JP2013119487A - Method for treating hydrosilicofluoric acid-containing liquid - Google Patents

Method for treating hydrosilicofluoric acid-containing liquid Download PDF

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JP2013119487A
JP2013119487A JP2011266921A JP2011266921A JP2013119487A JP 2013119487 A JP2013119487 A JP 2013119487A JP 2011266921 A JP2011266921 A JP 2011266921A JP 2011266921 A JP2011266921 A JP 2011266921A JP 2013119487 A JP2013119487 A JP 2013119487A
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anion exchange
acid
liquid
exchange resin
hydrofluoric acid
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Nobuhiro Oda
信博 織田
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Kurita Water Industries Ltd
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Abstract

PROBLEM TO BE SOLVED: To provide a method for treating hydrosilicofluoric acid-containing liquid capable of separating hydrosilicofluoric acid stably from liquid to be treated containing the hydrosilicofluoric acid.SOLUTION: This method for treating hydrosilicofluoric acid-containing liquid for removing hydrosilicofluoric acid from liquid to be treated containing hydrosilicofluoric acid includes: an adsorption step in which the liquid to be treated is brought into contact with a weakly-basic anion exchange resin to allow the anion exchange resin to adsorb hydrosilicofluoric acid ion, and to thereby remove the ion from the liquid to be treated, and an elution step of eluting the ion thereafter.

Description

本発明は、ケイフッ化水素酸含有液からケイフッ化水素酸含有液を除去するケイフッ化水素酸含有液の処理方法に係り、特にアニオン交換樹脂を用いてケイフッ化水素酸を除去するケイフッ化水素酸含有液の処理方法に関する。   The present invention relates to a method for treating a hydrofluoric acid-containing liquid that removes a hydrofluoric acid-containing liquid from a hydrofluoric acid-containing liquid, and in particular, hydrosilicofluoric acid that removes hydrosilicofluoric acid using an anion exchange resin. The present invention relates to a method for treating a contained liquid.

半導体、ガラス加工等の工場では、フッ酸を主とする表面処理剤由来のフッ素を含有する廃水が発生する。このようなガラス加工の表面処理工程排水には、未反応のフッ酸、溶解したケイ素、そしてケイ素とフッ素が結合したケイフッ化物イオン(SiF 2−)が存在することが多い。このようなケイフッ化水素酸含有液は、排水基準(フッ素:8mg/L以下)以下となるように適切な処理を行う必要がある。この場合SiF 2−は、鉛の電解精錬、金属の表面処理、陶磁器の硬化促進剤、繊維の媒染剤、リチウムバッテリーの電解質などに用いられる有価物であるため、ケイフッ化水素酸を回収し易い処理が望まれる。 In factories such as semiconductors and glass processing, wastewater containing fluorine derived from a surface treatment agent mainly containing hydrofluoric acid is generated. In such glass processing surface treatment process wastewater, unreacted hydrofluoric acid, dissolved silicon, and silicofluoride ions (SiF 6 2− ) in which silicon and fluorine are bonded are often present. Such a hydrosilicofluoric acid-containing liquid needs to be appropriately treated so as to be below the wastewater standard (fluorine: 8 mg / L or less). In this case, SiF 6 2− is a valuable material used for electrolytic refining of lead, surface treatment of metal, ceramic hardening accelerator, fiber mordant, lithium battery electrolyte, and the like, and it is easy to recover hydrofluoric acid. Processing is desired.

従来、SiF 2−を含有する廃水の処理方法としては、消石灰で凝集沈殿する方法が採られていた。 Conventionally, a method of coagulating and precipitating with slaked lime has been adopted as a method for treating wastewater containing SiF 6 2− .

3Ca(OH)+HSiF → 3CaF+SiO+4H
しかしこの反応により生じる沈殿物は、CaFとSiOとを含み、CaF(蛍石)含有量が低いため、フッ素資源の回収・再資源化には不利である。
3Ca (OH) 2 + H 2 SiF 6 → 3CaF 2 + SiO 2 + 4H 2 O
However, the precipitate produced by this reaction contains CaF 2 and SiO 2 and has a low CaF 2 (fluorite) content, which is disadvantageous for the recovery and recycling of fluorine resources.

また、表面処理剤液中にはケイフッ化水素酸以外にもフッ酸、硝酸などの酸が残っており、そのまま中和するとアルカリ剤のCa(OH)が多量に必要となる上、Ca汚泥が大量に発生するので不経済である。 Further, in addition to silicofluoric acid, acids such as hydrofluoric acid and nitric acid remain in the surface treating agent liquid, and if neutralized as it is, a large amount of alkaline agent Ca (OH) 2 is required and Ca sludge Is uneconomical because it occurs in large quantities.

また、前述の通り、ケイフッ化水素酸は有価物であり、回収が望まれるが、上記の方法ではSiF 2−がCaFとSiOとに分解するため、SiF 2−が回収されない。 Further, as described above, silicohydrofluoric acid is a valuable material and is desired to be recovered. However, in the above method, SiF 6 2− is decomposed into CaF 2 and SiO 2 , so that SiF 6 2− is not recovered.

特許文献1には、ケイフッ化水素酸含有液を蒸留し、ケイフッ化水素酸を分留して回収する方法が記載されているが、設備が大掛りとなる。   Patent Document 1 describes a method of distilling a silicohydrofluoric acid-containing liquid and fractionating and recovering silicohydrofluoric acid, but requires a large amount of equipment.

