JP2854934B2 - Method for producing nitrogen trifluoride gas - Google Patents
Method for producing nitrogen trifluoride gasInfo
- Publication number
- JP2854934B2 JP2854934B2 JP2164031A JP16403190A JP2854934B2 JP 2854934 B2 JP2854934 B2 JP 2854934B2 JP 2164031 A JP2164031 A JP 2164031A JP 16403190 A JP16403190 A JP 16403190A JP 2854934 B2 JP2854934 B2 JP 2854934B2
- Authority
- JP
- Japan
- Prior art keywords
- molten salt
- gas
- electrolysis
- electrode
- anode
- 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 - Lifetime
Links
Landscapes
- Electrolytic Production Of Non-Metals, Compounds, Apparatuses Therefor (AREA)
Description
【発明の詳細な説明】 （産業上の利用分野） 本発明は三弗化窒素ガス（NF3）の製造方法に関す
る。Description: TECHNICAL FIELD The present invention relates to a method for producing nitrogen trifluoride gas (NF 3 ).
更に詳しくは、フッ化水素とアンモニアを原料とする
NH4F・HF系溶融塩の電解法によるNF3ガスの製造方法に
関する。More specifically, using hydrogen fluoride and ammonia as raw materials
The present invention relates to a method for producing NF 3 gas by electrolysis of NH 4 F · HF molten salt.
（従来の技術及び発明が解決しようとする課題） NF3は沸点が−129℃、融点が−207℃の物性を示す無
色の気体である。(Problems to be Solved by the Related Art and the Invention) NF 3 is a colorless gas having a boiling point of −129 ° C. and a melting point of −207 ° C. and exhibiting physical properties.
NF3ガスは半導体のドライエッチング剤やCVD装置のク
リーニングガスとして近年注目されているが、これらの
用途に使用されるNF3ガスは、高純度のものが要求され
ている。Although NF 3 gas has recently attracted attention as a dry etching agent for semiconductors and a cleaning gas for CVD equipment, high purity NF 3 gas is required for these applications.
しかしながら製造されたNF3ガスは、窒素（N2）、二
弗化二窒素（N2F2）、亜酸化窒素（N2O）、二酸化炭素
（CO2）、二弗化酸素（OF2）、酸素（O2）、未反応の弗
化水素（HF）等の不純物を比較的多量に含んでおり、本
発明で対象とするNH4F・HF系溶融塩電解法で製造された
NF3ガスも同様に不純物を含有している。従って、上記
用途としての高純度のNF3ガスを得るためには精製が必
要である。However, the produced NF 3 gas includes nitrogen (N 2 ), dinitrogen difluoride (N 2 F 2 ), nitrous oxide (N 2 O), carbon dioxide (CO 2 ), and oxygen difluoride (OF 2 ), oxygen (O 2), it contains impurities such as unreacted hydrogen fluoride (HF) in relatively large amount, produced in NH 4 F · HF molten salts electrolysis of interest in the present invention
NF 3 gas also contains impurities. Therefore, purification is necessary in order to obtain high-purity NF 3 gas for the above uses.
NF3ガス中のこれらの不純物を除去する精製方法とし
ては、下記する方法が知られている。The following method is known as a purification method for removing these impurities in the NF 3 gas.
このうち、N2F2、HF、CO2、N2、O2は比較的容易に除
去あるいは含有量を低減させる方法が知られている。Among them, a method of relatively easily removing or reducing the content of N 2 F 2 , HF, CO 2 , N 2 , and O 2 is known.
即ち、１）N2F2はKI、Na2S、Na2S2O3等の水溶液と接
触させる方法〔J.Massonne,ケミー・インジェニュール
・テヒニール（Chem.Ing.Techn.）41,（12）,695,（196
9）〕や148.9〜537.8℃の温度で金属と接触させる方法
（特公昭59−15081号）等を用い、ガススクラッバーあ
るいは熱分解装置を設置することで工業的にも簡単に除
去することができる。２）HFは水あるいは弱アルカリ性
水溶液への吸収が容易なことから、ガススクラッバーを
設置することで簡単に除去することが可能である。３）
CO2はアルカリ性水溶液への吸収が良好であるため、HF
同様にガススクラッバーを設置することで工業的にも簡
単に除去が可能である。４）N2やO2等の低沸点成分は、
−150〜１−190℃の温度に冷却してNF3を液化すること
で除去することができる。That is, 1) a method in which N 2 F 2 is brought into contact with an aqueous solution of KI, Na 2 S, Na 2 S 2 O 3, etc. [J. Massonne, Chemie Ingeneur Techinil (Chem. Ing. Techn.) 41, ( 12), 695, (196
9)] or a method of contacting with metal at a temperature of 148.9-537.8 ° C (Japanese Patent Publication No. 59-15081), etc., and can be easily removed industrially by installing a gas scrubber or a thermal decomposition device. it can. 2) HF can be easily removed by installing a gas scrubber because it is easily absorbed into water or a weakly alkaline aqueous solution. 3)
Because CO 2 absorbs well into alkaline aqueous solutions, HF
Similarly, by installing a gas scrubber, it can be easily removed industrially. 4) Low boiling components such as N 2 and O 2
-150～1-190 cooled to a temperature of ℃ it can be removed by liquefying NF 3.
