JPH0687923B2 - Aqueous solution purification method - Google Patents
Aqueous solution purification methodInfo
- Publication number
- JPH0687923B2 JPH0687923B2 JP2044008A JP4400890A JPH0687923B2 JP H0687923 B2 JPH0687923 B2 JP H0687923B2 JP 2044008 A JP2044008 A JP 2044008A JP 4400890 A JP4400890 A JP 4400890A JP H0687923 B2 JPH0687923 B2 JP H0687923B2
- Authority
- JP
- Japan
- Prior art keywords
- aqueous solution
- activated carbon
- acid
- zinc chloride
- iron
- 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 - Fee Related
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D15/00—Separating processes involving the treatment of liquids with solid sorbents; Apparatus therefor
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/05—Preparation or purification of carbon not covered by groups C01B32/15, C01B32/20, C01B32/25, C01B32/30
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Analytical Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Treatment Of Liquids With Adsorbents In General (AREA)
- Inorganic Fibers (AREA)
- Spinning Methods And Devices For Manufacturing Artificial Fibers (AREA)
- Solid-Sorbent Or Filter-Aiding Compositions (AREA)
- Inorganic Compounds Of Heavy Metals (AREA)
Description
【発明の詳細な説明】 ［産業上の利用分野］ 本発明は、活性炭による水溶液精製方法に関し、さらに
詳しくは、活性炭からの鉄分の溶出を抑制することがで
きて、特にポリアクリロニトリル系繊維の製造に用いる
塩化亜鉛系水溶液の精製に好適に利用することのできる
水溶液精製方法に関する。Description: TECHNICAL FIELD The present invention relates to a method for purifying an aqueous solution using activated carbon, more specifically, it is possible to suppress the elution of iron from activated carbon, and particularly to produce polyacrylonitrile-based fibers. The present invention relates to an aqueous solution purification method that can be suitably used for the purification of a zinc chloride-based aqueous solution used in.
［従来の技術及び発明が解決しようとする課題］ 活性炭は吸着力に優れることから、たとえば食品、医薬
品、各種化学製品等の分野において広く利用されるに至
っている。[Problems to be Solved by Conventional Techniques and Inventions] Activated carbon has been widely used in the fields of, for example, foods, pharmaceuticals, and various chemical products because of its excellent adsorptivity.
たとえばポリアクリロニトリル系繊維の製造において
は、塩化亜鉛系水溶液の精製に活性炭が使用されてい
る。For example, in the production of polyacrylonitrile fiber, activated carbon is used for refining a zinc chloride aqueous solution.
すなわち、近年、炭素繊維の前駆体繊維として需要の大
きいポリアクリロニトリル系繊維は、たとえばアクリロ
ニトリルまたはアクリロニトリルと他のビニル化合物モ
ノマーを重合して得られる紡糸原液を紡糸することによ
って製造されており、この重合は塩化亜鉛系水溶液中で
行なわれている。That is, in recent years, polyacrylonitrile-based fibers, which are in great demand as precursor fibers for carbon fibers, are produced by spinning a spinning dope obtained by polymerizing acrylonitrile or acrylonitrile and other vinyl compound monomers, for example, and polymerizing the same. Is performed in a zinc chloride-based aqueous solution.
また、紡糸原液の調製に用いる溶剤にも塩化亜鉛系水溶
液が用いられている。Further, a zinc chloride-based aqueous solution is also used as a solvent used for preparing a spinning dope.
さらに、凝固浴に使用する凝固液にも塩化亜鉛系水溶液
が用いられている。Furthermore, a zinc chloride-based aqueous solution is also used as the coagulating liquid used in the coagulating bath.
そして、ポリアクリロニトリル系繊維の製造において
は、使用に供した塩化亜鉛系水溶液を粗塩化亜鉛系水溶
液として回収し、再生処理を行なった後に再使用に供し
ている。In the production of polyacrylonitrile-based fibers, the zinc chloride-based aqueous solution used is recovered as a crude zinc chloride-based aqueous solution, regenerated, and then reused.