特許文献2には、ケイフッ化水素酸とシリカゲルを反応させたハイシリカケイフッ化水素酸を陽イオン交換樹脂及び弱塩基性イオン交換樹脂と接触させて、アルカリ金属、アルカリ土類金属、フッ化アルミニウムイオンなどの不純物を除去するハイシリカケイフッ化水素酸の精製方法が記載されているが、ケイフッ化水素酸含有液からケイフッ化水素酸を分離する技術的目的及び構成は記載されていない。   In Patent Document 2, high silica silicofluoric acid obtained by reacting silicohydrofluoric acid and silica gel is brought into contact with a cation exchange resin and a weakly basic ion exchange resin to obtain alkali metal, alkaline earth metal, aluminum fluoride. Although a purification method of high silica silicohydrofluoric acid that removes impurities such as ions is described, the technical purpose and constitution for separating hydrosilicofluoric acid from a hydrofluoric acid-containing liquid is not described.

また、特許文献3にはケイフッ化水素酸を含むフッ酸を強塩基性アニオン交換樹脂に通液した後にフッ化アンモニウムで再生することが記載されているが、過剰に添加する必要があり経済的でない上、そもそもケイフッ化水素酸を分離回収できない。   Further, Patent Document 3 describes that hydrofluoric acid containing silicofluoric acid is regenerated with ammonium fluoride after passing through a strongly basic anion exchange resin. In addition, silicohydrofluoric acid cannot be separated and recovered in the first place.

特開2008−189484JP2008-189484 特開平6−298516JP-A-6-298516 特開昭53−68694JP 53-68694 A

本発明は、簡易な設備により、ケイフッ化水素酸を含有する被処理液から、ケイフッ化水素酸を安定して分離することができるケイフッ化水素酸含有液の処理方法であって、アニオン交換樹脂に吸着されたSiF 2−をケイフッ化水素酸(HSiF)として回収できる方法を提供することを目的とする。 The present invention relates to a method for treating a hydrofluoric acid-containing liquid that can stably separate hydrofluoric acid from a liquid to be treated containing silicofluoric acid with a simple facility, and an anion exchange resin An object of the present invention is to provide a method capable of recovering SiF 6 2− adsorbed on silica as hydrofluoric acid (H 2 SiF 6 ).

本発明のケイフッ化水素酸含有液の処理方法は、ケイフッ化水素酸を含む被処理液をアニオン交換樹脂に接触させてケイフッ化水素酸イオンを該アニオン交換樹脂に吸着させて被処理液から除去する吸着工程を有するケイフッ化水素酸含有液の処理方法であって、前記アニオン交換樹脂が弱塩基性アニオン交換樹脂であり、前記吸着工程後に、ケイフッ化水素酸が吸着した弱塩基性アニオン交換樹脂に溶離剤を接触させてケイフッ化水素酸を溶離する溶離工程をさらに有し、該溶離剤は、ケイフッ化水素酸より選択性が大きく、アルカリと反応して不溶化物を生成しない化合物であることを特徴とするものである。   In the method for treating a hydrofluoric acid-containing liquid of the present invention, the liquid to be treated containing hydrofluoric acid is brought into contact with the anion exchange resin and the hydrofluoric acid ions are adsorbed on the anion exchange resin to be removed from the liquid to be treated. A method of treating a hydrofluoric acid-containing liquid having an adsorption step, wherein the anion exchange resin is a weakly basic anion exchange resin, and after the adsorption step, the weakly basic anion exchange resin adsorbed with hydrofluoric acid And an elution step of elution of silicohydrofluoric acid by contacting with eluent, and the eluent is more selective than silicofluoric acid and does not react with alkali to form an insolubilized product. It is characterized by.

この吸着工程は、アニオン交換樹脂を充填したカラムに被処理液を通液することにより行うことが好ましく、ケイフッ化水素酸以外の酸成分が該カラムを貫流しても被処理液の通液を継続し、ケイフッ化水素酸の貫流が検出されるまで被処理液を通液することが好ましい。   This adsorption step is preferably performed by passing the liquid to be treated through a column filled with an anion exchange resin. Even if an acid component other than hydrofluoric acid flows through the column, the liquid to be treated is passed through. It is preferable that the liquid to be treated is passed until the flow of silicohydrofluoric acid is detected.

この溶離剤は、過塩素酸、チオシアン酸及びジチオン酸からなる群から選ばれる少なくとも1種であることが好ましい。   This eluent is preferably at least one selected from the group consisting of perchloric acid, thiocyanic acid and dithionic acid.

前記溶離工程後に、前記弱塩基性アニオン交換樹脂にアルカリを接触させて前記弱酸性アニオン交換樹脂をOH形に再生する再生工程をさらに有することが好ましい。   It is preferable to further include a regeneration step of regenerating the weakly acidic anion exchange resin into an OH form by contacting the weakly basic anion exchange resin with an alkali after the elution step.

前記再生工程後に、前記弱塩基性アニオン交換樹脂にフッ酸含有液を接触させて前記弱塩基性アニオン交換樹脂をF形に調整するF形調整工程をさらに有することが好ましい。   After the regeneration step, it is preferable to further include an F-type adjustment step of adjusting the weak basic anion exchange resin into an F shape by bringing a hydrofluoric acid-containing liquid into contact with the weak basic anion exchange resin.

本発明では、ケイフッ化水素酸含有被処理液を弱塩基性のアニオン交換樹脂に接触させてケイフッ化水素酸イオンを該アニオン交換樹脂に吸着させてケイフッ化水素酸を被処理液から除去し、ケイフッ化水素酸イオンを吸着したアニオン交換樹脂からケイフッ化水素酸イオンを溶離させることにより、高純度のケイフッ化水素酸を回収することができる。また、この方法では、蒸留装置のような大掛りな装置は不要である。   In the present invention, the hydrofluoric acid-containing liquid to be treated is brought into contact with a weakly basic anion exchange resin to adsorb silicofluoric acid ions to the anion exchange resin to remove silicofluoric acid from the liquid to be treated. By eluting the silicohydrofluoric acid ion from the anion exchange resin adsorbing the silicohydrofluoric acid ion, it is possible to recover the high purity hydrosilicic acid. Further, this method does not require a large apparatus such as a distillation apparatus.

