JPH0657466A - Method for recovering mixed acid of nitric acid with hydrofluoric acid or nitric acid, hydrofluoric acid from pickling waste water - Google Patents
Method for recovering mixed acid of nitric acid with hydrofluoric acid or nitric acid, hydrofluoric acid from pickling waste waterInfo
- Publication number
- JPH0657466A JPH0657466A JP23291292A JP23291292A JPH0657466A JP H0657466 A JPH0657466 A JP H0657466A JP 23291292 A JP23291292 A JP 23291292A JP 23291292 A JP23291292 A JP 23291292A JP H0657466 A JPH0657466 A JP H0657466A
- Authority
- JP
- Japan
- Prior art keywords
- acid
- nitric acid
- hydrofluoric
- hydrofluoric acid
- concentration
- 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.)
- Pending
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
- C23G1/00—Cleaning or pickling metallic material with solutions or molten salts
- C23G1/36—Regeneration of waste pickling liquors
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Cleaning And De-Greasing Of Metallic Materials By Chemical Methods (AREA)
- Separation Using Semi-Permeable Membranes (AREA)
- Heat Treatment Of Water, Waste Water Or Sewage (AREA)
- Extraction Or Liquid Replacement (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、酸洗廃液より硝酸と弗
酸の混合酸又は硝酸、弗酸を回収する方法に関し、詳細
には、ステンレス鋼板などの表面を硝酸と弗酸の混合酸
水溶液で酸洗いした廃液から混合酸又は硝酸、弗酸とし
て回収し、該回収酸を酸洗用酸として再循環使用するこ
とを意図する酸洗廃液より硝酸と弗酸の混合酸又は硝
酸、弗酸を回収する方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for recovering a mixed acid of nitric acid and hydrofluoric acid or nitric acid and hydrofluoric acid from a pickling waste liquid. More specifically, the surface of a stainless steel plate is mixed with nitric acid and hydrofluoric acid. A mixed acid of nitric acid and hydrofluoric acid, or nitric acid, or hydrofluoric acid is recovered from the pickling waste solution, which is intended to be recovered as a mixed acid, nitric acid, or hydrofluoric acid from the waste solution pickled with an aqueous solution, and to reuse the recovered acid as a pickling acid. It relates to a method of recovering an acid.
【０００２】[0002]
【従来の技術】ステンレス鋼板などの表面を仕上げるた
めにメッキ、研磨、塗装、焼付等の方法が従来より採用
されている。そして、これらの仕上げをするに先立って
鋼板表面のサビ、スケ−ル等を取除く必要があるが、こ
の除去手段としては、一般に鋼板表面を酸洗いする方法
が採用されている。2. Description of the Related Art Conventionally, methods such as plating, polishing, painting, and baking have been adopted to finish the surface of stainless steel plates and the like. It is necessary to remove rust, scale, etc. on the surface of the steel sheet prior to finishing these, and as a removing means, a method of pickling the surface of the steel sheet is generally adopted.
【０００３】この酸洗用としては、鋼板の種類により各
種酸或いは混合酸が使用されているが、その代表的な酸
としては、硫酸、塩酸又は硝酸と弗酸の混合酸である。
これらの酸の使用量は、鋼板の生産量の増加、多用化に
伴って増加しており、その結果として酸洗廃液も多量排
出されている。そして、このような酸洗廃液、特に硫酸
廃液や塩酸廃液では、環境公害防止の観点から、また、
資源の再利用の見地から各使用酸の夫々に適合した処理
法が開発され、実用化されている。For this pickling, various acids or mixed acids are used depending on the type of steel sheet. Typical acids are sulfuric acid, hydrochloric acid or a mixed acid of nitric acid and hydrofluoric acid.
The amount of these acids used is increasing with the increase in the production amount of steel sheets and the increasing usage, and as a result, a large amount of pickling waste liquid is also discharged. And in such pickling waste liquid, especially sulfuric acid waste liquid or hydrochloric acid waste liquid, from the viewpoint of environmental pollution prevention,
From the viewpoint of resource reuse, a treatment method suitable for each acid used has been developed and put into practical use.
