JPS6140462B2 - - Google Patents
Info
- Publication number
- JPS6140462B2 JPS6140462B2 JP54031773A JP3177379A JPS6140462B2 JP S6140462 B2 JPS6140462 B2 JP S6140462B2 JP 54031773 A JP54031773 A JP 54031773A JP 3177379 A JP3177379 A JP 3177379A JP S6140462 B2 JPS6140462 B2 JP S6140462B2
- Authority
- JP
- Japan
- Prior art keywords
- exchange resin
- anion exchange
- cation
- anion
- cation exchange
- 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
- 239000003957 anion exchange resin Substances 0.000 claims description 211
- NWUYHJFMYQTDRP-UHFFFAOYSA-N 1,2-bis(ethenyl)benzene;1-ethenyl-2-ethylbenzene;styrene Chemical compound C=CC1=CC=CC=C1.CCC1=CC=CC=C1C=C.C=CC1=CC=CC=C1C=C NWUYHJFMYQTDRP-UHFFFAOYSA-N 0.000 claims description 149
- 239000003729 cation exchange resin Substances 0.000 claims description 131
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 55
- 238000011069 regeneration method Methods 0.000 claims description 44
- 230000008929 regeneration Effects 0.000 claims description 42
- 238000000926 separation method Methods 0.000 claims description 38
- 239000011347 resin Substances 0.000 claims description 18
- 229920005989 resin Polymers 0.000 claims description 18
- 238000000034 method Methods 0.000 claims description 15
- 238000011001 backwashing Methods 0.000 claims description 14
- 150000001768 cations Chemical class 0.000 claims description 11
- 150000001450 anions Chemical class 0.000 claims description 10
- 230000001172 regenerating effect Effects 0.000 claims description 7
- 229940023913 cation exchange resins Drugs 0.000 claims description 6
- 238000005342 ion exchange Methods 0.000 claims description 6
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 159
- 235000011121 sodium hydroxide Nutrition 0.000 description 53
- 239000003456 ion exchange resin Substances 0.000 description 44
- 229920003303 ion-exchange polymer Polymers 0.000 description 44
- 239000002245 particle Substances 0.000 description 29
- 239000007788 liquid Substances 0.000 description 9
- 229920001429 chelating resin Polymers 0.000 description 3
- 238000007796 conventional method Methods 0.000 description 3
- 238000010612 desalination reaction Methods 0.000 description 3
- OKIZCWYLBDKLSU-UHFFFAOYSA-M N,N,N-Trimethylmethanaminium chloride Chemical compound [Cl-].C[N+](C)(C)C OKIZCWYLBDKLSU-UHFFFAOYSA-M 0.000 description 2
- FKNQFGJONOIPTF-UHFFFAOYSA-N Sodium cation Chemical group [Na+] FKNQFGJONOIPTF-UHFFFAOYSA-N 0.000 description 2
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- LDKDGDIWEUUXSH-UHFFFAOYSA-N Thymophthalein Chemical compound C1=C(O)C(C(C)C)=CC(C2(C3=CC=CC=C3C(=O)O2)C=2C(=CC(O)=C(C(C)C)C=2)C)=C1C LDKDGDIWEUUXSH-UHFFFAOYSA-N 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 238000001125 extrusion Methods 0.000 description 2
- 239000012530 fluid Substances 0.000 description 2
- 230000000630 rising effect Effects 0.000 description 2
- 238000005406 washing Methods 0.000 description 2
- 239000002699 waste material Substances 0.000 description 2
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- NIXOWILDQLNWCW-UHFFFAOYSA-N acrylic acid group Chemical group C(C=C)(=O)O NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 238000005349 anion exchange Methods 0.000 description 1
- 125000000129 anionic group Chemical group 0.000 description 1
- 238000005341 cation exchange Methods 0.000 description 1
- 125000001309 chloro group Chemical group Cl* 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 238000004062 sedimentation Methods 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 239000011780 sodium chloride Substances 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
Landscapes
- Treatment Of Water By Ion Exchange (AREA)
Description
本発明は塔外再生型の混床式イオン交換装置に
おいて、使用済みの陽・陰両混合イオン交換樹脂
を再生する際に陰イオン交換樹脂中に混入する微
細な陽イオン交換樹脂、特に80メツシユ以下の陽
イオン交換樹脂を効率的に分離する方法に関する
ものであり、使用済みの陽・陰両混合イオン交換
樹脂を水で逆洗する際に、新たに陰イオン交換樹
脂を添加して水で逆洗を行ない、下部に陽イオン
交換樹脂、上部に陰イオン交換樹脂の二層に分離
し、当該陰イオン交換樹脂層の上層部に混入する
微細な陽イオン交換樹脂を、陰イオン交換樹脂層
の上層部の陰イオン交換樹脂とともに系外に取り
出すことによつて混床式イオン交換装置の通水系
統に混入するナトリウム形の陽イオン交換樹脂の
量を極力低下させて高純度の処理水を得ることを
目的とする。
従来から混床式イオン交換装置によつて高純度
の処理水を得るためには、陽イオン交換樹脂およ
び陰イオン交換樹脂を酸およびアルカリで再生す
る前に両イオン交換樹脂を完全に分離し、再生後
の状態でナトリウム形陽イオン交換樹脂およびク
ロール形陰イオン交換樹脂などの未再生のイオン
交換樹脂を残さないことが必要な要素となること
は当業者間では周知のことであつた。またこれら
の未再生のイオン交換樹脂を残留させない第一の
条件としては、陽イオン交換樹脂と陰イオン交換
樹脂を完全に分離することが必要である。しかし
実際上従来では両イオン交換樹脂の完全分離は達
成困難である。
すなわち、陽イオン交換樹脂と陰イオン交換樹
脂を分離するにあたり通常は水による逆洗分離が
行なわれるが、本操作ではどうしても陰イオン交
換樹脂層と陽イオン交換樹脂層の中間部に両イオ
ン交換樹脂の混合層が形成され、さらに陰イオン
交換樹脂層中に微細な陽イオン交換樹脂が混入す
る。このような陰イオン交換樹脂中に混入してい
る粒径の小さい陽イオン交換樹脂を分離する方法
として、発明者は先に特願昭53−4391号を提案し
た。これは陽イオン交換樹脂と陰イオン交換樹脂
を分離するにあたり、2ないし8重量%のか性ソ
ーダ溶液をLV0.5ないし4m/Hの流速でイオン交
換樹脂層の下部より上昇流で流入させることによ
り、上部が陰イオン交換樹脂層、下部が陽イオン
交換樹脂層となつている明確なる積層を形成さ
せ、ひきつづき当該両イオン交換樹脂の中間の密
度を有するか性ソーダ溶液を低流速の上昇流で流
入させることにより上部の陰イオン交換樹脂のみ
を浮上させ、浮上させた陰イオン交換樹脂と沈降
している陽イオン交換樹脂との間に当該中間の密
度を有するか性ソーダ溶液の液層を形成させ、次
いで浮上させた陰イオン交換樹脂と陽イオン交換
樹脂とを別々に系外に取り出す方法である。
本方法は陰イオン交換樹脂層中に含まれている
微細な陽イオン交換樹脂の粒径が60メツシユ前後
である場合、特に効果的に作用し、陽・陰イオン
交換樹脂を完全に分離することができるが、60メ
ツシユよりも小さい粒径、特に80メツシユ以下の
粒径の微細な陽イオン交換樹脂が多く含まれてい
る場合、2ないし8重量%のか性ソーダをLV0.5
ないし4m/Hの流速でイオン交換樹脂の下部か
ら上昇流で流入させると、微細な陽イオン交換樹
脂が陰イオン交換樹脂の上層部に浮上しやすく、
陰イオン交換樹脂と陽イオン交換樹脂の二層に完
全に分離するのに長時間を要するという欠点があ
る。
本発明者は上述した80メツシユ以下の微細な陽
イオン交換樹脂が多く含まれている場合における
先願方法の欠点を改良するために実験を重ねた結
果、通水塔で使用済みの陽・陰両混合イオン交換
樹脂を水で逆洗して下部に陽イオン交換樹脂、上
部に陰イオン交換樹脂の二層に分離した際の上部
の陰イオン交換樹脂層中に混入している微細な陽
イオン交換樹脂の分布状態をみると、80メツシユ
以下の微細な陽イオン交換樹脂は陰イオン交換樹
脂層の上層域に多く混入することに注目し、本発
明を構成するに至つた。
すなわち、本発明は塔外再生型の混床式イオン
交換装置において、使用済みの陽、陰両混合イオ
ン交換樹脂を水で逆洗する際に、当該陰イオン交
換樹脂の15ないし60容量%の陰イオン交換樹脂を
新たに添加して水で逆洗分離し、上部に陰イオン
交換樹脂層、下部に陽イオン交換樹脂層を形成
し、次いで逆洗分離された陰イオン交換樹脂層の
上層部の逆洗分離する際に添加した陰イオン交換
樹脂量に相当する量の陰イオン交換樹脂を取り出
した後、陽・陰両イオン交換樹脂を再生すること
を特徴とする陰イオン交換樹脂中に混入する微細
な陽イオン交換樹脂の分離方法である。
以下本発明を復水脱塩装置を例にして図面を用
いて説明する。本発明を実施するにあたり、まず
復水脱塩装置の通水塔(図示せず)において使用
済みの陰イオン交換樹脂と陽イオン交換樹脂の混
合イオン交換樹脂を第1図の分離塔1に水流によ
つて移送し、分離塔1の下部より逆洗水2を流入
