JPH1018071A - Method for electrolyzing aqueous salt solution - Google Patents
Method for electrolyzing aqueous salt solutionInfo
- Publication number
- JPH1018071A JPH1018071A JP17773096A JP17773096A JPH1018071A JP H1018071 A JPH1018071 A JP H1018071A JP 17773096 A JP17773096 A JP 17773096A JP 17773096 A JP17773096 A JP 17773096A JP H1018071 A JPH1018071 A JP H1018071A
- Authority
- JP
- Japan
- Prior art keywords
- bromine
- saline solution
- chlorine
- ions
- salt
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Landscapes
- Electrolytic Production Of Non-Metals, Compounds, Apparatuses Therefor (AREA)
Abstract
Description
【０００１】[0001]
【発明が属する技術分野】本発明は、食塩水溶液の電解
方法に関する。詳しくは、工業用食塩水溶液中に含まれ
る臭素イオンを次亜塩素酸イオンで酸化し、臭素として
系外に除去して電解槽に供給する臭素イオン濃度を特定
値未満に制御する食塩水溶液の電解方法に関する。The present invention relates to a method for electrolyzing a saline solution. More specifically, the electrolysis of a saline solution, in which bromine ions contained in an industrial saline solution are oxidized with hypochlorite ion, removed as bromine outside the system, and the bromine ion concentration supplied to the electrolytic cell is controlled to a specific value or less. About the method.
【０００２】[0002]
【従来の技術】塩素、苛性ソーダ等は食塩水溶液を電気
分解することにより製造される。通常、食塩には不純物
として臭化ナトリウム、臭化マグネシウム等の臭化物が
含まれるため、食塩水溶液には可成りの量の臭素イオン
が存在する。かかる食塩水溶液をそのまま電解処理する
と、得られる塩素中には多量の臭素が含まれることとな
る。そのため、高純度の塩素を製造するためには、電解
槽に供給する食塩水溶液を精製するか、または、得られ
た塩素を精製することにより臭素イオン、臭素等を除去
する必要がある。2. Description of the Related Art Chlorine, caustic soda and the like are produced by electrolyzing a saline solution. Usually, salt contains bromide such as sodium bromide and magnesium bromide as impurities, so that a considerable amount of bromine ion is present in the salt solution. If such a saline solution is subjected to electrolytic treatment as it is, a large amount of bromine will be contained in the obtained chlorine. Therefore, in order to produce high-purity chlorine, it is necessary to purify a saline solution supplied to the electrolytic cell or to purify the obtained chlorine to remove bromine ions, bromine, and the like.
【０００３】食塩水溶液の電解により得られた塩素に不
純物として含まれる臭素を除去する方法として、例え
ば、特開昭５９−９２９０３号公報には、２５００ｍｇ
／ｋｇ以下の臭素を含有する塩素を１重量倍以上の実質
的に臭素を含まない水で洗浄する塩素中の臭素の除去方
法が開示されている。そして、好ましい態様を示した実
施例には、充填塔式洗浄塔の下部から臭素を２５６ｍｇ
／ｋｇ含有する塩素ガスを１ｋｇ／ｈｒで供給し、塔上
部から４５℃の水を１２５ｋｇ／ｈｒで噴霧して、除去
率９８％で塩素中の臭素を除去する方法が記載されてい
る。As a method for removing bromine contained as an impurity in chlorine obtained by electrolysis of a saline solution, for example, JP-A-59-92903 discloses 2500 mg
A method for removing bromine in chlorine by washing chlorine containing 1 kg / kg or less of bromine with 1-fold weight or more of substantially bromine-free water is disclosed. In the example showing the preferred embodiment, 256 mg of bromine was added from the lower part of the packed tower type washing tower.
A method is described in which chlorine gas containing 1 kg / hr is supplied at 1 kg / hr, and water at 45 ° C. is sprayed at 125 kg / hr from the top of the tower to remove bromine in chlorine at a removal rate of 98%.
【０００４】該方法は、臭素の除去率が高い点では優れ
た方法である。しかし、大量の洗浄水を用いて洗浄する
ので、臭素と共に塩素も溶解し、その塩素及び臭素を含
む水を利用または消費することができる他の製造設備等
が併設されている場合には有用な方法であるが、かかる
設備が併設されていない場合には、排水処理設備等の付
帯設備が必要となるだけでなく、塩素の収率が低く、必
ずしも満足できる方法とはいえない。This method is an excellent method in that the removal rate of bromine is high. However, since washing is carried out using a large amount of washing water, chlorine is dissolved together with bromine, and this is useful when other manufacturing equipment or the like capable of utilizing or consuming water containing the chlorine and bromine is provided. When such a facility is not provided, not only an additional facility such as a wastewater treatment facility is required, but also the yield of chlorine is low, and the method is not always satisfactory.
