JPH0146596B2 - - Google Patents
Info
- Publication number
- JPH0146596B2 JPH0146596B2 JP56031143A JP3114381A JPH0146596B2 JP H0146596 B2 JPH0146596 B2 JP H0146596B2 JP 56031143 A JP56031143 A JP 56031143A JP 3114381 A JP3114381 A JP 3114381A JP H0146596 B2 JPH0146596 B2 JP H0146596B2
- Authority
- JP
- Japan
- Prior art keywords
- electrode
- expanded metal
- anode
- cathode
- membrane
- 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
- 229910052751 metal Inorganic materials 0.000 claims description 59
- 239000002184 metal Substances 0.000 claims description 59
- 238000005096 rolling process Methods 0.000 claims description 16
- 238000005868 electrolysis reaction Methods 0.000 claims description 13
- 238000000034 method Methods 0.000 claims description 9
- 239000003513 alkali Substances 0.000 claims description 7
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 claims description 6
- 239000012528 membrane Substances 0.000 description 24
- 239000003014 ion exchange membrane Substances 0.000 description 14
- 230000000694 effects Effects 0.000 description 11
- 229910001220 stainless steel Inorganic materials 0.000 description 11
- 239000010935 stainless steel Substances 0.000 description 11
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 10
- 230000000052 comparative effect Effects 0.000 description 10
- 239000010936 titanium Substances 0.000 description 10
- 229910052719 titanium Inorganic materials 0.000 description 10
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 9
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 7
- 239000007789 gas Substances 0.000 description 7
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 6
- 239000004809 Teflon Substances 0.000 description 5
- 229920006362 Teflon® Polymers 0.000 description 5
- KZBUYRJDOAKODT-UHFFFAOYSA-N Chlorine Chemical compound ClCl KZBUYRJDOAKODT-UHFFFAOYSA-N 0.000 description 4
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 4
- 238000005341 cation exchange Methods 0.000 description 4
- 239000000243 solution Substances 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 3
- 238000009826 distribution Methods 0.000 description 3
- 239000001257 hydrogen Substances 0.000 description 3
- 229910052739 hydrogen Inorganic materials 0.000 description 3
- 229910052742 iron Inorganic materials 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 3
- 238000012545 processing Methods 0.000 description 3
- 239000011780 sodium chloride Substances 0.000 description 3
- 235000011121 sodium hydroxide Nutrition 0.000 description 3
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 2
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- 229910052791 calcium Inorganic materials 0.000 description 2
- 239000011575 calcium Substances 0.000 description 2
- 239000003518 caustics Substances 0.000 description 2
- 239000000460 chlorine Substances 0.000 description 2
- 229910052801 chlorine Inorganic materials 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 238000005520 cutting process Methods 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000007872 degassing Methods 0.000 description 2
- 238000001514 detection method Methods 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 238000009413 insulation Methods 0.000 description 2
- 229910052759 nickel Inorganic materials 0.000 description 2
- 238000012856 packing Methods 0.000 description 2
- 150000003839 salts Chemical class 0.000 description 2
- 238000004904 shortening Methods 0.000 description 2
- 125000000391 vinyl group Chemical group [H]C([*])=C([H])[H] 0.000 description 2
- 229920002554 vinyl polymer Polymers 0.000 description 2
- 229920000557 Nafion® Polymers 0.000 description 1
- 229910001361 White metal Inorganic materials 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- 230000001154 acute effect Effects 0.000 description 1
- 229910001854 alkali hydroxide Inorganic materials 0.000 description 1
- 150000008044 alkali metal hydroxides Chemical class 0.000 description 1
- 239000010425 asbestos Substances 0.000 description 1
- 239000002585 base Substances 0.000 description 1
- 239000012267 brine Substances 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 239000002360 explosive Substances 0.000 description 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 239000010931 gold Substances 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 238000003672 processing method Methods 0.000 description 1
- 230000008844 regulatory mechanism Effects 0.000 description 1
- 229910052895 riebeckite Inorganic materials 0.000 description 1
- HPALAKNZSZLMCH-UHFFFAOYSA-M sodium;chloride;hydrate Chemical compound O.[Na+].[Cl-] HPALAKNZSZLMCH-UHFFFAOYSA-M 0.000 description 1
- 125000006850 spacer group Chemical group 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 238000013022 venting Methods 0.000 description 1
- 239000010969 white metal Substances 0.000 description 1
Landscapes
- Electrodes For Compound Or Non-Metal Manufacture (AREA)
- Electrolytic Production Of Non-Metals, Compounds, Apparatuses Therefor (AREA)
Description
【発明の詳細な説明】
本発明は隔膜法、特に陽イオン交換膜法による
塩化アルカリ電解を高電流密度、低電圧で行い経
済的に水酸化アルカリを製造する改良された電解
方法に関するものである。[Detailed Description of the Invention] The present invention relates to an improved electrolytic method for economically producing alkali hydroxide by carrying out alkali chloride electrolysis using a diaphragm method, particularly a cation exchange membrane method, at high current density and low voltage. .
