JPS638189B2 - - Google Patents
Info
- Publication number
- JPS638189B2 JPS638189B2 JP23684184A JP23684184A JPS638189B2 JP S638189 B2 JPS638189 B2 JP S638189B2 JP 23684184 A JP23684184 A JP 23684184A JP 23684184 A JP23684184 A JP 23684184A JP S638189 B2 JPS638189 B2 JP S638189B2
- Authority
- JP
- Japan
- Prior art keywords
- cathode
- iron
- active material
- cathode active
- deposits
- 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
Links
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 50
- 229910052742 iron Inorganic materials 0.000 claims description 25
- 238000000034 method Methods 0.000 claims description 18
- 239000000758 substrate Substances 0.000 claims description 14
- 239000007864 aqueous solution Substances 0.000 claims description 11
- 239000013543 active substance Substances 0.000 claims description 4
- YXVFQADLFFNVDS-UHFFFAOYSA-N diammonium citrate Chemical compound [NH4+].[NH4+].[O-]C(=O)CC(O)(C(=O)O)CC([O-])=O YXVFQADLFFNVDS-UHFFFAOYSA-N 0.000 claims description 4
- 230000001172 regenerating effect Effects 0.000 claims description 4
- 229910000640 Fe alloy Inorganic materials 0.000 claims description 3
- 239000006182 cathode active material Substances 0.000 description 27
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 15
- 238000012360 testing method Methods 0.000 description 13
- MUBZPKHOEPUJKR-UHFFFAOYSA-N Oxalic acid Chemical compound OC(=O)C(O)=O MUBZPKHOEPUJKR-UHFFFAOYSA-N 0.000 description 12
- 238000002474 experimental method Methods 0.000 description 11
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 10
- 238000005868 electrolysis reaction Methods 0.000 description 10
- 230000000694 effects Effects 0.000 description 9
- 239000000243 solution Substances 0.000 description 8
- 238000003756 stirring Methods 0.000 description 8
- 150000003839 salts Chemical class 0.000 description 7
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 6
- 239000000463 material Substances 0.000 description 6
- 239000002253 acid Substances 0.000 description 5
- 238000010306 acid treatment Methods 0.000 description 5
- 239000010406 cathode material Substances 0.000 description 5
- 235000011121 sodium hydroxide Nutrition 0.000 description 5
- 239000010410 layer Substances 0.000 description 4
- 229910052751 metal Inorganic materials 0.000 description 4
- 239000002184 metal Substances 0.000 description 4
- 229910052759 nickel Inorganic materials 0.000 description 4
- 235000006408 oxalic acid Nutrition 0.000 description 4
- 239000003929 acidic solution Substances 0.000 description 3
- 239000011248 coating agent Substances 0.000 description 3
- 238000000576 coating method Methods 0.000 description 3
- 239000002344 surface layer Substances 0.000 description 3
- 229920000298 Cellophane Polymers 0.000 description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 239000011247 coating layer Substances 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 238000007747 plating Methods 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 229910000990 Ni alloy Inorganic materials 0.000 description 1
- 229910021607 Silver chloride Inorganic materials 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 1
- 229910001297 Zn alloy Inorganic materials 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Substances [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 1