この溶離剤として過塩素酸、チオシアン酸、ジチオン酸など、ケイフッ化水素酸より選択性が大きく、アルカリと反応して不溶化物を生成しないものを用いることにより、効率よくケイフッ化水素酸イオンを溶離させることができる。   As this eluent, perchloric acid, thiocyanic acid, dithionic acid, etc., which has higher selectivity than hydrofluoric acid and does not react with alkali to produce insolubilized substances, can be used to efficiently elute silicohydrofluoric acid ions. Can be made.

アニオン交換樹脂充填カラムにケイフッ化水素酸含有被処理液を通液する場合、ケイフッ化水素酸イオンのアニオン交換樹脂に対する吸着性が他の成分より大きいので、すでに吸着したフッ化水素酸、他の酸およびその他の成分を追出しながら、流入するケイフッ化水素酸イオンがアニオン交換樹脂に吸着する。このためフッ化水素酸、他の酸およびその他の成分がリークする点、すなわちこれらの他の成分の貫流点が検出された後もさらに通液を続けて、吸着を行わせることが好ましい。このように通液を続けると、最終的にはアニオン交換樹脂全体にケイフッ化水素酸イオンが吸着して飽和した状態になる。この状態になるとケイフッ化水素酸イオンがリークするので、この点をケイフッ化水素酸イオンの貫流点として、アニオン交換樹脂の再生や交換を行うことが望ましい。これにより、アニオン交換樹脂に対しケイフッ化水素酸を効率よく吸着させることができる。   When the hydrofluoric acid-containing liquid to be treated is passed through the anion exchange resin-packed column, the adsorption property of silicofluoric acid ions to the anion exchange resin is greater than that of other components. While expelling the acid and other components, the inflowing hydrofluoric acid ions are adsorbed on the anion exchange resin. For this reason, it is preferable to continue adsorption after the point where hydrofluoric acid, other acids and other components leak, that is, the flow-through point of these other components is detected. If the liquid flow is continued in this way, the fluoroanion ion is finally adsorbed and saturated on the entire anion exchange resin. In this state, the hydrofluoric acid ion leaks, and it is desirable to regenerate or replace the anion exchange resin using this point as the through-flow point of the hydrofluoric acid ion. Thereby, hydrofluoric acid can be efficiently adsorbed to the anion exchange resin.

溶離工程後に、ケイフッ化水素酸イオンが溶離したアニオン交換樹脂をアルカリと接触させ、溶離剤のアニオンを水酸化物イオンと交換して、アニオン交換樹脂をOH形に調整することによりアニオン交換樹脂を再生することができる。   After the elution step, the anion exchange resin eluted with silicohydrofluoric acid ions is brought into contact with alkali, the anion of the eluent is exchanged with hydroxide ions, and the anion exchange resin is adjusted to the OH form to obtain an anion exchange resin. Can be played.

被処理液がケイフッ化水素酸とフッ酸とを含むものである場合、被処理液からケイフッ化水素酸を除去してフッ酸を回収することができる。この場合、アニオン交換樹脂としてF形アニオン交換樹脂を用いることにより、吸着工程においてフッ酸の濃度を低下させることなくフッ酸を回収することができる。アニオン交換樹脂をF形とするには、例えば、OH形に調整したアニオン交換樹脂にフッ酸含有液を接触させて水酸化物イオンとフッ化物イオンを交換してF形に調整することができる。   In the case where the liquid to be treated contains silicofluoric acid and hydrofluoric acid, hydrofluoric acid can be recovered by removing the hydrofluoric acid from the liquid to be treated. In this case, by using the F-type anion exchange resin as the anion exchange resin, the hydrofluoric acid can be recovered without reducing the concentration of hydrofluoric acid in the adsorption step. In order to change the anion exchange resin to the F form, for example, the hydrofluoric acid-containing liquid is brought into contact with the anion exchange resin adjusted to the OH form to exchange hydroxide ions and fluoride ions, thereby adjusting the F form. .

実施の形態に係るケイフッ化水素酸含有液の処理方法を説明するブロック図である。It is a block diagram explaining the processing method of the silicofluoric acid containing liquid which concerns on embodiment. 実験結果を示すグラフである。It is a graph which shows an experimental result.

以下、本発明についてさらに詳細に説明する。   Hereinafter, the present invention will be described in more detail.

[ケイフッ化水素酸含有液]
被処理液としてのケイフッ化水素酸含有液としては、半導体製造工程、ガラス表面処理工程、電解精錬工程、アセタール合成工程、繊維の媒染工程などからの排水が例示されるが、これに限定されない。
[Silica hydrofluoric acid-containing liquid]
Examples of the hydrofluoric acid-containing liquid as the liquid to be treated include wastewater from a semiconductor manufacturing process, a glass surface treatment process, an electrolytic refining process, an acetal synthesis process, a fiber mordanting process, and the like, but are not limited thereto.

これらのケイフッ化水素酸含有液中のケイフッ化水素酸濃度は、通常は100mg/L〜10mg/L程度である。このケイフッ化水素酸含有液中にはケイフッ化水素酸以外のフッ化水素酸、ホウフッ化水素酸、硝酸、塩酸、硫酸などの酸成分や、アルミニウム、鉛、銅などの金属イオン、あるいはホウフッ化物などを含むことがある。   The concentration of silicohydrofluoric acid in these silicohydrofluoric acid-containing liquids is usually about 100 mg / L to 10 mg / L. This hydrofluoric acid-containing liquid contains acid components such as hydrofluoric acid, borohydrofluoric acid, nitric acid, hydrochloric acid and sulfuric acid other than silicohydrofluoric acid, metal ions such as aluminum, lead and copper, or borofluoride. May be included.

