JPH0971415A - Production of spherical rare-earth metal oxide - Google Patents
Production of spherical rare-earth metal oxideInfo
- Publication number
- JPH0971415A JPH0971415A JP7224916A JP22491695A JPH0971415A JP H0971415 A JPH0971415 A JP H0971415A JP 7224916 A JP7224916 A JP 7224916A JP 22491695 A JP22491695 A JP 22491695A JP H0971415 A JPH0971415 A JP H0971415A
- Authority
- JP
- Japan
- Prior art keywords
- rare earth
- oxalate
- spherical
- rare
- earth metal
- 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.)
- Granted
Links
Landscapes
- Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
- Luminescent Compositions (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は蛍光体原料として有
用な球状希土類酸化物の製造方法に関するものである。TECHNICAL FIELD The present invention relates to a method for producing a spherical rare earth oxide useful as a phosphor raw material.
【０００２】[0002]
【従来の技術】希土類酸化物は蛍光ランプ、CRT などの
蛍光体の原料として用いられているが、蛍光体としては
粒子の形状が球状に近いほど塗布性能、発光効率共に良
く、球状希土類酸化物粒子に対する要望は強い。蛍光体
は一般に希土類酸化物と蛍光体の種類によって必要な他
の元素（Ｓ、Ｐ、Ｓi 、Ｂ、Ａl 等）の原料および融剤
とを粉体で混合して焼成して得られるが、希土類酸化物
の粒子が球状であればそれを使って得られ蛍光体の粒子
も大部分が球状になる。特開平３−271117号公報、特開
平３−271118号公報には、反応温度を20℃以下に保つこ
とで球状希土類蓚酸塩粒子が得られ、それを焼成するこ
とで球状希土類酸化物が得られることが開示されてい
る。しかしこれらの実施例は全て濾別した蓚酸塩の沈殿
を、付着水分を除去する目的でメタノールで洗浄してい
るが、工業化を考えた場合、作業環境面、また排水公害
対策としてメタノールを流出させないための回収再生の
コストなどの問題があり、また引き続き行う焼成工程の
前にメタノールを完全に揮発させておかないと焼成炉内
で爆発の危険性があることからも大量生産には不向きで
ある。2. Description of the Related Art Rare earth oxides are used as a raw material for fluorescent materials such as fluorescent lamps and CRTs. However, as the shape of the particles of the fluorescent material is closer to spherical, the coating performance and the luminous efficiency are better. The demand for particles is strong. Phosphors are generally obtained by mixing powders of rare earth oxides and raw materials of other elements (S, P, Si, B, Al, etc.) necessary depending on the type of phosphor and a flux, and firing. If the particles of the rare earth oxide are spherical, most of the particles of the phosphor obtained by using them are also spherical. In JP-A-3-271117 and JP-A-3-271118, spherical rare earth oxalate particles are obtained by keeping the reaction temperature at 20 ° C. or lower, and spherical rare earth oxides are obtained by firing the particles. It is disclosed. However, in all of these examples, the filtered oxalate precipitate is washed with methanol for the purpose of removing adhering water, but when considering industrialization, methanol is not allowed to flow out as a work environment and as a wastewater pollution countermeasure. Therefore, it is not suitable for mass production because there is a problem such as the cost of recovery and regeneration, and there is a danger of explosion in the firing furnace unless methanol is completely volatilized before the subsequent firing step. .
【０００３】[0003]
【発明が解決しようとする課題】本発明は上記諸欠点を
解決した製造方法であり、球状の整った粒子を安定かつ
容易に得られる製造方法を提供しようとするものであ
る。DISCLOSURE OF THE INVENTION The present invention is a manufacturing method which solves the above-mentioned various drawbacks, and an object of the invention is to provide a manufacturing method capable of stably and easily obtaining spherical regular particles.
【０００４】[0004]
【課題を解決するための手段】本発明者等は、前記課題
を解決するために検討を重ね、大量処理、工業化の容易
な球状希土類酸化物の製造方法を見出し、整った球状粒
子を安定かつ容易に得られる製造条件を確立し、本発明
を完成させたもので、その要旨は、希土類イオンと蓚酸
イオンとの反応において、反応系を−５℃以上20℃以下
に保って反応させ、生成した希土類蓚酸塩を前記温度範
囲下に所定時間保持した後沈殿を分離し、該沈殿を水に
分散、懸濁させ、該懸濁液を噴霧乾燥法によって乾燥し
た後、焼成することを特徴とする球状希土類酸化物の製
造方法、並びに噴霧乾燥の条件が、ｌ）噴霧乾燥方式を
直径20〜 200mmの高速回転している円盤上に希土類蓚酸
塩懸濁液を滴下することにより液滴とし、熱風で乾燥す
る方式とする、２）噴霧乾燥にかける希土類蓚酸塩懸濁
液濃度を希土類元素濃度で 0.2〜3.0mol/Lとする、３）
回転円盤の回転速度を7000〜25000rpmとする、４）熱風
温度を120〜 300℃とする、５）熱風の単位時間当たり
供給量を供給懸濁液の５万〜 100万倍体積とする、の５
項目からなる球状希土類酸化物の製造方法にある。Means for Solving the Problems The inventors of the present invention have conducted extensive studies to solve the above problems, and have found a method for producing spherical rare earth oxides that can be easily mass-produced and industrialized. The present invention has been completed by establishing easily obtainable production conditions, and the gist thereof is that in the reaction of a rare earth ion and an oxalate ion, the reaction system is kept at -5 ° C or higher and 20 ° C or lower to generate a product. The obtained rare earth oxalate is held in the temperature range for a predetermined time, and then the precipitate is separated, the precipitate is dispersed and suspended in water, and the suspension is dried by a spray drying method, and then baked. The method for producing a spherical rare earth oxide and the conditions for spray drying are as follows: 1) The spray drying method is used to form a droplet by dropping a rare earth oxalate suspension onto a disc rotating at a high speed with a diameter of 20 to 200 mm, 2) Spraying with hot air drying method Rare earth oxalate suspension concentration for fog drying is 0.2-3.0mol / L in rare earth element concentration 3)
The rotation speed of the rotating disk is 7,000 to 25,000 rpm, 4) the hot air temperature is 120 to 300 ° C., and 5) the supply amount of hot air per unit time is 50,000 to 1,000,000 times the volume of the supply suspension. 5
It is a method for producing a spherical rare earth oxide consisting of items.