させ常法によつて逆洗分離し、分離塔1の下部に
陽イオン交換樹脂3、分離塔1の上部に陰イオン
交換樹脂4を形成させる。なお水による逆洗では
陽イオン交換樹脂3と陰イオン交換樹脂4は完全
に分離することができず、陽イオン交換樹脂3と
陰イオン交換樹脂4の中間部に両イオン交換樹脂
の混合イオン交換樹脂5が形成され、さらに前記
したように陰イオン交換樹脂4の上層部に80メツ
シユ以下の微細な陽イオン交換樹脂Kが混入す
る。このようにして逆洗によつて分離された微細
な陽イオン交換樹脂Kを含む陰イオン交換樹脂4
の全量を混合イオン交換樹脂5およびその下部に
存在する一部の陽イオン交換樹脂3′とともに水
流によつて第2図に示した陰イオン交換樹脂再生
塔6に移送し、その後分離塔1に残留させた陽イ
オン交換樹脂3は常法により酸で再生する。一
方、陰イオン交換樹脂再生塔6にこれらのイオン
交換樹脂の移送が終了した後に、陰イオン交換樹
脂再生塔6に陰イオン交換樹脂4の15ないし60容
量%に相当する陰イオン交換樹脂を新たに添加
し、陰イオン交換樹脂再生塔6の下部より逆洗水
2を流入させ再度常法により逆洗分離を行なう。
本逆洗を行なうと第2図に示したごとく陰イオン
交換樹脂再生塔6の下部に陽イオン交換樹脂
3′、その上部に混合イオン交換樹脂5、その上
部に樹脂量が15ないし60容量%増加した陰イオン
交換樹脂4′が形成し、当該陰イオン交換樹脂
4′の上層部に微細な陽イオン交換樹脂Kが含ま
れる。80メツシユ以下の微細な陽イオン交換樹脂
Kの沈降速度は通常の粒径の陰イオン交換樹脂の
沈降速度より小さく、このような微細な陽イオン
交換樹脂Kは通常の水による逆洗においては浮上
し、上部の陰イオン交換樹脂層の上面と上方から
約15ないし40%の樹脂層高の間に混入しやすいの
で、逆洗分離する際使用済みの陰イオン交換樹脂
の15ないし60容量%、好ましくは30ないし40容量
%の陰イオン交換樹脂を新たに添加して水による
逆洗分離を行なうと、微細な陽イオン交換樹脂K
は、陰イオン交換樹脂4の上方から新たに添加し
た陰イオン交換樹脂量に相当する部分に混入す
る。次に、陰イオン交換樹脂再生塔6に設けた取
り出し管7から陰イオン交換樹脂4′の上部の逆
洗分離する際に添加した陰イオン交換樹脂量に相
当する陰イオン交換樹脂を取り出す。本操作によ
つて陰イオン交換樹脂4′の上層部に混入してい
た微細な陽イオン交換樹脂Kも同時に取り出すこ
とができ、第3図に示すように陰イオン交換樹脂
再生塔6に微細な陽イオン交換樹脂Kを除去し、
通水塔で使用済みの陰イオン交換樹脂量と同等量
の陰イオン交換樹脂4の層を形成することができ
る。
陰イオン交換樹脂再生塔6から取り出した微細
な陽イオン交換樹脂Kを含む陰イオン交換樹脂は
そのまま次回の逆洗分離する際に添加して繰り返
し使用してもよいが、数回繰り返し添加する間に
取り出された陰イオン交換樹脂中に微細な陽イオ
ン交換樹脂量がだんだん蓄積するので、取り出さ
れた陰イオン交換樹脂は微細な陽イオン交換樹脂
Kの含有率によつて破棄するか、または陽イオン
交換樹脂と陰イオン交換樹脂の中間の密度を有す
る液体を用いて陽イオン交換樹脂Kを分離し、再
び逆洗分離する際に添加することができる。
また本発明の他の方法として、第4図に示した
ように通水塔において使用済みの陽・陰両混合イ
オン交換樹脂を分離塔1に水流によつて移送し、
当該陽・陰両混合イオン交換樹脂に当該陰イオン
交換樹脂の15ないし60容量%の陰イオン交換樹脂
を新たに添加し、分離塔1の下部より逆洗水2を
流入させ、常法によつて逆洗分離し、分離塔1の
下方から上方にしたがつて陽イオン交換樹脂3、
陽イオン交換樹脂と陰イオン交換樹脂の混合イオ
ン交換樹脂5および15ないし60容量%の樹脂量が
増加した陰イオン交換樹脂4′を形成し、次いで
分離塔1に設けた取り出し管8から陰イオン交換
樹脂4′の上層部の逆洗分離する際に添加した陰
イオン交換樹脂量に相当する陰イオン交換樹脂を
取り出してもよい。かくすることにより陰イオン
交換樹脂4′の上層部に混入していた微細な陽イ
オン交換樹脂Kも取り出し、微細な陽イオン交換
樹脂Kが混入していない陰イオン交換樹脂4を分
離塔1に残留させることができる。次にこうして
得られた陰イオン交換樹脂4と陽イオン交換樹脂
と陰イオン交換樹脂の混合イオン交換樹脂5およ
びその下部に存在する一部の陽イオン交換樹脂
3′とともに水流によつて陰イオン交換樹脂再生
塔6に移送し、陰イオン交換樹脂再生塔6の下部
から逆洗水2を流入させ再度常法による逆洗分離
を行なうと、先に述べた本発明方法の第3図のよ
うに陰イオン交換樹脂再生塔6内に下方から上方
にしたがつて陽イオン交換樹脂3′、陽イオン交
換樹脂と陰イオン交換樹脂の混合イオン交換樹脂
5および陰イオン交換樹脂4の層を形成できる。
なお後に述べた本発明の実施態様のように分離塔
1において通水塔から移送された陽・陰両混合イ
オン交換樹脂に新たに陰イオン交換樹脂を添加す
ると、全イオン交換樹脂量が増大し、大きな分離
塔1が必要となるので、先に述べた本発明方法の
実施態様のように、陰イオン交換樹脂再生塔6に
陰イオン交換樹脂4を分離して移送し、これに新
たに陰イオン交換樹脂を加えて逆洗分離を行なう
方が実施しやすい。
次に本発明によつて微細な陽イオン交換樹脂K
を除去した陰イオン交換樹脂を再生するにあた
り、第3図に示すように陰イオン交換樹脂再生塔
6の上部から再生剤9を下降流で通液し、微細な
陽イオン交換樹脂Kが除去された陰イオン交換樹
脂4の再生処理を行ない、次いで陰イオン交換樹
脂再生塔6から再生済みの陰イオン交換樹脂4を
イオン交換樹脂貯槽(図示せず)に移送して同貯
槽において十分に洗浄し、そして前記した分離塔
1で再生され洗浄済みの陽イオン交換樹脂3を分
離塔1から水流により同貯槽に移送し、十分に混
合することによつて復水の通水に備えてもよい。
ところで本発明において、第2図に示したよう
な陰イオン交換樹脂4′の上層部に混入する80メ
ツシユ以下の微細な陽イオン交換樹脂は、上層部
の陰イオン交換樹脂とともに陰イオン交換樹脂再
生塔6から塔外へ取り出すが、60メツシユ前後の
比較的粒径の小さい陽イオン交換樹脂が含まれて
いると、このような陽イオン交換樹脂は水による
逆洗分離によつて陰イオン交換樹脂4′の下層部
に混入しやすいので本発明では除去することがむ
ずかしい。したがつて第3図の陰イオン交換樹脂
4にこのような60メツシユ前後の比較的粒径の小
さい陽イオン交換樹脂が残留している場合、前述
の再生方法のように、このような陽イオン交換樹
脂を除去せずに陰イオン交換樹脂4の再生を行な
うと、ナトリウム形の陽イオン交換樹脂が生成
し、これをそのまま通水塔に供給すれば処理水の
純度を低下させる原因となる。また前述の再生方
法では陰イオン交換樹脂塔1に残留する混合イオ
ン交換樹脂5および陽イオン交換樹脂3′は分離
塔1に返送するが、混合イオン交換樹脂5には水
による逆洗分離操作だけでは完全に分離できない
陰イオン交換樹脂が含まれているので、陰イオン
交換樹脂再生塔6で再生してイオン交換樹脂貯槽
に移送する陰イオン交換樹脂の回収率が低いとい
う欠点がある。
したがつて本発明によつて逆洗分離を行ない陰
イオン交換樹脂に混入する特に80メツシユ以下の
微細な陽イオン交換樹脂を除去した陰イオン交換
樹脂に次に述べるような再生方法を行なうと、よ
り一層本発明における効果が上がり、純度の高い
処理水を得ることができる。
本発明によつて80メツシユ以下の微細な陽イオ
ン交換樹脂を除去した陰イオン交換樹脂の再生を
するにあたり、第1工程として2ないし8重量%
のか性ソーダ溶液10を第5図に示したように
LV0.5ないし4m/Hの流速で陰イオン交換樹脂再
生塔6の下部より流入させる。
これによつて陰イオン交換樹脂4が流動性のあ
る状態となるので、陰イオン交換樹脂4の下層部
に混入している60メツシユ前後の比較的粒径の小
さい陽イオン交換樹脂が徐々に陰イオン交換樹脂
再生塔6の下部に沈降し、また同時に混合イオン
交換樹脂5内の陰イオン交換樹脂が陰イオン交換
樹脂再生塔6の上部に移動し、最終的に第5図に
示したように陰イオン交換樹脂再生塔6内の下部
が陽イオン交換樹脂3′、その上部が陰イオン交
換樹脂4となつた陰イオン交換樹脂と陽イオン交
換樹脂の明確なる積層を形成することができる。
なお、陰イオン交換樹脂4はすでに本発明により
特に分離しにくい80メツシユ以下の微細な陽イオ
ン交換樹脂を除去しているので、本操作は短時間
で陽・陰両イオン交換樹脂を完全に分離すること
ができる。
本操作は陰イオン交換樹脂4を十分に流動化さ
せて比較的粒径の小さい陽イオン交換樹脂を陰イ
オン交換樹脂再生塔6の下部に沈降させ、より完
全な陽・陰両イオン交換樹脂の分離を行なうこと
を目的としているので、本操作で使用するか性ソ
ーダ溶液の密度が陰イオン交換樹脂の密度より大
であると都合が悪く、またか性ソーダ溶液の密度
が水の密度とあまり近似していても都合が悪い。
また当該か性ソーダ溶液を陰イオン交換樹脂再生
塔6の下部より上昇流で流入させるとき、あまり
高流速で流入すると比較的粒径の小さい陽イオン
交換樹脂が沈降しないばかりか、陰イオン交換樹
脂4中に陽イオン交換樹脂3′が混入してしま
い、また極端に低流速であると陰イオン交換樹脂
4が流動しないため比較的粒径の小さい陽イオン
交換樹脂の沈降が妨げられる。また本操作で使用
するか性ソーダ溶液の濃度と、当該溶液を上昇流
で流入する際の流速には相関関係があり、第1表
に示した濃度と上昇流速の組み合わせで行なうと
よい。
The present invention is directed to an external regeneration type mixed bed ion exchange equipment in which fine cation exchange resins, especially 80 mesh, are mixed into the anion exchange resin when regenerating used cation and anion mixed ion exchange resins. This article concerns a method for efficiently separating the following cation exchange resins. When backwashing used cation and anion mixed ion exchange resins with water, a new anion exchange resin is added to the water. Backwashing is performed to separate the cation exchange resin into two layers: a cation exchange resin at the bottom and an anion exchange resin at the top. By removing the anion exchange resin from the upper layer of the system together with the anion exchange resin, the amount of sodium cation exchange resin that enters the water flow system of the mixed bed ion exchange equipment is minimized, and highly purified treated water is produced. The purpose is to obtain. Conventionally, in order to obtain high-purity treated water using a mixed bed ion exchange device, it is necessary to completely separate both ion exchange resins and anion exchange resins before regenerating them with acid and alkali. It is well known among those skilled in the art that it is a necessary factor to not leave unregenerated ion exchange resins such as sodium type cation exchange resins and chloro type anion exchange resins in the regenerated state. Furthermore, the first condition for not leaving these unregenerated ion exchange resins is to completely separate the cation exchange resin and the anion exchange resin. However, in practice, it is difficult to achieve