【０００５】[0005]
【発明が解決しようとする課題】本発明の目的は、上記
の問題に鑑み、電解槽に供給する食塩水溶液を予め処理
して系内に持ち込む臭素イオン量を低下して、塩素を殆
ど損失することなしに得られる塩素中の臭素量を低下し
得る、食塩水溶液の電解方法を提供することにある。SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to preliminarily treat a saline solution to be supplied to an electrolytic cell to reduce the amount of bromine ions brought into the system, thereby almost losing chlorine. An object of the present invention is to provide a method for electrolyzing a saline solution, which can reduce the amount of bromine in chlorine obtained without any problem.
【０００６】[0006]
【課題を解決するための手段】本発明者らは、鋭意検討
した結果、食塩水溶液中の臭素イオンを特定の条件下で
次亜塩素酸イオンにより酸化して臭素とし、それを系外
に排出して臭素イオンの含有量が１０ｍｇ／リットル未
満に制御された食塩水溶液を電解槽に供給することによ
り、上記目的が達成できることを見出し、本発明に到っ
た。Means for Solving the Problems As a result of intensive studies, the present inventors oxidized bromine ions in a saline solution with hypochlorite ions under specific conditions to form bromine, which was discharged out of the system. The inventors have found that the above object can be achieved by supplying a saline solution in which the bromine ion content is controlled to less than 10 mg / liter to the electrolytic cell, and have reached the present invention.
【０００７】すなわち、本発明は、食塩水溶液中の臭素
イオン１モルに対して次亜塩素酸イオン１〜２モルを添
加、酸化し、該食塩水溶液をｐＨ４以下の塩酸酸性に調
整した後、不活性気体０．１〜１０ｍ3／ｍ3・ｍｉｎを
用いて少なくとも３０分間バブリングして生成した臭素
を系外に除去し、電解槽に供給する食塩水溶液中の臭素
イオン濃度を１０ｍｇ／リットル未満に制御することを
特徴とする食塩水溶液の電解方法である。That is, according to the present invention, 1 to 2 mol of hypochlorite ion is added to 1 mol of bromide ion in a salt solution and oxidized, and the salt solution is adjusted to pH 4 or less and acidified with hydrochloric acid. The generated bromine is removed from the system by bubbling with an active gas of 0.1 to 10 m 3 / m 3 · min for at least 30 minutes, and the bromine ion concentration in the saline solution supplied to the electrolytic cell is reduced to less than 10 mg / liter. A method for electrolyzing a saline solution characterized by controlling.
【０００８】本発明の特徴は、特定の処理を施すことに
より電解系内に持ち込む臭素イオン量を１０ｍｇ／リッ
トル未満に制御することにある。臭素イオンを未処理の
まま電解槽に供給する従来の方法の如き、塩素の損失の
原因となる生成塩素の精製なしに臭素の含有量が１５ｍ
ｇ／ｋｇ以下である高純度の塩素を製造することができ
る。A feature of the present invention is to control the amount of bromine ions brought into the electrolytic system to less than 10 mg / liter by performing a specific treatment. As in the conventional method of supplying untreated bromine ions to the electrolytic cell, the bromine content is 15 m without purification of the generated chlorine which causes the loss of chlorine.
g / kg or less of high-purity chlorine can be produced.
【０００９】[0009]
【発明の実施の形態】本発明の概要は、食塩を水に溶解
して食塩水溶液を調製し、得られた食塩水溶液に次亜塩
素酸イオンを含む次亜塩素酸ナトリウム水溶液等を添加
して、食塩水溶液に含まれる臭素イオンを酸化して０価
の臭素となし、次いで、該食塩水溶液に塩酸を加えてｐ
Ｈ４以下の酸性に調整し、さらに、生成した臭素をバブ
リングにより系外に除去して、食塩水溶液中の臭素イオ
ン濃度を１０ｍｇ／リットル未満となし、これを電解槽
に供給する方法である。BEST MODE FOR CARRYING OUT THE INVENTION The outline of the present invention is to prepare a saline solution by dissolving salt in water and adding an aqueous solution of sodium hypochlorite containing hypochlorite ions to the obtained saline solution. , The bromine ions contained in the saline solution are oxidized to form zero-valent bromine, and then hydrochloric acid is added to the saline solution to form p-valent bromine.