【０００５】以下、本発明を詳細に説明する。本発明の
適用範囲は、希土類としてはイットリウムおよび原子番
号が57〜71のランタノイドであり、特にランタノイドの
内原子番号63（ユウロピウム）以上の元素とイットリウ
ムである。本発明における球状とは真球、および短径に
対する長径の比が1.5 以下の略球形の粒子を意味する。
これは用途上充分な範囲であり、また大部分の粒子がこ
のような粒子で構成される球状希土類酸化物は、通常の
不定形粒子からなるものと比べて流動性が良く、従って
その指標である安息角は小さく、また嵩密度は大きい。
平均粒径（Ｄ50）は体積基準で表わしたもので、全粒子
体積の50％が平均粒径以下の粒子で占められる。粒度分
布の測定法はコールターカウンター（コールター社製商
品名）を用いた。安息角は傾斜法で測定した。嵩密度は
ゆるみ見掛け比重である。また非凝集とは、個々の粒子
が独立して存在しており、実質的に凝集部分が無いこと
を意味する。Hereinafter, the present invention will be described in detail. The scope of application of the present invention is yttrium as a rare earth and lanthanoids having an atomic number of 57 to 71, and particularly, yttrium and an element having an atomic number of 63 (europium) or more of the lanthanoids. The spherical shape in the present invention means a true spherical shape and a substantially spherical particle having a ratio of the major axis to the minor axis of 1.5 or less.
This is a sufficient range for applications, and spherical rare earth oxides, which are mostly composed of such particles, have better fluidity than those composed of ordinary irregularly shaped particles, and therefore, they are used as indicators. Some angles of repose are small and bulk density is large.
The average particle size (D 50 ) is expressed on a volume basis, and 50% of the total particle volume is occupied by particles having an average particle size or less. A Coulter counter (trade name, manufactured by Coulter, Inc.) was used for measuring the particle size distribution. The angle of repose was measured by the tilt method. Bulk density is the apparent apparent specific gravity. In addition, non-aggregation means that individual particles exist independently and that there is substantially no aggregation portion.
【０００６】球状希土類酸化物の製造方法としては、ま
ず、希土類イオンと蓚酸イオンとを、−５℃以上20℃以
下の温度で反応させ、球状の希土類元素蓚酸塩を沈殿さ
せる。希土類イオン源としては、希土類の塩化物、硝酸
塩等の水に可溶性の化合物の水溶液が挙げられる。希土
類元素の種類は１種でも、２種以上でも良く、また全希
土類濃度はあまり低いと生産性が悪いので、通常0.02mo
l/L 以上、好ましくは0.05〜0.5mol/Lの範囲が良い。蓚
酸イオン源としては、蓚酸あるいは蓚酸アンモニウム、
蓚酸ナトリウム等の水溶性蓚酸塩の水溶液または粉体が
使用できるが、蓚酸金属塩は蛍光体用原料としては一般
にアルカリ金属等の混入は嫌われるので好ましくなく、
また蓚酸アンモニウムは特公昭57−035853号等に記載さ
れているように NH4R(C2O4)2（ここにＲは希土類元素）
という複塩を生成し、これは球状にならないので好まし
くなく、蓚酸を用いるのが良い。As a method for producing a spherical rare earth oxide, first, a rare earth ion and an oxalate ion are reacted at a temperature of -5 ° C to 20 ° C to precipitate a spherical rare earth oxalate. Examples of the rare earth ion source include aqueous solutions of water-soluble compounds such as rare earth chlorides and nitrates. The number of rare earth elements may be one, two or more, and productivity is poor if the total rare earth concentration is too low.
It is preferably l / L or more, preferably 0.05 to 0.5 mol / L. As the oxalate ion source, oxalic acid or ammonium oxalate,
Although an aqueous solution or powder of a water-soluble oxalate such as sodium oxalate can be used, metal oxalate is not preferable as a raw material for a phosphor because it is generally disliked to mix alkali metal or the like,
Ammonium oxalate is NH 4 R (C 2 O 4 ) 2 (where R is a rare earth element) as described in JP-B-57-035853.
This is not preferable because it produces a double salt, which does not become spherical, and it is preferable to use oxalic acid.
【０００７】蓚酸イオンの量は希土類総量に対してモル
比で 1.5〜2.0 の範囲が良い。1.5未満では希土類が完
全に沈殿せず収率が悪く、また2.0 あれば十分である。
反応を行うには希土類の水溶液、蓚酸水溶液を調整し、
いずれも−５℃以上20℃以下に保ってから混合する。こ
の混合時の温度は重要であり、低温ほど球形度の良いも
のが得られる傾向があるので、好ましくは反応系水溶液
の凝固点以上で10℃以下とするのが良い。希土類水溶液
と蓚酸水溶液の混合速度は粒径に大きな影響を及ぼすの
で、後から加える方の全液量を１〜30分間で加えるのが
良い。時間が長いほど粒径が大きくなり、極端に短いと
粒子が微細になり球状になりにくい。但し蓚酸を固形で
加える場合、徐々に溶解した蓚酸が反応してゆくので、
速く加えても良い。The amount of oxalate ions is preferably in the range of 1.5 to 2.0 with respect to the total amount of rare earths. If it is less than 1.5, the rare earth is not completely precipitated and the yield is poor, and 2.0 is sufficient.