この粗塩化亜鉛系水溶液の再生処理方法には、粗塩化亜
鉛系水溶液に酸化剤を添加して溶存第１鉄イオンを第２
鉄イオンに変え、次に酸化亜鉛を添加して液のpHを上げ
て水酸化第２鉄を沈降させ、さらに金属亜鉛を添加して
銅を析出させてから、活性炭を充填した吸着塔に通して
残存有機物と金属イオンとを吸着除去する方法が採用さ
れている。In this method for regenerating a crude zinc chloride-based aqueous solution, an oxidizing agent is added to the crude zinc chloride-based aqueous solution to dissolve the dissolved ferrous iron
After changing to iron ions, zinc oxide is added to raise the pH of the solution to precipitate ferric hydroxide, and further metallic zinc is added to precipitate copper, which is then passed through an adsorption tower filled with activated carbon. A method of adsorbing and removing the remaining organic matter and metal ions is adopted.
しかしながら、この方法において、粗塩化亜鉛系水溶液
と活性炭とを接触させると、粗塩化亜鉛系水溶液中の有
機物は除去されるものの活性炭中の鉄分が溶出するの
で、再生処理を行なって得られる塩化亜鉛系水溶液に鉄
分が混入してしまうという問題がある。However, in this method, when the crude zinc chloride-based aqueous solution is brought into contact with the activated carbon, the organic matter in the crude zinc chloride-based aqueous solution is removed, but the iron content in the activated carbon is eluted, so that the zinc chloride obtained by the regeneration treatment is obtained. There is a problem that iron is mixed in the system aqueous solution.
この問題は前記の再生処理を行なって得られる塩化亜鉛
系水溶液を濃縮して、ポリアクリロニトリル系繊維の紡
糸原液の重合に使用する場合に、紡糸原液に鉄分が混入
するという事態を招く。鉄の存在は塩化亜鉛系水溶液中
でのアクリロニトリルの重合に大きく影響する。This problem causes a situation where iron content is mixed in the spinning dope when the zinc chloride aqueous solution obtained by performing the above-mentioned regeneration treatment is concentrated and used for polymerization of the spinning dope of polyacrylonitrile fiber. The presence of iron has a great influence on the polymerization of acrylonitrile in a zinc chloride-based aqueous solution.
たとえば、得られるポリアクリロニトリルの分子量を低
下させたり、重合率を下げたりする。For example, the molecular weight of the obtained polyacrylonitrile is lowered, or the polymerization rate is lowered.
したがって、粘度やポリマー濃度の変動を実用的な範囲
に抑えるためには、重合時の塩化亜鉛水溶液中の鉄イオ
ン濃度は1ppm以下に管理されなければならない。Therefore, in order to suppress fluctuations in viscosity and polymer concentration within a practical range, the iron ion concentration in the aqueous zinc chloride solution during polymerization must be controlled to 1 ppm or less.
上記紡糸原液から得られた繊維を炭素繊維の前駆体繊維
に用いて、炭素繊維を製造する場合には、得られる炭素
繊維の強度が低下するという問題を生じる。When the carbon fiber is produced by using the fiber obtained from the above spinning dope as the precursor fiber of the carbon fiber, there arises a problem that the strength of the obtained carbon fiber is lowered.
したがって、特にポリアクリロニトリル系繊維の製造に
おいては、活性炭からの鉄分の溶出を抑制することが望
まれている。Therefore, especially in the production of polyacrylonitrile fiber, it is desired to suppress the elution of iron from activated carbon.
本発明は前記事情に基いてなされたものである。The present invention has been made based on the above circumstances.
すなわち、本発明の目的は、活性炭からの鉄分の溶出を
抑制することができて、特にポリアクリロニトリル系繊
維の製造に用いる粗塩化亜鉛系水溶液の再生処理に好適
に利用することのできる水溶液精製方法を提供すること
にある。That is, the object of the present invention is an aqueous solution purification method which can suppress the elution of iron from activated carbon and can be preferably used particularly for the regeneration treatment of a crude zinc chloride-based aqueous solution used for the production of polyacrylonitrile-based fibers. To provide.