- -1 platinum metals Chemical class 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000008929 regeneration Effects 0.000 description 1
- 238000011069 regeneration method Methods 0.000 description 1
- HKZLPVFGJNLROG-UHFFFAOYSA-M silver monochloride Chemical compound [Cl-].[Ag+] HKZLPVFGJNLROG-UHFFFAOYSA-M 0.000 description 1
- 238000007751 thermal spraying Methods 0.000 description 1
- 239000010936 titanium Substances 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- YWYZEGXAUVWDED-UHFFFAOYSA-N triammonium citrate Chemical compound [NH4+].[NH4+].[NH4+].[O-]C(=O)CC(O)(CC([O-])=O)C([O-])=O YWYZEGXAUVWDED-UHFFFAOYSA-N 0.000 description 1
- 239000001393 triammonium citrate Substances 0.000 description 1
- 235000011046 triammonium citrate Nutrition 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
- 239000011701 zinc Substances 0.000 description 1
Description
〔発明の目的〕
（産業上の利用分野）
本発明は、食塩電解に使用して表面に鉄系デポ
ジツトが析出した陰極を再生する方法に関する。
（従来技術）
食塩電解においては、電槽電圧を減少させ、経
済的に水酸化ナトリウムを製造するための一つの
方法として、使用する陰極物質を改良して水素過
電圧を低下させることが従来から種々提案されて
いる。これらの陰極物質は、触媒活性を持つ各種
金属から構成され、経済的見地から、鉄、銅、ニ
ツケル等の基材の表面に触媒活性を持つ金属の層
を形成し、使用されている。この陰極を食塩電解
用として長期間使用すると、電解槽の壁面から鉄
が溶出して陰極表面に析出したり、また陰極物質
が多孔質で基材が鉄系の場合には基材から鉄が溶
出して陰極表面に析出し、電圧を向上させるとい
う現象が生じることが指摘されている。陰極表面
に鉄系のデポジツトが発生すると、有効陰極面積
の減少および電圧の上昇等の不都合が生じる。な
お、陰極の使用がさらに長期に及ぶと、陰極表面
に鉄が析出するだけでなく、陰極物質自体の活性
が低下する。
陰極物質の活性が低下した陰極の再生について
は、表層部を機械的手段で除去して酸洗し、その
後陰極活性物質を被覆する方法が提案されている
（特開昭59―50195号公報）。この方法は、表層部
除去の後、陰極活性物質を被覆するため、表層部
除去の際陰極活性物質の傷つける可能のある機械
的手段を採用している。従つてこの方法は、鉄系
デポジツトが析出したのみで、陰極活性物質自体
の活性が低下していない陰極の再生に使用するに
は不適当である。
（発明が解決しようとする問題点）
本発明者は、表面に鉄系デポジツトが析出した
陰極のデポジツトを機械的手段によることなく、
簡単かつ確実に陰極活性物質及び基体を傷つけず
に除去する方法につき種々検討した結果、本発明
に到達したものである。
〔発明の構成〕
本発明は、鉄または鉄合金から成る基体上に多
孔質の陰極活性物質を被覆して成る陰極を、食塩
電解に使用してその表面に析出した鉄系のデポジ
ツトを除去して陰極を再生する方法において、デ
ポジツトが生じた陰極を、陰極活性物質を溶解さ
せないPH３〜６の酸性溶液中に浸漬してデポジツ
トを除去する陰極の再生方法である。
以下、本発明につき詳細に説明する。
本発明方法に使用する陰極基体は、鉄又は鉄合
金であり、その形状は、エクスパンデツドメタル
状、金網状、パンチングプレート状等、各種のも
のを制限なく使用することができる。次に、基材
上に被覆される陰極活性物質は、ニツケル、チタ
ン、白金属系金属あるいはそれらの酸化物等従来
のものを制限なく使用でき、基材への被覆方法も
陰極活性物質が多孔質となるよう被覆できるもの
であれば、どのような方法を採用してもよい。た
とえば、ニツケルとアルミニウムの混合被覆層を
溶射により設けた後、該被覆層を水酸化ナトリウ
ム水溶液に接触させてアルミニウムを溶出させて
多孔質とすることができる。
この陰極を長期間食塩電解用として使用してい
くと、生成する水酸化ナトリウムが、陰極活性物
質の多孔内を通つて陰極基体と接触して、あるい
は電解槽の壁面と接触して鉄を溶出し、この溶出
した鉄が陰極表面にデポジツトとして析出する。
本発明に使用する劣化した陰極は、比較的短期間
の使用により陰極活性物質の活性が低下せず鉄系
デポジツトが析出したものが好ましいが、比較的
長期間の使用により陰極活性物質の活性が低下し
たものでもよい。このデポジツトを除去するに
は、機械的手段を使用することもできるが、陰極
活性物質を傷めたり、除去が不均一となつたりす
るおそれがあるので、本発明では酸処理を行うこ
とにより除去する。
本発明では、多孔質の陰極活性物質を使用して
いるので強酸性溶液で酸処理を行うと、基体と陰
極活性物質の密着面に酸溶液が含浸して陰極活性
物質が剥離しやすくなり、電解に耐えられなくな
る。従つて弱酸性下、陰極活性物質と基体との密
着性がほとんど低下しないような条件下で酸処理
を行うが、弱酸性であつても陰極活性物質を溶解
したり、活性を低下させたりしないよう使用する
酸を選択する。
本発明者の検討によると使用する酸性溶液のPH
範囲は３〜６とする必要がある。PH値を３より小
さくすると陰極活性物質が剥離し、また６より大
きくするとデポジツトを除去することができない
かあるいは除去速度が非常に小さく経済的でな
い。また使用する酸性溶液は、陰極活性物質を溶
解せないものである必要がある。たとえばニツケ
ルを陰極活性物質として使用した場合、クエン酸
２アンモニウム水溶液（PH約５）を用いるのが最
も好ましく、酸処理後の陰極活性物質と基体の密
着性及びデポジツトの除去状態とも良好である。
このほか希硫酸やシユウ酸を用いることもできる
が、PH３程度の希硫酸を用いるとデポジツトの除
去は十分であるが、陰極活性物質と基体の密着性
がやや悪くなり、またPH６程度のシユウ酸を用い
ると陰極活性物質と基体の密着性は低下しない
が、デポジツトの除去に長時間を有する。
クエン酸２アンモニウム水溶液を用いた場合
は、室温下、無撹拌で劣化した陰極を数時間放置
しておくだけで鉄系デポジツトが消失する。若干
加温したり、撹拌したりして処理時間を短縮する
こともできる。また希塩酸を用いた場合、室温
下、無撹拌で１時間処理すればデポジツトが消失
する。この場合は、陰極活性物質と基体との剥離
が起こりやすいため、加温したり、撹拌したりす
ることは好ましくない。さらにシユウ酸系を用い
た場合は、１日程度放置しなければデポジツトは
除去されない。しかし、この場合は条件が緩和で
あるため加温したり、撹拌したりして除去を促進
させることができる。
本発明方法により表面の鉄系デポジツトが除去
された陰極は、再度食塩電解に使用することによ
り、未使用の陰極とほぼ等しい電圧で運転でき、
しかも鉄系デポジツトが完全に除去されているた