【０００４】例えば、硫酸廃液に対しては、該廃液を濃
縮（蒸発）し、硫酸成分を濃硫酸（回収酸）として再利
用し、一方、金属イオンは金属塩として回収し、これを
水処理用凝集剤として使用されている。また、塩酸廃液
に対しては、噴霧焙焼し、塩酸成分を濃塩酸（回収酸）
として再使用し、一方、副生する酸化鉄は、磁性材の原
料として利用されている。このように硫酸廃液や塩酸廃
液に対しては、廃液中の酸を回収酸として再利用し、ま
た、副産物も各種用途に利用されており、確実に資源リ
サイクルがなされている。For example, with respect to a sulfuric acid waste liquid, the waste liquid is concentrated (evaporated) and the sulfuric acid component is reused as concentrated sulfuric acid (recovered acid), while the metal ions are recovered as a metal salt and treated with water. It is used as a flocculant. Also, for hydrochloric acid waste liquid, spray roasting is performed, and the hydrochloric acid component is concentrated hydrochloric acid (recovered acid).
On the other hand, iron oxide produced as a by-product is used as a raw material for magnetic materials. As described above, with respect to the sulfuric acid waste liquid and the hydrochloric acid waste liquid, the acid in the waste liquid is reused as a recovered acid, and by-products are also used for various purposes, so that the resources are surely recycled.
【０００５】一方、硝酸と弗酸の混合酸により酸洗いし
た廃液（以下‘混合酸廃液’という。）に対しては、拡
散透析法、電気透析法、有機溶媒抽出法、イオン交換樹
脂法等により処理されているものの、回収酸として再使
用するには余りにも酸濃度が低く、これを濃縮（蒸発）
しようとしても蒸発塔に対する腐蝕が著しく、このた
め、上記処理液をそのまま中和処理し或いは更に希釈し
て放流する場合が多く、回収酸としての再利用は余りな
されていない。また、後記するように、混合酸廃液を単
に消石灰中和法により処理し、処理水を放流することも
従来より行われている。On the other hand, for waste liquid pickled with a mixed acid of nitric acid and hydrofluoric acid (hereinafter referred to as "mixed acid waste liquid"), diffusion dialysis method, electrodialysis method, organic solvent extraction method, ion exchange resin method, etc. However, the acid concentration is too low to be reused as a recovered acid, and it is concentrated (evaporated).
Even if an attempt is made, the evaporation column is significantly corroded, and therefore, the treatment liquid is often neutralized as it is or further diluted and discharged, and reuse as a recovered acid is rarely performed. Further, as will be described later, it has been conventionally performed that the mixed acid waste liquid is simply treated by the slaked lime neutralization method and the treated water is discharged.
【０００６】本発明は、混合酸廃液の処理に係るもので
あるので、以下、該混合酸による鋼板表面の酸洗いにつ
いて、また、その廃液に対する従来の処理法について説
明する。例えばステンレス鋼表面を洗浄する際、混合酸
中の硝酸は鋼表面のＣｒ、Ｎｉを主として除去し、弗酸
は同じくＦｅを除去する。そして、上記酸洗いで生成す
る廃液は、前記したとおり、(1)拡散透析法、(2)有機溶
媒抽出法等が従来より知られている。Since the present invention relates to the treatment of a mixed acid waste liquid, the pickling of the steel sheet surface with the mixed acid and the conventional treatment method for the waste liquid will be described below. For example, when cleaning the surface of stainless steel, nitric acid in the mixed acid mainly removes Cr and Ni on the surface of the steel, and hydrofluoric acid also removes Fe. As described above, as the waste liquid generated by the above-mentioned pickling, (1) diffusion dialysis method, (2) organic solvent extraction method and the like have been conventionally known.