一般に陽イオン交換膜を含む隔膜法電解槽は隔
膜によつて陽極室と陰極室に区画され陽極と陰極
は膜をはさんで等間隔に対峙して配置される。通
常、アスベスト隔膜は一般に陰極に密着して取付
けられるが陽イオン交換膜による電解の場合は普
通、膜を陽極に接近させ陰極室内液圧を陽極室内
液圧よりも高くして膜を陽極に接触保持すること
により陽極室および陰極室のガス吸引圧の多少の
アンバランスに影響されず電解電圧の変動を来た
さないように配慮されている。又陽極および陰極
は極面で発生する塩素ガス又は水素ガスの気泡の
遮蔽効果によつて電解電圧が上昇するのを防止す
る為に、気泡を電解の障害とならない電極の背後
に抜く為の孔又は間隙を設けた多孔性電極が使用
されている。 Generally, a diaphragm electrolytic cell containing a cation exchange membrane is divided into an anode chamber and a cathode chamber by a diaphragm, and the anode and cathode are arranged facing each other at equal intervals with the membrane in between. Normally, an asbestos diaphragm is installed in close contact with the cathode, but in the case of electrolysis using a cation exchange membrane, the membrane is usually brought close to the anode, and the liquid pressure in the cathode chamber is made higher than the liquid pressure in the anode chamber, so that the membrane is brought into contact with the anode. By holding it, consideration is given so that it is not affected by a slight imbalance in the gas suction pressures of the anode chamber and the cathode chamber and does not cause fluctuations in the electrolytic voltage. In addition, in order to prevent the electrolytic voltage from increasing due to the shielding effect of chlorine gas or hydrogen gas bubbles generated on the electrode surface, the anode and cathode are provided with holes to draw out the bubbles behind the electrodes where they will not interfere with electrolysis. Alternatively, porous electrodes with gaps are used.
一般にガス発生を伴う電解に用いられる電極は
溝状、棒状、網状、多孔板状、など種々あるが、
所謂エキスパンドメタルと称する多孔板は金属板
の加工ロスが極めて少なく製作費が他に比べて廉
価であり、且つガス抜効果が良いことから広く利
用されている。 Generally, there are various types of electrodes used for electrolysis that involve gas generation, such as groove-shaped, rod-shaped, mesh-shaped, and perforated plate-shaped electrodes.
A perforated plate called expanded metal is widely used because it has very little processing loss, is cheaper to manufacture than other metal plates, and has a good degassing effect.
このエキスパンドメタルの素材となる金属板は
陽極としてはチタンがあり、又陰極としては鉄、
ステンレス、ニツケル等がある。これらの金属板
を刻切拡張することによつて得られる特異な突起
と傾斜をもつた菱形又は亀甲形の開口部を有する
エキスパンドメタルは開口部がガス抜孔として気
泡が透過し易い形状であることから賞用され、チ
タン製エキスパンドメタルの表面を白金属金属又
はそれらの酸化物等をコーテイングして低塩素過
電圧および不溶性としたものが陽極として、又
鉄、ステンレス、ニツケル等のエキスパンドメタ
ルをそのまま、又はそれらの表面に活性化処理を
行つて低水素過電圧としたものが陰極として工業
的に利用されている。 The metal plate that is the material of this expanded metal has titanium as the anode, and iron and iron as the cathode.
There are stainless steel, nickel, etc. Expanded metal, which is obtained by cutting and expanding these metal plates, has unique protrusions and slanted diamond-shaped or tortoise-shell-shaped openings, and the openings act as gas vent holes that allow air bubbles to easily pass through. The surface of expanded titanium metal is coated with white metal or its oxide to make it low chlorine overvoltage and insoluble, and expanded metals such as iron, stainless steel, and nickel can be used as anodes. Alternatively, those whose surfaces are activated to have a low hydrogen overvoltage are used industrially as cathodes.
しかし、エキスパンドメタルをイオン交換膜法
電解の電極として用いる時にはその金属格子の陵
線が鋭角になつている為に厚みの極めて薄いイオ
ン交換膜が陽極室と陰極室の圧力変動などにより
振動してその鋭利な金属面に接触すると損傷を受
け、その性能を劣化するばかりでなく、切損開孔
して陽極室と陰極室のガス、液の混合を生じ、爆
鳴気の形成、生成苛性アルカリの純度汚損、電極
の損傷などの支障を来たす恐れがある。これを避
ける目的でイオン交換膜と電極との間隔にスペー
サーを挿入するか、余裕の距離を持たせるかな
ど、膜を電極に接触させない対策がとられている
がこれらの対策はいづれも電解電圧を大きくして
工業的に経済性を損ねる不都合を有する。 However, when expanded metal is used as an electrode for ion-exchange membrane electrolysis, the ridge lines of the metal lattice are at acute angles, so the extremely thin ion-exchange membrane vibrates due to pressure fluctuations between the anode and cathode chambers. If it comes into contact with sharp metal surfaces, it will not only be damaged and its performance deteriorated, but also be cut and opened, causing gas and liquid in the anode and cathode chambers to mix, forming explosive gas, and producing caustic alkali. There is a risk of problems such as contamination of purity and damage to electrodes. In order to avoid this, measures have been taken to prevent the membrane from coming into contact with the electrode, such as inserting a spacer between the ion exchange membrane and the electrode, or creating a sufficient distance between the membrane and the electrode. This has the disadvantage of increasing the value and impairing industrial efficiency.
