JPH0442802A - Production of high-purity metal fluoride - Google Patents
Production of high-purity metal fluorideInfo
- Publication number
- JPH0442802A JPH0442802A JP14437890A JP14437890A JPH0442802A JP H0442802 A JPH0442802 A JP H0442802A JP 14437890 A JP14437890 A JP 14437890A JP 14437890 A JP14437890 A JP 14437890A JP H0442802 A JPH0442802 A JP H0442802A
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- Prior art keywords
- fluoride
- precipitate
- impurities
- purity metal
- oxygen
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Abstract
(57)【要約】本公報は電子出願前の出願データであるた
め要約のデータは記録されません。(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.
Description
【発明の詳細な説明】
（発明の属する技術分野）
本発明は高純度金属フッ化物の製造方法、更に詳細には
フッ化物光フアイバ用高純度フッ化物原料の製造方法に
関するものである。DETAILED DESCRIPTION OF THE INVENTION (Technical field to which the invention pertains) The present invention relates to a method for producing a high-purity metal fluoride, and more particularly to a method for producing a high-purity fluoride raw material for a fluoride optical fiber.
（従来の技術および問題点）
フッ化物光ファイバは石英系を凌ぐ１Ｏ−２ｄ Ｂ ／
ｋ ｍ以下の伝送損失が期待されており、長距離無中
継が可能な伝送媒体として有望視されている。しかし、
これまで報告されているフッ化物光ファイバの伝送値は
１ｄＢ／ｋｍ前後である。(Conventional technology and problems) Fluoride optical fiber has a 1O-2d B/
It is expected to have a transmission loss of less than km, and is seen as a promising transmission medium that can be used over long distances without repeating. but,
The transmission value of fluoride optical fibers reported so far is around 1 dB/km.
フッ化物光ファイバの超低損失化を阻害する要因として
Ｃｒ、Ｆｅ、Ｃｏ、Ｎｉ、Ｃｕなとの遷移金属不純物に
よる吸収損失および酸素不純物による散乱損失がある。Factors that inhibit ultra-low loss in fluoride optical fibers include absorption loss due to transition metal impurities such as Cr, Fe, Co, Ni, and Cu, and scattering loss due to oxygen impurities.
これらの不純物は出発フッ化物原料から来るものが最も
多いと考えられるため、遷移金属不純物、酸素不純物を
含まない高純度フッ化物原料の作製が強く望まれている
。Since most of these impurities are thought to come from the starting fluoride raw material, it is strongly desired to produce a high purity fluoride raw material that does not contain transition metal impurities or oxygen impurities.
光フアイバ用フッ化物ガラス組成にはＺｒＦ４系が主に
使われており、その主成分はＺｒＦ４、ＡｌＦ３、Ｌａ
、Ｆｅなどの網目形成（４価、３価）フッ化物と、Ｂａ
Ｆ２、ＮａＦなどのアルカリ土類（２価）、アルカリ金
属（１価）フッ化物である。The ZrF4 system is mainly used in the composition of fluoride glass for optical fibers, and its main components are ZrF4, AlF3, and La.
, network-forming (tetravalent, trivalent) fluorides such as Fe, and Ba
These are alkaline earth (divalent) and alkali metal (monovalent) fluorides such as F2 and NaF.
従来のフッ化物精製法には昇華法や気相反応法などの乾
式精製法と溶媒抽出やイオン交換による湿式精製法があ
った。昇華精製法はＺｒＦ４、ＡｌＦ３などには適用可
能であり、遷移金属および酸化物の除去が同時に行われ
る。Conventional fluoride purification methods include dry purification methods such as sublimation and gas phase reaction methods, and wet purification methods such as solvent extraction and ion exchange. The sublimation purification method is applicable to ZrF4, AlF3, etc., and removes transition metals and oxides at the same time.
しかし、ＢａＦ２については昇華精製では遷移金属は揮
発除去できるが、ＢａＦ２の蒸気圧が低いため高温で昇
華精製すると酸化物が残存し、光フアイバ原料としては
適さないという欠点があった。However, although the transition metals of BaF2 can be volatilized and removed by sublimation purification, BaF2 has a low vapor pressure and oxides remain when sublimation purification is performed at high temperatures, making it unsuitable as a raw material for optical fibers.