め、蓄積鉄系デポジツトが隔膜と接触し、隔膜を
傷めることを事前に防止できる。
以下に、本発明の実施例を記載するが、本発明
はこれにより限定されるものではない。
（実施例 １）
陰極基体に次のメツキ条件で、ニツケルと亜鉛
の合金層を形成した。
メツキ浴
組成 NiCl2 250ｇ／
ZnCl2 45ｇ／
PH 4.5（HClで調整）
電流密度 3A／ｄm2
温 度 45℃
時 間 ２時間
合金層を被覆した陰極基体を10重量％のカセイ
ソーダ中に40℃で８時間浸漬し、混合層中の亜鉛
を溶出除去して陰極を製造した。
電解に先立つて電位を計測したところ、−
1.27V（vsAg／AgCl）であつた。この陰極を断面
積2.5dm2の実験槽の陰極として食塩電解を水酸化
ナトリウム濃度が約32％となるように95日間行つ
た。その後陰極を実験槽から取りはずし、40cm×
50cmに切断し、試験片とした。
この試験片をそれぞれ市販のクエン酸２アンモ
ニウム水溶液の50g／水溶液（実験１）、
100g／水溶液（実験２）及び150g／水溶液
（実験３）に室温下無撹拌で第１表に示すPH、処
理時間で酸処理を行つた。所定時間経過後の各試
験片の電位は第１表に示す通りであつた。また各
試験片の表面にセロテープの接着面を押しつけた
後、剥し取り、セロテープ面に付着する陰極活性
物質の量により密着性を判定した。付着量の少な
い方から優、良、可、不可の４段階で評価した。
（実施例 ２）
実施例１と同一の試験片をPH３に調整した希硫
酸に室温下無撹拌で１時間浸漬した。表面のデポ
ジツトは完全に除去されたが、密着性試験の結果
は可であつた。
（実施例 ３）
実施例１と同一の試験片をPH６に調整したシユ
ウ酸水溶液に60〜70℃に加温しながら、15時間浸
漬した。密着性試験の結果は優であつたが、表面
に若干の鉄系デポジツトが残存していた。
[Object of the Invention] (Industrial Application Field) The present invention relates to a method for regenerating a cathode that is used in salt electrolysis and has an iron-based deposit deposited on its surface. (Prior art) In salt electrolysis, various methods have been used to reduce the hydrogen overvoltage by improving the cathode material used, as one method to reduce the cell voltage and economically produce sodium hydroxide. Proposed. These cathode materials are composed of various catalytically active metals, and from an economical standpoint, they are used by forming a catalytically active metal layer on the surface of a base material such as iron, copper, or nickel. If this cathode is used for salt electrolysis for a long period of time, iron may be leached from the walls of the electrolytic tank and deposited on the cathode surface, or if the cathode material is porous and the base material is iron-based, iron may be removed from the base material. It has been pointed out that a phenomenon occurs in which it is eluted and deposited on the cathode surface, increasing the voltage. When iron-based deposits occur on the surface of the cathode, problems such as a decrease in the effective cathode area and an increase in voltage occur. Note that if the cathode is used for a longer period of time, not only will iron be deposited on the surface of the cathode, but the activity of the cathode material itself will decrease. Regarding the regeneration of a cathode whose cathode material activity has decreased, a method has been proposed in which the surface layer is removed by mechanical means, pickled, and then coated with a cathode active material (Japanese Patent Laid-Open No. 59-50195). . This method uses mechanical means that can damage the cathode active material during removal of the surface layer in order to cover the cathode active material after removal of the surface layer. Therefore, this method is not suitable for use in regenerating a cathode in which only iron-based deposits are deposited and the activity of the cathode active material itself is not reduced. (Problems to be Solved by the Invention) The present inventor has devised a method for removing deposits from a cathode on which iron-based deposits have been deposited on the surface of the cathode without using mechanical means.