【０００７】上記(1)の拡散透析法は、拡散透析膜を用
い、廃液中の酸成分は、この膜中を拡散して濃度勾配に
より移動し、脱離する。一方、廃液中の金属イオンは、
膜不透過性であるので残存し、酸成分と分離する。ま
た、上記(2)の有機溶媒抽出法は、溶媒としてTBP、DEPA
を用い、このうちTBPは廃液中の硝酸成分及び弗酸成分
を選択的に吸着し、各遊離酸として回収する。また、DE
PAは、金属イオン特に鉄イオンを選択的に除去する。例
えば廃液中の弗化鉄（FeF2）の鉄成分を選択的に除去
し、弗酸（HF）として回収する。In the diffusion dialysis method (1), a diffusion dialysis membrane is used, and the acid component in the waste liquid diffuses in the membrane, moves by a concentration gradient, and is desorbed. On the other hand, the metal ions in the waste liquid are
Since it is impermeable to the membrane, it remains and separates from the acid component. In addition, the organic solvent extraction method of (2) above uses TBP and DEPA as the solvent.
Among them, TBP selectively adsorbs nitric acid components and hydrofluoric acid components in the waste liquid and collects them as free acids. Also, DE
PA selectively removes metal ions, especially iron ions. For example, the iron component of iron fluoride (FeF 2 ) in the waste liquid is selectively removed and recovered as hydrofluoric acid (HF).
【０００８】[0008]
【発明が解決しようとする課題】ところで、混合酸廃液
は、前記したとおり、(1)拡散透析法、(2)有機溶媒抽出
法等によって処理されているが、回収された酸は、いず
れも酸洗用酸原料組成濃度よりもうすく、回収酸として
の再利用は余りなされていない。例えば、混合酸原料組
成濃度として、硝酸200g/l、弗酸40g/l程度を必要とす
るが、従来の上記(1)、(2)等の方法では、硝酸は120g/l
程度以下に希釈され、また、弗酸は25g/l程度以下に希
釈され、いずれもうすく、そのままでは回収酸として使
用することができず、この一部に新酸を添加し、一部の
みを再利用するか、或いは、放流されている。By the way, the mixed acid waste liquor is treated by (1) diffusion dialysis method, (2) organic solvent extraction method, etc. as described above. The acid concentration for pickling is less than the concentration of the raw material composition, and it is rarely reused as a recovered acid. For example, nitric acid 200 g / l and hydrofluoric acid 40 g / l are required as the mixed acid raw material composition concentration, but in the conventional methods (1) and (2), nitric acid is 120 g / l.
Diluted to less than approximately, and hydrofluoric acid was diluted to less than about 25 g / l, and it will no longer be used as a recovered acid as it is. It is either reused or released.
【０００９】また、上記(1)及び(2)の方法で処理して得
られた処理液（硝酸、弗酸含有希釈混合酸）を濃縮（蒸
発）しようとしても、蒸発塔に対する腐蝕が著しいた
め、さらには、後記するとおり、共沸混合物が生成し、
有効に濃縮することができないこともあって、加熱蒸発
による濃縮法も実用化されていない。更に、硝酸、弗酸
の使用量は、硫酸、塩酸のそれに比して量的に少ないこ
ともあって、上記(1)及び(2)の方法に代えて、これらの
方法よりも簡単でしかも廉価な消石灰中和法により混合
酸廃液を処理し、得られた処理液を放流し、一方、多量
のスラッジを投棄（例えば埋立用）することも行われて
いる。Further, even if an attempt is made to concentrate (evaporate) the treatment liquid (diluted mixed acid containing nitric acid and hydrofluoric acid) obtained by the treatments of the above (1) and (2), the corrosion of the evaporation tower is remarkable. , And further, as described below, an azeotropic mixture is formed,
The concentration method by heating and evaporation has not been put into practical use because it cannot be effectively concentrated. Further, since the amounts of nitric acid and hydrofluoric acid used are smaller than those of sulfuric acid and hydrochloric acid, the methods (1) and (2) can be replaced with simpler methods than these methods. It is also practiced to treat a mixed acid waste liquid by an inexpensive slaked lime neutralization method and discharge the obtained treatment liquid, while discarding a large amount of sludge (for landfill, for example).
【００１０】上記(1)及び(2)の方法で処理して得られた
処理液や消石灰中和法による処理液には、窒素分を多量
含んでおり、この放流によって海、河川の富栄養化とな
り、例えば赤潮発生の原因ともなっており、スラッジの
多量投棄と共に環境汚染の原因ともなっている。The treatment liquid obtained by the treatments of the above (1) and (2) and the treatment liquid obtained by the slaked lime neutralization method contain a large amount of nitrogen, and this release causes eutrophication in the sea and rivers. It is becoming a cause of red tide, for example, and is a cause of large amount of sludge dumping and environmental pollution.