In this method, the acidity is adjusted to H4 or less, and the generated bromine is removed from the system by bubbling to reduce the bromine ion concentration in the saline solution to less than 10 mg / liter, and then supplied to the electrolytic cell.
【００１０】以下、本発明について詳細に説明する。本
発明が適用できる電解法には特に制限はなく、隔膜電解
法、水銀電解法等の公知の方法が適用できる。しかし、
環境汚染等を考慮すると隔膜電解法が好ましい。また、
本発明に用いる食塩水溶液の濃度には制限はないが、電
流効率等を考慮すると２０〜２５重量％程度のものが好
ましく使用される。Hereinafter, the present invention will be described in detail. The electrolysis method to which the present invention can be applied is not particularly limited, and known methods such as a diaphragm electrolysis method and a mercury electrolysis method can be applied. But,
In consideration of environmental pollution and the like, a diaphragm electrolysis method is preferable. Also,
The concentration of the saline solution used in the present invention is not limited, but a concentration of about 20 to 25% by weight is preferably used in view of current efficiency and the like.
【００１１】次亜塩素酸イオンを用いて、食塩水溶液に
含まれる臭素イオンを酸化する場合、両者が等モルであ
って、且つ、そのｐＨが４以下であるとその酸化反応は
下記式（１）〔化１〕When bromide ions contained in a saline solution are oxidized using hypochlorite ions, if both are equimolar and the pH is 4 or less, the oxidation reaction is represented by the following formula (1). ) [Formula 1]
【００１２】[0012]
【化１】 で表される。しかし、反応系がｐＨ４を超えると下記式
（２）〔化２〕Embedded image It is represented by However, when the pH of the reaction system exceeds 4, the following formula (2)
【００１３】[0013]
【化２】 で表されるように、臭素イオンが臭素酸イオンまで酸化
される。この場合、食塩水溶液を空気、不活性ガス等と
接触させても臭素として系外に排出することができな
い。従って、本発明においては、ｐＨ４以下の酸性下に
おいて酸化反応を行うことが重要である。また、反応系
のｐＨを酸性に調整するための酸として塩酸を用いる
と、下記式（３）〔化３〕Embedded image The bromine ion is oxidized to bromate ion as represented by In this case, even if the saline solution is brought into contact with air, an inert gas or the like, it cannot be discharged out of the system as bromine. Therefore, in the present invention, it is important to carry out the oxidation reaction under an acidic condition of pH 4 or less. When hydrochloric acid is used as an acid for adjusting the pH of the reaction system to be acidic, the following formula (3)
【００１４】[0014]
【化３】 で表されるように、系内の次亜塩素酸イオンが塩酸によ
り酸化され塩素が生成する。この塩素が、臭素イオンの
酸化剤として作用し、下記式（４）〔化４〕Embedded image As shown in the formula, hypochlorite ion in the system is oxidized by hydrochloric acid to generate chlorine. This chlorine acts as an oxidizing agent for bromine ions, and is represented by the following formula (4)
【００１５】[0015]
【化４】 により、系内（食塩水溶液中）の臭素イオンが臭素に酸
化され、上記式（１）による酸化反応に加えて、さらに
系内の臭素イオンが酸化されて臭素となる利点がある。
塩酸を用いずに例えば硫酸を用いてｐＨ調整を行うと、
電解槽に硫酸イオンが供給されることとなり、イオン交
換膜電解の場合にはイオン交換膜に悪影響を及ぼす。従
って、本発明においては、上記式（１）の酸化反応は塩
酸酸性下のｐＨ４以下で行うことが重要である。上記式
（２）の反応を抑制するためには、反応系のｐＨは低い
方が好ましいが、装置の腐食等他の問題もある。かかる
点を総合的に考慮すると、好ましいｐＨ領域は２〜３．
５程度である。Embedded image Accordingly, bromine ions in the system (in a saline solution) are oxidized to bromine, and in addition to the oxidation reaction of the above formula (1), bromine ions in the system are further oxidized to be bromine.
If the pH is adjusted using, for example, sulfuric acid without using hydrochloric acid,
Sulfate ions are supplied to the electrolytic cell, which adversely affects the ion exchange membrane in the case of ion exchange membrane electrolysis. Therefore, in the present invention, it is important that the oxidation reaction of the above formula (1) is carried out at pH 4 or less under hydrochloric acid. In order to suppress the reaction of the above formula (2), it is preferable that the pH of the reaction system is low, but there are other problems such as corrosion of the apparatus. Considering such points comprehensively, a preferable pH range is 2-3.