OF2、N2Oも次に述べるような方法で、除去することは
可能であるが、工業的には完全とは言い難い。OF 2 and N 2 O can also be removed by the following method, but they are not industrially complete.
即ち、５）OF2は、Na2S2O3、KI、Na2SO3、HI、Na2S等
の水溶液と接触させる方法で除去することができる。し
かし、吸収効率が比較的低いため、OF2を含有する含有
と該水溶液の接触効率を上げるべく、大型のガススクラ
ッバーを設置したり、高い濃度の水溶液を使用しなくて
はならず、付帯する問題が多い。また、６）N2Oはゼオ
ライト等の吸着剤と接触させることで効率よく除去する
ことができる〔Chem.Eng.,84,116,（1977）等〕。しか
し、N2Oを含有するガスの通気後、ゼオライトの再生が
必要であること、また吸着能力の劣化によりゼオライト
の更新が必要となる等の問題がある。That, 5) OF 2 can be removed with Na 2 S 2 O 3, KI , Na 2 SO 3, HI, a method of contacting an aqueous solution, such as Na 2 S. However, because the absorption efficiency is relatively low, a large gas scrubber must be installed or a high-concentration aqueous solution must be used in order to increase the contact efficiency between the content containing OF 2 and the aqueous solution. There are many problems. 6) N 2 O can be efficiently removed by contact with an adsorbent such as zeolite [Chem. Eng., 84, 116, (1977), etc.]. However, there are problems such as the necessity of regenerating the zeolite after passing the gas containing N 2 O, and the necessity of renewing the zeolite due to the deterioration of the adsorption capacity.
NH4F−HF系の溶融塩電解における陽極材料として最も
耐蝕性に優れた陽極材料は炭素である。しかし、炭素電
極においては陽極効果の発生が実際の使用上の障害とな
る。The anode material having the highest corrosion resistance as an anode material in molten salt electrolysis of NH 4 F-HF is carbon. However, in the carbon electrode, the occurrence of the anodic effect is an obstacle in actual use.
陽極効果とは表面エネルギーの極めて低い膜が炭素電
極表面に形成されることによる二次的現象として電圧が
以上に上昇し、電流が殆ど流れなくなる現象を言う。陽
極効果は溶融塩中の微量水分によって引き起こされるも
のであり、陽極現象発生を防ぐための水分の許容上限は
数100ppmとされている。The anodic effect is a secondary phenomenon caused by the formation of a film having a very low surface energy on the surface of the carbon electrode, in which the voltage rises more and almost no current flows. The anodic effect is caused by a trace amount of water in the molten salt, and the allowable upper limit of water for preventing the occurrence of the anodic phenomenon is several hundred ppm.
ところが、酸性フッ化アンモニア（NH2F2H）あるいは
フッ化アンモニア（NH4F）に無水フッ化水素（HF）を加
えて調製された、溶融塩は原料自体が既に数1000ppmの
水分を含有するため、調製された溶融塩にも少なくとも
数1000ppmの水分混入は避けられず、この溶融塩をその
まま使用して炭素電極での電解を行うことは、前記、陽
極効果の発生があり不可能である。However, the molten salt prepared by adding anhydrous hydrogen fluoride (HF) to ammonia fluoride (NH 2 F 2 H) or ammonium fluoride (NH 4 F), the raw material itself already contains several thousand ppm of water Therefore, mixing of at least several thousand ppm of water is inevitable even in the prepared molten salt, and performing electrolysis with a carbon electrode using the molten salt as it is is impossible because of the occurrence of the anodic effect. is there.
そこで、このような場合一般的には、溶融塩中の水分
を除去する方法が採られる。これには通常、脱水電解と
呼ばれる方法が用いられ、このためには陽極効果を起こ
さない電極材料、即ちニッケル（Ni）を電極として使用
する。Therefore, in such a case, a method of removing water in the molten salt is generally employed. For this purpose, a method called dehydration electrolysis is usually used, and for this purpose, an electrode material that does not cause an anodic effect, that is, nickel (Ni) is used as an electrode.
脱水電解を伴う操業形態としては、脱水電解の実施後
に引続き電極を炭素電極に切り替えての本電解を行な
い、溶融塩が消費されるに従い、溶融塩を補給して再び
脱水電解に戻る回分的方法と、脱水電解終了後の炭素電
極での本電解中に消費量見合い分の溶融塩を少量づつ補
給し、連続的に本電解を行なう方法とがある。As an operation mode involving dehydration electrolysis, after the dehydration electrolysis is performed, the electrode is continuously switched to a carbon electrode to perform main electrolysis, and as the molten salt is consumed, the molten salt is replenished and the batch method is returned to dehydration electrolysis again. In addition, there is a method in which molten salt corresponding to the consumption amount is replenished little by little during the main electrolysis at the carbon electrode after the dehydration electrolysis, and the main electrolysis is continuously performed.