このケイフッ化水素酸含有液は、そのままアニオン交換樹脂による吸着工程に供給されてもよく、アニオン交換樹脂によるホウフッ化水素酸除去などによる前処理を行った後に吸着工程に供給されてもよい。   This hydrofluoric acid-containing liquid may be supplied as it is to the adsorption step using an anion exchange resin, or may be supplied to the adsorption step after performing a pretreatment such as removal of borohydrofluoric acid using an anion exchange resin.

[吸着工程]
吸着工程では、ケイフッ化水素酸含有液(原水)とアニオン交換樹脂とを接触させてアニオン交換樹脂にケイフッ化水素酸を吸着させる。原水がフッ酸を含有する場合は、ケイフッ化水素酸が除去されることにより精製フッ酸が回収される。
[Adsorption process]
In the adsorption step, the hydrofluoric acid-containing liquid (raw water) is brought into contact with the anion exchange resin to adsorb the hydrofluoric acid on the anion exchange resin. In the case where the raw water contains hydrofluoric acid, purified hydrofluoric acid is recovered by removing the hydrofluoric acid.

吸着工程で用いるアニオン交換樹脂としては、一般に水処理で用いられているアニオン交換樹脂が使用できるが、本発明においては溶離工程で溶離できるように弱塩基性アニオン交換樹脂を用いる。好ましいアニオン交換樹脂としては、ジビニルベンゼンで架橋したポリスチレン系アニオン交換樹脂で、アルキルまたはアルカノールアミン型のアニオン交換基を有するものがあげられ、弱塩基性アニオン交換樹脂の場合は第1級〜3級アミン型のアニオン交換基を有するものがあげられる。交換基としてはフリー形、OH形(水酸化物イオン)又はF形(フッ化物イオン)を用いることができる。   As the anion exchange resin used in the adsorption step, an anion exchange resin generally used in water treatment can be used. In the present invention, a weakly basic anion exchange resin is used so that it can be eluted in the elution step. Preferred anion exchange resins include polystyrene anion exchange resins cross-linked with divinylbenzene, and those having alkyl or alkanolamine type anion exchange groups. In the case of weakly basic anion exchange resins, primary to tertiary. Examples thereof include those having an amine type anion exchange group. As the exchange group, free form, OH form (hydroxide ion) or F form (fluoride ion) can be used.

被処理液とアニオン交換樹脂との接触は単なる浸漬でもよいが、一般的にはアニオン交換樹脂をカラム(塔)に充填してアニオン交換樹脂層を形成し、これに被処理液を通液してケイフッ化水素酸イオンを吸着させるものが好ましい。また、吸着後は再生剤を通液して再生するカラム構成となっていることが好ましい。カラムの構造は特に限定しないが、回収ケイフッ化水素酸が希釈されないようにデッドボリュームが小さい構造が望ましい。樹脂層は固定床として上向流または下向流、好ましくは下向流通液する場合と、流動床として通液する場合とがあるが、吸着工程では固定床として通液し、再生工程では流動床として通液するのが好ましい。   The contact between the liquid to be treated and the anion exchange resin may be simple immersion, but in general, an anion exchange resin is packed in a column to form an anion exchange resin layer, and the liquid to be treated is passed through the column. Those that adsorb silicofluoric acid ions are preferred. In addition, it is preferable that the column structure be regenerated by passing a regenerant after adsorption. The structure of the column is not particularly limited, but a structure with a small dead volume is desirable so that the recovered silicohydrofluoric acid is not diluted. The resin layer has an upward flow or a downward flow as a fixed bed, preferably a downward flowing liquid and a fluidized bed. However, the resin layer flows as a fixed bed in the adsorption process and flows in the regeneration process. It is preferable to pass through as a bed.

吸着工程において被処理液中のケイフッ化水素酸イオンをアニオン交換樹脂に吸着させるに際し、前処理で他の成分を除去している場合には、前処理したケイフッ化水素酸含有液をアニオン交換樹脂層の固定床に上向流または下向流、好ましくは下向流で通液して、ケイフッ化水素酸イオンをアニオン交換樹脂に吸着させることができる。前処理していない場合、あるいは前処理してもなお他の成分が残留する場合は、ケイフッ化水素酸含有液をアニオン交換樹脂層に上記と同様に通液すると、ケイフッ化水素酸とともにフッ化水素酸、他の酸およびその他の成分がアニオン交換樹脂に吸着し、これらが除去された処理液が得られる。吸着工程における被処理液の通液速度はSV100h−1以下が好ましく、SV1〜10h−1が特に好ましい。 When adsorbing silicohydrofluoric acid ions in the liquid to be treated in the adsorption process to the anion exchange resin, if other components are removed in the pretreatment, the pretreated hydrofluoric acid-containing liquid is treated with the anion exchange resin. It is possible to adsorb the hydrofluoric acid ions to the anion exchange resin by passing the fluid through the fixed bed of the bed in an upward flow or a downward flow, preferably a downward flow. When the pretreatment is not performed, or when other components remain even after the pretreatment, the fluorosilicic acid-containing liquid is passed through the anion exchange resin layer in the same manner as described above to fluorinate with the silicohydrofluoric acid. Hydrochloric acid, other acids and other components are adsorbed on the anion exchange resin, and a treatment liquid from which these have been removed is obtained. Liquid permeation speed of the liquid to be treated in the adsorption step is preferably SV100h -1 or less, SV1~10h -1 is particularly preferred.