The present invention was arrived at as a result of various studies on a method for easily and reliably removing the cathode active material and the substrate without damaging them. [Structure of the Invention] The present invention uses a cathode formed by coating a porous cathode active material on a substrate made of iron or an iron alloy for salt electrolysis to remove iron-based deposits deposited on the surface. In this method, the cathode with deposits formed thereon is immersed in an acidic solution of pH 3 to 6 that does not dissolve the cathode active substance to remove the deposits. Hereinafter, the present invention will be explained in detail. The cathode substrate used in the method of the present invention is made of iron or an iron alloy, and various shapes can be used without limitation, such as an expanded metal shape, a wire mesh shape, and a punched plate shape. Next, as the cathode active material coated on the base material, conventional materials such as nickel, titanium, platinum metals, or their oxides can be used without restriction, and the method for coating the base material is such that the cathode active material is porous. Any method may be used as long as it can provide a high quality coating. For example, after a mixed coating layer of nickel and aluminum is provided by thermal spraying, the coating layer can be brought into contact with an aqueous sodium hydroxide solution to dissolve the aluminum and make it porous. When this cathode is used for salt electrolysis for a long period of time, the generated sodium hydroxide passes through the pores of the cathode active material and comes into contact with the cathode substrate or the wall of the electrolytic tank, eluting iron. However, this eluted iron is deposited on the surface of the cathode.
The deteriorated cathode used in the present invention is preferably one in which the activity of the cathode active material does not decrease even after use for a relatively short period of time, and iron-based deposits have precipitated. It may be lowered. Mechanical means can be used to remove this deposit, but there is a risk of damaging the cathode active material or uneven removal, so in the present invention, acid treatment is used to remove it. . In the present invention, since a porous cathode active material is used, if acid treatment is performed with a strong acid solution, the acid solution will impregnate the contact surface between the substrate and the cathode active material, making it easier for the cathode active material to peel off. It will not be able to withstand electrolysis. Therefore, acid treatment is carried out under conditions where the adhesion between the cathode active material and the substrate is hardly reduced under weak acidity, but even if it is weakly acidic, it does not dissolve the cathode active material or reduce its activity. Choose the acid you want to use. According to the inventor's study, the pH of the acidic solution used is
The range should be 3-6. If the pH value is less than 3, the cathode active material will peel off, and if it is greater than 6, the deposits cannot be removed or the removal rate is very low, making it uneconomical. Furthermore, the acidic solution used must be one that cannot dissolve the cathode active substance. For example, when nickel is used as the cathode active material, it is most preferable to use a diammonium citrate aqueous solution (PH about 5), as it provides good adhesion between the cathode active material and the substrate after acid treatment and good deposit removal.