アルカリ土類金属、アルカリ金属中の遷移金属不純物除
去に関しては湿式精製法が知られているが、水溶液のフ
ッ素化処理および乾燥において、水酸基の残留、最終的
には酸素不純物の残留があり、フッ化物光フアイバ用原
料としては適さないと考えられていた。例えば、Ｂａ（
ＮＯ３）２、Ｎａ２Ｃ○３水溶液を用いて湿式精製した
後、フッ素化して作製した沈殿物には陰イオンの共沈に
よるＮＯ３−１ＣＯ３２−の混入が確認された。さらに
、ＨＦと８２０を含む沈殿物を乾燥するなめ、ＨＦの離
脱と共にＯＨ基の脱水縮合反応が進行し、最終的に酸素
不純物の残留がある。ＢａＣｌ２水溶液を用いた場合は
、フッ素化工程でＢａＣＩＦが生成・沈殿し、ＢａＦ２
は得られない。Wet purification methods are known for removing transition metal impurities in alkaline earth metals and alkali metals, but during the fluorination treatment and drying of aqueous solutions, hydroxyl groups and eventually oxygen impurities remain, resulting in It was thought that it was not suitable as a raw material for compound optical fibers. For example, Ba(
After wet purification using an aqueous solution of NO3)2 and Na2C○3, the precipitate produced by fluorination was confirmed to be contaminated with NO3-1CO32- due to coprecipitation of anions. Furthermore, as the precipitate containing HF and 820 is dried, a dehydration condensation reaction of OH groups progresses as HF is removed, and eventually oxygen impurities remain. When a BaCl2 aqueous solution is used, BaCIF is generated and precipitated during the fluorination process, and BaF2
cannot be obtained.
ＢａＣＩＦをさらに水分存在下でＦ２ガス処理し、Ｂａ
Ｆ２・ＨＦを作製する方法（文献：Ｆ。BaCIF is further treated with F2 gas in the presence of moisture to form BaCIF.
Method for producing F2・HF (Reference: F.
Ｃｈａｔｅｌｕｔ、 Ｃ，Ｅｙｒａｕｄ、 Ｂｕｌｌ、
Ｓｏｃ、 Ｃｈｉ ｍ、、 （１９７３） ｐ、 ２
６４６〜）が提案されているが、Ｆ２処理操作の危険性
およびＢａＦ２・ＨＦ作製工程の複雑さが欠点に挙げら
れる。Chatelut, C. Eiraud, Bull.
Soc, Chim, (1973) p. 2
646~) have been proposed, but the disadvantages include the risk of the F2 treatment operation and the complexity of the BaF2.HF production process.
（発明の目的）
本発明の目的は、高純度金属フッ化物の製造において、
湿式精製法を適用して遷移金属不純物を低減し、かつ酸
化物不純物の低減を可能とするもので、光フアイバ用高
純度金属フッ化物を提供することにある。(Object of the invention) The object of the present invention is to
The object of the present invention is to provide a high-purity metal fluoride for optical fibers, which can reduce transition metal impurities and oxide impurities by applying a wet refining method.
（問題点を解決するための手段）
上記問題点を解決するため、本発明による高純度金属フ
ッ化物の製造方法は、高純度金属フッ化物を製造する方
法において、当該金属の酢酸塩水溶液の状態で湿式精製
し、その後、フッ素化剤を用いて沈殿を作製し、当該沈
殿を脱水、乾燥することを特徴とする。(Means for Solving the Problems) In order to solve the above problems, the method for producing a high-purity metal fluoride according to the present invention includes: The method is characterized in that it is wet-purified, then a precipitate is produced using a fluorinating agent, and the precipitate is dehydrated and dried.
本発明は湿式精製による遷移金属不純物除去の長所を活
かしつつ、酢酸塩水溶液の状態から酸性フッ化物として
沈殿させることを最も主要な特徴とする。従来の技術で
は、塩化物、硝酸塩、炭酸塩などの水溶液を用いていた
ため、陰イオンの共沈現象、生成酸性フッ化物沈殿中の
吸着水などがあったが、酢酸塩ではこれらの現象が見ら
れない点が異なる。従って、得られる高純度金属フッ化
物は酸素不純物が大幅に低減されるという特徴がある。The main feature of the present invention is to precipitate the transition metal impurities from an acetate aqueous solution as an acidic fluoride while taking advantage of wet purification to remove transition metal impurities. Conventional technology used aqueous solutions of chlorides, nitrates, carbonates, etc., which caused coprecipitation of anions and adsorption of water in the acidic fluoride precipitate, but these phenomena were not observed with acetate. The difference is that it cannot be used. Therefore, the obtained high-purity metal fluoride is characterized by significantly reduced oxygen impurities.