この状態でそのまま通液を続けると、ケイフッ化水素酸イオンのアニオン交換樹脂に対する吸着性が他の成分より大きいので、すでに吸着したフッ化水素酸、他の酸およびその他の成分を追出しながら、流入するケイフッ化水素酸イオンがアニオン交換樹脂に吸着する。このためフッ化水素酸、他の酸およびその他の成分がリークする点、すなわちこれらの他の成分の貫流点が検出された後もさらに通液を続けて、吸着を行わせることが好ましい。このように通液を続けると、最終的にはアニオン交換樹脂全体にケイフッ化水素酸イオンが吸着して飽和した状態になる。この状態になるとケイフッ化水素酸イオンがリークするので、この点をケイフッ化水素酸イオンの貫流点として、アニオン交換樹脂の再生や交換を行うことが望ましい。これにより、アニオン交換樹脂に対しケイフッ化水素酸を効率よく吸着させることができる。   If liquid flow is continued in this state, the adsorption property of silicofluoric acid ion to the anion exchange resin is greater than that of other components. Therefore, while adsorbing hydrofluoric acid, other acids and other components already adsorbed, The silicohydrofluoric acid ions adsorb to the anion exchange resin. For this reason, it is preferable to continue adsorption after the point where hydrofluoric acid, other acids and other components leak, that is, the flow-through point of these other components is detected. If the liquid flow is continued in this way, the fluoroanion ion is finally adsorbed and saturated on the entire anion exchange resin. In this state, the hydrofluoric acid ion leaks, and it is desirable to regenerate or replace the anion exchange resin using this point as the through-flow point of the hydrofluoric acid ion. Thereby, hydrofluoric acid can be efficiently adsorbed to the anion exchange resin.

[溶離工程と再生工程]
吸着工程において用いるアニオン交換樹脂が弱塩基性であるので、溶離工程後に再生工程を行うことによってアニオン交換樹脂の再生を行うことができる。溶離工程を行わずにNaOHなどの強アルカリを用いて再生工程を行うと、SiF 2−を水酸化物イオンと交換してアニオン交換樹脂をOH形に再生する際に、不溶性のSiOが発生・析出してアニオン交換樹脂の表面に付着するため、再生操作を完結することができない。
[Elution process and regeneration process]
Since the anion exchange resin used in the adsorption process is weakly basic, the anion exchange resin can be regenerated by performing the regeneration process after the elution process. When the regeneration step is performed using a strong alkali such as NaOH without performing the elution step, insoluble SiO 2 is generated when the anion exchange resin is regenerated to OH form by exchanging SiF 6 2− with hydroxide ions. Since it occurs and precipitates and adheres to the surface of the anion exchange resin, the regeneration operation cannot be completed.

溶離工程では、ケイフッ化水素酸イオンよりも選択性が大きく、化学的に安定であり、アルカリにより不溶化物を生成しない酸の水溶液を溶離剤としてアニオン交換樹脂と接触させ、ケイフッ化水素酸イオンを溶離剤のアニオンと交換してアニオン交換樹脂からケイフッ化水素酸として溶離させる。溶離工程で用いる高選択性の溶離剤としては過塩素酸(HClO)、チオシアン酸、ジチオン酸が例示される。溶離剤に含まれる酸の濃度は高濃度ほど溶離効率が高いので、0.1mol/L以上が望ましく、0.5〜2mol/Lが特に望ましい。 In the elution step, an aqueous solution of an acid that is more selective and chemically stable than the silicofluoride ion and does not produce an insolubilized product by alkali is contacted with an anion exchange resin as an eluent, The anion of the eluent is exchanged and eluted from the anion exchange resin as hydrofluoric acid. Examples of the highly selective eluent used in the elution step include perchloric acid (HClO 4 ), thiocyanic acid, and dithionic acid. Since the elution efficiency is higher as the concentration is higher, the concentration of the acid contained in the eluent is preferably 0.1 mol / L or more, and more preferably 0.5 to 2 mol / L.

再生工程では、ケイフッ化水素酸イオンが溶離したアニオン交換樹脂をアルカリと接触させ、溶離剤のアニオンを水酸化物イオンと交換して、アニオン交換樹脂をOH形に調整することによりアニオン交換樹脂を再生する。アルカリとしては水酸化ナトリウム(NaOH)、水酸化カリウム(KOH)が例示され、特にNaOHを好適に用いることができる。アルカリ濃度は特に限定されないが、高濃度の方が再生効率が高いため0.1mol/L以上が望ましく、1〜10mol/Lが特に望ましい。   In the regeneration step, the anion exchange resin eluted with the hydrofluoric acid ions is brought into contact with alkali, the anion of the eluent is exchanged with hydroxide ions, and the anion exchange resin is adjusted to the OH form to change the anion exchange resin. Reproduce. Examples of the alkali include sodium hydroxide (NaOH) and potassium hydroxide (KOH), and NaOH can be particularly preferably used. The alkali concentration is not particularly limited, but a higher concentration has a higher regeneration efficiency, and is preferably 0.1 mol / L or more, and more preferably 1 to 10 mol / L.

[ケイフッ化水素酸の精製工程]
溶離工程で発生したケイフッ化水素酸を含有する溶離排液には、未反応の溶離剤も混在している。この溶離排液については、予めSiF 2−形に調整したアニオン交換樹脂塔に通液することにより、溶離剤中のアニオンを選択的にケイフッ化物イオンと交換して除去してケイフッ化水素酸を精製することができる。また必要に応じて蒸発濃縮などの手段をさらに用いて濃縮することもできる。
[Purification process of silicohydrofluoric acid]
An unreacted eluent is also mixed in the elution drainage containing silicofluoric acid generated in the elution step. About this elution drainage, the anion in the eluent is selectively exchanged with silicofluoride ions and removed by passing through an anion exchange resin tower that has been previously adjusted to SiF 6 2-type. Can be purified. Moreover, it can also concentrate using means, such as evaporation concentration, as needed.