【００１１】そこで、本発明者等は、混合酸廃液から濃
厚な混合酸又は濃厚な硝酸、弗酸の単酸として回収し、
該回収酸を酸洗用混合酸として再循環使用することを技
術的課題とし、鋭意研究を重ねた結果、本発明を完成し
たものである。即ち、本発明の目的は、前記処理液の放
流による環境汚染を防止し、回収酸として有効に利用す
る酸洗い廃液より硝酸と弗酸の混酸又は硝酸、弗酸を回
収する方法を提供するにある。Therefore, the inventors of the present invention collected the mixed acid waste liquid as a concentrated mixed acid or a concentrated nitric acid or a monoacid of hydrofluoric acid,
The present invention has been completed as a result of intensive research conducted on the technical problem of recycling the recovered acid as a mixed acid for pickling. That is, an object of the present invention is to provide a method for preventing environmental pollution due to discharge of the treatment liquid, and recovering a mixed acid of nitric acid and hydrofluoric acid or nitric acid, hydrofluoric acid from a pickling waste liquid which is effectively used as a recovered acid. is there.
【００１２】[0012]
【課題を解決するための手段】そして、本発明者等は、
(a) 混合酸廃液の蒸発塔に対する腐蝕性を解決し、更
に、(b) 硝酸−弗酸−水系の３成分系に対する気液平衡
曲線に着目し、この気液平衡曲線に基づいて最適条件を
見出し、この(a)及び(b)により混合酸廃液の加熱蒸発濃
縮法を初めて可能にしたものである。The inventors of the present invention have
(a) Solving the corrosiveness of the mixed acid waste liquid to the evaporation tower, and (b) focusing on the vapor-liquid equilibrium curve for the three-component system of nitric acid-hydrofluoric acid-water system, and based on this vapor-liquid equilibrium curve, optimum conditions It was found that (a) and (b) made it possible for the first time to evaporate and concentrate the mixed acid waste liquid by heating.
【００１３】即ち、本発明は、「硝酸、弗酸含有酸洗廃
液（混合酸廃液）を拡散透析法、有機溶媒抽出法等で処
理し、得られた回収酸を蒸発、濃縮することを特徴とす
る酸洗廃液より硝酸と弗酸の混合酸又は硝酸、弗酸を回
収する方法。」であり、また、「蒸発（濃縮）塔とし
て、カ−ボン製又はテフロン耐蝕性材料で内張りした塔
を用いることを特徴とする酸洗廃液より硝酸と弗酸の混
合酸又は硝酸、弗酸を回収する方法。」を要旨とするも
のである。That is, the present invention is characterized in that "a nitric acid / hydrofluoric acid-containing pickling waste liquid (mixed acid waste liquid) is treated by a diffusion dialysis method, an organic solvent extraction method or the like, and the obtained recovered acid is evaporated and concentrated. And a method of recovering a mixed acid of nitric acid and hydrofluoric acid, nitric acid, or hydrofluoric acid from the pickling waste liquid. " A method for recovering a mixed acid of nitric acid and hydrofluoric acid, nitric acid, or hydrofluoric acid from a pickling waste liquid, which is characterized in that
【００１４】以下、本発明を詳細に説明すると、本発明
は、混合酸廃液を拡散透析法、有機溶媒抽出法等で処理
し、得られた回収酸に対して加熱蒸発濃縮法を適用する
ものである。本発明では、この拡散透析法、有機溶媒抽
出法のみに限定するものではなく、これ以外に例えばイ
オン交換樹脂法、拡散透析法、電気透析法など周知の手
段のいずれをも採用することができる。The present invention will be described in detail below. According to the present invention, a mixed acid waste liquid is treated by a diffusion dialysis method, an organic solvent extraction method or the like, and a heating evaporation concentration method is applied to the obtained recovered acid. Is. The present invention is not limited to the diffusion dialysis method and the organic solvent extraction method, and other known means such as an ion exchange resin method, a diffusion dialysis method, and an electrodialysis method can be adopted. .