To carry out the reaction, prepare an aqueous solution of rare earth and an aqueous solution of oxalic acid,
In either case, keep the temperature above -5 ° C and below 20 ° C before mixing. The temperature at the time of this mixing is important, and the lower the temperature, the better the sphericity tends to be obtained. Since the mixing speed of the rare earth aqueous solution and the oxalic acid aqueous solution has a great influence on the particle size, it is advisable to add the total amount of liquid to be added later in 1 to 30 minutes. If the time is long, the particle size becomes large, and if it is extremely short, the particle becomes fine and it is difficult to be spherical. However, when adding oxalic acid as a solid, gradually dissolved oxalic acid reacts,
You can add it quickly.
【０００８】生成沈殿した球状希土類蓚酸塩はスラリー
状のまま噴霧乾燥を行う。このスラリーには純度低下や
乾燥中の形状崩れを防ぐため、球状希土類蓚酸塩および
水以外に可溶性塩などの共存物がなるべく含まれない方
がよい。そこで沈殿生成後、母液と遠心分離、濾過など
によって分離し、さらに必要ならば水洗した後、再び純
水を加えて分散懸濁して噴霧乾燥用のスラリーとする
か、または、沈殿生成した液を静置するなどして沈殿を
沈降させた後、上澄液を捨て、純水を加えて撹拌してス
ラリーとすればよい（必要に応じてこの操作を繰り返
す）。これらの洗浄、希釈、分散懸濁に用いられる水の
温度は20℃以下、好ましくは15℃以下であることが望ま
しい。20℃を超える水を用いると、蓚酸塩粒子の形状が
崩れるおそれがある。また、噴霧乾燥にかけるスラリー
は希土類元素の濃度で0.2〜3.0mol/Lの範囲になるよう
に調整する必要がある。0.2mol/L未満では生産性が悪い
のみならず、噴霧乾燥に持ち込む水分が多すぎて、蓚酸
塩の水分除去が不十分になるおそれがあり、また3.0mol
/Lを超えると、スラリーの粘度が高すぎて噴霧乾燥を行
うのに必要な流動性が得られなくなる。スラリーに共存
する水溶性成分に関しては、濾過などによって一度固液
分離を行った後に水に再分散する場合は実質的に問題は
ない。静置沈降などで上澄液を捨てる方法の場合、蓚酸
濃度および塩濃度が希土類元素濃度の10分の１以下にな
っていることが必要で、操作としては水を加えて撹拌
し、静置沈降後に上澄液を捨てることを２〜３回以上行
えばよい。酸類や塩類が残留している場合、噴霧乾燥装
置の腐食の恐れがあると共に、乾燥後の球状希土類蓚酸
塩に多く残留した場合、次の焼成工程で粒子形状が崩れ
る原因になったり、あるいはその成分によっては焼成後
も不純物として残留するので純度低下となり蛍光体原料
として不適となる場合もある。The formed and precipitated spherical rare earth oxalate is spray-dried in a slurry form. In order to prevent deterioration of purity and shape collapse during drying, it is preferable that the slurry contain as little as possible a coexisting substance such as a soluble salt in addition to the spherical rare earth oxalate and water. Therefore, after the precipitate is formed, it is separated from the mother liquor by centrifugation, filtration, etc., and further washed with water if necessary, and then pure water is added again to disperse and suspend it to form a slurry for spray drying, or After allowing the precipitate to settle by allowing it to stand still, the supernatant may be discarded, pure water may be added, and the mixture may be stirred to form a slurry (this operation is repeated if necessary). It is desirable that the temperature of water used for these washing, dilution, and dispersion suspension is 20 ° C. or lower, preferably 15 ° C. or lower. If water above 20 ° C. is used, the shape of the oxalate particles may collapse. Further, it is necessary to adjust the slurry for spray drying so that the concentration of the rare earth element is in the range of 0.2 to 3.0 mol / L. If it is less than 0.2 mol / L, not only productivity is poor, but too much water is brought into spray drying, which may result in insufficient water removal of the oxalate.
When it exceeds / L, the viscosity of the slurry is too high and the fluidity required for spray drying cannot be obtained. With respect to the water-soluble components that coexist in the slurry, there is substantially no problem when solid-liquid separation is once performed by filtration or the like and then redispersed in water. In the case of the method of discarding the supernatant by static sedimentation, etc., it is necessary that the oxalic acid concentration and the salt concentration be 1/10 or less of the rare earth element concentration. After the sedimentation, the supernatant may be discarded 2-3 times or more. If acids and salts remain, there is a risk of corrosion of the spray dryer, and if a large amount of spherical rare earth oxalate remains after drying, it may cause the particle shape to collapse in the next firing step, or Since some components remain as impurities even after firing, the purity may be lowered and the phosphor may not be suitable as a raw material.