complete separation of both ion exchange resins. In other words, backwash separation using water is normally performed to separate the cation exchange resin and anion exchange resin, but in this operation, both ion exchange resins must be placed between the anion exchange resin layer and the cation exchange resin layer. A mixed layer is formed, and fine cation exchange resin is further mixed into the anion exchange resin layer. The inventor previously proposed Japanese Patent Application No. 53-4391 as a method for separating cation exchange resins with small particle sizes mixed in such anion exchange resins. This is done by flowing an upward flow of 2 to 8% by weight caustic soda solution from the bottom of the ion exchange resin layer at a flow rate of LV 0.5 to 4 m/H to separate the cation exchange resin and anion exchange resin. , a clear laminated layer is formed with an anion exchange resin layer on the top and a cation exchange resin layer on the bottom, and then a caustic soda solution having a density intermediate between the two ion exchange resins is added in an upward flow at a low flow rate. By flowing in, only the upper anion exchange resin is floated, and a liquid layer of caustic soda solution having an intermediate density is formed between the floated anion exchange resin and the precipitated cation exchange resin. This is a method in which the anion exchange resin and the cation exchange resin that have been floated are separately taken out of the system. This method works particularly effectively when the particle size of the fine cation exchange resin contained in the anion exchange resin layer is around 60 mesh, and it is possible to completely separate the cation and anion exchange resins. However, if it contains a large amount of fine cation exchange resin with a particle size smaller than 60 mesh, especially less than 80 mesh, 2 to 8% by weight of caustic soda can be added to LV 0.5.
When flowing upward from the bottom of the ion exchange resin at a flow rate of 4 m/h to 4 m/h, fine cation exchange resin tends to float to the upper layer of the anion exchange resin.
It has the disadvantage that it takes a long time to completely separate into two layers, an anion exchange resin and a cation exchange resin. As a result of repeated experiments to improve the shortcomings of the prior application method in cases where a large amount of fine cation exchange resin of 80 mesh or less is contained, the present inventor found that When the mixed ion exchange resin is backwashed with water and separated into two layers: a cation exchange resin at the bottom and an anion exchange resin at the top, fine cation exchange particles are mixed in the upper anion exchange resin layer. When looking at the distribution state of the resin, it was noted that the fine cation exchange resin of 80 mesh or less is mostly mixed in the upper layer region of the anion exchange resin layer, and the present invention was constructed based on this finding. That is, the present invention provides an external regeneration type mixed bed type ion exchange apparatus in which when backwashing a used cation-exchange resin and an anion-exchange resin with water, 15 to 60% by volume of the anion-exchange resin is Anion exchange resin is newly added and backwashed and separated with water to form an anion exchange resin layer on the top and a cation exchange resin layer on the bottom, and then the upper layer of the anion exchange resin layer that has been backwashed and separated. Mixed into an anion exchange resin characterized in that after removing an anion exchange resin in an amount equivalent to the amount of anion exchange resin added during backwash separation, both cation and anion exchange resins are regenerated. This is a method for separating fine cation exchange resins. The present invention will be explained below using a condensate desalination apparatus as an example with reference to the drawings. In carrying out the present invention, first, a used mixed ion exchange resin of an anion exchange resin and a cation exchange resin is passed through a water flow tower (not shown) of a condensate desalination apparatus to a separation tower 1 shown in FIG. Then, backwash water 2 is introduced from the lower part of the separation column 1 and backwashed and separated by a conventional method.The cation exchange resin 3 is placed in the bottom of the separation column 1, and the anion exchange resin is placed in the top of the separation column 1. Form 4. Note that the cation exchange resin 3 and anion exchange resin 4 cannot be completely separated by backwashing with water, and a mixed ion exchange resin of both ion exchange resins is placed between the cation exchange resin 3 and anion exchange resin 4. Resin 5 is formed, and as described above, fine cation exchange resin K of 80 mesh or less is mixed into the upper layer of anion exchange resin 4. Anion exchange resin 4 containing fine cation exchange resin K separated by backwashing in this way
The entire amount of the mixed ion exchange resin 5 and a portion of the cation exchange resin 3' present below it are transferred by a water stream to the anion exchange resin regeneration tower 6 shown in FIG. 2, and then to the separation tower 1. The remaining cation exchange resin 3 is regenerated with acid in a conventional manner. On the other hand, after the transfer of these ion exchange resins to the anion exchange resin regeneration tower 6 is completed, new anion exchange resin corresponding to 15 to 60% by volume of the anion exchange resin 4 is added to the anion exchange resin regeneration tower 6. and backwash water 2 is introduced from the lower part of the anion exchange resin regeneration tower 6 to carry out backwash separation again in a conventional manner.