It is about 5.
【００１６】また、本発明では、上記式（１）の酸化反
応は臭素イオンと次亜塩素酸イオンとを等モル、または
次亜塩素酸イオンが過剰の状態で反応させることが好ま
しい。次亜塩素酸イオンを過剰に用いれば、上記式
（１）の酸化反応は促進されるが、系内に過剰の次亜塩
素酸イオンが存在することとなるので、これの処理が必
要となり大過剰の次亜塩素酸イオンを用いることは好ま
しくない。上限については２倍モル程度が好ましい。In the present invention, in the oxidation reaction of the above formula (1), it is preferable to react bromide ions and hypochlorite ions in equimolar amounts or in a state where hypochlorite ions are in excess. If the hypochlorite ion is used in excess, the oxidation reaction of the above formula (1) is promoted, but excess hypochlorite ion is present in the system, so that it is necessary to treat it. It is not preferable to use excess hypochlorite ion. The upper limit is preferably about 2 moles.
【００１７】通常、食塩は不純物としてマグネシウム化
合物、カルシウム化合物、硫酸塩等を含むので電解槽に
供給する食塩水溶液は、これらの不純物を除去するため
に前処理が施される。この前処理の際に上記式（１）の
酸化反応で消費された後の余剰の次亜塩素酸イオンが悪
影響を及ぼす。余剰の次亜塩素酸イオンは、上記式
（３）による酸化で処理されるが、チオ硫酸ナトリウム
等の還元剤を加えて中和等により処理することが好まし
い。チオ硫酸ナトリウム等の還元剤を加えることにより
上記式（３）の酸化反応で生じた塩素も同時に処理する
ことができる。Normally, salt contains magnesium compounds, calcium compounds, sulfates, and the like as impurities. Therefore, the salt solution to be supplied to the electrolytic cell is subjected to a pretreatment to remove these impurities. During this pretreatment, the surplus hypochlorite ion after being consumed by the oxidation reaction of the above formula (1) has an adverse effect. Excessive hypochlorite ion is treated by oxidation according to the above formula (3), but is preferably treated by adding a reducing agent such as sodium thiosulfate and neutralizing. By adding a reducing agent such as sodium thiosulfate, chlorine generated by the oxidation reaction of the above formula (3) can be simultaneously treated.
【００１８】上記式（１）の酸化剤である次亜塩素酸イ
オンとして次亜塩素酸ナトリウム等が使用される。食塩
水溶液中の臭素イオンを酸化する反応の温度には特に制
限はないが、通常１５〜９０℃である。好ましくは４０
〜６０℃である。As the hypochlorite ion as the oxidizing agent of the above formula (1), sodium hypochlorite or the like is used. The temperature of the reaction for oxidizing bromine ions in the saline solution is not particularly limited, but is usually 15 to 90 ° C. Preferably 40
６０60 ° C.
【００１９】本発明においては、食塩水溶液中の臭素イ
オンを臭素に酸化した後、食塩水溶液中に空気、窒素等
の食塩水溶液と反応しない不活性ガスを吹き込む、所
謂、バブリングすることにより生成した臭素を系外へ排
出、除去する。これは上記式（１）の酸化反応が平衡反
応であり、生成系の臭素を系外に排出することにより反
応を促進させることが可能となる。In the present invention, bromine generated by so-called bubbling, which is obtained by oxidizing bromine ions in a saline solution to bromine and then blowing an inert gas such as air or nitrogen which does not react with the saline solution into the saline solution. Is discharged out of the system and removed. This is because the oxidation reaction of the above formula (1) is an equilibrium reaction, and the reaction can be promoted by discharging bromine of the production system out of the system.
【００２０】食塩水溶液と不活性ガスの量比は、食塩水
溶液１ｍ3当たり不活性ガス０．１〜１０ｍ3／ｍｉｎ程
度を使用することが好ましい。空気または不活性ガスの
量が少な過ぎると、酸化反応で生成した臭素の系外への
排出、除去率が悪くなるばかりでなく、バブリングによ
り空気等を食塩水溶液に吹き込む際にガス導管部に食塩
が析出して導管を閉塞し、ガスの流れを著しく低下させ
る原因となる。逆に多過ぎると臭素と同時に食塩水も飛
沫となって損失することになる。空気等のバブリングに
代えてスクラバー等を用いて食塩水溶液と空気とを向流
接触する方法でもよい。It is preferable to use about 0.1 to 10 m 3 / min of inert gas per 1 m 3 of the saline solution as the ratio of the amount of the saline solution to the amount of the inert gas. If the amount of air or inert gas is too small, not only will the bromine generated by the oxidation reaction be discharged and removed from the system poorly, but also, when air or the like is blown into the saline solution by bubbling, the salt is introduced into the gas conduit. Precipitates and clogs the conduit, causing a significant decrease in gas flow. Conversely, if the amount is too large, the bromine and the salt solution will also be sprayed and lost. A method in which a saline solution and air are brought into countercurrent contact using a scrubber or the like instead of bubbling with air or the like may be used.