前者は溶融塩中の水分量の許容範囲は比較的広いもの
の、たびたびNi電極を使用することによる後述のスラッ
ジの問題、及び頻繁な電極の切り替えが必要であること
から実際的な方法とは言えない。Although the former is relatively wide in the allowable range of the amount of water in the molten salt, it can be said that it is a practical method since the sludge problem described later due to the frequent use of Ni electrodes and frequent electrode switching is required. Absent.
後者は操業形態として理想的であるが、補給する溶融
塩の水分量は、好ましくは500ppm以下である必要があ
り、現状の溶融塩中の水分量では陽極効果が発生するた
め不可能である。補給する溶融塩も脱水電解により脱水
することも出来るが、やはり後述のスラッジの問題を避
けることはできない。The latter is ideal as an operation mode, but the water content of the molten salt to be replenished must preferably be 500 ppm or less, and is not possible with the current water content in the molten salt because the anodic effect occurs. The molten salt to be replenished can also be dehydrated by dehydration electrolysis, but the sludge problem described below cannot be avoided.
以上の理由により現在のところ、該溶融塩中での耐蝕
性が金属材料中で最も優れている、Ni或はNiを主成分と
する合金が陽極として使用される。Niは陽極効果を起こ
す虞はない。しかし、電解に供される電流の内、Niの溶
解に使われる電流の割合（溶解の電流効率）は数％程度
あり、陽極のNi電極の消耗が避けられない。このことは
陽極のNiの電極の更新、あるいはNi電極の溶解により生
成した溶融塩中のスラッジの除去を頻繁に実施しなくて
はならず、大きな問題となっている。For the above reasons, at present, Ni or an alloy containing Ni as the main component, which has the best corrosion resistance in the molten salt among metal materials, is used as the anode. Ni has no possibility of causing the anodic effect. However, the ratio of the current used for dissolving Ni (current efficiency of dissolution) to the current used for electrolysis is about several percent, and the consumption of the Ni electrode of the anode is inevitable. This is a major problem because the renewal of the anode Ni electrode or the removal of sludge in the molten salt generated by the dissolution of the Ni electrode must be performed frequently.
（課題を解決するための手段） 本発明者等はかかる状況に鑑み、鋭意検討を重ねた結
果、NH4F・HF系溶融塩の原料として、NH4F2HあるいはNH
4Fを使用せず、溶融塩中のアンモニア源としてアンモニ
アによる水分含有量の少ないアンモニア、並びにフッ化
水素を使用すれば、陽極効果を引き起こさない水分含有
量が、500ppm以下である原料溶融塩を、供給しながら耐
蝕性の最も優れた炭素電極での連続的な電解を可能と
し、さらにN2O、OF2等の水分に由来する不純物の低減が
図れることを突き止め、本発明を完成するに至ったもの
である。In view of the present inventors, such a situation (Means for Solving the Problems) As a result of intensive studies, as a raw material of NH 4 F · HF molten salts, NH 4 F 2 H or NH
If 4F is not used and ammonia having a low water content due to ammonia as a source of ammonia in the molten salt and hydrogen fluoride are used, a raw material molten salt having a water content of 500 ppm or less that does not cause an anode effect is produced. In order to complete the present invention, it has been found that continuous electrolysis can be performed with the carbon electrode having the highest corrosion resistance while being supplied, and that impurities derived from moisture such as N 2 O and OF 2 can be reduced. It has been reached.
即ち、溶融塩電解法により三弗化窒素ガスを製造する
において、フッ化水素とアンモニアより調整された溶融
塩を原料とし、溶融塩電解法により電解を行なうことを
特徴とする三弗化窒素ガスの製造方法に関する。That is, in producing nitrogen trifluoride gas by a molten salt electrolysis method, an electrolysis is performed by a molten salt electrolysis method using a molten salt prepared from hydrogen fluoride and ammonia as a raw material. And a method for producing the same.
（発明の詳細な開示） 以下、本発明を詳細に説明する。(Detailed Disclosure of the Invention) Hereinafter, the present invention will be described in detail.
本発明を実施するためにまず、調製された溶融塩に外
部からの水分の侵入しないような密閉された溶融塩調製
用容器を用意する。該溶融塩調製用容器はフッ化水素ガ
スとアンモニアの導入、溶融塩の抜き出し、溶融塩調製
用容器内部の圧力調整用のための乾燥不活性ガス導出入
ができる構造となっている。その他に温度計、圧力計、
液面計が取り付けられる構造となっていれば更に好まし
い。また、溶融塩調製中の除熱、溶融塩保存時の保温が
できるよう加熱、冷却ができる構造となっている。溶融
塩調製用容器はテフロン製のものを使用するなが好まし
い。ニッケル等の耐蝕性金属材料も使用できるが、フッ
素樹脂製あるいはフッ素樹脂をライニングあるいはコー
ティングした容器が望ましい。尚、使用直前において該
溶融塩調製用容器内部は十分な乾燥を行なう必要があ
る。In order to carry out the present invention, first, a sealed molten salt preparation container is prepared so that moisture from the outside does not enter the prepared molten salt. The molten salt preparation container has a structure capable of introducing hydrogen fluoride gas and ammonia, extracting the molten salt, and introducing and receiving a dry inert gas for adjusting the pressure inside the molten salt preparation container. In addition, thermometer, pressure gauge,
It is more preferable that the liquid level gauge be attached. Further, the structure is such that heating and cooling can be performed so that heat can be removed during preparation of the molten salt and the temperature can be maintained during storage of the molten salt. It is preferable not to use a Teflon-made container for the molten salt preparation. A corrosion-resistant metal material such as nickel can be used, but a container made of a fluororesin or a lining or coating of a fluororesin is preferable. Immediately before use, it is necessary to sufficiently dry the inside of the molten salt preparation container.