When main backwashing is performed, as shown in Fig. 2, the cation exchange resin 3' is placed in the lower part of the anion exchange resin regeneration tower 6, the mixed ion exchange resin 5 is placed in the upper part of the cation exchange resin 3', and the resin amount is 15 to 60% by volume in the upper part. An increased amount of anion exchange resin 4' is formed, and fine cation exchange resin K is contained in the upper layer of the anion exchange resin 4'. The sedimentation rate of fine cation exchange resin K of 80 mesh or less is lower than that of anion exchange resin with a normal particle size, and such fine cation exchange resin K does not float to the surface during backwashing with normal water. However, since it is easy to mix between the upper surface of the upper anion exchange resin layer and the resin layer height of about 15 to 40% from above, when backwashing and separating, 15 to 60 volume % of the used anion exchange resin, Preferably, when 30 to 40% by volume of anion exchange resin is newly added and backwash separation with water is performed, fine cation exchange resin K is removed.
is mixed into a portion corresponding to the amount of newly added anion exchange resin from above the anion exchange resin 4. Next, an anion exchange resin corresponding to the amount of anion exchange resin added when backwashing and separating the upper part of the anion exchange resin 4' is taken out from a take-out pipe 7 provided in the anion exchange resin regeneration tower 6. Through this operation, the fine cation exchange resin K mixed in the upper layer of the anion exchange resin 4' can also be taken out at the same time, and the fine cation exchange resin K is transferred to the anion exchange resin regeneration tower 6 as shown in FIG. Remove cation exchange resin K,
A layer of anion exchange resin 4 can be formed in an amount equivalent to the amount of anion exchange resin used in the water tower. The anion exchange resin containing the fine cation exchange resin K taken out from the anion exchange resin regeneration tower 6 may be added as is to the next backwash separation and used repeatedly; The amount of fine cation exchange resin gradually accumulates in the anion exchange resin taken out, so depending on the content of fine cation exchange resin K, the taken out anion exchange resin is either discarded or cation exchanged. It can be added when the cation exchange resin K is separated using a liquid having an intermediate density between that of the ion exchange resin and the anion exchange resin, and then backwashed and separated again. Further, as another method of the present invention, as shown in FIG. 4, the used positive and negative mixed ion exchange resin is transferred to the separation tower 1 by water flow in the water passing tower,
An anion exchange resin of 15 to 60% by volume of the anion exchange resin is newly added to the cation and anion mixed ion exchange resin, backwash water 2 is introduced from the lower part of the separation column 1, and the mixture is washed using a conventional method. cation exchange resin 3,
A mixed ion exchange resin 5 of a cation exchange resin and an anion exchange resin and an anion exchange resin 4' in which the resin amount has been increased by 15 to 60% by volume are formed, and then anions are extracted from a take-off pipe 8 provided in the separation column 1. An anion exchange resin corresponding to the amount of anion exchange resin added when backwashing and separating the upper layer of the exchange resin 4' may be taken out. By doing this, the fine cation exchange resin K mixed in the upper layer of the anion exchange resin 4' is also removed, and the anion exchange resin 4 that is not contaminated with fine cation exchange resin K is transferred to the separation column 1. It can be left behind. Next, the anion exchange resin 4 obtained in this way, the mixed ion exchange resin 5 of a cation exchange resin and an anion exchange resin, and a part of the cation exchange resin 3' present in the lower part are subjected to anion exchange using a water stream. When the resin is transferred to the resin regeneration tower 6, backwash water 2 is introduced from the lower part of the anion exchange resin regeneration tower 6, and backwash separation is performed again using the conventional method, as shown in FIG. 3 of the method of the present invention described above. In the anion exchange resin regeneration tower 6, layers of a cation exchange resin 3', a mixed ion exchange resin 5 of a cation exchange resin and an anion exchange resin, and an anion exchange resin 4 can be formed from the bottom to the top.
Furthermore, as in the embodiment of the present invention described later, when an anion exchange resin is newly added to the mixed ion exchange resin of cation and anion transferred from the water tower in the separation column 1, the total amount of ion exchange resin increases, Since a large separation column 1 is required, as in the embodiment of the method of the present invention described above, the anion exchange resin 4 is separated and transferred to the anion exchange resin regeneration column 6, and new anions are added to the anion exchange resin 4. It is easier to perform backwash separation by adding exchange resin. Next, according to the present invention, fine cation exchange resin K
To regenerate the anion exchange resin from which the cation exchange resin K has been removed, a regenerating agent 9 is passed downward from the upper part of the anion exchange resin regeneration tower 6, as shown in FIG. 3, to remove fine cation exchange resin K. Then, the recycled anion exchange resin 4 is transferred from the anion exchange resin regeneration tower 6 to an ion exchange resin storage tank (not shown) and thoroughly washed in the storage tank. Then, the cation exchange resin 3 that has been regenerated and washed in the separation column 1 described above may be transferred from the separation column 1 to the same storage tank by a water stream and sufficiently mixed to prepare for the passage of condensate water. By the way, in the present invention, the fine cation exchange resin of 80 mesh or less mixed in the upper layer of the anion exchange resin 4' as shown in FIG. 2 is recycled together with the anion exchange resin in the upper layer. The cation exchange resin is taken out of the column from column 6, but if it contains cation exchange resin with a relatively small particle size of around 60 mesh, such cation exchange resin is separated into anion exchange resin by backwash separation with water. It is difficult to remove it in the present invention because it tends to get mixed into the lower layer of 4'. Therefore, if such cation exchange resin with a relatively small particle size of around 60 meshes remains in the anion exchange resin 4 shown in FIG. If the anion exchange resin 4 is regenerated without removing the exchange resin, a sodium-type cation exchange resin will be produced, and if this is supplied as it is to the water tower, it will cause a decrease in the purity of the treated water. In addition, in the above-mentioned regeneration method, the mixed ion exchange resin 5 and cation exchange resin 3' remaining in the anion exchange resin column 1 are returned to the separation column 1, but the mixed ion exchange resin 5 is only subjected to backwashing and separation with water. Since this method contains anion exchange resin that cannot be completely separated, there is a drawback that the recovery rate of the anion exchange resin regenerated in the anion exchange resin regeneration tower 6 and transferred to the ion exchange resin storage tank is low. Therefore, when the anion exchange resin is subjected to backwash separation to remove fine cation exchange resin of 80 mesh or less mixed in the anion exchange resin according to the present invention, the following regeneration method is performed. The effects of the present invention are further improved, and highly purified treated water can be obtained. In regenerating anion exchange resin from which fine cation exchange resin of 80 meshes or less has been removed according to the present invention, 2 to 8% by weight is used as the first step.
As shown in Fig. 5, the caustic soda solution 10 is
It is introduced from the lower part of the anion exchange resin regeneration tower 6 at a flow rate of LV 0.5 to 4 m/H. As a result, the anion exchange resin 4 becomes fluid, so that the cation exchange resin with a relatively small particle size of around 60 mesh mixed in the lower layer of the anion exchange resin 4 gradually becomes anionic. The ion exchange resin settles at the bottom of the ion exchange resin regeneration tower 6, and at the same time, the anion exchange resin in the mixed ion exchange resin 5 moves to the top of the anion exchange resin regeneration tower 6, and finally as shown in FIG. In the anion exchange resin regeneration tower 6, the lower part is the cation exchange resin 3', and the upper part is the anion exchange resin 4, so that a clear stack of anion exchange resin and cation exchange resin can be formed.
In addition, since the anion exchange resin 4 has already removed the fine cation exchange resin of 80 mesh or less which is particularly difficult to separate, this operation can completely separate both the cation and anion exchange resin in a short time. can do. In this operation, the anion exchange resin 4 is sufficiently fluidized to allow the cation exchange resin with a relatively small particle size to settle at the bottom of the anion exchange resin regeneration tower 6, thereby producing a more complete cation and anion exchange resin. Since the purpose is to perform separation, it is inconvenient if the density of the caustic soda solution used in this operation is higher than the density of the anion exchange resin. Even if it is an approximation, it is inconvenient.