本発明によれば、まず製造する金属フッ化物の前記金属
の酢酸塩水溶液の状態で湿式精製する。According to the present invention, first, the metal fluoride to be produced is wet-purified in the form of an aqueous acetate solution of the metal.
このような金属としては、例えばアルキル金属およびア
ルカリ土類金属などを例としてあげることができる。Examples of such metals include alkyl metals and alkaline earth metals.
この湿式精製の方法は、本発明において基本的に限定さ
れるものではなく、たとえば溶媒抽出などの方法で、Ｃ
ｒ、Ｆｅ、Ｃｏ、Ｎｉ、Ｃｕなどの遷移金属不純物など
を除去してもよく、イオン交換法によって不純物を除去
してもよい。This wet purification method is basically not limited in the present invention, and for example, a method such as solvent extraction may be used.
Impurities of transition metals such as r, Fe, Co, Ni, and Cu may be removed, or impurities may be removed by an ion exchange method.
上述のように湿式精製しｆＳ後、フッ素化剤を添加し、
フッ化物沈殿を生じしめる。このフッ素化剤は、本発明
において基本的に限定されるものではなく、金属フッ化
物沈殿を生じしめるものであれば基本的にいかなるもの
でもよい。たとえばフッ化水素酸、フッ化アンモニウム
水溶液、フッ化水素ガスのいずれか１つ、ｔたは２つ以
上の混合物であることができる。After wet purification and fS as described above, a fluorinating agent was added,
Causes fluoride precipitation. This fluorinating agent is not fundamentally limited in the present invention, and basically any agent may be used as long as it causes metal fluoride precipitation. For example, it can be any one of hydrofluoric acid, ammonium fluoride aqueous solution, and hydrogen fluoride gas, or a mixture of two or more of them.
このようにフッ素化剤によって沈殿を生じしめた後、前
記沈殿を脱水、乾燥させる。脱水、感想工程は、本発明
において基本的に限定されるものではない。例えば、真
空雰囲気、不活性雰囲気で行なうことができる。After the fluorinating agent produces the precipitate in this manner, the precipitate is dehydrated and dried. The dehydration and impression steps are not fundamentally limited in the present invention. For example, it can be carried out in a vacuum atmosphere or an inert atmosphere.
以下、実施例によって本発明の詳細な説明する。Hereinafter, the present invention will be explained in detail with reference to Examples.
（実施例１）
Ｂａ （ＣＨ３ＣＯＯ）２塩を出発とするＢａＦ２の製
造方法について以下に説明する。(Example 1) A method for producing BaF2 starting from Ba(CH3COO)2 salt will be described below.
Ｂａ （ＣＨ３ＣＯＯ）２を秤量後純水に溶解し、溶媒
抽出によりＣｒ、Ｆｅ、Ｃｏ、Ｎｉ、Ｃｕの遷移金属不
純物を抽出精製した後、フッ素化剤としてフッ化水素酸
を加え、フッ化物沈殿とする。After weighing Ba (CH3COO)2, it was dissolved in pure water, and transition metal impurities such as Cr, Fe, Co, Ni, and Cu were extracted and purified by solvent extraction, and then hydrofluoric acid was added as a fluorinating agent to precipitate fluoride. shall be.
フッ化物沈殿は希フッ化水素酸で洗浄後、室温にて真空
脱水乾燥を行った。得られた乾燥物の電子顕微鏡写真か
ら結晶小面のはつきりした単結晶であり、Ｂａ （ＮＯ
３）２水溶液からの沈殿乾燥物が針状であることと大き
く異なっている。さらに、第１図は真空乾燥後のフッ化
物のＤ Ｔ Ａ−Ｔ ０曲線であり、１２０℃から減量
し、２３５℃で完了し、重量減少率は１０．２％である
。ＤＴＡ曲線は２２３℃、１３５３℃に吸熱ピークがあ
る。２２３℃の吸熱ピークはＨＦ離脱に伴う単一ピーク
であり、脱水縮合による吸熱ピークは見られない。The fluoride precipitate was washed with dilute hydrofluoric acid and then vacuum dehydrated and dried at room temperature. An electron micrograph of the obtained dry product shows that it is a single crystal with sharp crystal facets, and Ba (NO
3) This is greatly different from the fact that the dried precipitate from the aqueous solution is needle-shaped. Furthermore, FIG. 1 is a D T AT 0 curve of fluoride after vacuum drying, the weight loss starts from 120°C and is completed at 235°C, and the weight loss rate is 10.2%. The DTA curve has endothermic peaks at 223°C and 1353°C. The endothermic peak at 223°C is a single peak associated with HF separation, and no endothermic peak due to dehydration condensation is observed.