【００２１】バブリングの際の食塩水溶液の温度は１５
〜９０℃、好ましくは４０〜６０℃である。温度が高過
ぎると水が蒸発してガス導管部に食塩が析出し易くな
り、ガス流路を閉塞して流量を低下させる。また、水の
蒸発により過飽和食塩水溶液となり食塩が析出する。本
発明により系外に除去、排出された臭素は、苛性ソーダ
等を用いて処理することが好ましい。The temperature of the saline solution during bubbling is 15
To 90 ° C, preferably 40 to 60 ° C. If the temperature is too high, the water evaporates and salt easily precipitates in the gas conduit, which blocks the gas flow path and reduces the flow rate. In addition, a supersaturated saline solution is formed by evaporation of water, and sodium chloride is precipitated. The bromine removed and discharged outside the system according to the present invention is preferably treated using caustic soda or the like.
【００２２】工業用食塩は、通常、臭素イオンとして１
００〜２００ｍｇ／ｋｇ程度の臭素化合物を含む。従っ
て、通常、電解槽に供給される食塩水溶液の濃度は２５
重量％程度であることを考慮すると、食塩水溶液中に
は、２５〜５０ｍｇ／リットル程度の臭素イオンが含ま
れる。上記方法により酸化、バブリング等を施すことに
より、その臭素イオンを１０ｍｇ／リットル未満に低下
することが可能である。除去率は７０％以上である。電
解槽に供給する食塩水溶液中の臭素イオン濃度の下限は
０に近い程度に低いことが好ましいが、臭素の水への溶
解性を考慮すると、空気等のバブリングを上記条件で１
時間以上行えば、その下限は通常０．５ｍｇ／リットル
程度である。Industrial salt is usually 1 as bromine ion.
It contains about 00 to 200 mg / kg of a bromine compound. Therefore, the concentration of the saline solution supplied to the electrolytic cell is usually 25
Considering that the amount is about% by weight, the saline solution contains about 25 to 50 mg / liter of bromine ions. By performing oxidation, bubbling, and the like by the above method, the bromine ion can be reduced to less than 10 mg / liter. The removal rate is 70% or more. The lower limit of the bromine ion concentration in the saline solution supplied to the electrolytic cell is preferably as low as close to 0.
If performed for more than an hour, the lower limit is usually about 0.5 mg / liter.
【００２３】通常、電解法により、食塩水溶液から塩素
を製造する際には、電解槽を一回通過させる時に電解槽
で消費される食塩は供給量の３０〜４０重量％程度であ
り、残りは戻り食塩水溶液として循環再利用される。従
って、工業的電解法では、電解槽内で消費された食塩の
量に相当する食塩を新たに溶解して系内に追加される。
かかる工程を考慮したとき、本発明の好ましい適用方法
は、食塩を新たに溶解して調製した食塩水溶液に対し
て、上記臭素イオンの酸化、バブリングによる臭素の除
去を施す方法である。因に、戻り食塩水溶液系にのみ上
記臭素イオンの酸化、バブリングによる臭素の除去を適
用した場合でも食塩水溶液中の臭素イオンの低減を図る
ことができる。しかし、その場合、電解槽から排出され
た食塩水溶液中には３０００ｍｇ／リットル程度の塩素
が存在するため、臭素と共に塩素も除去されることとな
り経済的でない。Normally, when chlorine is produced from a saline solution by an electrolysis method, the amount of salt consumed in the electrolytic cell when it is passed once through the electrolytic cell is about 30 to 40% by weight of the supplied amount, and the balance is the balance. It is circulated and reused as a return salt solution. Therefore, in the industrial electrolysis method, the salt corresponding to the amount of the salt consumed in the electrolytic cell is newly dissolved and added to the system.
In consideration of such a step, a preferred method of application of the present invention is a method of oxidizing bromine ions and removing bromine by bubbling a saline solution prepared by newly dissolving salt. Incidentally, even when the above-described oxidation of bromine ions and the removal of bromine by bubbling are applied only to the return saline solution system, the amount of bromine ions in the saline solution can be reduced. However, in this case, since about 3000 mg / liter of chlorine is present in the saline solution discharged from the electrolytic cell, chlorine is removed together with bromine, which is not economical.