なお、OH形に調整した弱塩基性アニオン交換樹脂に試薬工業薬品などのケイフッ化水素酸(HSiF)溶液を通液することにより、アニオン交換樹脂をSiF 2−形に調整することができる。精製工程において精製ケイフッ化水素酸が採取できれば、以後は精製ケイフッ化水素酸を用いてアニオン交換樹脂をSiF 2−形に調整することができる。なお、調整後の排液に含まれる過塩素酸ナトリウム(NaClO)は電気分解することによって、水酸化ナトリウム(NaOH)と過塩素酸(HClO)にして再利用してもよい。 The anion exchange resin is adjusted to the SiF 6 2-type by passing a hydrofluoric acid (H 2 SiF 6 ) solution such as a reagent industrial chemical through the weakly basic anion exchange resin adjusted to the OH form. Can do. If purified silicofluoric acid can be collected in the purification step, the anion exchange resin can be adjusted to SiF 6 2-type using purified silicohydrofluoric acid thereafter. Note that sodium perchlorate (NaClO 4 ) contained in the effluent after adjustment may be reused by electrolysis to form sodium hydroxide (NaOH) and perchloric acid (HClO 4 ).

[F形調整工程]
本発明において、被処理液がケイフッ化水素酸とフッ酸とを含むものである場合、被処理液からケイフッ化水素酸を除去してフッ酸を回収することができる。この場合、アニオン交換樹脂としてF形アニオン交換樹脂を用いることにより、吸着工程においてフッ酸の濃度を低下させることなくフッ酸を回収することができる。アニオン交換樹脂をF形とするには、例えば、OH形に調整したアニオン交換樹脂にフッ酸含有液を接触させて水酸化物イオンとフッ化物イオンを交換してF形に調整することができる。
[F-shaped adjustment process]
In the present invention, when the liquid to be treated contains silicofluoric acid and hydrofluoric acid, hydrofluoric acid can be recovered by removing the hydrofluoric acid from the liquid to be treated. In this case, by using the F-type anion exchange resin as the anion exchange resin, the hydrofluoric acid can be recovered without reducing the concentration of hydrofluoric acid in the adsorption step. In order to change the anion exchange resin to the F form, for example, the hydrofluoric acid-containing liquid is brought into contact with the anion exchange resin adjusted to the OH form to exchange hydroxide ions and fluoride ions, thereby adjusting the F form. .

図1は本発明方法を実施するための装置の一例を示している。   FIG. 1 shows an example of an apparatus for carrying out the method of the present invention.

原水槽1内の被処理液がポンプ2、配管3及び三方弁4を介してアニオン交換塔5に下向流にて通液される。アニオン交換塔5には弱塩基性アニオン交換樹脂が充填されている。ケイフッ化水素酸の吸着を行う場合には、アニオン交換塔5の流出液は三方弁6、配管7、三方弁8、配管9を通って系外に排出される。原水がフッ酸とケイフッ化水素酸を含有し、アニオン交換塔5でケイフッ化水素酸を除去してフッ酸を回収する場合には、この系外排出液がフッ酸回収液として回収される。   The liquid to be treated in the raw water tank 1 is passed through the anion exchange tower 5 in a downward flow through the pump 2, the pipe 3 and the three-way valve 4. The anion exchange column 5 is filled with a weakly basic anion exchange resin. When adsorbing hydrofluoric acid, the effluent of the anion exchange tower 5 is discharged out of the system through the three-way valve 6, the pipe 7, the three-way valve 8, and the pipe 9. When the raw water contains hydrofluoric acid and silicohydrofluoric acid and hydrofluoric acid is recovered by removing hydrofluoric acid in the anion exchange tower 5, this out-of-system discharged liquid is recovered as a hydrofluoric acid recovery liquid.

アニオン交換塔5内のアニオン交換樹脂に吸着されたケイフッ化水素酸を溶離させる場合には、溶離剤タンク10内の溶離剤が配管11、三方弁12、配管13、三方弁4を介してアニオン交換塔5に通液され、アニオン交換塔5の流出液(溶離液)が三方弁6、配管14を介してケイフッ化水素酸回収槽15に導入される。このケイフッ化水素酸回収槽15内のケイフッ化水素酸溶液は、ポンプ16、配管17、三方弁18を介して精製用アニオン交換塔19に通液される。この精製用アニオン交換塔19内には、予めSiF 2−形に調製されたアニオン交換樹脂が充填されており、溶離液(ケイフッ化水素酸溶液)中のケイフッ化水素酸以外のアニオンがケイフッ化物イオンとイオン交換して吸着除去され、ケイフッ化水素酸溶液が精製される。精製されたケイフッ化水素酸溶液は、三方弁20、配管21を介して精製ケイフッ化水素酸回収槽22に導入される。 When eluting the hydrofluoric acid adsorbed on the anion exchange resin in the anion exchange column 5, the eluent in the eluent tank 10 is anion through the pipe 11, the three-way valve 12, the pipe 13, and the three-way valve 4. The liquid is passed through the exchange column 5, and the effluent (eluent) of the anion exchange column 5 is introduced into the hydrofluoric acid recovery tank 15 through the three-way valve 6 and the pipe 14. The hydrofluoric acid solution in the silicohydrofluoric acid recovery tank 15 is passed through the pump 16, the pipe 17, and the three-way valve 18 to the anion exchange tower 19 for purification. The anion exchange column 19 for purification is filled with an anion exchange resin prepared in advance in SiF 6 2− form, and anion other than silicohydrofluoric acid in the eluent (silicohydrofluoric acid solution) It is adsorbed and removed by ion exchange with fluoride ions, and the hydrofluoric acid solution is purified. The purified hydrofluoric acid solution is introduced into the purified hydrofluoric acid recovery tank 22 via the three-way valve 20 and the pipe 21.

アニオン交換塔5を再生するときには、タンク23内のNaOH溶液が配管24、三方弁12、配管13、三方弁4を介してアニオン交換塔5に通液される。再生廃液は、三方弁6、配管7、三方弁8、配管9を介して系外へ排出される。   When the anion exchange tower 5 is regenerated, the NaOH solution in the tank 23 is passed through the anion exchange tower 5 through the pipe 24, the three-way valve 12, the pipe 13, and the three-way valve 4. The recycled waste liquid is discharged out of the system through the three-way valve 6, the pipe 7, the three-way valve 8, and the pipe 9.