次に該溶融塩調製用容器内部を液体窒素より得た乾燥
窒素（N2）ガスで十分に置換する。アルゴン（Ar）、ヘ
リウム（He）が如く不活性なガスも使用可能であるが、
液化ガスを気化させた乾燥ガスを使用する必要があり、
コストを勘案するとN2ガスが好適に使用される。容器の
内圧はガスシールと乾燥窒素を供給する圧力調整器によ
り調製され、常時大気圧よりやや高く保たれるのが好ま
しい。Next, the inside of the container for preparing molten salt is sufficiently replaced with dry nitrogen (N 2 ) gas obtained from liquid nitrogen. Inert gases such as argon (Ar) and helium (He) can be used,
It is necessary to use dry gas which vaporized liquefied gas,
Considering the cost, N 2 gas is preferably used. It is preferable that the internal pressure of the container is adjusted by a gas seal and a pressure regulator for supplying dry nitrogen, and is always kept slightly higher than the atmospheric pressure.
アンモニア（NH3）およびフッ化水素（HF）はいずれ
もNH3及びHFの気化ガスを用いる。これらに含まれる水
分含有量は一般的に100〜300ppm以下であり、外部から
の水分侵入が無が無い容器を用いれば、調製された溶融
塩の水分含有量も低く保つことができる。Both ammonia (NH 3 ) and hydrogen fluoride (HF) use NH 3 and HF gas. The water content of these is generally 100 to 300 ppm or less, and the use of a container free of external water intrusion can keep the water content of the prepared molten salt low.
NH3ガスおよびHFガスはガス導入口を通じ容器内部へ
導入されるが、NH3ガスとHFガスの反応は極めて速やか
に進み、また発熱も大きいため、一時に多量に導入する
ことは避けるべきである。供給速度は容器の大きさ、除
熱能力を勘案し、適宜選択される。Although NH 3 gas and HF gas are introduced into the container through the gas inlet, the reaction between NH 3 gas and HF gas proceeds very quickly and generates a large amount of heat. is there. The supply speed is appropriately selected in consideration of the size of the container and the heat removal capacity.
次に、調製された溶融塩の水分の定量を行なった。溶
融塩が含有する水分は、およそ500ppm以下であり、簡易
や水分測定法であるカールフィシャー法で水分を定量す
ることは難しい。そこで、溶融塩中の水分含有量は、19
88年（財）電気化学協会秋季大会において、同志社大
学、堀雅彦等によって発表された論文「溶融フッ化物浴
中の水分定量法の検討」に記載の方法によって測定し
た。Next, the water content of the prepared molten salt was quantified. The water content of the molten salt is about 500 ppm or less, and it is difficult to quantify the water content by the Karl Fischer method, which is a simple and moisture measuring method. Therefore, the water content in the molten salt is 19
It was measured by the method described in the paper "Study on Determination of Water in Molten Fluoride Bath" published by Doshisha University and Masahiko Hori at the Electrochemical Society Autumn Meeting in 1988.
該測定方法は、バインダーレスカーボンを試験電極と
して陽極に用い、白金／電解液の示す基準電極電位に対
し電位走査を行なう。この時現れる２つの電流ピークの
高さの比率より、水分を定量する。即ち、2V付近に現れ
るピーク高さは、試験電極の有効表面積に接する溶融塩
中の水分量に比例する。試験電極の有効表面積は8V付近
に現れるピーク高さに比例する。よって２つのピーク高
さの比は溶融塩中に水分量に比例するので、これにより
電解液中の水分含有量の検量線を求めることができる。In this measurement method, potential scan is performed with respect to a reference electrode potential indicated by platinum / electrolyte solution, using binderless carbon as an anode as a test electrode. Water is quantified from the ratio of the heights of the two current peaks appearing at this time. That is, the peak height appearing near 2 V is proportional to the amount of water in the molten salt in contact with the effective surface area of the test electrode. The effective surface area of the test electrode is proportional to the peak height that appears around 8V. Therefore, the ratio between the two peak heights is proportional to the amount of water in the molten salt, and thus a calibration curve for the amount of water in the electrolytic solution can be obtained.