Furthermore, when the caustic soda solution is caused to flow upward from the lower part of the anion exchange resin regeneration tower 6, if it flows in at too high a flow rate, not only will the cation exchange resin with a relatively small particle size not settle, but the anion exchange resin If the flow rate is extremely low, the anion exchange resin 4 will not flow, which will prevent the cation exchange resin 4, which has a relatively small particle size, from settling. There is also a correlation between the concentration of the caustic soda solution used in this operation and the flow rate at which the solution flows in an upward flow, and it is preferable to use the combinations of concentration and upward flow rate shown in Table 1.
【表】
なお、本操作に使用するか性ソーダ溶液の濃度
が低い場合は、前述したごとく比較的粒径の小さ
い陽イオン交換樹脂の分離効率が若干低下し、ま
た逆に濃度が高い場合は、陰イオン交換樹脂の流
動が緩慢となるため、比較的粒径の小さい陽イオ
ン交換樹脂の沈降に長時間を要するので、好まし
くはか性ソーダ溶液の濃度は3ないし6%の範囲
を選定するとよい。
また、先に出願した特願昭53−4391号において
は2ないし8重量%のか性ソーダ溶液の上昇流で
両イオン交換樹脂を分離する際に、上昇LVを0.5
ないし4m/Hとしたが、陰イオン交換樹脂4は
本発明によつて80メツシユ以下の微細な陽イオン
交換樹脂Kを除去しているのでもう少し上昇LV
を高くしても実質的に分離効果は変化せず、最大
でLV8m/Hまで実施可能である。ただしLV8m/
H以上の上昇流速とすると前述したように比較的
粒径の小さい陽イオン交換樹脂が沈降しないばか
りか、陰イオン交換樹脂4中に陽イオン交換樹脂
3′が混入するので好ましくない。逆にLV1.5m/
H以下の上昇流速ではLV0.5m/Hまでなら分離が
可能ではあるがしかし分離に長時間を要するので
好ましくない。このような理由により本操作にお
ける2ないし8重量%のか性ソーダ溶液の上昇流
速はLV4m/H前後とするのが最も好ましい。
以上のように本操作により第5図に示したごと
く陰イオン交換樹脂再生塔6内の下部に陽イオン
交換樹脂3′、その上部に陰イオン交換樹脂4と
なつた陰イオン交換樹脂と陽イオン交換樹脂の明
確なる積層を形成することができ、故に混合イオ
ン交換樹脂5を陰イオン交換樹脂4と陽イオン交
換樹脂3′とに、および陰イオン交換樹脂4の下
層部に含まれていた比較的粒径の小さい陽イオン
交換樹脂を陰イオン交換樹脂4から、ほとんど完
全に分離することが可能となる。
次に第2工程として第6図に示したように陰イ
オン交換樹脂再生塔6上部から陰イオン交換樹脂
4の密度より小さい密度を有するか性ソーダ溶液
11を下降流で流入して陰イオン交換樹脂4を再
生し、その再生廃液12を陰イオン交換樹脂再生
塔6の下部より排出する。このようにして当該か
性ソーダ溶液11を下降流で流入することによ
り、第1工程の終了とともに陰イオン交換樹脂
4、およびフリーボード13の部分に滞留してい
た2ないし8重量%のか性ソーダ溶液10を塔上
部から流入する当該か性ソーダ溶液11で押し出
して陰イオン交換樹脂4の層に再び下降流で通過
するので前操作において主に陽イオン交換樹脂と
陰イオン交換樹脂の分離のために使用していた2
ないし8重量%のか性ソーダ溶液10を再度陰イ
オン交換樹脂4の再生のために有効に使用でき、
そして陰イオン交換樹脂再生塔6の上部から流入
する新しいか性ソーダ溶液11が陰イオン交換樹
脂4層を通過することによりさらに陰イオン交換
樹脂4を再生するので、か性ソーダ溶液の有効的
な利用を計ることができる。第2工程で用いるか
性ソーダ溶液11は必ず陰イオン交換樹脂4の密
度より小さい密度のものを使用する必要がある。
何故ならば陰イオン交換樹脂4の密度より大きい
密度のか性ソーダ溶液を用いると通液中に陰イオ
ン交換樹脂4が密度差によつて浮上してしまい、
再生効率が極端に低下するからである。
第2工程で用いる陰イオン交換樹脂4より小さ
い密度を有するか性ソーダ溶液11の濃度として
は一般に陰イオン交換樹脂を再生する濃度すなわ
ち5重量%前後のものが望ましい。
なお、第2工程において当該か性ソーダ溶液1
1を塔上部から流入する前に、塔上部より純水を
流入して陰イオン交換樹脂再生塔6内に滞留して
いる第1工程に使用したか性ソーダ溶液10をあ
らかじめ押し出してもさしつかえない。
このようにして当該か性ソーダ溶液11の流入
が終了した後、常法により純水を用いて押し出し
および洗浄を行なう。
以上説明した二つの操作により、陰イオン交換
樹脂の下層部に含まれている比較的粒径の小さい
陽イオン交換樹脂を分離するとともに陰イオン交
換樹脂を効率よく再生することができる。したが
つて第6図に示した再生済みの陰イオン交換樹脂
4のみを陰イオン交換樹脂再生塔6から取り出せ
ばイオン交換樹脂貯槽にナトリウム形の陽イオン
交換樹脂が混入することはない。陰イオン交換樹
脂再生塔6から陰イオン交換樹脂4を取り出す方
法として第7図に示すごとく陰イオン交換樹脂と
陽イオン交換樹脂の中間の密度を有するか性ソー
ダ溶液15を陰イオン交換樹脂再生塔6の下部よ
り低流速の上昇流で流入させると同時に、同塔の
上部より空気または純水14を流入させながら陰
イオン交換樹脂4の下層部に設けた陰イオン交換
樹脂取り出しノズル16より陰イオン交換樹脂4
をスラリー状で取り出し樹脂貯槽に移送する方法
を行なうとよい。
本方法を実施すると、陰イオン交換樹脂4が
徐々に取り出され、塔内に残留する陰イオン交換
樹脂の量が小さくなるにしたがい第8図に示した
ように陰イオン交換樹脂4は浮上し、そして陰イ
オン交換樹脂4と陽イオン交換樹脂3′の間に当
該中間の密度を有するか性ソーダ溶液の液層17
が形成され、そして最終的に同塔の上部より流入
される空気または純水14の流入圧力によりこの
浮上した陰イオン交換樹脂4はそのすべてがイオ
ン交換樹脂貯槽に移送される。さらに本方法を詳
しく説明すると、本操作に使用する陽イオン交換
樹脂と陰イオン交換樹脂の中間の密度を有するか
性ソーダ溶液15の濃度は使用する陽イオン交換
樹脂と陰イオン交換樹脂の密度によつて多少の幅
はあるが通常10ないし20重量%からその目的にあ
つた最適な濃度を選定するとよい。また、当該中
間の密度を有するか性ソーダ溶液15を陰イオン
交換樹脂再生塔6に上昇流で流入させる際の流速
をあまり大とすると前述の第5図のように折角分
離した陽イオン交換樹脂3′が流動化し、特に陽
イオン交換樹脂3′の上層部に存在する粒径の小
さい陽イオン交換樹脂が当該か性ソーダ溶液15
の上向きの流れに乗つて陰イオン交換樹脂4内に
混入するので好ましくない。したがつて当該か性
ソーダ溶液15を上昇流で流入するときはなるべ
く陽イオン交換樹脂3′が流動化しないような低
流速の上昇流とすることが好ましく、通常LV2
m/H以下とするとよい。また陰イオン交換樹脂
と陽イオン交換樹脂の分離に使用した当該中間の
密度を有するか性ソーダ溶液15は回収すること
により十分に繰り返して使用することが可能であ
る。
すなわち、当該か性ソーダ溶液を用いて陰イオ
ン交換樹脂を移送した後の状態は第9図に示した
ごとく陰イオン交換樹脂再生塔6の下部に陽イオ
ン交換樹脂3′、その上部に当該か性ソーダ溶液
の液層17を形成しており、さらにその上部のフ
リーボード13は、陰イオン交換樹脂を取り出す
際に同塔の上部から空気を流入した場合には空気
層となつており、同様に同塔の上部から純水を流
入した場合は純水層となつている。したがつて第
9図に示したごとく陰イオン交換樹脂再生塔6の
上部から空気または純水14を流入することによ
り同塔の下部からほとんど希釈されていないか性
ソーダ溶液を回収することが可能である。またこ
のようにして回収した中間密度のか性ソーダ溶液
は陰イオン交換樹脂をすでに前に行なつた再生操
作によつて再生じているので純度がほとんど低下
していない。したがつて当該回収か性ソーダ溶液
は十分に繰り返して使用することが可能となり、
これにより全体としてのか性ソーダの使用量を低
減させることができる。
以上説明したような方法により陰イオン交換樹
脂再生塔6内の再生済みの陰イオン交換樹脂をイ