【０００９】噴霧乾燥方法は、高速回転している円盤上
にスラリーを滴下し、遠心力で高速で切線方向に振り切
って微細な液滴とし、高温熱風で素早く乾燥させる一般
的な乾燥方式であるが、本発明では低温晶出させた球状
希土類蓚酸塩に最適の乾燥条件を確立した。この場合、
直径20〜200mm の円盤を使用し、円盤の回転数は7000〜
25000rpm、熱風温度 120〜 300℃、熱風の単位時間当
たりの供給量は供給スラリーの50,000〜 1,000,000倍体
積が望ましい条件である。円盤の回転数が7000rpm 未満
では生成液滴の大きさが大きくなり過ぎ、そのために脱
水、乾燥の初期速度が遅くなって、粒子形状が崩れる恐
れがある。また25000rpmを超えると粒径制御効果がな
く、乾燥効率も上がらず装置に負担をかけるのみであ
る。熱風温度は 120℃未満ではスラリーからの脱水が遅
く、粒子形状が崩れ易くなる。また 300℃を超えても乾
燥効率は上がらず不経済なだけである。熱風供給量がス
ラリー供給量に対して上記の範囲より少ないと乾燥が遅
く、粒子形状が崩れる恐れがあるが、上記の範囲を超え
ても効果はなく不経済である。The spray-drying method is a general drying method in which a slurry is dropped on a disk rotating at a high speed, centrifugally shaken at high speed in a cutting line direction to form fine liquid droplets, which are quickly dried by hot hot air. However, in the present invention, optimum drying conditions have been established for low-temperature crystallized spherical rare earth oxalates. in this case,
A disk with a diameter of 20 to 200 mm is used, and the rotation speed of the disk is 7000 to
The conditions are 25000 rpm, hot air temperature 120 to 300 ° C, and the supply amount of hot air per unit time is 50,000 to 1,000,000 times the volume of the supplied slurry. If the rotation speed of the disk is less than 7000 rpm, the size of the generated droplets becomes too large, which may slow down the initial speed of dehydration and drying and cause the particle shape to collapse. Further, if it exceeds 25,000 rpm, there is no particle size control effect, the drying efficiency does not increase, and only a load is imposed on the device. If the hot air temperature is less than 120 ° C, dehydration from the slurry is slow and the particle shape is likely to collapse. Moreover, even if the temperature exceeds 300 ° C, the drying efficiency does not increase and it is only uneconomical. When the amount of hot air supplied is less than the above range with respect to the amount of slurry supplied, drying may be slow and the particle shape may collapse, but if it exceeds the above range, no effect is obtained and it is uneconomical.
【００１０】噴霧乾燥によって水分を除去した希土類蓚
酸塩を 600℃以上の温度で焼成すれば、球状希土類酸化
物が得られる。乾燥が十分なされていれば、焼成条件は
限定的ではないが、好ましくは昇温速度は 600℃／hrで
あることが望ましい。Spherical rare earth oxides can be obtained by firing the rare earth oxalate from which water has been removed by spray drying at a temperature of 600 ° C. or higher. If the drying is sufficient, the firing conditions are not limited, but the rate of temperature increase is preferably 600 ° C./hr.
【００１１】[0011]
【発明の実施の形態】本発明の作用は、低温晶出された
球状希土類蓚酸塩の球形を保持したまま乾燥しようとい
うもので、噴霧乾燥法により高温熱風で瞬時にスラリー
液滴を脱水すれば粒子界面の溶解による形状崩れを起こ
す暇もなく乾燥させることができるというものである。
以下、本発明の実施形態を実施例と比較例を挙げて具体
的に説明するが、本発明はこれらに限定されるものでは
ない。BEST MODE FOR CARRYING OUT THE INVENTION The function of the present invention is to dry a spherical rare earth oxalate crystallized at low temperature while maintaining the spherical shape. If slurry droplets are instantly dehydrated by high temperature hot air by a spray drying method. It can be dried without time to lose the shape due to the dissolution of the particle interface.
Hereinafter, the embodiments of the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited thereto.
【００１２】[0012]
（実施例１）濃度0.3mol/L、pH 1.5の硝酸イットリウム
水溶液 4.5Ｌをバッフル、温度計、撹拌翼を取り付けた
10Ｌビーカー中に仕込み、５℃に保持した。濃度0.5mol
/Lの蓚酸水溶液 4.5Ｌを別に調整して７℃に保持した。
300rpmで撹拌しながら蓚酸水溶液全量を７分かけて添加
した。さらに５分間撹拌を続けた後生成した希土類蓚酸
塩の沈殿をブフナー濾斗で濾別し、10℃の水３Ｌで振り
かけ洗浄した。この希土類蓚酸塩を回収し、２Ｌビーカ
ーに移し入れ、撹拌しながら５℃の水450mL を加えて均
一なスラリーを調整した。このスラリーを噴霧乾燥機に
かけた。回転円盤は直径55mmのものを用い、回転数は 1
3000rpm 、熱風温度200 ℃、熱風供給量3.5ｍ3/minで運
転した。スラリーは緩やかに撹拌しながら定量ポンプで
一定速度で供給し、全量 800mLの供給に30分要した。46
3gの球状粒子からなる乾燥希土類蓚酸塩を得た。ついで
この乾燥蓚酸塩を石英製の容器に入れて電気炉にセット
し、２時間かけて 850℃まで昇温し、引き続き１時間 8
50℃に保った後放冷して203gの酸化イットリウムを得
た。（乾燥蓚酸塩／酸化物＝2.28（重量比）） この酸化物を電子顕微鏡で観察したところ非凝集性で球
状の粒子からなっており、平均粒径 6.9μm 、安息角37
°、嵩密度1.51g/cm3 であった。(Example 1) 4.5 L of an yttrium nitrate aqueous solution having a concentration of 0.3 mol / L and a pH of 1.5 was equipped with a baffle, a thermometer, and a stirring blade.