精製用アニオン交換塔19を再生するときには、タンク23内のNaOH溶液を配管25、三方弁26、配管27、三方弁18を介して精製用アニオン交換塔19に通液し、再生廃液を三方弁20,8、配管9を介して系外に排出し、アニオン交換樹脂をまずOH形に再生する。次いで、精製ケイフッ化水素酸回収槽22内のケイフッ化水素酸を配管28、三方弁26、配管27、三方弁18を介して精製用アニオン交換塔19に通液し、アニオン交換樹脂をSiF 2−形に調製する。この際のアニオン交換塔19からの調整廃液も、三方弁20,8、配管9を介して系外に排出される。 When regenerating the anion exchange tower 19 for purification, the NaOH solution in the tank 23 is passed through the pipe 25, the three-way valve 26, the pipe 27, and the three-way valve 18 to the purification anion exchange tower 19, and the regeneration waste liquid is passed through the three-way valve. 20, 8 and piping 9 are discharged out of the system, and the anion exchange resin is first regenerated into OH form. Next, the hydrosilicofluoric acid in the purified silicohydrofluoric acid recovery tank 22 is passed through the pipe 28, the three-way valve 26, the pipe 27, and the three-way valve 18 to the anion exchange tower 19 for purification, and the anion exchange resin is converted into SiF 6. Prepare in 2- form. The adjusted waste liquid from the anion exchange tower 19 at this time is also discharged out of the system through the three-way valves 20 and 8 and the pipe 9.

なお、アニオン交換塔5のアニオン交換樹脂をF形に調整するときは図示しないフッ酸タンクからフッ酸をアニオン交換塔5に通液し、アニオン交換塔の流出液が三方弁6、配管7、三方弁8、配管9を介して系外に排出されるようにすればよい。   In addition, when adjusting the anion exchange resin of the anion exchange column 5 to F form, hydrofluoric acid is passed through the anion exchange column 5 from a hydrofluoric acid tank (not shown), and the effluent of the anion exchange column is the three-way valve 6, the pipe 7 What is necessary is just to make it discharge | emit out of the system through the three-way valve 8 and the piping 9.

実施例1
図1に示すフローに従って、HSiFを含む合成廃水のアニオン交換樹脂処理と、該処理によりSiF 2−を吸着したアニオン交換樹脂の再生、HSiFの回収精製を行った。
Example 1
According to the flow shown in FIG. 1, the anion exchange resin treatment of the synthetic waste water containing H 2 SiF 6 , the regeneration of the anion exchange resin adsorbing SiF 6 2− by the treatment, and the recovery purification of H 2 SiF 6 were performed.

<試験条件>
廃水組成:HSiF 1.0w/v%、HNO 5w/v%、HF 2.0w/v%
アニオン交換樹脂:三菱化学(株)製ダイヤイオンWA−30
(1)通水による吸着工程
アニオン交換樹脂3Lを充填したアニオン交換塔5を使用した。合成廃液をSV5で4h通水した。
(2)溶離工程
アニオン交換塔5内の残留液を排出し、溶離剤として1mol/LのHClO溶液5LをSV1で通液した。流出液はHSiF回収液として採取した。
(3)HSiF精製工程
別途用意したOH形アニオン樹脂に1 mol/LのHSiF溶液を通液倍率2BVで通液し、純水を通液倍率5BVで通液して洗浄して、SiF形樹脂に調整した。このSiF形樹脂に、前記(2)のHSiF回収液をSV1で通液して、ClOイオンを除去し、精製HSiF液を得た。
(4)アニオン交換樹脂再生工程
上述の溶離後のアニオン交換塔5内のアニオン交換樹脂に、2N−NaOH溶液をSV2で4BV通液、純水5BVで洗浄して、OH形アニオン交換樹脂を調整した。
(5)繰り返し
上記の(1)〜(4)工程を繰り返した。ただし、2回目以降にあっては、(3)工程のSiF形樹脂の調整操作には(3)の操作で得られた精製HSiF溶液を用いた。
<Test conditions>
Wastewater composition: H 2 SiF 6 1.0 w / v%, HNO 3 5 w / v%, HF 2.0 w / v%
Anion exchange resin: Diaion WA-30 manufactured by Mitsubishi Chemical Corporation
(1) Adsorption process by water flow An anion exchange column 5 packed with anion exchange resin 3L was used. The synthetic waste liquid was passed through with SV5 for 4 hours.
(2) Elution step The residual liquid in the anion exchange column 5 was discharged, and 5 L of a 1 mol / L HClO 4 solution was passed through SV1 as an eluent. The effluent was collected as a H 2 SiF 6 recovery solution.
(3) H 2 SiF 6 purification step A 1 mol / L H 2 SiF 6 solution was passed through a separately prepared OH-type anion resin at a rate of 2 BV, and pure water was passed at a rate of 5 BV for washing. Then, it was adjusted to SiF 6 type resin. This SiF 6 form resin, said solution were passed at SV1 with H 2 SiF 6 recovered solution of (2) to remove ClO 4 ion, to obtain a purified H 2 SiF 6 solution.
(4) Anion exchange resin regeneration step The OH type anion exchange resin is prepared by washing the anion exchange resin in the anion exchange column 5 after the elution with a 2N-NaOH solution with 4 BV through SV2 and 5 BV with pure water. did.
(5) Repeat The above steps (1) to (4) were repeated. However, in the second and subsequent times, the purified H 2 SiF 6 solution obtained in the operation (3) was used for the adjustment operation of the SiF 6 type resin in the step (3).