オン交換樹脂貯槽に取り出した後、必要に応じて
イオン交換樹脂貯槽内の陰イオン交換樹脂を水洗
し、そして分離塔1にて再生、水洗済みの陽イオ
ン交換樹脂を同塔に移送し、ここでよく混合し次
回の通水塔への移送に備える。一方、陰イオン交
換樹脂再生塔6の下部に残留した陽イオン交換樹
脂3′は水洗後、すでに陽イオン交換樹脂3の移
送が終了して空となつている分離塔1に移送し、
次回の通水塔から移送されてくる使用済みの陽・
陰両混合イオン交換樹脂と合して次回の再生に供
することによりイオン交換樹脂の容量バランスを
保つようにする。
以上説明したように本発明により単なる水逆洗
によつては分離が不可能な陰イオン交換樹脂に混
入する微細な陽イオン交換樹脂、特に陰イオン交
換樹脂の上層部に混入する80メツシユ以下の微細
な陽イオン交換樹脂を比較的簡単な操作によりほ
ぼ完全に分離することができるので、塔外再生型
の混床式イオン交換装置の通水系統に混入するナ
トリウム形の陽イオン交換樹脂の量を著しく低下
せしめることができ、よつて高純度の処理水を得
ることが可能となる。
以下に本発明の実施例を説明する。
実施例
強塩基性陰イオン交換樹脂アンバーライト(登
録商標、以下同様)IRA−900(密度1.09)と強
酸性陽イオン交換樹脂アンバーライト200C(密
度1.21)を使用している火力発電所の復水脱塩装
置から、通水塔において使用済みの両混合イオン
交換樹脂をサンプリングし、以下の実験に供し
た。まずチモールフタレインで青色に着色したア
ンバーライトIRA−900 24を、アンバーライト
200Cの80〜100メツシユ150ml、60〜70メツシユ
150ml、および50メツシユ以下の粒径のもの2.5
の合計2.8と混合し、分離用のアクリル製のカ
ラム(直径160mm、全長4000mm)に充填した。
上記カラムの下部よりLV 9m/Hの流速の上
昇流で約20分間純水を流入させ、両イオン交換樹
脂を逆洗分離した。その結果カラムの下部に褐色
の陽イオン交換樹脂のみの層が、その上部に褐色
の陽イオン交換樹脂と青色の陰イオン交換樹脂の
混合層が、さらにその上部に微細な褐色の陽イオ
ン交換樹脂を含む青色の陰イオン交換樹脂の層を
形成した。
次に上記カラムにチモールフタレインで青色に
着色したアンバーライトIRA−900 9.6を新た
に添加し、カラムの下部よりLV 9m/Hの流速
の上昇流で約20分間純水を流入させ、両イオン交
換樹脂を逆洗分離した。その結果再びカラムの下
部に褐色の陽イオン交換樹脂のみの層が、その上
部に褐色の陽イオン交換樹脂と青色の陰イオン交
換樹脂の混合層が、さらにその上部に上層部に微
細な褐色の陽イオン交換樹脂を含む青色の陰イオ
ン交換樹脂の層を形成した。
次に上記カラムの陰イオン交換樹脂層表面から
下方に向かつて480mmの位置に設けた取り出し管
から、取り出し管の上方に存在する9.6の陰イ
オン交換樹脂を取り出した。取り出した陰イオン
交換樹脂の9.6を2回に分けて分液ロートに移
し、密度約1.16(約15重量%)に調整したか性ソ
ーダ溶液を加えて十分に撹拌して、陰イオン交換
樹脂を完全に液上部に浮上させた。その後、時間
を置いて浮上させた陰イオン交換樹脂を再度撹拌
して静置することをそれぞれ5回繰り返して分液
ロートの下部に陽イオン交換樹脂が沈降してくる
かを確認した。その結果、分液ロートの下部に陽
イオン交換樹脂が沈降し、2回に分けた陽イオン
交換樹脂を合わせた容量は202mlであつた。な
お、そのうち80〜100メツシユの粒径のものが138
ml、60〜70メツシユの粒径のものが64mlあり、も
ともと含まれていた微細な陽イオン交換樹脂のう
ち、80〜100メツシユの粒径のものの92%および
60〜70メツシユの粒径のものの42%を除去した。
次に上記のカラムの下部から温度20℃の密度
1.054g/cm3の5重量%のか性ソーダ溶液をLV 4
m/Hの流速の上昇流で20分間流入した。その結
果、カラムの上部の青色の陰イオン交換樹脂は逆
洗時の時よりは少ないが、約40%膨脹し流動状態
を呈していた。さらに当該混合層と陰イオン交換
樹脂層の下層部に含まれていた褐色の粒径の小さ
い陽イオン交換樹脂は徐々にカラムの下部に沈降
するのを観察した。そして最終的にカラムの上部
に青色の陰イオン交換樹脂、その下部に上から下
に向かつて次第に粒径が大となつている褐色の陽
イオン交換樹脂となつた明確なる陰イオン交換樹
脂と陽イオン交換樹脂の積層を形成した。
10分間沈整させた後、カラムの上部から温度20
℃の密度1.054g/cm3の5%のか性ソーダ溶液を約
LV 6m/Hの流速の下向流で30分間流した後、
カラム上部から純水をLV9m/Hの流速の下向流
で30分間流して押し出しおよび洗浄を行なつた。
次にカラム下部から温度20℃の密度1.131g/cm3の
12重量%のか性ソーダ溶液をLV2m/Hの上昇流
で流入し、上部からLV 9m/Hの流速で純水を
流して陽イオン交換樹脂の上面から200mm上の陰
イオン交換樹脂層に位置する箇所に設けた陰イオ
ン交換樹脂取り出しノズルから陰イオン交換樹脂
を12重量%のか性ソーダ溶液に浮上させながらカ
ラムの外に全量を取り出した。
取り出した陰イオン交換樹脂の約5を同伴し
たか性ソーダ溶液とともに分液ロートに移し、分
液ロートに濃厚なか性ソーダ溶液を加え、同伴か
性ソーダ溶液の密度を約1.16(約15重量%)に調
整して十分に撹拌して、陰イオン交換樹脂を完全
に液上部に浮上させた。その後、時間を置いて浮
上させた陰イオン交換樹脂を再度撹拌して静置す
ることを5回繰り返して分液ロートの下部に陽イ
オン交換樹脂が沈降してくるかを確認した。その
結果、分液ロートの下部に微量の陽イオン交換樹
脂が沈降していることを確認し、この容量は0.7
ml以下であつた。
一方、取り出した陰イオン交換樹脂の500mlを
別に採取し、純水でよく水洗した後OH形陰イオ
ン交換樹脂の再生率を測定したところ95%以上と
なつていた。
なお本実施例に要したか性ソーダの使用量は5
%のか性ソーダ溶液をLV 4m/Hで20分間上昇
流で流入したものと、5%のか性ソーダ溶液を
LV 6m/Hで30分間下降流で流入したものの合
計量で陰イオン交換樹脂1あたり100%換算で
190gを要し、陰イオン交換樹脂と陽イオン交換
樹脂の分離のために用した12重量%のか性ソーダ
溶液は回収したが、約1.5相当は希釈されたの
で回収できなかつた。この回収できなかつたか性
ソーダは陰イオン交換樹脂1あたり100%換算
で約9gとなり、したがつて陰イオン交換樹脂を
再生するのに要した全か性ソーダ使用量は100%
換算で約200g/-Rとなつた。
また回収したか性ソーダの純度はとんど低下し
てなく、十分に次回の分離のために使用可能なも
のであつた。
本実施例で明らかなごとく、本発明によつて陰
イオン交換樹脂層に混入している微細な陽イオン
交換樹脂をほぼ完全に除去することができた。[Table] Note that if the concentration of the caustic soda solution used in this operation is low, the separation efficiency of the cation exchange resin, which has a relatively small particle size, will decrease slightly as described above, and conversely, if the concentration is high, the separation efficiency of the cation exchange resin will decrease slightly. Since the flow of the anion exchange resin becomes slow, it takes a long time for the cation exchange resin, which has a relatively small particle size, to settle, so the concentration of the caustic soda solution is preferably selected in the range of 3 to 6%. good. In addition, in the previously filed Japanese Patent Application No. 53-4391, when separating both ion exchange resins with an upward flow of 2 to 8% by weight caustic soda solution, the increase in LV was 0.5.
However, since the anion exchange resin 4 removes the fine cation exchange resin K of 80 mesh or less according to the present invention, the LV increases a little more.