これにより求めた溶融塩中の水分含有量は400ppm以下
であり、NH4F2HあるいはNH4Fより調製した場合と比較し
て半分以下であった。The water content in the molten salt thus determined was 400 ppm or less, which was less than half that in the case of preparation from NH 4 F 2 H or NH 4 F.
次に電解を行なうが、炭素電極を用いたNH4F・HF系溶
融塩電解の運転形態は前述した理由により連続的方法を
適用する。Next, electrolysis is performed. The operation mode of NH 4 F · HF molten salt electrolysis using a carbon electrode employs a continuous method for the above-described reason.
まず電解槽に溶融塩を仕込んだ。溶融塩は前述で調製
したNH3ガスとHFガスからの溶融塩を用いたが、電解開
始時だけならば脱水電解を行うことは差し支えないの
で、NH4F・HFあるいはNH4Fを原料として調製された溶融
塩を用いても構わない。First, the molten salt was charged in the electrolytic cell. As the molten salt, the molten salt prepared from the NH 3 gas and the HF gas prepared above was used.However, if it is only at the start of electrolysis, dehydration electrolysis can be performed, so NH 4 FHF or NH 4 F is used as a raw material. The prepared molten salt may be used.
脱水電解はNi電極を陽極として、電流密度20mA/cm2程
度で通電量40 A・hr/l−溶融点、以上の電解を行なう。
尚、陰極には鉄（Fe）を使用した。In the dehydration electrolysis, a Ni electrode is used as an anode, and a current density of about 20 mA / cm 2 and an electric current of 40 A · hr / l—melting point, and the above electrolysis is performed.
In addition, iron (Fe) was used for the cathode.
脱水電解が終了したならば、次に電極を炭素電極に切
り替えた本電解を行なう。連続電解において供給される
溶融塩は電解槽とは別に設けられた溶融塩調製用容器中
で調製された溶融塩を供給しながら行なうが、電解槽そ
のものを該溶融塩調製用容器と考えても、本発明ではこ
れを等価に実施出来るものである。即ち、電解槽にNH3
ガスとHFガスの導入口、槽内圧力調製用の設備を新たに
設けるだけでよい。電解が進み溶融塩が消費されるに従
い、NH3ガスとHFガスを供給すれば良いが、電解槽内の
圧力変動をできるだけ少なくするために、NH3ガスとHF
ガスの吹き出し口は、電解槽内の気相部より溶融塩の液
中に設けられているのが好ましい。該吹き出し口は、出
来るだけ接近している方が電解槽中の溶融塩の組成が均
一となるため好ましい。またNH3ガス、HFガス共に溶融
塩にはきわめて速やかに吸収されるため供給量が少ない
場合等は、供給管を逆流する虞がある。このためNH3ガ
スおよびHFガスに乾燥N2ガスを10〜20％程度同伴させる
と逆流は起こらずに安定に供給が可能となる。After the completion of the dehydration electrolysis, the main electrolysis is performed with the electrode switched to a carbon electrode. The molten salt supplied in the continuous electrolysis is performed while supplying the molten salt prepared in a molten salt preparation container provided separately from the electrolytic cell, but the electrolytic cell itself may be considered as the molten salt preparation container. In the present invention, this can be implemented equivalently. That is, NH 3
It is only necessary to newly provide gas and HF gas inlets and equipment for adjusting the pressure in the tank. According molten salt electrolysis proceeds are consumed, may be supplied to the NH 3 gas and HF gas, in order to minimize the pressure fluctuations in the electrolytic cell, NH 3 gas and HF
The gas outlet is preferably provided in the liquid of the molten salt rather than the gas phase in the electrolytic cell. The outlet is preferably as close as possible because the composition of the molten salt in the electrolytic cell becomes uniform. In addition, since both NH 3 gas and HF gas are absorbed very quickly by the molten salt, when the supply amount is small, the supply pipe may flow backward. For this reason, when dry NH 2 gas is entrained in the NH 3 gas and HF gas by about 10 to 20%, the back flow does not occur and the supply can be performed stably.
尚、本発明は炭素電極を用いてNH4F・HF系溶融塩の電
解を行うことを主目的に実施されるものであるが、Ni等
の金属電極において電解を行なうことも、水分含有量の
少ない溶融塩を供給できるため、不純物であるOF2，N2O
等の不純物生成量を低く抑えられる利点を有している。Incidentally, the present invention is intended to be carried out mainly for electrolysis of NH 4 F.HF-based molten salt using a carbon electrode, it is also possible to perform electrolysis on a metal electrode such as Ni, water content It is possible to supply a molten salt with a low content of impurities, so that impurities such as OF 2 and N 2 O
Has the advantage that the amount of generated impurities can be kept low.
（実施例） 以下、実施例により本発明を更に具体的に説明する。
尚、以下において％、ppmは特記しない限り容量基準を
表わす。(Examples) Hereinafter, the present invention will be described more specifically with reference to examples.
In the following,% and ppm are based on the capacity unless otherwise specified.
実施例１ 第１図に示す装置を使用して溶融塩を調製した。Example 1 A molten salt was prepared using the apparatus shown in FIG.