The mixture was placed in a 10 L beaker and kept at 5 ° C. 0.5 mol
4.5 L of an aqueous oxalic acid solution of / L was separately prepared and kept at 7 ° C.
The total amount of the oxalic acid aqueous solution was added over 7 minutes while stirring at 300 rpm. After continuing stirring for further 5 minutes, the precipitate of the rare earth oxalate formed was filtered off with a Buchner funnel and sprinkled with 3 L of water at 10 ° C. to wash. This rare earth oxalate was recovered, transferred to a 2 L beaker, and 450 mL of water at 5 ° C. was added with stirring to prepare a uniform slurry. The slurry was spray dried. The rotating disk has a diameter of 55 mm and the number of rotations is 1
It was operated at 3000 rpm, hot air temperature of 200 ° C., and hot air supply rate of 3.5 m 3 / min. The slurry was fed at a constant rate with a metering pump while gently stirring, and it took 30 minutes to feed the total amount of 800 mL. 46
A dry rare earth oxalate consisting of 3 g of spherical particles was obtained. Then put this dry oxalate in a quartz container and set it in an electric furnace, raise the temperature to 850 ° C over 2 hours, and continue for 1 hour 8
The mixture was kept at 50 ° C. and then left to cool to obtain 203 g of yttrium oxide. (Dry oxalate / oxide = 2.28 (weight ratio)) This oxide was observed by an electron microscope and found to be non-aggregating and spherical particles with an average particle size of 6.9 μm and a repose angle of 37.
The bulk density was 1.51 g / cm 3 .
【００１３】（実施例２）濃度0.3mol/L、pH 1.4の硝酸
イットリウムと硝酸ユウロピウム混合水溶液（Ｅu ／Ｙ
＝0.034 モル比）を用いることのほかは実施例１と同様
にして、473gの球状粒子からなる乾燥蓚酸塩を得た。そ
れを実施例１と同様に焼成してイットリウム、ユウロピ
ウム混合酸化物206gを得た。電子顕微鏡で観察したとこ
ろ非凝集性で球状の粒子からなっており、平均粒径 6.7
μm 、安息角39°、嵩密度1.49g/cm3 であった。Example 2 A mixed aqueous solution of yttrium nitrate and europium nitrate (Eu / Y) having a concentration of 0.3 mol / L and pH 1.4.
= 0.034 molar ratio) and in the same manner as in Example 1 to obtain 473 g of dry oxalate composed of spherical particles. It was fired in the same manner as in Example 1 to obtain 206 g of a mixed oxide of yttrium and europium. Observation with an electron microscope revealed that it consisted of non-aggregating, spherical particles with an average particle size of 6.7.
The particle size was μm, the angle of repose was 39 °, and the bulk density was 1.49 g / cm 3 .
【００１４】（実施例３）濃度0.3mol/L、pH 1.3の硝酸
ガドリニウム水溶液を用いることのほかは実施例１と同
様にして、580gの球状粒子からなる乾燥蓚酸塩を得た。
これを実施例１と同様に焼成して酸化ガドリニウム326g
を得た。電子顕微鏡で観察したところ非凝集性で球状の
粒子からなっており、平均粒径 7.0μm 、安息角39°、
嵩密度1.49g/cm3 であった。Example 3 Dry oxalate consisting of 580 g of spherical particles was obtained in the same manner as in Example 1 except that a gadolinium nitrate aqueous solution having a concentration of 0.3 mol / L and pH 1.3 was used.
This was fired in the same manner as in Example 1 to give 326 g of gadolinium oxide.
I got Observed with an electron microscope, it consists of non-aggregating and spherical particles, with an average particle size of 7.0 μm, repose angle of 39 °,
The bulk density was 1.49 g / cm 3 .
【００１５】（比較例１）実施例１と同条件で沈殿生
成、分離、洗浄した蓚酸塩を乾燥工程を設けることなく
そのまま石英容器に入れた。この時蓚酸塩の極少量を採
取し、電子顕微鏡で観察したところ、非凝集性で球状の
粒子からなっていた。これを実施例１と同条件で焼成し
て204gの酸化イットリウムを得た。電子顕微鏡で観察し
たところ、棒状、板状、不定形の粒子からなっており、
平均粒径 3.2μm 、安息角70°以上で測定困難、嵩密度
0.53g/cm3 であった。(Comparative Example 1) Under the same conditions as in Example 1, the oxalate salt which had been precipitated, separated and washed was placed in a quartz container as it was without a drying step. At this time, a very small amount of oxalate was collected and observed by an electron microscope, and it was found to be non-aggregating and spherical particles. This was fired under the same conditions as in Example 1 to obtain 204 g of yttrium oxide. When observed with an electron microscope, it consists of rod-shaped, plate-shaped, and amorphous particles,
Average particle size 3.2 μm, angle of repose above 70 °, difficult to measure, bulk density
It was 0.53 g / cm 3 .