Even if the value is increased, the separation effect does not substantially change, and it can be achieved up to LV8m/H. However, LV8m/
If the rising flow rate is higher than H, as mentioned above, not only the cation exchange resin having a relatively small particle size will not settle, but also the cation exchange resin 3' will be mixed into the anion exchange resin 4, which is not preferable. On the contrary, LV1.5m/
At a rising flow rate of less than H, separation is possible up to LV 0.5 m/H, but this is not preferable because separation takes a long time. For these reasons, it is most preferable that the upward flow rate of the 2 to 8% by weight caustic soda solution in this operation be around LV4 m/H. Through this operation, as shown in FIG. 5, the anion exchange resin and cations are formed such that the cation exchange resin 3' is in the lower part of the anion exchange resin regeneration tower 6, and the anion exchange resin 4 is in the upper part. A distinct stack of exchange resins can be formed, thus comparing the mixed ion exchange resin 5 contained in the anion exchange resin 4 and the cation exchange resin 3', and in the lower layer of the anion exchange resin 4. It becomes possible to almost completely separate the cation exchange resin having a small target particle size from the anion exchange resin 4. Next, as a second step, as shown in FIG. 6, a caustic soda solution 11 having a density lower than that of the anion exchange resin 4 flows downward from the upper part of the anion exchange resin regeneration tower 6 to exchange anions. The resin 4 is regenerated, and the regenerated waste liquid 12 is discharged from the lower part of the anion exchange resin regeneration tower 6. In this way, by flowing the caustic soda solution 11 in a downward flow, 2 to 8% by weight of the caustic soda remaining in the anion exchange resin 4 and the free board 13 is removed at the end of the first step. The solution 10 is pushed out by the caustic soda solution 11 flowing from the upper part of the column and passes through the layer of anion exchange resin 4 again in a downward flow, so the pre-operation is mainly used to separate the cation exchange resin and anion exchange resin. was used for 2
to 8% by weight caustic soda solution 10 can be effectively used again for regenerating the anion exchange resin 4,
Then, the new caustic soda solution 11 flowing from the upper part of the anion exchange resin regeneration tower 6 passes through the four layers of anion exchange resin to further regenerate the anion exchange resin 4. Usage can be measured. The caustic soda solution 11 used in the second step must always have a density lower than that of the anion exchange resin 4.
This is because if a caustic soda solution with a density higher than that of the anion exchange resin 4 is used, the anion exchange resin 4 will float to the surface due to the density difference during the passage of the solution.
This is because the regeneration efficiency is extremely reduced. The concentration of the caustic soda solution 11 having a density lower than that of the anion exchange resin 4 used in the second step is generally desirably a concentration that regenerates the anion exchange resin, that is, about 5% by weight. In addition, in the second step, the caustic soda solution 1
1 may be flowed in from the upper part of the tower to extrude the caustic soda solution 10 used in the first step remaining in the anion exchange resin regeneration tower 6 in advance. . After the inflow of the caustic soda solution 11 is completed in this manner, extrusion and washing are performed using pure water in a conventional manner. By the above-described two operations, it is possible to separate the cation exchange resin having a relatively small particle size contained in the lower layer of the anion exchange resin, and to efficiently regenerate the anion exchange resin. Therefore, if only the regenerated anion exchange resin 4 shown in FIG. 6 is taken out from the anion exchange resin regeneration tower 6, no sodium-type cation exchange resin will be mixed into the ion exchange resin storage tank. As a method for taking out the anion exchange resin 4 from the anion exchange resin regeneration tower 6, as shown in FIG. At the same time, air or pure water 14 is introduced from the upper part of the column through the anion exchange resin take-out nozzle 16 provided in the lower part of the anion exchange resin 4. Replacement resin 4
It is preferable to take out the resin in the form of a slurry and transfer it to a resin storage tank. When this method is carried out, the anion exchange resin 4 is gradually taken out, and as the amount of the anion exchange resin remaining in the column becomes smaller, the anion exchange resin 4 floats up as shown in FIG. and a liquid layer 17 of caustic soda solution having an intermediate density between the anion exchange resin 4 and the cation exchange resin 3'.
is formed, and finally all of this floating anion exchange resin 4 is transferred to the ion exchange resin storage tank by the inflow pressure of air or pure water 14 flowing from the upper part of the column. To further explain this method in detail, the concentration of the caustic soda solution 15, which has an intermediate density between the cation exchange resin and anion exchange resin used in this operation, depends on the density of the cation exchange resin and anion exchange resin used. Therefore, it is best to select the optimum concentration for the purpose, usually from 10 to 20% by weight, although there is some variation. Moreover, if the flow rate when flowing the caustic soda solution 15 having an intermediate density into the anion exchange resin regeneration tower 6 in an upward flow is too high, the cation exchange resin may be separated as shown in FIG. 3' is fluidized, and the cation exchange resin with small particle size present in the upper layer of the cation exchange resin 3' becomes the caustic soda solution 15.
This is not preferable because it gets mixed into the anion exchange resin 4 along with the upward flow of the water. Therefore, when the caustic soda solution 15 flows in an upward flow, it is preferable that the flow rate is low so as not to fluidize the cation exchange resin 3'.
It is best to keep it below m/H. Further, the caustic soda solution 15 having an intermediate density used for separating the anion exchange resin and the cation exchange resin can be used repeatedly by recovering it. That is, the state after the anion exchange resin is transferred using the caustic soda solution is as shown in FIG. A liquid layer 17 of the sodium chloride solution is formed, and the free board 13 above it becomes an air layer when air is introduced from the top of the column when taking out the anion exchange resin. When pure water is introduced from the top of the tower, it forms a pure water layer. Therefore, as shown in FIG. 9, by flowing air or pure water 14 from the upper part of the anion exchange resin regeneration tower 6, it is possible to recover almost undiluted caustic soda solution from the lower part of the tower. It is. Moreover, since the medium density caustic soda solution thus recovered has been regenerated by the previous regeneration operation of the anion exchange resin, its purity has hardly decreased. Therefore, the recovered caustic soda solution can be used repeatedly,
This makes it possible to reduce the overall amount of caustic soda used. After taking out the regenerated anion exchange resin in the anion exchange resin regeneration tower 6 into the ion exchange resin storage tank by the method explained above, the anion exchange resin in the ion exchange resin storage tank is washed with water as necessary. Then, the cation exchange resin that has been regenerated and washed in the separation tower 1 is transferred to the same tower, where it is thoroughly mixed and prepared for the next transfer to the water tower. On the other hand, the cation exchange resin 3' remaining at the bottom of the anion exchange resin regeneration tower 6 is washed with water and then transferred to the separation tower 1, which is empty after the transfer of the cation exchange resin 3 has already been completed.
Used solar cells transferred from the next water tower
The capacity balance of the ion exchange resin is maintained by combining it with the anion and mixed ion exchange resin and providing it for the next regeneration. As explained above, the present invention enables the removal of fine particles of cation exchange resin that are mixed into the anion exchange resin that cannot be separated by simple backwashing with water, especially 80 mesh or less that are mixed in the upper layer of the anion exchange resin. Since fine cation exchange resin can be almost completely separated by relatively simple operations, the amount of sodium cation exchange resin mixed into the water flow system of an external regeneration type mixed bed ion exchange equipment can be reduced. This makes it possible to significantly reduce the amount of water, thereby making it possible to obtain highly purified treated water. Examples of the present invention will be described below. Example: Condensate from a thermal power plant using strong basic anion exchange resin Amberlite (registered trademark, same hereinafter) IRA-900 (density 1.09) and strong acidic cation exchange resin Amberlite 200C (density 1.21) The used mixed ion exchange resins were sampled from the desalination equipment in the water tower and used in the following experiment. First, add Amberlite IRA-900 24, which has been colored blue with thymolphthalein, to Amberlite.