【００１５】ところで、硝酸、弗酸の単酸における気液
平衡曲線図は文献に見受けられるが、硝酸−弗酸−水系
の３成分系に係る気液平衡曲線図は見受けられない。こ
れは、混合酸廃液の処理が資源のリサイクル化、環境公
害の面から余り考慮されていなかったからであり、ま
た、硝酸と弗酸の混合酸に対する耐腐蝕材についても考
慮されていなかったからであると考えられる。By the way, although a vapor-liquid equilibrium curve diagram of nitric acid and hydrofluoric acid in a single acid is found in the literature, a vapor-liquid equilibrium curve diagram of a ternary system of nitric acid-hydrofluoric acid-water system is not found. This is because the treatment of the mixed acid waste liquid was not considered so much in terms of resource recycling and environmental pollution, and the corrosion resistant material against the mixed acid of nitric acid and hydrofluoric acid was also not considered. it is conceivable that.
【００１６】このため、混合酸廃液は、前記した(1)拡
散透析法、(2)有機溶媒抽出法等によって処理されてい
るものの、少なくともその一部は放流しており、また、
多くは簡単で廉価な消石灰中和法で処理し、この処理液
を放流しており、今日に至るも、混合酸廃液中の有効成
分である硝酸、弗酸を回収するための工業装置が開発さ
れていない。Therefore, although the mixed acid waste liquid is treated by the above-mentioned (1) diffusion dialysis method, (2) organic solvent extraction method, etc., at least a part thereof is discharged, and
Most of them are treated by a simple and inexpensive slaked lime neutralization method, and the treated solution is discharged.To date, industrial equipment has been developed to recover nitric acid and hydrofluoric acid, which are the active ingredients in the mixed acid waste liquid. It has not been.
【００１７】本発明者等は、第１に、混合酸廃液の蒸発
塔に対する腐蝕性を解決したものである。即ち、本発明
は、蒸発（濃縮）塔として、カ−ボン製又はテフロン耐
蝕性材料で内張りした塔を用いるものであり、この塔を
用いることにより腐蝕させることなく有効に濃縮するこ
とができる。The present inventors firstly solved the corrosiveness of the mixed acid waste liquid with respect to the evaporation tower. That is, in the present invention, a column made of carbon or lined with a Teflon corrosion-resistant material is used as the evaporation (concentration) column, and by using this column, it is possible to effectively concentrate without corroding.
【００１８】また、本発明者等は、第２に、硝酸−弗酸
−水系の３成分系に対する気液平衡曲線を調査研究し、
その結果、混合酸廃液の蒸発（濃縮）する最適条件を見
出したものである。上記第１及び第２の知見により、混
合酸廃液の加熱蒸発濃縮法を初めて確立したものであ
る。Secondly, the present inventors investigated and studied the gas-liquid equilibrium curve for the ternary system of nitric acid-hydrofluoric acid-water,
As a result, they have found optimum conditions for evaporating (concentrating) the mixed acid waste liquid. Based on the above-mentioned first and second findings, a heating evaporation concentration method of a mixed acid waste liquid has been established for the first time.
【００１９】次に、本発明者等が調査研究した硝酸−弗
酸−水系の３成分系に対する気液平衡曲線を図２及び図
３に基づいて説明する。 （弗酸気液平衡曲線について）図２は、HNO3濃度を変え
て得られたHFの気液平衡曲線図であって、図２中の
は、HNO3濃度360〜550g/lの回収酸に対しHF濃度70〜80g
/l、40〜50g/l、20〜30g/lの各液を蒸発（濃縮）させて
液相、気相中のHF濃度を測定したHFの気液平衡曲線であ
る。また、図２中のは、HNO3濃度100〜200g/lの回収
酸に対しHF濃度70〜80g/l、40〜50g/l、20〜30g/lの各
液を蒸発（濃縮）させて液相、気相中のHF濃度を測定し
たHFの気液平衡曲線である。Next, the vapor-liquid equilibrium curves for the ternary system of nitric acid-hydrofluoric acid-water system investigated by the present inventors will be described with reference to FIGS. 2 and 3. (Dorusanki liquid equilibrium for curve) Figure 2 is a vapor-liquid equilibrium curves of HF obtained by changing the HNO 3 concentration, the in Figure 2, the recovery acid HNO 3 concentration 360~550g / l Against HF concentration 70-80g
FIG. 3 is a gas-liquid equilibrium curve of HF in which HF concentrations in a liquid phase and a gas phase were measured by evaporating (concentrating) each liquid of / l, 40 to 50 g / l, and 20 to 30 g / l. Moreover, in FIG. 2, each of the HF concentrations of 70 to 80 g / l, 40 to 50 g / l, and 20 to 30 g / l is evaporated (concentrated) with respect to the recovered acid having a HNO 3 concentration of 100 to 200 g / l. It is a gas-liquid equilibrium curve of HF in which HF concentrations in a liquid phase and a gas phase are measured.