In addition, dilute sulfuric acid or oxalic acid can also be used; however, although it is sufficient to remove deposits using dilute sulfuric acid with a pH of about 3, the adhesion between the cathode active material and the substrate becomes somewhat poor, and oxalic acid with a pH of about 6 When using this method, the adhesion between the cathode active material and the substrate does not decrease, but it takes a long time to remove the deposit. When a diammonium citrate aqueous solution is used, the iron-based deposit disappears simply by leaving the deteriorated cathode for several hours at room temperature without stirring. The processing time can also be shortened by slightly heating or stirring. In addition, when dilute hydrochloric acid is used, the deposit disappears after treatment for 1 hour at room temperature without stirring. In this case, it is not preferable to heat or stir because the cathode active material and the substrate are likely to separate. Furthermore, if an oxalic acid type is used, the deposit will not be removed unless it is left for about a day. However, in this case, since the conditions are mild, removal can be promoted by heating or stirring. By using the cathode from which surface iron deposits have been removed by the method of the present invention for salt electrolysis again, it can be operated at almost the same voltage as an unused cathode.
Moreover, since the iron-based deposits are completely removed, it is possible to prevent the accumulated iron-based deposits from coming into contact with the diaphragm and damaging the diaphragm. Examples of the present invention are described below, but the present invention is not limited thereto. (Example 1) A nickel and zinc alloy layer was formed on a cathode substrate under the following plating conditions. Plating bath Composition NiCl 2 250g / ZnCl 2 45g / PH 4.5 (adjusted with HCl) Current density 3A/dm 2 Temperature 45℃ Time 2 hours The cathode substrate coated with the alloy layer was placed in 10% by weight of caustic soda at 40℃. After immersion for 8 hours, zinc in the mixed layer was eluted and removed to produce a cathode. When the potential was measured prior to electrolysis, -
It was 1.27V (vsAg/AgCl). Using this cathode as the cathode in an experimental tank with a cross-sectional area of 2.5 dm 2 , salt electrolysis was carried out for 95 days so that the sodium hydroxide concentration was approximately 32%. After that, remove the cathode from the experimental tank and
It was cut into 50 cm pieces and used as test pieces. These test pieces were each mixed with 50g/aqueous solution of commercially available diammonium citrate aqueous solution (Experiment 1),
100 g/aqueous solution (Experiment 2) and 150 g/aqueous solution (Experiment 3) were acid-treated at room temperature without stirring at the pH and treatment time shown in Table 1. The potential of each test piece after a predetermined period of time was as shown in Table 1. In addition, after pressing the adhesive side of cellophane tape onto the surface of each test piece, it was peeled off, and the adhesion was determined by the amount of cathode active material adhering to the surface of the cellophane tape. Evaluation was made in four stages: excellent, good, fair, and poor in descending order of the amount of adhesion. (Example 2) The same test piece as in Example 1 was immersed in dilute sulfuric acid adjusted to pH 3 for 1 hour at room temperature without stirring. Although the surface deposits were completely removed, the results of the adhesion test were acceptable. (Example 3) The same test piece as in Example 1 was immersed in an oxalic acid aqueous solution adjusted to pH 6 for 15 hours while being heated to 60 to 70°C. Although the results of the adhesion test were excellent, some iron-based deposits remained on the surface.
【表】
（比較例 １）
実施例１の試験片をそれぞれ、サンカイ化成株
式会社脱錆剤SRC＃1000の５倍希釈液（実験
４）、10倍希釈液（実験５）、20倍希釈液（実験
６）および40倍希釈液（実験７）に室温、無撹拌
下で第２表に示すPH処理時間で酸処理を行つた。
所定時間経過後の実験５〜７の各試験片の電位と
密着性試験の結果は第２表に示す通りであつた。[Table] (Comparative Example 1) The test pieces of Example 1 were treated with a 5-fold diluted solution (Experiment 4), a 10-fold diluted solution (Experiment 5), and a 20-fold diluted solution of Sankai Kasei Co., Ltd.'s derusting agent SRC #1000. (Experiment 6) and the 40-fold diluted solution (Experiment 7) were acid-treated at room temperature without stirring for the PH treatment times shown in Table 2.