まず、予め内面を十分に乾燥させた容量5lの溶融塩調
製用容器１に乾燥N2ガスを3l/minにて30分間供給し、容
器内部を完全に乾燥N2ガスで置換した。First, dry N 2 gas was supplied at a rate of 3 l / min for 30 minutes to a molten salt preparation container 1 having a capacity of 5 liters whose inner surface was sufficiently dried in advance, and the inside of the container was completely replaced with dry N 2 gas.
次に溶融塩調製用容器１本体を80℃の調温浴５に浸
し、液化NH3ガスボンベより供給されるNH3ガス３および
HFガスボンベより供給されるHFガス４を各々11g/min、3
9g/minにて約100分間供給し、組成NH4F・2HFの溶融塩5k
gを調製した。Next, the main body of the molten salt preparation vessel 1 is immersed in a temperature control bath 5 at 80 ° C., and NH 3 gas 3 supplied from a liquefied NH 3 gas cylinder and
HF gas 4 supplied from HF gas cylinder is 11g / min, 3
Supplied at 9 g / min for about 100 minutes, molten salt of composition NH 4 F ・ 2HF 5k
g was prepared.
この間、溶融塩調製用容器１内圧の若干の変動が微圧
計６で観測されたが、圧力は正圧に常時保たれた。調製
された溶融塩７の一部を水分定量用の小型セルに導入
し、水分量を測定したところ約300ppmであった。During this time, a slight change in the internal pressure of the molten salt preparation vessel 1 was observed by the micromanometer 6, but the pressure was always maintained at a positive pressure. A part of the prepared molten salt 7 was introduced into a small cell for water content measurement, and the water content was measured to be about 300 ppm.
次に容量約20lの電解槽９に溶融塩調製用容器１で調
製された溶融塩７で満たし、陽極にNi電極を使用して電
流密度20mA/cm2で約1000A・hrの脱水電解を行なった
後、陽極のNi電極を炭素電極に切り替え、電流密度100m
A/cm2で本電解を約１カ月行なった。この間、溶融塩調
製用容器１で調製された溶融塩を適宜補給し、電解槽中
の溶融塩量を一定に保った。Next, an electrolytic cell 9 having a capacity of about 20 liters is filled with the molten salt 7 prepared in the container 1 for preparing a molten salt, and dehydration electrolysis of about 1000 A · hr is performed at a current density of 20 mA / cm 2 using a Ni electrode as an anode. After that, switch the Ni electrode of the anode to a carbon electrode, and set the current density to 100 m.
The main electrolysis was performed at A / cm 2 for about one month. During this time, the molten salt prepared in the molten salt preparation container 1 was appropriately replenished, and the amount of the molten salt in the electrolytic cell was kept constant.
以上の結果、炭素電極を使用しての連続運転におい
て、陽極効果は発生せず、電解運転を継続することが出
来た。As a result, in the continuous operation using the carbon electrode, the anode effect did not occur, and the electrolytic operation could be continued.
実施例２ 実施例１において最初に電解槽９に仕込む溶融塩20l
のみをNH4F・HFおよびHF各々17kgと6.5kgにより調製さ
れた水分含有量0.2％の溶融塩を使用した他は実施例１
と同様の方法で行なった。Example 2 In Example 1, 20 l of molten salt initially charged in the electrolytic cell 9
Example 1 except that only a molten salt having a water content of 0.2% prepared with NH 4 F.HF and HF of 17 kg and 6.5 kg respectively was used.
Was performed in the same manner as described above.
その結果、炭素電極を使用しての連続運転において、
陽極効果は発生せず、電解運転を継続することが出来
た。As a result, in continuous operation using carbon electrodes,
The anode operation did not occur, and the electrolysis operation could be continued.
実施例３ 実施例１で使用した電解槽９にNH3ガス導入口10とHF
ガス導入口11の供給口を設けた。この電解槽９に実施例
１と同様の方法で調製された溶融塩７を仕込み、Ni陽極
を使用して脱水電解を行なった。この後、炭素電極に切
り替え電流密度を100mA/cm2にて１カ月の本電解を行っ
た。この間、消費された溶融塩の補給は、乾燥N2ガスを
10％同伴させた液化NH3ガスボンベより供給されるNH3ガ
スをNH3ガス導入口10より、無水HFガスボンベより供給
されるHFガスをHFガス導入口11より直接電解槽中の溶融
塩に吹き込む方法で行なった。Example 3 The NH 3 gas inlet 10 and the HF were connected to the electrolytic cell 9 used in Example 1.
A supply port for the gas inlet 11 was provided. The molten salt 7 prepared in the same manner as in Example 1 was charged into the electrolytic cell 9, and dehydration electrolysis was performed using a Ni anode. Thereafter, the electrode was switched to a carbon electrode and main electrolysis was performed at a current density of 100 mA / cm 2 for one month. During this time, supply of the consumed molten salt, the dry N 2 gas
The NH 3 gas supplied from the 10% entrained liquefied NH 3 gas cylinder were from the NH 3 gas inlet 10 is blown into the HF gas supplied from anhydrous HF gas cylinder in a molten salt of direct electrolysis bath than HF gas inlet 11 Performed by the method.