［前記課題を解決するための手段］ 前記課題を解決するために、本発明者が鋭意検討を重ね
た結果、予め高濃度の酸で洗浄し、酸を吸着させたまま
の状態になっている活性炭は、特定のpHに調整された水
溶液をその活性炭で洗浄すると、鉄分の溶出を抑制する
ことを見出して、本発明に到達した。[Means for Solving the Problems] In order to solve the problems, as a result of extensive studies by the present inventor, it has been washed with a high-concentration acid in advance, and the acid is still adsorbed. The present inventors have found that activated carbon can suppress the elution of iron when an aqueous solution adjusted to a specific pH is washed with the activated carbon, and arrived at the present invention.
酸に浸漬処理された活性炭であって、活性炭と平衡して
いる水溶液のpHが６以下になっている活性炭で、pHが３
〜5.5に調整された水溶液を精製することを特徴とする
水溶液精製方法である。Activated carbon that has been soaked in an acid, and the pH of the aqueous solution that is in equilibrium with the activated carbon is 6 or less.
A method for purifying an aqueous solution, which comprises purifying the aqueous solution adjusted to 5.5.
本発明において使用に供される活性炭は、粒状活性炭で
ある。The activated carbon used in the present invention is granular activated carbon.
前記粒状活性炭の粒子径は、通常、0.1〜1.5mm、好まし
くは0.3〜1mmである。The particle size of the granular activated carbon is usually 0.1 to 1.5 mm, preferably 0.3 to 1 mm.
前記活性炭は、たとえばヤシ殻、木炭、ピッチ系活性炭
などを賦活することにより得ることができる。The activated carbon can be obtained by activating coconut shell, charcoal, pitch-based activated carbon or the like.
本発明において、前記活性炭に吸着させる酸はプロトン
酸であり、好ましくは無機酸である。なお、活性炭と反
応するもの、たとえば酸化剤として作用するものは好ま
しくない。In the present invention, the acid adsorbed on the activated carbon is a protic acid, preferably an inorganic acid. It should be noted that a substance that reacts with activated carbon, for example, a substance that acts as an oxidizing agent is not preferable.
前記無機酸としては、たとえば、塩酸、シアン化水素
酸、フッ化水素酸、ヨウ素酸、亜硝酸などが挙げられ
る。Examples of the inorganic acid include hydrochloric acid, hydrocyanic acid, hydrofluoric acid, iodic acid, nitrous acid and the like.
これらの酸は、被精製水溶液との組み合わせで選択され
る。被精製水溶液には用いた酸が若干混入することがあ
るので、混入しても差し支えないものを選ぶのが好まし
い。被精製水溶液が、アクリロニトリルの重合溶剤とし
て用いられる塩化亜鉛水溶液の場合は、塩酸が好適であ
る。These acids are selected in combination with the aqueous solution to be purified. Since the acid used may be slightly mixed in the aqueous solution to be purified, it is preferable to select one that can be mixed. Hydrochloric acid is suitable when the aqueous solution to be purified is an aqueous zinc chloride solution used as a polymerization solvent for acrylonitrile.
本発明において使用に供する前記酸の濃度については、
前記酸の種類によって一概に決定することはできない
が、たとえば塩酸を使用する場合には、通常、0.5〜５
％である。Regarding the concentration of the acid used in the present invention,
It cannot be unconditionally determined depending on the type of the acid, but when hydrochloric acid is used, it is usually 0.5 to 5
%.
本発明においては、前記活性炭に予め前記酸を吸着させ
る。In the present invention, the acid is previously adsorbed on the activated carbon.