１３５３℃の吸熱ピークはＢａＦ２の融点に相当するも
のである。The endothermic peak at 1353°C corresponds to the melting point of BaF2.
真空乾燥後のフッ化物はＢａＦ２・ＨＦであることをＸ
線回折で確認した。また、前記フッ化物を４００℃で真
空乾燥し、これについてＸ線回折を行い、立方晶のＢａ
Ｆ２が作製されていることを確認した。第１表は本発明
で製造したＢａＦ２の中性子放射化分析による遷移金属
不純物、荷電粒子放射化分析による酸素不純物の定量結
果であり、酸素ｌｐｐｍ未満、クロム、鉄、コバルト、
ニッケル、銅いずれも１ｐｐｂ未満の値が得られた。放
射化分析によるフッ化物の酸素の検出下限はｌｐｐｍで
あり、酸素不純物について検出下限値まで高純度化でき
ている。X indicates that the fluoride after vacuum drying is BaF2・HF.
Confirmed by line diffraction. In addition, the fluoride was vacuum dried at 400°C, and X-ray diffraction was performed on it.
It was confirmed that F2 was produced. Table 1 shows the quantitative results of transition metal impurities by neutron activation analysis and oxygen impurities by charged particle activation analysis of BaF2 produced according to the present invention, including less than 1 ppm of oxygen, chromium, iron, cobalt,
Values of less than 1 ppb were obtained for both nickel and copper. The lower detection limit for oxygen in fluoride by activation analysis is 1 ppm, and oxygen impurities have been highly purified to the lower detection limit.
本発明で作製したＢａＦ２をフッ化物光フアイバ原料成
分として使用し、その効果としては散乱損失の小さい良
好な光ファイバが製造できた。真空乾燥後のＢａＦ２・
ＨＦを原料に使用しても同様に良好な光ファイバが製造
できた。BaF2 produced according to the present invention was used as a raw material component for a fluoride optical fiber, and as a result, a good optical fiber with low scattering loss could be produced. BaF2 after vacuum drying
Even when HF was used as a raw material, a similarly good optical fiber could be manufactured.
フッ素化剤にフッ化アンモニウム水溶液を使用してフッ
化物沈殿を作製しても、前記と同様にＢａＦ２・ＨＦが
製造できた。Even when a fluoride precipitate was produced using an ammonium fluoride aqueous solution as a fluorinating agent, BaF2.HF could be produced in the same manner as described above.
第１表
（実施例２）
Ｎａ （ＣＨ３ＣＯＯ）塩を出発とするＮａＦの製造方
法について以下に説明する。Table 1 (Example 2) A method for producing NaF starting from Na (CH3COO) salt will be described below.
Ｎａ （ＣＨ３ＣＯＯ）塩を溶解復水溶液とし、溶媒抽
出精製により遷移金属不純物を除去後、フッ素化剤とし
てフッ化水素ガスを水溶液内にバブルさせを、フッ化物
沈殿とする。フッ化物沈殿はＡｒ乾燥ガス気流で乾燥さ
せたものについてＤＴＡ−ＴＧおよび赤外吸収スペクト
ル測定を行った。After dissolving Na (CH3COO) salt as a condensate solution and removing transition metal impurities by solvent extraction and purification, hydrogen fluoride gas is bubbled into the aqueous solution as a fluorinating agent to precipitate fluoride. The fluoride precipitate was dried with an Ar drying gas stream and subjected to DTA-TG and infrared absorption spectroscopy measurements.
第２図は前記乾燥物の赤外吸収スペクトルであり、２１
００ｃｍ 、１５０Ｃ１−１７００ｃｍ−’１２１０
ｃｍ−’にＨＦ２−に相当する吸収ピークがあった。ま
た、前記乾燥物のＤ Ｔ Ａ−Ｔ Ｇは第１図のＤＴＡ
の第１番目の吸熱ピークと同様に単一ピークであり、脱
水縮合は見られず、Ｘ線回折結果からＮａＦ−ＨＦであ
ることが確認された。Figure 2 shows the infrared absorption spectrum of the dried product, with 21
00cm, 150C1-1700cm-'1210
There was an absorption peak corresponding to HF2- at cm-'. In addition, DTA-TG of the dried material is DTA in FIG.