【００２４】[0024]
【実施例】以下、実施例を示して本発明についてさらに
詳細に説明する。なお、実施例に示した臭素イオン及び
臭素濃度は下記方法により測定した値である。 （１）臭素イオン濃度（ｍｇ／リットル） イオンクロマトグラフ（ダイオネックス社製、形式：Ｄ
ＩＯＮＥＸ４０００Ｉ、カラム：ＳＥＰＡＲＡＴＥＲ
ＡＳ４Ａ、ＳＵＰＰＲＥＳＳＯＲ ＡＭＭＳ−ＩＣＥ、
溶離液：炭酸水素ナトリウム（１ミリモル／リット
ル）、炭酸ナトリウム（２ミリモル／リットル）、溶離
液流速：１．２ミリリットル／ｍｉｎ、検出器〔日本分
光（株）製、形式：ＵＶ−９７０、ＵＶ２０５ｎｍ、カ
ラム及び検出器の温度：室温、試料注入量：５０μリッ
トル〕、及び、データ処理装置〔島津（株）製、形式：
ＣＲ−３Ａ〕を用いて、臭素イオンに基づくピーク面積
から、予め作成した検量線により測定する。The present invention will be described below in further detail with reference to examples. The bromine ion and bromine concentrations shown in the examples are values measured by the following methods. (1) Bromine ion concentration (mg / liter) Ion chromatograph (manufactured by Dionex, model: D
IONEX4000I, column: SEPARATER
AS4A, SUPPRESSOR AMMS-ICE,
Eluent: sodium hydrogen carbonate (1 mmol / l), sodium carbonate (2 mmol / l), eluent flow rate: 1.2 ml / min, detector [manufactured by JASCO Corporation, type: UV-970, UV205 nm , Temperature of column and detector: room temperature, sample injection volume: 50 μl], and data processor [manufactured by Shimadzu Corporation, type:
[CR-3A] using a calibration curve prepared in advance from the peak area based on bromine ions.
【００２５】（２）臭素濃度（ｍｇ／ｋｇ） ＪＩＳ Ｋ−０１０１に規定される方法に従い、塩素ガ
ス１０ｇを１５重量％の苛性ソーダ水溶液に吸収し、ヨ
ウ素滴定法により塩素濃度を求める。次いで、吸収液１
ミリリットルをヨードフラスコに採取し、塩酸でｐＨ２
以下に調整して塩素及び臭素を遊離させる。次いで、３
０重量％過酸化水素水溶液を加えて塩素及び臭素をイオ
ンに還元する。以下、前項の方法により、臭素イオン濃
度を求める。(2) Bromine concentration (mg / kg) According to the method specified in JIS K-0101, 10 g of chlorine gas is absorbed into a 15% by weight aqueous solution of caustic soda, and the chlorine concentration is determined by an iodine titration method. Next, absorbing liquid 1
Milliliters are collected in an iodine flask and adjusted to pH 2 with hydrochloric acid.
Release chlorine and bromine by adjusting as follows. Then 3
A 0% by weight aqueous hydrogen peroxide solution is added to reduce chlorine and bromine to ions. Hereinafter, the bromine ion concentration is determined by the method described in the preceding section.
【００２６】実施例１ 工業用食塩の２０重量％水溶液（臭素イオン濃度：２６
ｍｇ／リットル、０．３２ミリモル、２３℃）１ｍ3に
有効塩素１２重量％の次亜塩素酸ナトリウム２００ミリ
リットル（０．３４モル）を撹拌しながら加えた。次い
で、塩酸を加えてｐＨ３に調整した後、室温（２３℃）
で窒素ガスを０．５ｍ3／ｍｉｎ．の速度で３０分間吹
き込んだ。処理後の食塩水溶液中の臭素イオン濃度を上
記方法により測定した結果７．４ｍｇ／リットルであっ
た。処理後の食塩水溶液を６０℃に加熱した後、イオン
交換膜式電解槽（クロリン社製、形式：ＤＩ槽、電圧：
３．３Ｖ、電流：：６０，０００Ａ）に供給して電気分
解を行った。得られた塩素中の臭素を上記方法により測
定した結果、１４ｍｇ／ｋｇであった。得られた結果を
〔表１〕に示す。Example 1 A 20% by weight aqueous solution of industrial salt (bromine ion concentration: 26
mg / liter, 0.32 mmol, 23 ° C.) was added to 1 m 3 of 200 ml (0.34 mol) of sodium hypochlorite containing 12% by weight of available chlorine with stirring. Then, after adjusting the pH to 3 by adding hydrochloric acid, room temperature (23 ° C.)