ここにおいて「予め酸を吸着させる」とは、「使用直前
の酸処理において、活性炭と平衡している酸水溶液のpH
が６以下、好ましくは5.5以下」になるように処理する
ことである。Here, "adsorb the acid in advance" means "the pH of the acid aqueous solution that is in equilibrium with the activated carbon in the acid treatment immediately before use.
Is 6 or less, preferably 5.5 or less ”.
前記活性炭に前記酸を吸着させるには、たとえば前記酸
の中に前記活性炭を浸漬しても良いし、前記活性炭に前
記酸を摘下して含浸させても良い。In order to make the activated carbon adsorb the acid, for example, the activated carbon may be immersed in the acid, or the activated carbon may be impregnated with the acid.
前記活性炭における前記酸の含有率は、前記酸や活性炭
の種類によるので一概に決定することはできないが、活
性炭を酸に浸漬して１時間後に浸漬液が酸性（pHが６以
下）であればよい。The content of the acid in the activated carbon cannot be unconditionally determined because it depends on the type of the acid or activated carbon, but if the immersion liquid is acidic (pH 6 or less) 1 hour after the activated carbon is immersed in the acid. Good.
前記活性炭は、使用に供した後、たとえば特公昭56−19
288号に記載された再生処理を行なって再使用すること
ができるが、最後の酸処理後、加熱水で酸を脱着した
り、アルカリで中和させてはならない。After being used, the activated carbon may be used, for example, in Japanese Examined Patent Publication Sho 56-19.
Although it can be reused by performing the regeneration treatment described in No. 288, the acid should not be desorbed with heated water or neutralized with alkali after the final acid treatment.
活性炭の再生には、酸洗−水洗−アルカリ洗−水洗が行
なわれることがあるが、この場合には必ずその後に酸浸
漬の工程が必要である。In order to regenerate the activated carbon, pickling-water washing-alkali washing-water washing may be carried out, but in this case, a step of acid dipping is always required after that.
最終的に常温水で過剰の酸を洗い流すことは差し支えな
いものの、水洗液がpH6以上になるまで洗ってはいけな
い。好ましくはpH5.5以下に留める。Although it is safe to wash away excess acid with room temperature water, do not wash it until the pH of the washing solution is 6 or more. Preferably, the pH is kept below 5.5.
また、被精製液の酸性が強いと、この方法でも若干の鉄
が溶出してくるので、pHは３以上、好ましくは3.5以上
が好ましい。Further, if the liquid to be purified has a strong acidity, some iron will be eluted even by this method, so the pH is preferably 3 or higher, and more preferably 3.5 or higher.
塩化亜鉛水溶液の場合は、予め酸化亜鉛等を添加してpH
を高くしておくのが好ましい。重合溶媒として用いられ
る高濃度（55％以上）の塩化亜鉛水溶液では、充分にpH
を上げることが困難なので、水で希釈して45％以下好ま
しくは40％以下の濃度とし、本発明の方法で精製後濃縮
するのがよい。In the case of zinc chloride aqueous solution, add zinc oxide etc. in advance to adjust the pH.
It is preferable to keep the value high. The pH of a high concentration (55% or more) zinc chloride aqueous solution used as a polymerization solvent is sufficient.
Since it is difficult to raise the concentration, it is preferable to dilute with water to a concentration of 45% or less, preferably 40% or less, and purify by the method of the present invention and then concentrate.
したがって、溶媒として、60％塩化亜鉛水溶液を用い、
精製を25％の濃度で行う時、重合時の鉄イオンを1ppm以
下に抑えるためには、25％水溶液では0.4ppm以下にまで
精製される必要がある。Therefore, using a 60% zinc chloride aqueous solution as a solvent,
When purification is carried out at a concentration of 25%, it is necessary to purify it to 0.4 ppm or less in a 25% aqueous solution in order to suppress iron ions during polymerization to 1 ppm or less.
要するに、使用前の活性炭を浸漬している液、精製され
るべき水溶液のpHを６以下、好ましくは3.5〜5.5に保持
することにより、本発明の効果を得ることができる。In short, the effect of the present invention can be obtained by maintaining the pH of the liquid in which the activated carbon is immersed before use and the aqueous solution to be purified at 6 or less, preferably 3.5 to 5.5.