It was a single peak similar to the first endothermic peak of , no dehydration condensation was observed, and it was confirmed from the X-ray diffraction results that it was NaF-HF.
さらに、Ａｒ乾燥ガス気流中４００°Ｃまで加熱し、加
熱後のものについてＸ線回折を行い、ＮａＦであること
を確認した。ＮａＦ −ＨＦおよびＮａＦについて遷移
金属不純物分析、酸素不純物分析を行い、第１表に示し
たと同様、ＮａＦ −ＨＦ、ＮａＦの両方についてＣｒ
、Ｆｅ、Ｃｏ、Ｎｉ、Ｃｕは各々１ｐｐｂ以下、酸素は
ｌｐｐｍ以下となり、ＮａＦ −ＨＦと同様ＨＦを除去
したＮａＦについても酸素不純物分析結果に示すように
酸素を減少させる効果があった。Furthermore, the material was heated to 400° C. in an Ar dry gas flow, and the material after heating was subjected to X-ray diffraction, and it was confirmed that it was NaF. Transition metal impurity analysis and oxygen impurity analysis were conducted for NaF -HF and NaF, and as shown in Table 1, Cr was detected for both NaF -HF and NaF.
, Fe, Co, Ni, and Cu were each 1 ppb or less, and oxygen was 1 ppm or less. Similar to NaF-HF, NaF from which HF was removed also had the effect of reducing oxygen as shown in the oxygen impurity analysis results.
本発明で作製したＮａＦ−ＨＦあるいはＮａＦをフッ化
物光フアイバ原料成分として使用し、その効果としては
散乱損失の小さい良好な光ファイバが製造できた。NaF-HF or NaF produced according to the present invention was used as a raw material component of a fluoride optical fiber, and as a result, a good optical fiber with low scattering loss could be produced.
（実施例３）
Ｌｉ （ＣＨ３ＣＯＯ）塩を出発とするＬｉＦ（７）製
造方法について以下に説明する。(Example 3) A method for producing LiF (7) starting from Li (CH3COO) salt will be described below.
Ｌｉ （ＣＨ３ＣＯＯ）塩の水溶液中の遷移金属不純物
をイオン交換法により精製除去した後、フッ素化剤とし
てフッ化水素酸を加えフッ化物沈殿とする。フッ化物沈
殿物は、希フッ化水素酸で洗浄後、１２０℃で真空脱水
乾燥を行った。乾燥物についてＸ線回折を行いＬｉＦで
あることを確認した。本発明で作製したＬｉＦについて
酸素不純物、遷移金属不純物を分析し、分析結果は第１
表と同じく、酸素はｌｐｐｍ以下、Ｃｒ、Ｆｅ、Ｃｏ、
Ｎｉ、Ｃｕは各々１ｐｐｂ以下となり、実施例２で示し
たＮａＦ −ＨＦ、ＨＦと同様に酸素を減少させる効果
があった。After the transition metal impurities in the aqueous solution of Li (CH3COO) salt are purified and removed by an ion exchange method, hydrofluoric acid is added as a fluorinating agent to form a fluoride precipitate. The fluoride precipitate was washed with dilute hydrofluoric acid and then vacuum dehydrated and dried at 120°C. The dried product was subjected to X-ray diffraction and confirmed to be LiF. The LiF produced according to the present invention was analyzed for oxygen impurities and transition metal impurities, and the analysis results are as follows.
As in the table, oxygen is less than lppm, Cr, Fe, Co,
Ni and Cu were each 1 ppb or less, and had the same effect of reducing oxygen as NaF-HF and HF shown in Example 2.
本発明で作製したＬｉＦをフッ化物光フアイバ原料成分
として使用し、その効果としては散乱損失の小さい良好
な光ファイバが製造できた。LiF produced according to the present invention was used as a raw material component for a fluoride optical fiber, and as a result, a good optical fiber with low scattering loss could be produced.
（発明の効果）
以上説明したように、本発明による高純度金属フッ化物
の製造方法は、湿式精製法による超高純度化とあわせて
酸素不純物の除去が行えるため、遷移金属不純物、酸素
不純物の両方が少ない高純度フッ化物が得られる。これ
をフッ化物光フアイバ原料として用いることにより超低
損失のフッ化物光ファイバを製造できる利点がある。(Effects of the Invention) As explained above, the method for producing high-purity metal fluoride according to the present invention can remove oxygen impurities in addition to achieving ultra-high purity using a wet refining method. High purity fluoride with low amounts of both is obtained. By using this as a raw material for fluoride optical fiber, there is an advantage that a fluoride optical fiber with ultra-low loss can be manufactured.