【００１６】（比較例２）実施例１と同条件で沈殿生
成、分離、洗浄した蓚酸塩を 110℃に保った送風乾燥機
中に24時間置いた。この段階で蓚酸塩の極少量を採取
し、電子顕微鏡で観察したところ、球状粒子は見られ
ず、微細から粗大までさまざまなサイズの角張った粒子
からなっていた。重量は501gであった。この蓚酸塩を実
施例１と同条件で焼成して204gの酸化イットリウムを得
た。（乾燥蓚酸塩／酸化物＝2.46（重量比））電子顕微
鏡で観察したところ、棒状、板状、不定形の粒子からな
っており、平均粒径10.4μm 、安息角68°、嵩密度0.72
g/cm3 であった。(Comparative Example 2) Under the same conditions as in Example 1, the oxalate salt which had been precipitated, separated and washed was placed in a blow dryer kept at 110 ° C for 24 hours. At this stage, a very small amount of oxalate was collected and observed with an electron microscope. As a result, spherical particles were not seen, and it consisted of angular particles of various sizes from fine to coarse. The weight was 501 g. This oxalate salt was calcined under the same conditions as in Example 1 to obtain 204 g of yttrium oxide. (Dry oxalate / oxide = 2.46 (weight ratio)) When observed with an electron microscope, it consisted of rod-shaped, plate-shaped, and amorphous particles, average particle size 10.4 μm, repose angle 68 °, bulk density 0.72.
It was g / cm 3 .
【００１７】（比較例３）実施例ｌと同条件で沈殿生
成、分離、洗浄した蓚酸塩を回収し、10Ｌビーカーに入
れ、撹拌しながら５℃の水９Ｌを加えて均一なスラリー
を調製した。このスラリーを噴霧乾燥機にかけた。スラ
リー濃度とスラリー供給時間以外の、噴霧乾燥機の運転
条件は実施例ｌと同様とし、スラリーは緩やかに撹拌し
ながら定量ポンプで一定速度で供給し、全量略 9.4Ｌの
供給に 4.5時間要した。 475grの乾燥蓚酸塩を得た。こ
の段階で蓚酸塩の極く少量を採取し、電子顕微鏡で観察
したところ、球状粒子が全体積の凡そ半分ほどは見られ
るものの、角張った粒子がかなり混在していた。この蓚
酸塩を実施例ｌと同条件で焼成して 199grの酸化イット
リウムを得た。電子顕微鏡で観察したところ、球状粒子
は僅かしかなく、多くは株状、板状、不定形の粒子から
なっており、平均粒径 7.4μｍ、安息角69゜、嵩密度0.
66gr/cm3であった。(Comparative Example 3) Under the same conditions as in Example 1, precipitation, separation and washing of the washed oxalate salt were carried out, placed in a 10 L beaker and 9 L of water at 5 ° C was added with stirring to prepare a uniform slurry. . The slurry was spray dried. Except for the slurry concentration and slurry supply time, the operating conditions of the spray dryer were the same as in Example 1, the slurry was supplied at a constant rate with a metering pump while gently stirring, and it took 4.5 hours to supply the total volume of approximately 9.4L. . 475 gr of dry oxalate was obtained. At this stage, a very small amount of oxalate was collected and observed with an electron microscope. As a result, spherical particles were found to be about half of the total volume, but angular particles were considerably mixed. This oxalate was calcined under the same conditions as in Example 1 to obtain 199 gr of yttrium oxide. Observation with an electron microscope revealed that there were few spherical particles, most of which consisted of plant-shaped, plate-shaped, and amorphous particles, with an average particle size of 7.4 μm, repose angle of 69 °, and bulk density of 0.
It was 66 gr / cm 3 .
【００１８】（比較例４）実施例ｌと同条件で沈殿生
成、分離、洗浄した蓚酸塩を回収し、実施例ｌと略同濃
度になるようにスラリーを調整した。これを円盤の回転
数が 6000rpmであることのほかは実施例ｌと同条件で噴
霧乾燥にかけた。スラリーの供給は全量約 800mlに32分
かかった。 486grの乾燥蓚酸塩を得た。この段階で蓚酸
塩の極く少量を採取し、電子顕微鏡で観察したところ、
球状粒子も僅かにみられるものの、棒状、板状、不定形
の粒子が大部分であった。この蓚酸塩を実施例ｌと同条
件で焼成して 202grの酸化イットリウムを得た。平均粒
径 7.9μｍ、安息角70゜以上で測定困難、嵩密度0.62/c
m3であった。(Comparative Example 4) Under the same conditions as in Example 1, precipitation, separation and washing of the oxalate salt were recovered, and the slurry was adjusted so as to have substantially the same concentration as in Example 1. This was subjected to spray drying under the same conditions as in Example 1 except that the rotation speed of the disk was 6000 rpm. It took 32 minutes to supply the total amount of slurry of about 800 ml. 486 gr of dry oxalate was obtained. At this stage, a very small amount of oxalate was collected and observed with an electron microscope.
Although spherical particles were slightly observed, most of them were rod-shaped, plate-shaped, and amorphous particles. The oxalate salt was calcined under the same conditions as in Example 1 to obtain 202 gr of yttrium oxide. Average particle size 7.9μm, repose angle 70 ° or more, measurement is difficult, bulk density 0.62 / c
It was m 3 .
【００１９】（比較例５）
１ 実施例ｌと同条件で沈殿生成、分離、洗浄した蓚酸塩を
回収し、実施例ｌと略同濃度になるようにスラリーを調
整した。これを熱風温度が 100℃であることのほかは実
施例ｌと同条件で噴霧乾燥にかけた。スラリーの供給は
全量約 800mlに32分かかった。 518grの乾燥蓚酸塩を得
た。この段階で蓚酸塩の極く少量を採取し、電子顕微鏡
で観察したところ、球状粒子は見られず、棒状、板状、
不定形の粒子からなっていた。この蓚酸塩を実施例ｌと
同条件で焼成して 205grの酸化イットリウムを得た。平
均粒径 4.9μｍ、安息角70゜以上で測定困難、嵩密度0.