以上の結果、炭素電極を使用しての連続運転におい
て、陽極効果は発生せず、電解運転を継続することが出
来た。As a result, in the continuous operation using the carbon electrode, the anode effect did not occur, and the electrolytic operation could be continued.
実施例４ 実施例１において、脱水電解後の本電解においても引
続きNi電極を陽極として使用した他は実施例１と同様に
行なった。本電解中に陽極12より発生するNF3ガスを陽
極ガス出口管15をえて、液体窒素で冷却されたボンベを
用いて捕集した。該ガスを室温においてボンベ内で気化
させた後、ガスクロマトグラフィーにて分析を行なった
ところ、N2Oの含有量は約300ppm、OF2は検出限界以下で
あった。Example 4 Example 1 was carried out in the same manner as in Example 1 except that the Ni electrode was used as the anode in the main electrolysis after the dehydration electrolysis. The NF 3 gas generated from the anode 12 during the main electrolysis was collected by using a cylinder cooled with liquid nitrogen, with the anode gas outlet tube 15 provided. The gas was vaporized in a bomb at room temperature and analyzed by gas chromatography. As a result, the content of N 2 O was about 300 ppm, and the content of OF 2 was below the detection limit.
（比較例） 比較例１ 実施例１において本電解中に補給する溶融塩にNH4F・
HFおよびHFにより調製された組成NH4F・2HF、水分含有
量0.12％の溶融塩を使用し、陽極に炭素電極を用いて、
実施例１と同様の方法で行なった。(Comparative Example) Comparative Example 1 In Example 1, NH 4 F ·
Using a molten salt having a composition of NH 4 F · 2HF prepared with HF and HF and a water content of 0.12%, using a carbon electrode as an anode,
This was performed in the same manner as in Example 1.
その結果、本電解開始後３日目に陽極効果が発生し、
電解の継続が不可能となった。As a result, the anodic effect occurred on the third day after the start of the main electrolysis,
Continuation of electrolysis became impossible.
比較例２ 実施例４において、本電解中に供給する溶融塩にNH4F
・HFおよびHFにより調製された組成NH4F・2HF、水分含
有量0.2％の溶融塩を使用した他は実施例１と同様の方
法で行った。本電解中に陽極より発生するガスを液体窒
素で冷却されたボンベを用いて捕集した。該ガスを室温
においてボンベ内で気化させた後、該ガスをガスクロマ
トグラフィーにて分析を行なったところ、N2Oの含有量
は約2000ppm、OF2は約200ppmであった。Comparative Example 2 In Example 4, NH 4 F was added to the molten salt supplied during the main electrolysis.
-The same method as in Example 1 was used, except that HF and a composition NH 4 F · 2HF prepared by HF and a molten salt having a water content of 0.2% were used. The gas generated from the anode during the main electrolysis was collected using a cylinder cooled with liquid nitrogen. After the gas was vaporized in a cylinder at room temperature, the gas was analyzed by gas chromatography. As a result, the content of N 2 O was about 2000 ppm, and the content of OF 2 was about 200 ppm.
（発明の効果） 本発明は以上詳細に説明したように、NH4F・HF系溶融
塩の電解法によりNF3ガスを製造するに際し、不溶性の
炭素電極を用いる際に問題となる陽極効果を起こさず
に、安定に電解を継続させることの出来る非常に有効な
方法である。(Effects of the Invention) As described in detail above, the present invention provides an anodic effect which is a problem when an insoluble carbon electrode is used in producing NF 3 gas by an electrolysis method of NH 4 F · HF-based molten salt. This is a very effective method that can continue electrolysis stably without causing the electrolysis.
前述の通り、最近、不純物の生成量の非常に少ない炭
素電極が開発されたこともあり、炭素電極においても高
純度ガスが製造できる可能性が高まったが、炭素電極の
使用は陽極効果の発生が大きな障害となっていたもので
ある。As mentioned above, the development of a carbon electrode with a very small amount of impurities has recently been developed, and the possibility of producing a high-purity gas with a carbon electrode has been increased. Was a major obstacle.
更には、低い水分含有量の溶融塩を用い、継続して電
解を行えることから、水分が原因となる不純物であるN2
O、OF2等の生成量も従来に比較して低く抑えられる利点
も有している。このことはNi電極を陽極として使用する
従来の製造方法においても同様であることは言うまでも
ない。Furthermore, since the electrolysis can be continuously performed using a molten salt having a low water content, N 2 which is an impurity caused by water is used.
O, also has advantages kept low in comparison the amount in conventional such OF 2. Needless to say, this is the same in the conventional manufacturing method using the Ni electrode as the anode.