【００２０】更に、図２中のは、HNO3濃度80〜90g/l
の回収酸に対しHF濃度60〜70g/l、40〜50g/l、20〜30g/
lの各液を蒸発（濃縮）させて液相、気相中のHF濃度を
測定したHFの気液平衡曲線である。なお、図２中の文献
値は、硝酸の単酸（HNO3−H2O）での気液平衡曲線であ
る。Further, in FIG. 2, the HNO 3 concentration is 80 to 90 g / l.
HF concentration of 60-70g / l, 40-50g / l, 20-30g /
It is a vapor-liquid equilibrium curve of HF in which each liquid of 1 was evaporated (concentrated) to measure the HF concentration in the liquid phase and the gas phase. Note that the literature values in FIG. 2 are gas-liquid equilibrium curves of nitric acid monoacid (HNO 3 —H 2 O).
【００２１】図２から明らかなように、HNO3濃度が高い
場合、HFの蒸発は大きいが、HNO3濃度が低い場合にはHF
の蒸発（濃縮）は小さいことが理解でき、その結果、HF
の蒸発を増大させるためには、共存するHNO3濃度を高め
る必要があることが理解できる。As is clear from FIG. 2, when the HNO 3 concentration is high, the HF is largely evaporated, but when the HNO 3 concentration is low, the HF is evaporated.
It can be understood that the evaporation (concentration) of
It can be seen that the concentration of coexisting HNO 3 must be increased in order to increase the vaporization of HNO 3 .
【００２２】（硝酸気液平衡曲線について）図３は、HF
濃度を変えて得られたHNO3の気液平衡曲線図であって、
図３中のは、HF濃度70〜80g/lの回収酸に対しHNO3濃
度400〜550g/l、200〜300g/l、100〜150g/lの各液を蒸
発（濃縮）して液相、気相中のHNO3濃度を測定したHNO3
の気液平衡曲線である。(Regarding Nitric Acid Vapor-Liquid Equilibrium Curve) FIG.
It is a vapor-liquid equilibrium curve diagram of HNO 3 obtained by changing the concentration,
In Figure 3, the liquid phase is obtained by evaporating (concentrating) each liquid with HNO 3 concentrations of 400-550 g / l, 200-300 g / l, 100-150 g / l with respect to the recovered acid of HF concentration of 70-80 g / l. , HNO 3 of the measurement of the HNO 3 concentration in the gas phase
2 is a vapor-liquid equilibrium curve of
【００２３】また、図３中のは、HF濃度40〜60g/lの
回収酸に対しHNO3濃度40〜60g/l、100〜150g/l、200〜3
00g/lの各液を蒸発（濃縮）して液相、気相中のHNO3濃
度を測定したHNO3の気液平衡曲線である。更に、図３中
のは、HF濃度20〜30g/lの回収酸に対しHNO3濃度70〜9
0g/l、350〜450g/lの液を蒸発（濃縮）して液相、気相
中のHNO3濃度を測定したHNO3の気液平衡曲線である 。
なお、図３中の文献値は、弗酸の単酸（HF−H2O）での
気液平衡曲線である。Further, in FIG. 3, the HNO 3 concentration is 40 to 60 g / l, 100 to 150 g / l, 200 to 3 for the recovered acid having an HF concentration of 40 to 60 g / l.