エキスパンドメタル電極の鋭利な部分によるイ
オン交換膜の損傷防止を目的とする実開昭55−
83756号明細書には、電極として用いられるエキ
スパンドメタルに関し、従来よりプレスして平坦
な構造とした電極のあることが述べられている。
しかし、これを電解に供した場合、電解電圧が高
く、本来エキスパンドメタル電極が有する電解電
圧を低くする効果を減ずることも記述されてい
る。 Utility development in 1982 aimed at preventing damage to ion exchange membranes caused by sharp parts of expanded metal electrodes.
Regarding expanded metal used as an electrode, Patent No. 83756 states that there is an electrode that has been conventionally pressed into a flat structure.
However, it is also described that when this is subjected to electrolysis, the electrolytic voltage is high and the effect of lowering the electrolytic voltage that the expanded metal electrode originally has is reduced.
本発明者等はエキスパンドメタル電極がその加
工方法や利用法などによつて電解電圧の著しい低
減を可能にすることを見出し、本発明を完成する
に至つた。 The inventors of the present invention have discovered that an expanded metal electrode can significantly reduce the electrolytic voltage depending on its processing method and use, and have completed the present invention.
本発明の骨子とするところは、隔膜を陽極と陰
極との間に介在させた電解槽を用いて塩化アルカ
リ水溶液を電解するに当り、上記の陽極又は／お
よび陰極としてエキスパンドメタルの圧延加工に
よりその片面又は両面が平坦化され、かつ、圧延
加工後の見掛け厚みが上記圧延加工前のエキスパ
ンドメタルの見掛け厚みの60％以下で1.2mm以上
であり、開口率が20〜50％の範囲にある電極を用
い、該電極の平坦化された一面を隔膜表面より２
mm以下の接近状態で対面させて電解することを特
徴とする塩化アルカリ水溶液の電解方法である。 The gist of the present invention is that when an aqueous alkali chloride solution is electrolyzed using an electrolytic cell in which a diaphragm is interposed between an anode and a cathode, an expanded metal is used as the anode and/or cathode by rolling. An electrode that is flattened on one or both sides, has an apparent thickness after rolling of 60% or less of the apparent thickness of the expanded metal before rolling, and is 1.2 mm or more, and has an aperture ratio in the range of 20 to 50%. Using a diaphragm, place the flattened surface of the electrode 2
This is a method for electrolyzing an aqueous alkali chloride solution, which is characterized in that electrolysis is carried out in face-to-face contact with a distance of less than mm.
上記した本発明方法において、陽極又は／およ
び陰極としてエキスパンドメタルの片面又は両面
を圧延加工により平坦化せしめた電極を使用する
のであるが、かゝる電極（以下単に平坦状エキス
パンドメタル電極と称する）とは、表面に鋭利な
突起を有する本来無加工のエキスパンドメタル電
極（以下単に突起状エキスパンドメタル電極と称
する）の膜に面する突起部分を研磨或は切削して
その部分のみを平坦化又は彎曲化したものや、表
面および裏面の突起を鋭利でない程度に軽く平坦
化したものではなく、圧延加工により片面又は両
面を平坦化し、その圧延加工後の見掛け厚み
（こゝで云う見掛け厚みとは電極の一方の面より
他方の面までの最も突出した部分の距離で表わさ
れる厚みである。）が、圧延加工前のエキスパン
ドメタルの持つ見掛け厚みの60％以下、好ましく
は50％〜25％の範囲で、かつ1.2mm以上に圧延加
工を施したものであり、又電極の網目の開口率が
20〜50％、好ましくは25〜40％の範囲となるよう
に圧延加工を施したものである。平坦状エキスパ
ンドメタル電極の上記厚みは、これがうすい程開
口部に生成する気泡の滞留防止効果を増し、電気
流路を短くして電気抵抗の低下をもたらすが、極
端にうすくなるときには電極の強度が低下し、又
機械的強度を維持するため必然的に開口面積が減
少することからこれによる気泡除去効果が低下す
る。 In the method of the present invention described above, an electrode made of expanded metal with one or both sides flattened by rolling is used as the anode and/or cathode, and such an electrode (hereinafter simply referred to as a flat expanded metal electrode) is used. means polishing or cutting the protruding portion facing the film of an originally unprocessed expanded metal electrode (hereinafter simply referred to as a protruding expanded metal electrode) that has sharp protrusions on the surface, and flattening or curving only that portion. It is not a product that has been flattened or lightly flattened to the extent that the protrusions on the front and back surfaces are not sharp, but one or both sides are flattened by rolling, and the apparent thickness after rolling (the apparent thickness here refers to the electrode The thickness expressed as the distance of the most protruding part from one surface to the other surface is 60% or less, preferably in the range of 50% to 25%, of the apparent thickness of the expanded metal before rolling. and has been rolled to a thickness of 1.2 mm or more, and the aperture ratio of the electrode mesh is
It has been subjected to rolling processing so that it is in the range of 20 to 50%, preferably 25 to 40%. The thinner the flat expanded metal electrode is, the more effective it is in preventing the accumulation of air bubbles generated in the opening, shortening the electrical flow path and lowering the electrical resistance. However, when the thickness becomes extremely thin, the strength of the electrode decreases. In addition, since the opening area is necessarily reduced in order to maintain mechanical strength, the air bubble removal effect is reduced.