第１図は実施例及び比較例で使用した溶融塩調製装置及
び電解装置を示す断面図である。 図において、 １……溶融塩調製用容器、２……N2ガス導入口、３……
NH3ガス導入口、４……HFガス導入口、５……調温浴、
６……微圧計、７……溶融塩、８……溶融塩抜出口弁、
９……電解槽、10……NH3ガス導入口（電解槽吹き込み
用）、11……HFガス導入口（電解槽吹き込み用）、12…
…陽極、13……陰極、14……隔壁、15……陽極ガス出口
管、16……陰極ガス出口管、17……調温用ヒーター及び
クーラー、 を示す。FIG. 1 is a sectional view showing a molten salt preparation apparatus and an electrolysis apparatus used in Examples and Comparative Examples. In FIG, 1 ...... molten salt preparation vessel, 2 ...... N 2 gas inlet, 3 ......
NH 3 gas inlet, 4 ... HF gas inlet, 5 ... Temperature bath,
6 ... Micro pressure gauge, 7 ... Molten salt, 8 ... Molten salt outlet valve,
9 ...... electrolytic bath, 10 ...... NH 3 gas inlet (for blowing electrolytic cell), 11 ...... HF gas inlet (for blowing electrolytic cell), 12 ...
... Anode, 13 ... Cathode, 14 ... Partition wall, 15 ... Anode gas outlet tube, 16 ... Cathode gas outlet tube, 17 ... Heating heater and cooler.
Claims (1)
するにおいて、フッ化水素とアンモニアより調整された
溶融塩を原料とし、溶融塩電解法により電解を行なうこ
とを特徴とする三弗化窒素ガスの製造方法。1. A process for producing nitrogen trifluoride gas by a molten salt electrolysis method, comprising using a molten salt prepared from hydrogen fluoride and ammonia as a raw material and performing electrolysis by a molten salt electrolysis method. Method for producing nitrogen iodide gas.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2164031A JP2854934B2 (en) | 1990-06-25 | 1990-06-25 | Method for producing nitrogen trifluoride gas |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2164031A JP2854934B2 (en) | 1990-06-25 | 1990-06-25 | Method for producing nitrogen trifluoride gas |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0456789A JPH0456789A (en) | 1992-02-24 |
| JP2854934B2 true JP2854934B2 (en) | 1999-02-10 |
Family
ID=15785495
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2164031A Expired - Lifetime JP2854934B2 (en) | 1990-06-25 | 1990-06-25 | Method for producing nitrogen trifluoride gas |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2854934B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5633158B2 (en) * | 2010-03-01 | 2014-12-03 | セントラル硝子株式会社 | Method and apparatus for measuring moisture content in compounds containing hydrogen fluoride |
| CN106222688B (en) * | 2016-07-19 | 2018-01-09 | 浙江博瑞电子科技有限公司 | A kind of method of ammonium acid fluoride Electrowinning Nitrogen trifluoride |
-
1990
- 1990-06-25 JP JP2164031A patent/JP2854934B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0456789A (en) | 1992-02-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101213325B (en) | Electrolytic apparatus for producing fluorine or nitrogen trifluoride | |
| JPH0755807B2 (en) | Method for producing nitrogen trifluoride | |
| EP2143826B1 (en) | Method of electrolytically synthesizing nitrogen trifluoride | |
| US5628894A (en) | Nitrogen trifluoride process | |
| JP2854934B2 (en) | Method for producing nitrogen trifluoride gas | |
| KR102617579B1 (en) | Method for producing anode for electrolytic synthesis and fluorine gas or fluorine-containing compound | |
| KR100742484B1 (en) | The electrolyzer for manufacturing nitrogen tri-fluoride to minimize the amount of a vaporized hydrogen flouride and the manufacturing method using the same | |
| JP2854952B2 (en) | Method for producing nitrogen trifluoride gas | |
| JPS6261115B2 (en) | ||
| JP2896196B2 (en) | Method for producing nitrogen trifluoride gas | |
| Tasaka et al. | Effect of Trace Elements on the Electrolytic Production of NF 3 | |
| JPH049488A (en) | Production of gaseous nitrogen trifluoride | |
| JPH03296412A (en) | Collection of trifluoromethanesulfonyl fluoride | |
| JPH11267652A (en) | Method of generating ozone water and hydrogen water, and device therefor | |
| US3276981A (en) | Electrolytic production of oxygen difluoride | |
| JPH02263988A (en) | Production of gaseous nitrogen trifluoride | |
| JPH03170307A (en) | Production of nitrogen trifluoride | |
| JP3162594B2 (en) | Electrolytic solution and method for producing nitrogen trifluoride gas using the same | |
| JP3340273B2 (en) | Composite electrode and method for producing nitrogen trifluoride gas using the same | |
| JP2000104187A (en) | Electrolytic cell (1) | |
| JP2698457B2 (en) | Electrolytic cell | |
| US20230348272A1 (en) | Method of preparing sulfuryl fluoride | |
| US3454476A (en) | Electrolytic process for preparation of chlorine pentafluoride | |
| JPH02503931A (en) | Electrochemical generation of N2O5 | |
| JPH0261082A (en) | Electrolytic cell |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20081120 Year of fee payment: 10 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20091120 Year of fee payment: 11 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20101120 Year of fee payment: 12 |
|
| EXPY | Cancellation because of completion of term | ||
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20101120 Year of fee payment: 12 |