FIG. 3 is a vapor-liquid equilibrium curve of HNO 3 obtained by measuring the concentration of HNO 3 in a liquid phase and a vapor phase by evaporating (concentrating) each liquid of 00 g / l. Furthermore, in FIG. 3, the concentration of HNO 3 is 70 to 9 for the recovered acid having an HF concentration of 20 to 30 g / l.
It is the vapor-liquid equilibrium curve of HNO 3 which measured the HNO 3 density | concentration in a liquid phase and a vapor phase by evaporating (concentrating) the liquid of 0 g / l and 350-450 g / l.
Note that the literature values in FIG. 3 are gas-liquid equilibrium curves of hydrofluoric acid with monoacid (HF-H 2 O).
【００２４】図３から明らかなように、HF濃度が高い
（70〜80g/l）場合には、HNO3は濃縮して行くが、HF濃
度が低い（20〜30g/l）場合でもそれなりに濃縮する。
そして、HF濃度が低い方が濃縮が大きいことが理解でき
る。As is clear from FIG. 3, when the HF concentration is high (70 to 80 g / l), HNO 3 is concentrated, but even when the HF concentration is low (20 to 30 g / l), it is not so. Concentrate.
It can be seen that the lower the HF concentration, the greater the concentration.
【００２５】ところで、硝酸−弗酸−水系の３成分系で
は共弗混合物が生成し、各酸が共に所望濃度に濃縮する
ことができない。即ち、共弗混合物の生成により、通常
約３割程度濃縮されるにすぎず、これ以上に濃縮するこ
とができない。By the way, in the three-component system of nitric acid-hydrofluoric acid-water, an azeotropic mixture is formed, and each acid cannot be concentrated to a desired concentration. That is, due to the formation of the azeotropic mixture, the concentration is usually only about 30% and cannot be further increased.
【００２６】例えば、硝酸を所望濃度に濃縮しようとす
ると、弗酸濃度を低下させなければならず、（図３参
照）、一方、弗酸を所望濃度に濃縮しようとすると、硝
酸の濃度を低下させなければならない（図２参照）。こ
のように硝酸−弗酸−水系の３成分系では、相反するこ
ととなることを本発明者等は見出し、この事実に基づき
３成分系の濃縮において、最適条件を見出したものであ
る。For example, when trying to concentrate nitric acid to a desired concentration, the concentration of hydrofluoric acid must be lowered (see FIG. 3), while when trying to concentrate hydrofluoric acid to a desired concentration, the concentration of nitric acid is lowered. Must be done (see Figure 2). As described above, the present inventors have found that the three-component system of nitric acid-hydrofluoric acid-water system is in conflict with each other, and based on this fact, the optimum conditions have been found in the concentration of the three-component system.
【００２７】上記最適条件としては、回収酸中の硝酸成
分濃度を250〜550g/l、弗酸成分濃度を40〜80g/lとする
ものであり、これによって硝酸−弗酸−水系の３成分系
の混合酸を有効に濃縮することができる。The optimum conditions are such that the concentration of nitric acid component in the recovered acid is 250 to 550 g / l and the concentration of hydrofluoric acid component is 40 to 80 g / l, whereby three components of nitric acid-hydrofluoric acid-water system are prepared. The mixed acid of the system can be effectively concentrated.
【００２８】[0028]
【実施例】次に、本発明の実施例を図１（本発明の一実
施例を示す濃縮工程図）に基づいて詳細に説明する。原
料液を原料タンクＭからポンプ１により蒸発塔２に供給
する。この蒸発塔２は、カ−ボン製で製作されたもので
あり、上部に冷却器、中間部に複数段の蒸発段をもち、
下部に熱源をスチ−ムＳ1とする加熱器から構成されて
いる。一方、スチ−ムＳ2によりエジェクタ−６で減圧
状態（約500mmHg）とし、これを利用して蒸発塔２を減
圧にする。スチ−ムドレインＤ2は、No.2コンデンセ−
トタンク５に排出される。EXAMPLES Next, an example of the present invention will be described in detail with reference to FIG. 1 (concentration process diagram showing an example of the present invention). The raw material liquid is supplied from the raw material tank M to the evaporation tower 2 by the pump 1. The evaporation tower 2 is made of carbon and has a cooler in the upper part and a plurality of evaporation stages in the middle part.