一方、開口率はこれが極端に小さくなると上記
の如く気泡除去効果が減じて電解電圧の上昇をも
たらし、過大となると電極強度の低下および電気
抵抗が増加して均一な電流分布が保てなくなる。
従つてこの様な厚みと開口率との兼ね合いで適正
な平坦状エキスパンドメタル電極を選ぶべきであ
る。 On the other hand, if the aperture ratio becomes extremely small, the bubble removal effect will be reduced as described above and the electrolysis voltage will increase, and if it becomes too large, the electrode strength will decrease and the electrical resistance will increase, making it impossible to maintain a uniform current distribution.
Therefore, an appropriate flat expanded metal electrode should be selected in consideration of the thickness and aperture ratio.
本発明に使用する平坦状エキスパンドメタル電
極は圧延加工によりエキスパンドメタルの片面の
みを平坦化した電極でもよいが加工の容易性その
他の理由により、両面共に平坦化せしめた電極が
より好ましい。 The flat expanded metal electrode used in the present invention may be an expanded metal with only one side flattened by rolling, but for ease of processing and other reasons, it is more preferable to use an electrode with both sides flattened.
さて、電解操業における電解電圧の低減方法と
しては、塩素過電圧の小さい陽極、水素過電圧の
小さい陰極、気泡効果を小とする電極構造、極間
距離の縮少、イオン交換膜の電気比抵抗の減少
化、高温、加圧、陽極液および陰極液の強制循環
などが知られ、実施されているが、本発明者等
は、エキスパンドメタル電極に関して次の注目す
べき現象があることを究明した。即ち、極／膜間
距離および極間距離がある領域外では突起状エキ
スパンドメタル電極の方が平坦状エキスパンドメ
タル電極よりも電解電圧が低く有利であるが、
極／膜間および陽陰両極間を極端に接近させると
その差は逆転し平坦状エキスパンドメタル電極の
方が突起状エキスパンドメタル電極よりも電解電
圧が低く有利になるという現象である。 Now, methods for reducing the electrolysis voltage during electrolysis operations include an anode with a small chlorine overvoltage, a cathode with a small hydrogen overvoltage, an electrode structure that minimizes the bubble effect, a reduction in the distance between the electrodes, and a reduction in the electrical specific resistance of the ion exchange membrane. Although methods such as heating, high temperature, pressurization, and forced circulation of anolyte and catholyte are known and practiced, the present inventors have discovered the following remarkable phenomenon regarding expanded metal electrodes. That is, outside the area where there is a certain distance between the electrodes and the membrane and the distance between the electrodes, the protruding expanded metal electrode has a lower electrolytic voltage than the flat expanded metal electrode, which is advantageous.
When the electrode/membrane gap and the positive and negative electrodes are made extremely close to each other, the difference is reversed, and the flat expanded metal electrode has a lower electrolytic voltage than the protruding expanded metal electrode, which is a phenomenon.
突起状エキスパンドメタル電極に関してこの様
な現象の生ずる根拠は次の通りと推定される。即
ち、突起状エキスパンドメタル電極の突起部分で
は、所謂尖端効果と称する電流の集中が生ずる
が、極間距離が大きい程集中化が緩和されるた
め、或る距離以上では電流の集中化による電圧損
失よりもガス抜効果による気泡抵抗減少が大き
く、従つて突起状エキスパンドメタル電極が平坦
状エキスパンドメタル電極よりも低い電圧を示し
有利と考えられる。ところが、陽極と陰極とを接
近させるに従い電極の突起部分での電流集中が大
となり電極面およびイオン交換膜の電流密度が極
端に不均一になることによつて電極電位および膜
抵抗が増大するものと考えられるのである。 The reason why such a phenomenon occurs regarding the protruding expanded metal electrode is presumed to be as follows. In other words, current concentration occurs at the protruding portion of the protruding expanded metal electrode, which is called the so-called tip effect, but as the distance between the electrodes increases, the concentration is alleviated, so that over a certain distance, voltage loss due to current concentration occurs. The reduction in bubble resistance due to the gas venting effect is greater than that of the conventional method, and therefore, the protruding expanded metal electrode exhibits a lower voltage than the flat expanded metal electrode, which is considered to be advantageous. However, as the anode and cathode are brought closer together, the current concentration at the protruding portion of the electrode increases, and the current density on the electrode surface and ion exchange membrane becomes extremely non-uniform, resulting in an increase in electrode potential and membrane resistance. This is thought to be the case.