80-100 mesh 150ml at 200C, 60-70 mesh
150ml and 2.5 particles with a particle size of 50 mesh or less
2.8 in total and packed into an acrylic separation column (diameter 160 mm, total length 4000 mm). Pure water was allowed to flow upward from the bottom of the column at a flow rate of LV 9 m/H for about 20 minutes to backwash and separate both ion exchange resins. As a result, there is a layer of only brown cation exchange resin at the bottom of the column, a mixed layer of brown cation exchange resin and blue anion exchange resin at the top, and a layer of fine brown cation exchange resin above that. A layer of blue anion exchange resin was formed. Next, Amberlite IRA-900 9.6, which was colored blue with thymolphthalein, was newly added to the above column, and pure water was flowed from the bottom of the column at an upward flow rate of LV 9 m/H for about 20 minutes, and both ion The exchange resin was backwashed and separated. As a result, there is again a layer of brown cation exchange resin at the bottom of the column, a mixed layer of brown cation exchange resin and blue anion exchange resin at the top, and a layer of fine brown cation exchange resin in the upper layer. A layer of blue anion exchange resin containing cation exchange resin was formed. Next, 9.6 anion exchange resin present above the take-out tube was taken out from the take-out tube provided at a position 480 mm downward from the surface of the anion exchange resin layer of the column. Transfer 9.6 of the anion exchange resin taken out into a separating funnel in two portions, add caustic soda solution adjusted to a density of approximately 1.16 (approximately 15% by weight), and stir thoroughly to separate the anion exchange resin. It was completely floated to the top of the liquid. Thereafter, the anion exchange resin that had been floated was stirred again after a period of time and allowed to stand still, which was repeated five times each to check whether the cation exchange resin had settled at the bottom of the separating funnel. As a result, the cation exchange resin precipitated at the bottom of the separating funnel, and the combined volume of the cation exchange resin divided into two portions was 202 ml. Of these, 138 particles have a particle size of 80 to 100 mesh.
ml, there are 64ml of particles with a particle size of 60 to 70 mesh, and of the fine cation exchange resin originally contained, 92% of the particles with a particle size of 80 to 100 mesh and
42% of particles with a particle size of 60-70 mesh were removed. Next, from the bottom of the column above, the density at a temperature of 20℃ is
LV 4 5% by weight caustic soda solution of 1.054g/ cm3
The inflow was carried out for 20 minutes at an upward flow rate of m/H. As a result, the blue anion exchange resin at the top of the column expanded by about 40% and was in a fluid state, although the amount was less than during backwashing. Furthermore, it was observed that the brown cation exchange resin with small particle size contained in the mixed layer and the lower layer of the anion exchange resin layer gradually settled to the bottom of the column. Finally, the upper part of the column is a blue anion exchange resin, and the lower part is a brown cation exchange resin whose particle size gradually increases from top to bottom. A laminate of ion exchange resin was formed. After settling for 10 minutes, reduce the temperature from the top of the column to 20
A 5% caustic soda solution with a density of 1.054g/ cm3 is approximately
After flowing for 30 minutes in a downward flow at a flow rate of LV 6 m/H,
Extrusion and washing were performed by flowing pure water from the top of the column in a downward flow at a flow rate of LV9 m/H for 30 minutes.
Next, from the bottom of the column, a sample with a density of 1.131 g/cm 3 at a temperature of 20°C is
A 12% by weight caustic soda solution was introduced at an upward flow of LV 2 m/H, and pure water was flowed from the top at a flow rate of LV 9 m/H to position the anion exchange resin layer 200 mm above the top surface of the cation exchange resin. The entire amount of anion exchange resin was taken out of the column from an anion exchange resin take-out nozzle provided at a certain point while floating the anion exchange resin on a 12% by weight caustic soda solution. About 50% of the anion exchange resin taken out was transferred to a separatory funnel together with the accompanying caustic soda solution, and the concentrated caustic soda solution was added to the separating funnel until the density of the accompanying caustic soda solution was about 1.16 (about 15% by weight). ) and stirred sufficiently to completely float the anion exchange resin to the top of the liquid. Thereafter, the anion exchange resin that had floated to the surface after a while was stirred again and allowed to stand still, which was repeated five times to check whether the cation exchange resin had settled at the bottom of the separating funnel. As a result, it was confirmed that a small amount of cation exchange resin had settled at the bottom of the separating funnel, and this volume was 0.7
It was less than ml. On the other hand, 500 ml of the removed anion exchange resin was separately collected and thoroughly washed with pure water, and the regeneration rate of the OH type anion exchange resin was measured and found to be over 95%. The amount of caustic soda required in this example was 5
% caustic soda solution flowing upward for 20 minutes at LV 4 m/H, and 5% caustic soda solution flowing upward for 20 minutes.
Total amount of flow flowing down for 30 minutes at LV 6m/H, calculated as 100% per anion exchange resin.
Although 190 g of the 12% by weight caustic soda solution used to separate the anion exchange resin and cation exchange resin was recovered, the equivalent of about 1.5 was diluted and could not be recovered. This unrecoverable caustic soda amounts to approximately 9 g on a 100% basis per anion exchange resin, and therefore the total amount of caustic soda required to regenerate the anion exchange resin is 100%.
It was converted to about 200g/-R. Moreover, the purity of the recovered caustic soda did not decrease at all, and it was sufficiently usable for the next separation. As is clear from this example, according to the present invention, the fine cation exchange resin mixed in the anion exchange resin layer could be almost completely removed.
第1図、第2図、第3図、第4図、第5図、第
6図、第7図、第8図、第9図はいずれも本発明
の実施態様における各操作ごとの陰イオン交換樹
脂と陽イオン交換樹脂の分離状態を表わした説明
図である。
1……分離塔、2……逆洗水、3……陽イオン
交換樹脂、4……陰イオン交換樹脂、5……混合
イオン交換樹脂、6……陰イオン交換樹脂再生
塔、7……取り出し管、8……取り出し管、9…
…再生剤、10……2ないし8重量%のか性ソー
ダ溶液、11……陰イオン交換樹脂の密度より小
さい密度を有するか性ソーダ溶液、12……再生
廃液、13……フリーボード、14……空気また
は純水、15……陰イオン交換樹脂と陽イオン交
換樹脂の中間の密度を有するか性ソーダ溶液、1
6……陰イオン交換樹脂取り出しノズル、17…
…液層、K……微細な陽イオン交換樹脂。
Figures 1, 2, 3, 4, 5, 6, 7, 8, and 9 show anions for each operation in the embodiment of the present invention. FIG. 2 is an explanatory diagram showing a state of separation of an exchange resin and a cation exchange resin. 1... Separation tower, 2... Backwash water, 3... Cation exchange resin, 4... Anion exchange resin, 5... Mixed ion exchange resin, 6... Anion exchange resin regeneration tower, 7... Take-out pipe, 8... Take-out pipe, 9...
... Regenerating agent, 10 ... 2 to 8% by weight caustic soda solution, 11 ... Caustic soda solution having a density lower than the density of the anion exchange resin, 12 ... Regeneration waste liquid, 13 ... Freeboard, 14 ... ...air or pure water, 15...caustic soda solution having a density intermediate between anion exchange resin and cation exchange resin, 1
6... Anion exchange resin take-out nozzle, 17...
...liquid layer, K...fine cation exchange resin.
Claims (1)
て、使用済みの陽・陰両混合イオン交換樹脂を水
で逆洗分離する際に、当該陰イオン交換樹脂の15
ないし60容量%の陰イオン交換樹脂を新たに添加
して水で逆洗分離し、上部に陰イオン交換換樹
層、下部に陽イオン交換樹脂層を形成し、次い
で、逆洗分離した陰イオン交換樹脂層の上層部の
逆洗分離する際に添加した陰イオン交換樹脂量に
相当する量の陰イオン交換樹脂を取り出した後、
陽・陰両イオン交換樹脂を再生することを特徴と
する陰イオン交換樹脂中に混入する微細な陽イオ
ン交換樹脂の分離方法。1 In an off-column regeneration type mixed bed ion exchange equipment, when backwashing and separating a used cation-exchange resin and an anion-exchange resin with water, 15% of the anion exchange resin is
Or 60% by volume of anion exchange resin is newly added and backwashed and separated with water to form an anion exchange resin layer on the top and a cation exchange resin layer on the bottom, and then the backwashed and separated anions After removing an anion exchange resin in an amount corresponding to the amount of anion exchange resin added during backwash separation of the upper layer of the exchange resin layer,
A method for separating fine cation exchange resins mixed into an anion exchange resin, characterized by regenerating both cation and anion exchange resins.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP3177379A JPS55124548A (en) | 1979-03-20 | 1979-03-20 | Separating fine cation-exchange resin mixing into anion-exchange resin |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP3177379A JPS55124548A (en) | 1979-03-20 | 1979-03-20 | Separating fine cation-exchange resin mixing into anion-exchange resin |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS55124548A JPS55124548A (en) | 1980-09-25 |
JPS6140462B2 true JPS6140462B2 (en) | 1986-09-09 |
Family
ID=12340362
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP3177379A Granted JPS55124548A (en) | 1979-03-20 | 1979-03-20 | Separating fine cation-exchange resin mixing into anion-exchange resin |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS55124548A (en) |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP7184152B1 (en) * | 2021-12-23 | 2022-12-06 | 栗田工業株式会社 | Separation column for mixed ion exchange resin and method for separating mixed ion exchange resin using the same |
JP7405285B1 (en) * | 2023-01-05 | 2023-12-26 | 栗田工業株式会社 | Method for separating and regenerating anion exchange resin and cation exchange resin in mixed ion exchange resin |
-
1979
- 1979-03-20 JP JP3177379A patent/JPS55124548A/en active Granted
Also Published As
Publication number | Publication date |
---|---|
JPS55124548A (en) | 1980-09-25 |
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