At 0.5 m 3 / min. For 30 minutes. As a result of measuring the bromine ion concentration in the saline solution after the treatment by the above method, it was 7.4 mg / liter. After heating the treated saline solution to 60 ° C., an ion-exchange membrane electrolytic cell (manufactured by Chlorin, type: DI tank, voltage:
(3.3 V, current: 60,000 A) to perform electrolysis. As a result of measuring bromine in the obtained chlorine by the above method, it was 14 mg / kg. The results obtained are shown in [Table 1].
【００２７】実施例２ 工業用食塩の２５重量％水溶液（臭素イオン濃度：３２
ｍｇ／リットル ０．４モル）１ｍ3に有効塩素１２
重量％の次亜塩素酸ナトリウム３００ミリリットル
（０．５２モル）を撹拌しながら加えた。、次いで、塩
酸を加えてｐＨ２．３に調整した後、４０℃で空気を
０．１ｍ3／ｍｉｎ．の速度で３０分間吹き込んだ。処
理後の食塩水溶液中の臭素イオン濃度を上記方法により
測定した結果８．９ｍｇ／リットルであった。処理後の
食塩水溶液を実施例１と同様にして電気分解を行った。
得られた塩素中の臭素を上記方法により測定した結果、
１４ｍｇ／ｋｇであった。得られた結果を〔表１〕に示
す。Example 2 A 25% by weight aqueous solution of industrial salt (bromine ion concentration: 32
mg / l 0.4 mol) effective 1 m 3 chlorine 12
300 ml (0.52 mol) by weight of sodium hypochlorite were added with stirring. Then, after adding hydrochloric acid to adjust the pH to 2.3, air was added at 40 ° C. with 0.1 m 3 / min. For 30 minutes. As a result of measuring the bromine ion concentration in the saline solution after the treatment by the above method, it was 8.9 mg / liter. The treated saline solution was electrolyzed in the same manner as in Example 1.
As a result of measuring bromine in the obtained chlorine by the above method,
It was 14 mg / kg. The results obtained are shown in [Table 1].
【００２８】実施例３ 工業用食塩の２５重量％水溶液（臭素イオン濃度：３２
ｍｇ／リットル ０．２ミリモル）１ｍ3に有効塩素
１２重量％の次亜塩素酸ナトリウム３００ミリリットル
（０．５２モル）を撹拌しながら加えた。次いで、塩酸
を加えてｐＨ２．３に調整した後、４０℃で空気を０．
４ｍ3／ｍｉｎ．の速度で３０分間吹き込んだ。処理後
の食塩水溶液中の臭素イオン濃度を上記方法により測定
した結果６．７ｍｇ／リットルであった。処理後の食塩
水溶液を実施例１と同様にして電気分解を行った。得ら
れた塩素中の臭素を上記方法により測定した結果、１１
ｍｇ／ｋｇであった。得られた結果を〔表１〕に示す。Example 3 A 25% by weight aqueous solution of industrial salt (bromine ion concentration: 32
300 ml (0.52 mol) of sodium hypochlorite having 12% by weight of available chlorine was added to 1 m 3 of 1 mg (mg / l 0.2 mmol) with stirring. Next, the pH was adjusted to 2.3 by adding hydrochloric acid, and then air was added to the solution at 40 ° C. to a pH of 0.1.
4 m 3 / min. For 30 minutes. As a result of measuring the bromine ion concentration in the saline solution after the treatment by the above method, it was 6.7 mg / liter. The treated saline solution was electrolyzed in the same manner as in Example 1. As a result of measuring bromine in the obtained chlorine by the above method, 11
mg / kg. The results obtained are shown in [Table 1].
【００２９】比較例１ 実施例１で用いた工業用食塩の２０重量％水溶液（臭素
イオン濃度：２６ｍｇ／リットル、０．３２モル、２３
℃）を未処理のままで電解槽に供給した以外、実施例１
と同様にして食塩水溶液の電気分解を行った。得られた
塩素中の臭素を上記方法により測定した結果、５０ｍｇ
／ｋｇであった。得られた結果を〔表１〕に示す。Comparative Example 1 A 20% by weight aqueous solution of the industrial salt used in Example 1 (bromine ion concentration: 26 mg / liter, 0.32 mol, 23
Example 1 except that the raw material was supplied to the electrolytic cell in an untreated state.