又、イオン交換膜と突起状エキスパンドメタル
電極が極端に接近した場合には、特異な網目開口
部の形状は、膜に対面する開口部縁上にガスポケ
ツトを形成し、特に陰極では粒径の小さい水素気
泡が滞留し易く、ガス抜き効果は必ずしも良いと
は云えず、この点にも原因があると思われる。 In addition, when the ion exchange membrane and the protruding expanded metal electrode are extremely close together, the unique shape of the mesh openings forms gas pockets on the edges of the openings facing the membrane, and especially at the cathode, small particle size Hydrogen bubbles tend to remain, and the degassing effect is not necessarily good, and this seems to be another reason.
こゝで本発明者等が突起状エキスパンドメタル
電極としての形態をもつた白金属金属被覆チタン
陽極と、同じくステンレス陰極とを使用して両極
間を１mm以下に極端に接近させ、30A／ｄm2の電
流密度で長期間電解した場合のイオン交換膜と陽
極について詳しく調査した結果次の事実が明らか
になつた。 Therefore, the present inventors used a platinum metal-coated titanium anode in the form of a protruding expanded metal electrode and a stainless steel cathode, and brought the distance between the two electrodes extremely close to 1 mm or less, resulting in an output of 30 A/dm 2 . As a result of detailed investigation of the ion exchange membrane and anode during long-term electrolysis at a current density of , the following facts were clarified.
イオン交換膜については突起状エキスパンドメ
タル電極の突起した金属格子の投影部位と網目即
ち開口部の投影部位の膜面および膜中に附着した
カルシウム量を分析した結果、両者のカルシウム
密度に差があり前者が後者よりも大であつた。こ
の現象は膜面における電流分布が電極形状に影響
されて不均一であつたことを証左するものと考え
られ、又陽極について顕微鏡観察した結果イオン
交換膜に対面する突起部分のみ白金属金属被覆が
損なわれ基材であるチタンが露出している部分の
存在するのが観察された。これは突起部分におい
て強い電流集中を生じていたことを証左するもの
と考えられる。 As for the ion exchange membrane, we analyzed the amount of calcium deposited on the membrane surface and in the projected area of the protruding metal lattice of the protruding expanded metal electrode and the projected area of the mesh, or opening, and found that there was a difference in calcium density between the two. The former was larger than the latter. This phenomenon is considered to be evidence that the current distribution on the membrane surface was non-uniform due to the influence of the electrode shape, and microscopic observation of the anode revealed that only the protruding portion facing the ion exchange membrane was coated with platinum metal. It was observed that there were parts where the base material titanium was exposed. This is thought to prove that strong current concentration occurred at the protrusion.
ところが本発明による平坦状エキスパンドメタ
ル電極を使用しその平坦化された面を膜に対面さ
せて接近させると著しい電解電圧の低減が可能と
なるのであり、これには極間短縮によるイオン交
換膜および電極面における電流密度分布の均等化
が大きく影響していると思われる。 However, when the flat expanded metal electrode of the present invention is used and the flattened surface is brought close to the membrane, it is possible to significantly reduce the electrolytic voltage. It seems that the equalization of the current density distribution on the electrode surface has a large influence.
この場合、電極と膜との距離は従来の極／膜間
隔よりも遥かに小さくすることが必要であり、隔
膜表面より電極の平坦化された面までの距離とし
て２mm以下、好ましくは１mm以下である。通常陽
極で発生した塩素ガスは気泡径がかなり大きく本
発明における平坦化陽極をイオン交換膜に極度に
接近させても気泡効果は極／膜間距離に殆んど影
響されず、場合によつては殆んど接触する状態に
まで近づけてもよい。しかし陰極で発生した水素
ガスは気泡径が極めて小さく極／膜間距離を極度
に接近させると気泡遮蔽効果が現れて電極電圧の
増加が認められるので極／膜間距離の短縮には或
る限界があり、陽極／膜間距離よりも多少大きく
とることが望ましい。本発明方法において、使用
する突起状エキスパンドメタル電極は陽極、陰極
のいずれかに使用し、他の一方の電極は従来公知
のものを使用してもよい。又、陰陽極共に前記平
坦状エキスパンドメタル電極としてもよく、かく
することで最も好成績を得ることが出来る。 In this case, the distance between the electrode and membrane needs to be much smaller than the conventional electrode/membrane spacing, and the distance from the diaphragm surface to the flattened surface of the electrode is 2 mm or less, preferably 1 mm or less. be. Normally, the bubble size of the chlorine gas generated at the anode is quite large, and even if the flattened anode of the present invention is brought extremely close to the ion exchange membrane, the bubble effect is hardly affected by the electrode/membrane distance, and in some cases may be brought close to almost touching each other. However, the hydrogen gas generated at the cathode has an extremely small bubble diameter, and when the distance between the pole and membrane is made extremely close, a bubble shielding effect appears and an increase in electrode voltage is observed, so there is a certain limit to shortening the distance between the pole and membrane. Therefore, it is desirable to set the distance to be somewhat larger than the anode/membrane distance. In the method of the present invention, the protruding expanded metal electrode used may be used as either an anode or a cathode, and a conventionally known electrode may be used as the other electrode. Further, both the cathode and the anode may be made of the flat expanded metal electrodes, and by doing so, the best results can be obtained.
