外、参考例1と同様にして分離乾
燥させた。 炭酸リチウム粉末の収率は67.7%、平均粒径は
66μm、加熱減量成分は0.071%であつた。 参考例 4 参考例1で用いたのと同じ晶析槽を用いた。精
製した濃度8.0重量%の炭酸水素リチウム水溶液
を20を晶析槽にいれ、実施例1で用いたのと同
じ炭酸リチウム粉末89g加え、十分撹拌しながら
液温を90℃に昇温した。 液温を90℃に保ちながらガス吹き込み口よりア
ルゴンガスを毎分0.8入れ、炭酸水素リチウム
の分解により生じた二酸化炭素ガスを追い出しな
がら炭酸リチウムの晶析を行つた。晶析時間は約
2.5時間であつた。 得られた炭酸リチウムスラリーを参考例1と同
様に分離洗浄乾燥した。 平均粒径51μm、加熱減量成分は0.058%の炭酸
リチウム粉末が収率77.0%で得られた。 比較例1、参考例5〜7 参考例に用いたのと同じ晶析槽を使用し、炭酸
リチウム粉末を添加せず、リチウム化合物水溶液
の液温を次のようにする以外は実施例と同様に炭
酸リチウムの晶析を行つた。
[Table] Reference Example 3 Using the same crystallization tank as that used in Reference Example 1, the concentration
20 g of a 1.1% by weight aqueous lithium carbonate solution was put into the crystallization tank from the aqueous solution feed port, 63 g of the same lithium carbonate powder as used in Example 1 was added, and the liquid temperature was raised to 90° C. with thorough stirring. While thoroughly stirring and maintaining the liquid temperature at 90°C, the mixture was evacuated from the exhaust port and water was evaporated over 4 hours until the liquid volume became about 10%, thereby precipitating lithium carbonate. The obtained lithium carbonate slurry was soaked in 80℃ hot water 4
Separation and drying was carried out in the same manner as in Reference Example 1 except for washing with. The yield of lithium carbonate powder is 67.7%, the average particle size is
The diameter was 66 μm, and the weight loss component on heating was 0.071%. Reference Example 4 The same crystallization tank as used in Reference Example 1 was used. Twenty grams of purified lithium hydrogen carbonate aqueous solution having a concentration of 8.0% by weight was placed in a crystallization tank, 89 g of the same lithium carbonate powder as used in Example 1 was added, and the liquid temperature was raised to 90° C. with thorough stirring. While maintaining the liquid temperature at 90°C, argon gas was introduced through the gas inlet at a rate of 0.8 times per minute, and lithium carbonate was crystallized while expelling carbon dioxide gas generated by decomposition of lithium hydrogen carbonate. Crystallization time is approx.
It was hot for 2.5 hours. The obtained lithium carbonate slurry was separated, washed and dried in the same manner as in Reference Example 1. Lithium carbonate powder with an average particle size of 51 μm and a heating loss component of 0.058% was obtained in a yield of 77.0%. Comparative Example 1, Reference Examples 5 to 7 Same as the example except that the same crystallization tank as used in the reference example was used, lithium carbonate powder was not added, and the temperature of the lithium compound aqueous solution was set as follows. lithium carbonate was crystallized.

【表】 ウム水溶液
得られた炭酸リチウム粉末の収率、平均粒径、
加熱減量成分は次の通りであつた。
[Table] Um aqueous solution
Yield, average particle size, of the obtained lithium carbonate powder,
The components that lost weight on heating were as follows.

【表】【table】

Claims (1)

【特許請求の範囲】 1 水酸化リチウム水溶液より、晶析により炭酸
リチウムの粉末を得るに際し、5〜10重量%の水
酸化リチウム水溶液に、晶析の開始に先立つて該
水酸化リチウム水溶液中に晶析により生成する炭
酸リチウム100重量部あたり10〜50重量部の炭酸
リチウム粉末を添加し撹拌分散させ、且つ該水酸
化リチウム水溶液を70℃以上に加温し、次いで二
酸化炭素を吹込みながら晶析することを特徴とす
る炭酸リチウム粉末の製造方法。 2 晶析の開始に先立つて添加する炭酸リチウム
粉末の平均粒径が80μm以下である特許請求の範
囲第1項記載の炭酸リチウム粉末の製造方法。
[Claims] 1. When obtaining lithium carbonate powder by crystallization from an aqueous lithium hydroxide solution, a 5 to 10% by weight lithium hydroxide aqueous solution is added to the lithium hydroxide aqueous solution prior to the start of crystallization. 10 to 50 parts by weight of lithium carbonate powder is added to 100 parts by weight of lithium carbonate produced by crystallization, stirred and dispersed, and the lithium hydroxide aqueous solution is heated to 70°C or higher, and then crystallized while blowing carbon dioxide. 1. A method for producing lithium carbonate powder, the method comprising analyzing lithium carbonate powder. 2. The method for producing lithium carbonate powder according to claim 1, wherein the lithium carbonate powder added prior to the start of crystallization has an average particle size of 80 μm or less.
JP7144585A 1985-04-04 1985-04-04 Production of lithium carbonate powder Granted JPS61232205A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP7144585A JPS61232205A (en) 1985-04-04 1985-04-04 Production of lithium carbonate powder

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP7144585A JPS61232205A (en) 1985-04-04 1985-04-04 Production of lithium carbonate powder

Publications (2)

Publication Number Publication Date
JPS61232205A JPS61232205A (en) 1986-10-16
JPH0360772B2 true JPH0360772B2 (en) 1991-09-17

Family

ID=13460754

Family Applications (1)

Application Number Title Priority Date Filing Date
JP7144585A Granted JPS61232205A (en) 1985-04-04 1985-04-04 Production of lithium carbonate powder

Country Status (1)

Country Link
JP (1) JPS61232205A (en)

Also Published As

Publication number Publication date
JPS61232205A (en) 1986-10-16

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