The salt solution was electrolyzed in the same manner as described above. As a result of measuring bromine in the obtained chlorine by the above method, 50 mg was obtained.
/ Kg. The results obtained are shown in [Table 1].
【００３０】[0030]
【表１】 [Table 1]
【００３１】[0031]
【発明の効果】本発明によれば、電解槽から発生する塩
素を精製処理することなしに、臭素の含有量が１５ｍｇ
／リットル以下の高純度の塩素が得られる。According to the present invention, the content of bromine is reduced to 15 mg without purifying chlorine generated from the electrolytic cell.
Per liter or less of high purity chlorine is obtained.
Claims (2)
て次亜塩素酸イオン１〜２モルを添加、酸化し、該食塩
水溶液をｐＨ４以下の塩酸酸性に調整した後、不活性気
体０．１〜１０ｍ3／ｍ3・ｍｉｎを用いて少なくとも３
０分間バブリングして生成した臭素を系外に除去し、電
解槽に供給する食塩水溶液中の臭素イオン濃度を１０ｍ
ｇ／リットル未満に制御することを特徴とする食塩水溶
液の電解方法。1. A method of adding 1 to 2 mol of hypochlorite ion to 1 mol of bromide ion in a salt solution and oxidizing the solution to adjust the pH of the salt solution to hydrochloric acid of 4 or less. At least 3 using 1 to 10 m 3 / m 3 · min
The bromine generated by bubbling for 0 minute is removed out of the system, and the bromine ion concentration in the saline solution supplied to the electrolytic cell is reduced to 10 m.
A method for electrolyzing a saline solution, wherein the method is controlled to less than g / liter.
温度が１５〜９０℃であることを特徴とする請求項１記
載の食塩水溶液の電解方法。2. The concentration of a saline solution is 20 to 25% by weight,
The method according to claim 1, wherein the temperature is 15 to 90C.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17773096A JPH1018071A (en) | 1996-07-08 | 1996-07-08 | Method for electrolyzing aqueous salt solution |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17773096A JPH1018071A (en) | 1996-07-08 | 1996-07-08 | Method for electrolyzing aqueous salt solution |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH1018071A true JPH1018071A (en) | 1998-01-20 |
Family
ID=16036121
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP17773096A Pending JPH1018071A (en) | 1996-07-08 | 1996-07-08 | Method for electrolyzing aqueous salt solution |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH1018071A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2864969A1 (en) * | 2004-01-12 | 2005-07-15 | Solvay | Production of high quality chlorine by membrane electrolysis of a bromide-contaminated brine solution, in which the bromides are oxidised to bromates |
| JP2006167570A (en) * | 2004-12-15 | 2006-06-29 | Sumitomo Chemical Co Ltd | Method for removing bromine ion in saline solution |
| JP2011245484A (en) * | 2011-08-08 | 2011-12-08 | Tsurumi Soda Co Ltd | Salt water purification device and method |
| JP2014124600A (en) * | 2012-12-27 | 2014-07-07 | Sumitomo Heavy Industries Environment Co Ltd | Wastewater treatment system |
| JP2017009208A (en) * | 2015-06-23 | 2017-01-12 | 高知県公立大学法人 | Production system and production method of cooling medium capable of sterilization |
-
1996
- 1996-07-08 JP JP17773096A patent/JPH1018071A/en active Pending
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2864969A1 (en) * | 2004-01-12 | 2005-07-15 | Solvay | Production of high quality chlorine by membrane electrolysis of a bromide-contaminated brine solution, in which the bromides are oxidised to bromates |
| WO2005068686A3 (en) * | 2004-01-12 | 2006-01-19 | Solvay | Process for the production of high-purity chlorine |
| EA012069B1 (en) * | 2004-01-12 | 2009-08-28 | Солвей (Сосьете Аноним) | Process for the production of high-purity chlorine |
| JP2006167570A (en) * | 2004-12-15 | 2006-06-29 | Sumitomo Chemical Co Ltd | Method for removing bromine ion in saline solution |
| JP2011245484A (en) * | 2011-08-08 | 2011-12-08 | Tsurumi Soda Co Ltd | Salt water purification device and method |
| JP2014124600A (en) * | 2012-12-27 | 2014-07-07 | Sumitomo Heavy Industries Environment Co Ltd | Wastewater treatment system |
| JP2017009208A (en) * | 2015-06-23 | 2017-01-12 | 高知県公立大学法人 | Production system and production method of cooling medium capable of sterilization |
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