The potential and adhesion test results of each test piece in Experiments 5 to 7 after a predetermined period of time were as shown in Table 2.
【表】
(b)：１時間でほとんど除去
(c)：デポジツト残存
（比較例 ２）
実施例１と同一の試験片をクエン酸３アンモニ
ウムの50g／水溶液（実験８）、100g／水溶
液（実験９）および150g／水溶液（実験10）
に浸漬し、約60℃に加熱しながら第３表にPH、処
理時間で処理を行つた。処理後の各試験片の表面
にデポジツトが残存した。処理後の電位は第３表
に示す通りであつた。[Table] (b): Almost removed in 1 hour
(c): Deposit remaining (Comparative Example 2) The same test piece as in Example 1 was tested with 50 g/aqueous solution of triammonium citrate (Experiment 8), 100 g/Aqueous solution (Experiment 9), and 150 g/Aqueous solution (Experiment 10).
The samples were immersed in water and heated to about 60°C while being treated according to the pH and treatment time shown in Table 3. Deposits remained on the surface of each test piece after treatment. The potentials after treatment were as shown in Table 3.
【表】
(a) デポジツト残存
〔発明の効果〕
本発明は、電解に使用することにより表面に鉄
系デポジツトが析出した陰極を再生するにあた
り、使用する処理液を陰極活性物質をほとんど溶
解しないPH３〜６としてある。従つて陰極活性物
質と基体との密着性をほとんど損うことなく、か
つ陰極活性物質の活性を低下させることなく、鉄
系デポジツトの析出により劣化した陰極を再生使
用することができる。特に、本発明を比較的短期
間の使用により、陰極活性物質の活性が低下せ
ず、表面にデポジツトが生じたのみの陰極に適用
すると、酸処理のみで元の状態にほぼ回復するの
で好都合である。しかし、本発明は陰極活性物質
の活性が低下した陰極に適用することもでき、こ
の場合にも鉄系デポジツトを容易に除去すること
ができる。[Table] (a) Deposit Remaining [Effect of the Invention] In the present invention, when regenerating a cathode on which iron-based deposits have been deposited on the surface due to use in electrolysis, the treatment solution used is PH3, which hardly dissolves the cathode active material. ~6. Therefore, a cathode that has deteriorated due to the precipitation of iron-based deposits can be reused without substantially impairing the adhesion between the cathode active material and the substrate and without reducing the activity of the cathode active material. In particular, when the present invention is applied to a cathode in which the activity of the cathode active substance does not decrease after a relatively short period of use and only deposits have formed on the surface, it is advantageous because the cathode can almost be restored to its original state with only acid treatment. be. However, the present invention can also be applied to a cathode in which the activity of the cathode active material is reduced, and iron-based deposits can also be easily removed in this case.
Claims (1)
質を被覆した陰極に析出した鉄系のデポジツトを
除去して陰極を再出する方法において、デポジツ
トが析出した陰極をクエン酸２アンモニウム水溶
液に浸漬してデポジツトを除去することを特徴と
する陰極の再生方法。1 In a method of removing iron-based deposits deposited on a cathode coated with a cathode active substance on a substrate made of iron or an iron alloy and re-extracting the cathode, the cathode with the deposit deposited is immersed in an aqueous solution of diammonium citrate. A method for regenerating a cathode, the method comprising removing deposits using a method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23684184A JPS61143588A (en) | 1984-11-12 | 1984-11-12 | Method for regenerating cathode |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23684184A JPS61143588A (en) | 1984-11-12 | 1984-11-12 | Method for regenerating cathode |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS61143588A JPS61143588A (en) | 1986-07-01 |
| JPS638189B2 true JPS638189B2 (en) | 1988-02-22 |
Family
ID=17006581
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP23684184A Granted JPS61143588A (en) | 1984-11-12 | 1984-11-12 | Method for regenerating cathode |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS61143588A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2543026B2 (en) * | 1985-09-20 | 1996-10-16 | 旭硝子株式会社 | Electrode processing method |
-
1984
- 1984-11-12 JP JP23684184A patent/JPS61143588A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS61143588A (en) | 1986-07-01 |
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