たとえば本発明の方法を採用してポリアクリロニトリル
系繊維を製造するには、紡糸原液の重合等に使用した塩
化亜鉛系水溶液を粗塩化亜鉛系水溶液として回収した
後、常法によって精製し、この粗塩化亜鉛系水溶液と前
記酸を吸着させてなる前記活性炭とを接触させる。For example, in order to produce a polyacrylonitrile-based fiber by adopting the method of the present invention, the zinc chloride-based aqueous solution used for polymerization of the spinning dope is recovered as a crude zinc chloride-based aqueous solution, and then purified by a conventional method. The zinc chloride aqueous solution is brought into contact with the activated carbon obtained by adsorbing the acid.
このようにして得られるポリアクリロニトリル系繊維に
は鉄分の混入が著しく少ない。したがって、たとえばこ
のポリアクリロニトリル系繊維を炭素繊維の前駆体繊維
に用いた場合には、強度に優れた炭素繊維を得ることが
できる。The polyacrylonitrile-based fiber thus obtained has a significantly low iron content. Therefore, for example, when this polyacrylonitrile fiber is used as a precursor fiber of carbon fiber, carbon fiber having excellent strength can be obtained.
酸吸着により、活性炭中の鉄含有量は変わらないのに鉄
の溶出が著しく少なくなることは、驚くべきことであ
る。It is surprising that acid adsorption significantly reduces the elution of iron while the iron content in the activated carbon remains unchanged.
［実施例］ 次に本発明の実施例および比較例を示し、本発明につい
てさらに具体的に説明する。[Examples] Next, the present invention will be described more specifically with reference to Examples and Comparative Examples of the present invention.
（実施例１） 粒状活性炭［呉羽化学工業（株）製（クレハビーズ活性
炭A-BAC）］250gを、約500mlの２％塩酸に１時間浸漬し
た。(Example 1) 250 g of granular activated carbon [Kureha Beads Activated Carbon A-BAC] manufactured by Kureha Chemical Industry Co., Ltd. was immersed in about 500 ml of 2% hydrochloric acid for 1 hour.
次いで、塩酸を流し出し、活性炭を500mlのカラムに充
填した。Then, hydrochloric acid was poured out, and activated carbon was packed in a 500 ml column.
このカラムに脱イオン水を流速１/Hrで流した。１時
間後にカラムを出てきた水のpHが3.5まで上昇してきた
ので、水洗を中止した。Deionized water was passed through the column at a flow rate of 1 / Hr. After 1 hour, the pH of the water coming out of the column had risen to 3.5, so the washing with water was stopped.
このカラムに25％塩化亜鉛水溶液（酸化亜鉛を添加して
pH4とし、未溶解酸化亜鉛と沈降した鉄を決別したもの
を流速１/Hrで流した。流出してきた塩化亜鉛水溶液
中の鉄分は0.2ppmであった（測定は原子吸光法によっ
た）。Add 25% zinc chloride solution (add zinc oxide to this column)
The pH was adjusted to 4 and the undissolved zinc oxide and the precipitated iron were separated and flowed at a flow rate of 1 / Hr. The iron content in the zinc chloride aqueous solution that had flowed out was 0.2 ppm (measurement was by an atomic absorption method).
（比較例１） 実施例１と同じ粒状活性炭を、塩酸処理しないで同じカ
ラムに充填し、これに脱イオン水を流量１/Hrで流し
た後、実施例１の塩化亜鉛水溶液を流した。(Comparative Example 1) The same granular activated carbon as in Example 1 was packed in the same column without treatment with hydrochloric acid, deionized water was allowed to flow at a flow rate of 1 / Hr, and then the aqueous zinc chloride solution of Example 1 was allowed to flow.