<試験結果>
(i)通水試験
アニオン交換塔5内のアニオン交換樹脂のアニオン吸着量を図2に示す。図2の通り、通水量6L/L−樹脂の時点でF、NO は押し出され、SiF 2−のみが吸着した状態となった。
(ii)溶離試験
溶離液の組成はHSiF50g/L、HClO1g/Lであった。
(iii)精製試験
精製HSiF液中のClO は不検出であり、回収されたHSiF溶液の純度は98.0%以上であった。
(iv)繰り返し試験
3サイクル行った結果、樹脂へのSiF 2−吸着性能や回収精製純度に変化がないことが認められた。
<Test results>
(I) Water flow test The anion adsorption amount of the anion exchange resin in the anion exchange tower 5 is shown in FIG. As shown in FIG. 2, F and NO 3 were pushed out when the water flow rate was 6 L / L-resin, and only SiF 6 2− was adsorbed.
(Ii) Elution test The composition of the eluent was H 2 SiF 6 50 g / L and HClO 4 1 g / L.
(Iii) Purification test ClO 4 in the purified H 2 SiF 6 solution was not detected, and the purity of the recovered H 2 SiF 6 solution was 98.0% or more.
(Iv) Repeat test As a result of three cycles, it was confirmed that there was no change in the SiF 6 2- adsorption performance and the recovery purification purity to the resin.

5 アニオン交換塔
10 溶離剤タンク
15 ケイフッ化水素酸回収槽
19 精製用アニオン交換塔
22 精製ケイフッ化水素酸回収槽
5 Anion Exchange Tower 10 Eluent Tank 15 Silica Hydrofluoric Acid Recovery Tank 19 Purification Anion Exchange Tower 22 Purified Hydrofluoric Acid Recovery Tank

Claims (5)

ケイフッ化水素酸を含む被処理液をアニオン交換樹脂に接触させてケイフッ化水素酸イオンを該アニオン交換樹脂に吸着させて被処理液から除去する吸着工程を有するケイフッ化水素酸含有液の処理方法であって、
前記アニオン交換樹脂が弱塩基性アニオン交換樹脂であり、
前記吸着工程後に、ケイフッ化水素酸が吸着した弱塩基性アニオン交換樹脂に溶離剤を接触させてケイフッ化水素酸を溶離する溶離工程をさらに有し、
該溶離剤は、ケイフッ化水素酸より選択性が大きく、アルカリと反応して不溶化物を生成しない化合物である
ことを特徴とするケイフッ化水素酸含有液の処理方法。
A method for treating a hydrofluoric acid-containing liquid comprising an adsorption step in which a liquid to be treated containing hydrofluoric acid is brought into contact with an anion exchange resin, and hydrofluoric acid ions are adsorbed on the anion exchange resin and removed from the liquid to be treated. Because
The anion exchange resin is a weakly basic anion exchange resin;
After the adsorption step, the method further comprises an elution step of elution of silicohydrofluoric acid by bringing an eluent into contact with the weakly basic anion exchange resin adsorbed with hydrofluoric acid,
The eluent is a compound having a higher selectivity than hydrosilicofluoric acid and does not generate an insolubilized product by reacting with an alkali.
請求項1において、アニオン交換樹脂を充填したカラムに被処理液を通液することにより前記吸着工程を行う方法であって、
ケイフッ化水素酸以外の酸成分が該カラムを貫流しても被処理液の通液を継続し、ケイフッ化水素酸の貫流が検出されるまで被処理液を通液することを特徴とするケイフッ化水素酸含有液の処理方法。
The method of claim 1, wherein the adsorption step is performed by passing a liquid to be treated through a column filled with an anion exchange resin.
Even if an acid component other than hydrofluoric acid flows through the column, the flow of the liquid to be treated is continued, and the liquid to be treated is allowed to flow until the flow of silicofluoric acid is detected. A method for treating a hydrofluoric acid-containing liquid.
請求項2において、前記溶離剤が過塩素酸、チオシアン酸及びジチオン酸からなる群から選ばれる少なくとも1種であることを特徴とするケイフッ化水素酸含有液の処理方法。   3. The method for treating a hydrofluoric acid-containing liquid according to claim 2, wherein the eluent is at least one selected from the group consisting of perchloric acid, thiocyanic acid, and dithionic acid. 請求項2又は3において、前記溶離工程後に、前記弱塩基性アニオン交換樹脂にアルカリを接触させて前記弱酸性アニオン交換樹脂をOH形に再生する再生工程をさらに有することを特徴とするケイフッ化水素酸含有液の処理方法。   The hydrogen silicofluoride according to claim 2 or 3, further comprising a regeneration step of regenerating the weakly acidic anion exchange resin into OH form by contacting the weakly basic anion exchange resin with an alkali after the elution step. Treatment method of acid-containing liquid. 請求項4において、前記再生工程後に、前記弱塩基性アニオン交換樹脂にフッ酸含有液を接触させて前記弱塩基性アニオン交換樹脂をF形に調整するF形調整工程をさらに有する
ことを特徴とするケイフッ化水素酸含有液の処理方法。
5. The method according to claim 4, further comprising an F-shaped adjusting step of adjusting the weakly basic anion exchange resin to F-form by bringing the hydrobasic acid-containing liquid into contact with the weakly basic anion-exchange resin after the regeneration step. A method for treating a hydrofluoric acid-containing liquid.
JP2011266921A 2011-12-06 2011-12-06 Method for treating hydrosilicofluoric acid-containing liquid Pending JP2013119487A (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20150109744A (en) * 2014-03-20 2015-10-02 한국과학기술원 Metal-Supported Anion-Exchange Resins and Method for Remediating of Toxic Anions Using the Same

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20150109744A (en) * 2014-03-20 2015-10-02 한국과학기술원 Metal-Supported Anion-Exchange Resins and Method for Remediating of Toxic Anions Using the Same
KR101599367B1 (en) 2014-03-20 2016-03-04 한국과학기술원 Metal-Supported Anion-Exchange Resins and Method for Remediating of Toxic Anions Using the Same

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