以下に実施例を掲げて本発明を説明する。 The present invention will be explained below with reference to Examples.
実施例１、２および比較例１
厚み1.5mm、縦１ｍ、横１ｍのチタン板および
ステンレス板を用いて刻み巾（W1.5mm、板厚
T1.5mm、網目の短方向寸法SW8mm、網目の長方
向寸法LW12mmの寸法にエキスパンド加工を行つ
たエキスパンドメタルを用意した。その見掛け厚
みは2.8mmであつた。これを各々裁断して３分割
しＡ、Ｂ、Ｃに分けＡはそのままとし、Ｂ、Ｃに
ついてはロール圧延による圧延加工を行つた。こ
れらの見掛け厚みはＢが1.5mm、Ｃは1.2mmであり
ＣはＢよりも強度のロール圧延による圧延加工を
行つた結果、外観上パンチングメタルに類似した
略完全なフラツト面となつた。Examples 1 and 2 and Comparative Example 1 Using a titanium plate and a stainless steel plate with a thickness of 1.5 mm, a length of 1 m, and a width of 1 m, the notch width (W1.5 mm, plate thickness
Expanded metal was prepared which was expanded to have T1.5 mm, short mesh dimension SW 8 mm, and long mesh dimension LW 12 mm. Its apparent thickness was 2.8 mm. This was cut into three parts, A, B, and C. A was left as is, and B and C were rolled. The apparent thickness of these is 1.5 mm for B and 1.2 mm for C. As a result of C being rolled by roll rolling, which is stronger than B, it has an almost completely flat surface similar to punched metal in appearance.
チタン材Ａ、Ｂ、ＣおよびステンレスＡ、Ｂ、
Ｃの合計６種類のエキスパンドメタルを夫々縦10
cm、横10cmに裁断しエキスパンドチタンにはその
表面を白金属金、塩化物を主成分とする薬液の塗
布、電気炉による高温焼成を行つて陽極として必
要な活性被覆を施した。 Titanium materials A, B, C and stainless steel A, B,
A total of 6 types of expanded metal of C, 10 vertically each
The expanded titanium was cut into pieces of 10 cm wide and 10 cm wide, and its surface was coated with a chemical solution containing platinum metal gold and chloride as main components, and then fired at high temperature in an electric furnace to provide the active coating required for an anode.
エキスパンドステンレスには６規定塩酸溶液に
よるエツチングを施した。 The expanded stainless steel was etched with a 6N hydrochloric acid solution.
次に外形寸法縦15cm、横15cm、内形寸法縦10
cm、横10cm、厚み３mmのチタン製陽極枠の内側開
口部に活性被覆を施したエキスパンドチタン３種
類を夫々挿入し枠のイオン交換膜に対面するフラ
ンジ面と陽極となるエキスパンドメタルの表面と
が平滑となるように合わせて溶接し陽極とした。 Next, the external dimensions are 15 cm long, 15 cm wide, and the internal dimensions are 10 cm tall.
Three types of expanded titanium with active coating were inserted into the inner opening of a titanium anode frame measuring 10 cm wide and 3 mm thick, and the flange surface facing the ion exchange membrane of the frame and the surface of the expanded metal that would become the anode were inserted. The anode was welded together so that it was smooth.
これと全く同寸法のステンレス製陰極枠に上と
同様エツチングを施したエキスパンドステンレス
を溶接して陰極とした。 Expanded stainless steel, which had been etched in the same way as above, was welded to a stainless steel cathode frame of exactly the same dimensions to form a cathode.
電解槽の陽極室と陰極室は厚み５mmのチタン板
およびステンレス板で外形縦15cm、横15cm、巾５
cmの寸法で製作し陽極室には食塩水入口管と戻り
塩水および塩素ガス出口管ならびに温度検出口
を、又陰極室には純水入口管と苛性アルカリおよ
び水素ガス出口管、ならびに温度検出口を取り付
け夫々３槽分製作した。 The anode and cathode chambers of the electrolytic cell are made of titanium plates and stainless steel plates with a thickness of 5 mm, and the external dimensions are 15 cm long, 15 cm wide, and 5 mm wide.