第１図は真空乾燥後のＢａ−フッ化物のＤＴＡＴＧ曲線
、第２図はＡｒガスで乾燥したＮａ−フッ化物の赤外吸
収スペクトルである。
１・・・ＤＴＡ曲線、２・・・７０曲線。FIG. 1 shows a DTATG curve of Ba-fluoride after vacuum drying, and FIG. 2 shows an infrared absorption spectrum of Na-fluoride dried with Ar gas. 1...DTA curve, 2...70 curve.
Claims (2)
該金属の酢酸塩水溶液の状態で湿式精製し、その後、フ
ッ素化剤を用いて沈殿を作製し、当該沈殿を脱水、乾燥
することを特徴とする高純度金属フッ化物の製造方法。(1) A method for producing a high-purity metal fluoride, characterized in that the metal is wet-purified in the form of an acetate aqueous solution, then a precipitate is prepared using a fluorinating agent, and the precipitate is dehydrated and dried. A method for producing high-purity metal fluoride.
、フッ化アンモニウム水溶液、フッ化水素ガスのいずれ
か１つ、または２つ以上の混合物であることを特徴とす
る特許請求の範囲第１項記載の高純度金属フッ化物の製
造方法。(2) Claim 1, characterized in that the fluorinating agent in the precipitation preparation step is any one of hydrofluoric acid, ammonium fluoride aqueous solution, and hydrogen fluoride gas, or a mixture of two or more of them. A method for producing a high-purity metal fluoride as described in Section 1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14437890A JP2963905B2 (en) | 1990-06-04 | 1990-06-04 | Method for producing high-purity metal fluoride |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14437890A JP2963905B2 (en) | 1990-06-04 | 1990-06-04 | Method for producing high-purity metal fluoride |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0442802A true JPH0442802A (en) | 1992-02-13 |
| JP2963905B2 JP2963905B2 (en) | 1999-10-18 |
Family
ID=15360735
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP14437890A Expired - Lifetime JP2963905B2 (en) | 1990-06-04 | 1990-06-04 | Method for producing high-purity metal fluoride |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2963905B2 (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5599588A (en) * | 1994-11-23 | 1997-02-04 | Eastman Kodak Company | Process for preparing metal halides by the sol-gel-method |
| JP2009215138A (en) * | 2008-03-12 | 2009-09-24 | Stella Chemifa Corp | Method of purification of metal fluoride |
| CN101967003A (en) * | 2010-10-25 | 2011-02-09 | 宁波诺尔丽化学科技有限公司 | Method for preparing barium fluoride from organic fluoridation waste |
| US8583326B2 (en) * | 2010-02-09 | 2013-11-12 | Agjunction Llc | GNSS contour guidance path selection |
| CN113307296A (en) * | 2021-06-17 | 2021-08-27 | 秦皇岛微晶科技有限公司 | Preparation method of low-oxygen-content barium fluoride |
| CN117049582A (en) * | 2023-09-13 | 2023-11-14 | 上海太洋科技有限公司 | Impurity removing method for barium fluoride |
-
1990
- 1990-06-04 JP JP14437890A patent/JP2963905B2/en not_active Expired - Lifetime
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5599588A (en) * | 1994-11-23 | 1997-02-04 | Eastman Kodak Company | Process for preparing metal halides by the sol-gel-method |
| JP2009215138A (en) * | 2008-03-12 | 2009-09-24 | Stella Chemifa Corp | Method of purification of metal fluoride |
| US8583326B2 (en) * | 2010-02-09 | 2013-11-12 | Agjunction Llc | GNSS contour guidance path selection |
| CN101967003A (en) * | 2010-10-25 | 2011-02-09 | 宁波诺尔丽化学科技有限公司 | Method for preparing barium fluoride from organic fluoridation waste |
| CN113307296A (en) * | 2021-06-17 | 2021-08-27 | 秦皇岛微晶科技有限公司 | Preparation method of low-oxygen-content barium fluoride |
| CN113307296B (en) * | 2021-06-17 | 2023-08-18 | 秦皇岛微晶科技有限公司 | Preparation method of barium fluoride with low oxygen content |
| CN117049582A (en) * | 2023-09-13 | 2023-11-14 | 上海太洋科技有限公司 | Impurity removing method for barium fluoride |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2963905B2 (en) | 1999-10-18 |
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