55/cm3であった。(Comparative Example 5)
1 Under the same conditions as in Example 1, the oxalate salt that had been precipitated, separated, and washed was recovered, and the slurry was adjusted so that the concentration was approximately the same as in Example 1. This was subjected to spray drying under the same conditions as in Example 1 except that the hot air temperature was 100 ° C. It took 32 minutes to supply the total amount of slurry of about 800 ml. 518 gr of dry oxalate was obtained. At this stage, a very small amount of oxalate was collected and observed with an electron microscope. No spherical particles were found, and rod-shaped, plate-shaped,
It consisted of irregularly shaped particles. The oxalate salt was fired under the same conditions as in Example 1 to obtain 205 gr of yttrium oxide. Average particle size 4.9 μm, repose angle 70 ° or more, difficult to measure, bulk density 0.
It was 55 / cm 3 .
【００２０】（比報例６）実施例ｌと同条件で沈殿生
成、分離、洗浄した蓚酸塩を回収し、実施例ｌと略同濃
度になるようにスラリーを調整した。これを熱風の供給
量が 1.0ｍ3/min であることのほかは実施例ｌと同条件
で噴霧乾燥にかけた。スラリーの供給は全量約 800mlに
32分かかった。 490grの乾燥蓚酸塩を得た。この段階で
蓚酸塩の極く少量を採取し、電子顕微鏡で観察したとこ
ろ、球状粒子も主成分であるが、細かい棒状、板状の粒
子が混在し、また、球状粒子もその多くに深い割れ目が
見られた。この蓚酸塩を実施例ｌと同条件で焼成して 1
98grの酸化イットリウムを得た。電子顕微鏡で観察した
ところ、球状粒子も凡そ半分ほど見られるものの、球が
幾つかに割れたような粒子や、棒状、坂状の粒子が混じ
っており、平均粒径 6.4μｍ、安息角54゜、嵩密度1.22
/cm3であった。(Comparative Example 6) Oxalate which had been precipitated, separated and washed under the same conditions as in Example 1 was recovered, and the slurry was adjusted so as to have substantially the same concentration as in Example 1. This was subjected to spray drying under the same conditions as in Example 1 except that the hot air supply rate was 1.0 m 3 / min. The total amount of slurry supply is about 800 ml
It took 32 minutes. 490 gr of dry oxalate was obtained. At this stage, a very small amount of oxalate was collected and observed with an electron microscope.Spherical particles were the main component, but fine rod-shaped and plate-shaped particles were mixed, and many of the spherical particles also had deep cracks. It was observed. This oxalate was calcined under the same conditions as in Example 1 1
98 gr of yttrium oxide was obtained. Observation with an electron microscope reveals that about half of the spherical particles are also visible, but particles with several broken spheres, rod-shaped or slope-shaped particles are mixed, and the average particle size is 6.4 μm and the repose angle is 54 °. , Bulk density 1.22
It was / cm 3 .
【００２１】（比較例７）実施例ｌと同条件で沈殿生
成、分離、洗浄した蓚酸塩を回収し、実施例ｌと略同濃
度になるようにスラリーを調整した。これをスラリーの
供給速度のほかは実施例ｌと同条件で噴霧乾燥にかけ
た。スラリーの供給は全量約 800mlを６分で供給した。
481gr の乾燥蓚酸塩を得た。この段階で蓚酸塩の極く少
量を採取し、電子顕微鏡で観察したところ、球状粒子も
主成分であるが、細かい棒状、板状の粒子が混在し、ま
た、球状粒子もその多くに深い割れ目が見られた。この
蓚酸塩を実施例ｌと同条件で焼成して 200grの酸化イッ
トリウムを得た。電子顕微鏡で観察したところ、球状粒
子も凡そ半分ほど見られるものの、球が幾つかに割れた
ような粒子や、棒状、坂状の粒子が混じっており、平均
粒径 6.1μｍ、安息角58゜、嵩密度1.10/cm3であった。(Comparative Example 7) Under the same conditions as in Example 1, precipitation, separation and washing of the washed oxalate salt were carried out, and the slurry was adjusted so as to have substantially the same concentration as in Example 1. This was subjected to spray drying under the same conditions as in Example 1 except for the slurry feed rate. The total amount of slurry supplied was about 800 ml in 6 minutes.
481 gr of dry oxalate was obtained. At this stage, a very small amount of oxalate was collected and observed with an electron microscope.Spherical particles were the main component, but fine rod-shaped and plate-shaped particles were mixed, and many of the spherical particles also had deep cracks. It was observed. This oxalate was calcined under the same conditions as in Example 1 to obtain 200 gr of yttrium oxide. Observation with an electron microscope reveals that about half of the spherical particles are also visible, but particles with several broken spheres, rod-shaped or slope-shaped particles are mixed, and the average particle diameter is 6.1 μm and the repose angle is 58 °. The bulk density was 1.10 / cm 3 .
【００２２】[0022]
【発明の効果】本発明によれば、非凝集性球状希土類酸
化物粒子を安定且つ容易に得ることができ、産業上その
利用価値は極めて高い。Industrial Applicability According to the present invention, non-aggregating spherical rare earth oxide particles can be stably and easily obtained, and its industrial utility value is extremely high.
Claims (2)
て、反応系を−５℃以上20℃以下に保って反応させ、生
成した希土類蓚酸塩を前記温度範囲下に所定時間保持し
た後沈殿を分離し、該沈殿を水に分散、懸濁させ、該懸
濁液を噴霧乾燥法によって乾燥した後、焼成することを
特徴とする球状希土類酸化物の製造方法。1. In the reaction of a rare earth ion and an oxalate ion, the reaction system is kept at −5 ° C. or higher and 20 ° C. or lower to cause the reaction, and the generated rare earth oxalate is kept in the temperature range for a predetermined time and then the precipitate is separated. Then, the precipitate is dispersed and suspended in water, and the suspension is dried by a spray drying method, and then calcined, and a method for producing a spherical rare earth oxide.