The anode chamber has a saline inlet pipe, return salt water and chlorine gas outlet pipe, and temperature detection port, and the cathode chamber has a pure water inlet pipe, caustic alkali and hydrogen gas outlet pipe, and a temperature detection port. Three tanks were manufactured by installing the following.
次いでＡ、Ｂ、C3種類の陽極および陰極を各
種類の組合せ毎にイオン交換膜を中央として陽極
側は0.1mmのテフロンシート、陽極枠、テフロン
シールパツキング、陽極室、ビニール製絶縁板、
ステンレス製締付枠の順に又陰極側は1.5mmのテ
フロンシート、陰極枠、テフロンシールパツキン
グ、陰極室、ビニール製絶縁板、ステンレス製締
付枠の順に重ねて、両端の締付枠の四隅に設けた
ボルト孔を通した締付ボルトをトルクレンチによ
り80Kg／cm2の圧力で締付けて組立てた。これによ
り電極の圧延加工を行わない突起状エキスパンド
メタル電極の電解槽（Ａ槽………比較例１の電解
槽）、圧延加工を行つた平坦状エキスパンドメタ
ル電極の電解槽（Ｂ槽………実施例１の電解槽）、
強度の圧延加工を行つた平坦化エキスパンドメタ
ル電極の電解槽（Ｃ槽………実施例２の電解槽）
の３槽を組立てた。イオン交換膜はナフイオン
227（デユポン社製陽イオン交換膜）を使用した。
次にこれらの電解槽を自動電流、電圧調節機構を
備えた50A×30Vの直流整流器電源に直列に配置
し、食塩水、純水、塩素ガス、水素ガス、戻り塩
水、苛性ソーダの配管接続および陽極室、陰極室
の加温用赤外線ランプ、温度調節器、温度センサ
ー、の取付を行つて試験設備を完成させた。 Next, for each combination of three types of anodes and cathodes, A, B, and C, with the ion exchange membrane in the center, the anode side is a 0.1 mm Teflon sheet, an anode frame, Teflon seal packing, an anode chamber, a vinyl insulation board,
Layer the stainless steel clamping frame in this order, and on the cathode side, stack the 1.5 mm Teflon sheet, cathode frame, Teflon seal packing, cathode chamber, vinyl insulation board, and stainless steel clamping frame, and then secure the four corners of the clamping frame at both ends. A tightening bolt was passed through the bolt hole provided in , and was tightened with a torque wrench at a pressure of 80 kg/cm 2 . As a result, an electrolytic cell with a protruding expanded metal electrode without electrode rolling (tank A...the electrolytic cell of Comparative Example 1), and an electrolytic cell with a flat expanded metal electrode with rolled electrode (tank B...) Electrolytic cell of Example 1),
Electrolytic cell of flattened expanded metal electrode subjected to strong rolling process (C tank...electrolytic cell of Example 2)
Three tanks were assembled. The ion exchange membrane is Nafion
227 (cation exchange membrane manufactured by DuPont) was used.
These electrolyzers are then placed in series with a 50A x 30V DC rectifier power supply with automatic current and voltage regulation mechanisms to provide piping connections and anodes for saline water, pure water, chlorine gas, hydrogen gas, return brine, and caustic soda. The test equipment was completed by installing an infrared lamp for heating the chamber and cathode chamber, a temperature controller, and a temperature sensor.
次いで陽極室には300ｇ／の精製食塩水を、
陰極室には30wt％の苛性ソーダを満たし80℃に
加温した上通電し5A／20分のステツプで30Aと
し以後陽極液食塩濃度210〜220ｇ／、陰極液苛
性ソーダ濃度30〜31wt％、温度80℃に調節して
70日間連続運転した。この間の各電解槽の電圧は
第１図の通りであつた。 Next, 300g/purified saline was added to the anode chamber.
The cathode chamber was filled with 30 wt% caustic soda, heated to 80°C, and then energized to 30 A in steps of 5 A/20 minutes.Then, the anolyte salt concentration was 210-220 g/, the catholyte caustic soda concentration was 30-31 wt%, and the temperature was 80°C. Adjust to
Operated continuously for 70 days. The voltage of each electrolytic cell during this period was as shown in FIG.
これから明らかなように極間距離約２mmの条件
では圧延加工なしの突起状エキスパンドメタル電
極Ａ槽に比べて圧延加工した平坦状エキスパンド
メタル電極Ｂ槽およびＣ槽は電解電圧が有意に低
いことを認めた。尚圧延加工の程度については圧
延加工した平坦状エキスパンドメタル電極Ｂ槽よ
りも強度に圧延加工した平坦状エキスパンドメタ
ル電極Ｃ槽の方が更に低い電圧を示した。 As is clear from this, under the condition of a distance between electrodes of approximately 2 mm, the electrolytic voltage of the flat expanded metal electrodes B and C that were rolled was significantly lower than that of the protruding expanded metal electrode A that was not rolled. Ta. Regarding the degree of rolling, the flat expanded metal electrode tank C, which was rolled more strongly, showed an even lower voltage than the rolled flat expanded metal electrode tank B.