流出した塩化亜鉛水溶液中の鉄分の濃度は、11ppmであ
った。The concentration of iron in the zinc chloride aqueous solution that flowed out was 11 ppm.
（比較例２） 比較例１で用いたカラムに25％塩化亜鉛水溶液（酸化亜
鉛を添加せず、塩基塩濃度は0.2％、pH1）を流した。(Comparative Example 2) A 25% zinc chloride aqueous solution (without adding zinc oxide, the basic salt concentration was 0.2%, pH 1) was passed through the column used in Comparative Example 1.
流出液中の鉄分の濃度は30ppmであった。The iron concentration in the effluent was 30 ppm.
［発明の効果］ 本発明によると、 （１）予め活性炭に酸を吸着させるだけで、活性炭から
の鉄分の溶出を抑制することができる、 （２）したがって、特にポリアクリロニトリル系繊維の
製造に使用する粗塩化亜鉛系水溶液の再生処理に好適に
利用することができる、 等の利点を有する水溶液精製方法を提供することができ
る。[Advantages of the Invention] According to the present invention, (1) the elution of iron from activated carbon can be suppressed by simply adsorbing an acid to activated carbon in advance. (2) Therefore, it is particularly used for the production of polyacrylonitrile fiber. It is possible to provide a method for purifying an aqueous solution, which has advantages such as that it can be suitably used for regenerating the crude zinc chloride-based aqueous solution.
Claims (2)
炭と平衡している水溶液のpHが６以下になっている活性
炭で、pHが３〜5.5に調整された水溶液を精製すること
を特徴とする水溶液精製方法。1. A method of purifying an aqueous solution of activated carbon which has been subjected to an immersion treatment in an acid, wherein the pH of the aqueous solution in equilibrium with the activated carbon is 6 or less and whose pH is adjusted to 3 to 5.5. A characteristic aqueous solution purification method.
塩酸である前記請求項１に記載の水溶液精製方法。2. The method for purifying an aqueous solution according to claim 1, wherein the aqueous solution is a zinc chloride aqueous solution and the acid is hydrochloric acid.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2044008A JPH0687923B2 (en) | 1990-02-23 | 1990-02-23 | Aqueous solution purification method |
| KR1019900022688A KR0171052B1 (en) | 1990-02-23 | 1990-12-31 | Aqueous Purification Method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2044008A JPH0687923B2 (en) | 1990-02-23 | 1990-02-23 | Aqueous solution purification method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH03245802A JPH03245802A (en) | 1991-11-01 |
| JPH0687923B2 true JPH0687923B2 (en) | 1994-11-09 |
Family
ID=12679673
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2044008A Expired - Fee Related JPH0687923B2 (en) | 1990-02-23 | 1990-02-23 | Aqueous solution purification method |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JPH0687923B2 (en) |
| KR (1) | KR0171052B1 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101399129B1 (en) * | 2013-10-17 | 2014-05-30 | 순천대학교 산학협력단 | An apparatus and method of manufacturing biochar for waste water processing |
| KR101418702B1 (en) * | 2014-03-20 | 2014-07-14 | 경상대학교산학협력단 | An Apparatus for Manufacturing Biochar of Waste Heat Circulating Type |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3923689A (en) * | 1972-11-29 | 1975-12-02 | Ici America Inc | Removal of iron contaminants from porous materials |
| JPS5619288A (en) * | 1979-07-26 | 1981-02-23 | Dainippon Printing Co Ltd | Color solid state image pickup element plate |
| JPS6348262A (en) * | 1986-08-19 | 1988-02-29 | Mitsui Toatsu Chem Inc | Method for eluting l-tryptophan adsorbed on active carbon |
-
1990
- 1990-02-23 JP JP2044008A patent/JPH0687923B2/en not_active Expired - Fee Related
- 1990-12-31 KR KR1019900022688A patent/KR0171052B1/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH03245802A (en) | 1991-11-01 |
| KR0171052B1 (en) | 1999-01-15 |
| KR910015328A (en) | 1991-09-30 |
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