とを特徴とする請求項ｌに記載の球状希土類酸化物の製
造方法。 ｌ）噴霧乾燥の方式が、直径20〜 200mmの高速回転して
いる円盤上に希土類蓚酸塩懸濁液を滴下することにより
液滴とし、熱風で乾燥する方式であること。 ２）噴霧乾燥にかける希土類蓚酸塩懸濁液濃度が、希土
類元素濃度で 0.2〜3.0mol/Lであること。 ３）回転円盤の回転速度が7000〜25000rpmであること。 ４）熱風温度が 120〜 300℃であること。 ５）熱風の単位時間当たり供給量が供給懸濁液の５万〜
100万倍体積であること。2. The method for producing a spherical rare earth oxide according to claim 1, wherein the conditions for spray drying satisfy the following five items. l) The spray-drying method is a method in which a rare earth oxalate suspension is dropped onto a disc having a diameter of 20 to 200 mm and rotating at a high speed to form droplets, which is then dried with hot air. 2) The concentration of rare earth oxalate suspension applied for spray drying should be 0.2 to 3.0 mol / L in terms of rare earth element concentration. 3) The rotation speed of the rotating disk is 7000-25000 rpm. 4) The hot air temperature is 120 to 300 ° C. 5) The amount of hot air supplied per unit time is 50,000-
The volume should be one million times.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22491695A JP3300576B2 (en) | 1995-09-01 | 1995-09-01 | Method for producing spherical rare earth oxide |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22491695A JP3300576B2 (en) | 1995-09-01 | 1995-09-01 | Method for producing spherical rare earth oxide |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0971415A true JPH0971415A (en) | 1997-03-18 |
| JP3300576B2 JP3300576B2 (en) | 2002-07-08 |
Family
ID=16821179
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP22491695A Expired - Fee Related JP3300576B2 (en) | 1995-09-01 | 1995-09-01 | Method for producing spherical rare earth oxide |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3300576B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2008018582A1 (en) * | 2006-08-11 | 2008-02-14 | Ishihara Sangyo Kaisha, Ltd. | Europium-activated yttrium oxide and process for producing the same |
| JP2010272544A (en) * | 1998-08-27 | 2010-12-02 | Cabot Corp | Safety management product containing photoluminescence fluorophosphor particle |
-
1995
- 1995-09-01 JP JP22491695A patent/JP3300576B2/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010272544A (en) * | 1998-08-27 | 2010-12-02 | Cabot Corp | Safety management product containing photoluminescence fluorophosphor particle |
| JP2015018812A (en) * | 1998-08-27 | 2015-01-29 | キャボット コーポレイションＣａｂｏｔ Ｃｏｒｐｏｒａｔｉｏｎ | Safety management product containing photoluminescence phosphor particle |
| WO2008018582A1 (en) * | 2006-08-11 | 2008-02-14 | Ishihara Sangyo Kaisha, Ltd. | Europium-activated yttrium oxide and process for producing the same |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3300576B2 (en) | 2002-07-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR950003421B1 (en) | Method for the production of mixed ammonium rare earth oxalates and their application to the production of rare earth oxides | |
| CN103539195B (en) | Preparation method for nanometer yttrium oxide powder | |
| JPH0248415A (en) | Rare earth element trifluoride having novel morphological feature and manufacture thereof | |
| JPH07315816A (en) | Rare earth element salt particle of phosphoric acid and its production | |
| US5545386A (en) | Method for the preparation of globular particles of a rare earth oxide | |
| JPH0971415A (en) | Production of spherical rare-earth metal oxide | |
| KR950004771B1 (en) | Method for production of mixed ammonium-rare earth osalates and rare earth oxides so produced | |
| JP3025157B2 (en) | Method for producing spherical rare earth oxide | |
| JPH04310516A (en) | Production of rare earth element oxide | |
| CN106006701A (en) | Preparation method of micron-submicron-scale rare earth oxide powder | |
| JP3280689B2 (en) | Method for producing round rare earth oxide | |
| JPH0859234A (en) | Production of spherical rare earth metal oxide | |
| JPS60215527A (en) | Production of zirconium oxide fine powder | |
| JP2883522B2 (en) | Method for producing rare earth oxide fine powder | |
| JP3891252B2 (en) | Process for producing rare earth oxides and basic carbonates | |
| CN115340126B (en) | Rare earth zirconate particles and preparation method thereof | |
| JPH03271117A (en) | Spherical rare earth of oxalate and production thereof | |
| JPH03271118A (en) | Spherical rare earth oxide and production thereof | |
| JP3551428B2 (en) | Method for producing rare earth element-containing BaFI prismatic crystal | |
| JP2789751B2 (en) | Production method of raw material alumina for Bernoulli single crystal | |
| JPH04164810A (en) | Production of rare earth element oxide | |
| JP3394071B2 (en) | Method for producing rare earth oxide fine powder | |
| JP3350332B2 (en) | Method for producing aggregated rare earth hydroxide | |
| JPH07109118A (en) | Production of rare earth element oxide | |
| JPH05286716A (en) | Particles of oxide of rare earth element and their production |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20080419 Year of fee payment: 6 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110419 Year of fee payment: 9 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120419 Year of fee payment: 10 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130419 Year of fee payment: 11 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130419 Year of fee payment: 11 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20140419 Year of fee payment: 12 |
|
| LAPS | Cancellation because of no payment of annual fees |