これらの電極の開孔率を測定した結果はＡ槽の
電極51％、Ｂ槽の電極38％、Ｃ槽の電極32％であ
つた。 The results of measuring the porosity of these electrodes were 51% for the electrode in tank A, 38% for the electrode in tank B, and 32% for the electrode in tank C.
比較例 ２および３
極間距離が実施例１よりも大きい領域での突起
状エキスパンドメタル電極と平坦状エキスパンド
メタル電極の性能を調べる目的で実施例１と極〜
膜間に挿入するテフロンシートの厚みのみを膜〜
陽極間３mm、膜〜陰極間３mmとし極間距離を約
6.5mmとした以外は全て同じ条件にして突起状エ
キスパンドメタル電極Ａ槽（比較例２の電解槽）、
と実施例１で使用した平坦状エキスパンドメタル
電極Ｂ槽（比較例３の電解槽）、を組立てて60日
間電解運転を行つた。Comparative Examples 2 and 3 In order to investigate the performance of a protruding expanded metal electrode and a flat expanded metal electrode in a region where the distance between electrodes is larger than that of Example 1, Example 1 and electrodes were compared.
Only the thickness of the Teflon sheet inserted between the membranes
The distance between the electrodes is approximately 3 mm between the anodes and 3 mm between the membrane and the cathode.
Protruding expanded metal electrode A tank (electrolytic tank of Comparative Example 2) under all the same conditions except that it was set to 6.5 mm,
and the flat expanded metal electrode tank B used in Example 1 (electrolytic tank of Comparative Example 3) were assembled and electrolyzed for 60 days.
結果は第２図の通りでＡ槽が僅かに低い電圧を
示したがいずれも高い電解電圧に終始した。 The results are shown in FIG. 2, and although tank A showed a slightly low voltage, the electrolytic voltage was high in all cases.
第１図は、本発明の実施例１、２および比較例
１についての運転日数と電解電圧の関係を示すグ
ラフであり、図中の記号Ａは比較例１、Ｂは実施
例１、Ｃは実施例２の場合である。第２図は比較
例２、３についての運転日数と電解電圧の関係を
示し図中の記号Ａは比較例２、Ｂは比較例３の場
合である。
FIG. 1 is a graph showing the relationship between the number of operating days and electrolytic voltage for Examples 1 and 2 of the present invention and Comparative Example 1, where the symbol A in the figure is Comparative Example 1, B is Example 1, and C is This is the case of Example 2. FIG. 2 shows the relationship between the number of operating days and the electrolysis voltage for Comparative Examples 2 and 3, and symbol A in the figure is for Comparative Example 2, and symbol B is for Comparative Example 3.
Claims (1)
を用いて塩化アルカリ水溶液を電解するに当り、
上記の陽極又は／および陰極としてエキスパンド
メタルの圧延加工によりその片面又は両面が平坦
化され、かつ、圧延加工後の見掛け厚みが上記圧
延加工前のエキスパンドメタルの見掛け厚みの60
％以下で1.2mm以上であり、開口率が20〜50％の
範囲にある電極を用い、該電極の平坦化された一
面を隔膜表面より２mm以下の接近状態で対面させ
て電解することを特徴とする塩化アルカリ水溶液
の電解方法。1 When electrolyzing an aqueous alkali chloride solution using an electrolytic cell with a diaphragm interposed between the anode and cathode,
One or both sides of the expanded metal as the anode and/or cathode are flattened by rolling, and the apparent thickness after rolling is 60% of the apparent thickness of the expanded metal before rolling.
% or less and 1.2 mm or more, and the aperture ratio is in the range of 20 to 50%, and electrolysis is carried out with one flattened surface of the electrode facing the diaphragm surface at a distance of 2 mm or less. A method for electrolyzing an aqueous alkali chloride solution.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56031143A JPS57145991A (en) | 1981-03-06 | 1981-03-06 | Electrolyzing method for aqueous alkali chloride solution |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56031143A JPS57145991A (en) | 1981-03-06 | 1981-03-06 | Electrolyzing method for aqueous alkali chloride solution |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS57145991A JPS57145991A (en) | 1982-09-09 |
| JPH0146596B2 true JPH0146596B2 (en) | 1989-10-09 |
Family
ID=12323209
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP56031143A Granted JPS57145991A (en) | 1981-03-06 | 1981-03-06 | Electrolyzing method for aqueous alkali chloride solution |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS57145991A (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5477285A (en) * | 1977-12-02 | 1979-06-20 | Asahi Glass Co Ltd | Ion exchange membrane electrolysis |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5583756U (en) * | 1978-12-07 | 1980-06-09 |
-
1981
- 1981-03-06 JP JP56031143A patent/JPS57145991A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5477285A (en) * | 1977-12-02 | 1979-06-20 | Asahi Glass Co Ltd | Ion exchange membrane electrolysis |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS57145991A (en) | 1982-09-09 |
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