It is composed of a heater having a heat source of steam S 1 at the lower part. On the other hand, the pressure of the ejector 6 is reduced by the steam S 2 (about 500 mmHg), and this is used to reduce the pressure of the evaporation tower 2. Steam drain D 2 is No. 2 condenser
It is discharged to the tank 5.
【００２９】蒸発塔２に供給した原料液は、下部加熱器
で蒸発濃縮され、中間部のオ−バ−フロ−より濃縮酸と
して製品タンクＰに貯留される。原料液の加熱に使われ
たスチ−ムＳ1は、スチ−ムドレインＤ1としてスチ−ム
ドレインタンク３に排出する。蒸発塔２上部には、冷却
器が設置され、蒸発したガスは、冷水（浄水Ｗ）にて間
接冷却され、同ドレインは、No.1コンデンセ−トタンク
４に貯留される。冷却器から排出したガスは、前記エジ
ェクタ−６に吸引され、エジェクタ−用スチ−ムＳ2と
共にNo.2コンデンセ−トタンク５に排出する。The raw material liquid supplied to the evaporation tower 2 is evaporated and concentrated by the lower heater, and stored in the product tank P as concentrated acid from the overflow in the middle part. The steam S 1 used for heating the raw material liquid is discharged to the steam drain tank 3 as a steam drain D 1 . A cooler is installed above the evaporation tower 2, the evaporated gas is indirectly cooled by cold water (purified water W), and the drain is stored in the No. 1 condensate tank 4. The gas discharged from the cooler is sucked by the ejector 6 and discharged to the No. 2 condensate tank 5 together with the ejector steam S 2 .
【００３０】図１に示す上記蒸発フロ−に従って回収酸
を濃縮した。回収酸の原料液組成は、HF濃度20g/l、HNO
3濃度100g/lであった。この原料液を蒸発塔２に供給
し、450mmHgの減圧下で65℃で加熱した。その結果、HF
濃度60g/l、HNO3濃度400g/lの濃縮酸が得られた。The recovered acid was concentrated according to the above evaporation flow shown in FIG. The raw acid composition of the recovered acid is HF concentration 20g / l, HNO
The concentration was 100 g / l. This raw material liquid was supplied to the evaporation tower 2 and heated at 65 ° C. under a reduced pressure of 450 mmHg. As a result, HF
A concentrated acid having a concentration of 60 g / l and an HNO 3 concentration of 400 g / l was obtained.
【００３１】[0031]
【発明の効果】本発明は、以上詳記したとおり、硝酸、
弗酸含有酸洗廃液を拡散透析法、有機溶媒抽出法等で処
理し、得られた回収酸を蒸発、濃縮することにより、混
合酸廃液から濃縮酸として有効に回収することができる
効果が生ずる。そして、本発明によれば、気液平衡曲線
の特性を適用して設備化することにより、環境公害を低
減し、資源のリサイクル化に貢献することができる利点
を有する。INDUSTRIAL APPLICABILITY As described in detail above, the present invention provides nitric acid,
By treating the pickling waste solution containing hydrofluoric acid by a diffusion dialysis method, an organic solvent extraction method, etc., and evaporating and concentrating the obtained recovered acid, there is an effect that it can be effectively recovered as a concentrated acid from the mixed acid waste solution. . Further, according to the present invention, by applying the characteristics of the gas-liquid equilibrium curve and installing the equipment, it is possible to reduce environmental pollution and contribute to recycling of resources.
【図１】本発明の一実施例を示す濃縮工程図。FIG. 1 is a concentration process diagram showing an embodiment of the present invention.
【図２】HNO3濃度を変えて得られたHFの気液平衡曲線
図。FIG. 2 is a vapor-liquid equilibrium curve diagram of HF obtained by changing the HNO 3 concentration.
【図３】HF濃度を変えて得られたHNO3の気液平衡曲線
図。FIG. 3 is a vapor-liquid equilibrium curve diagram of HNO 3 obtained by changing the HF concentration.
Ｍ 原料タンク Ｐ 製品タンク Ｓ1、Ｓ2 スチ−ム Ｗ 浄水 Ｄ1、Ｄ2 スチ−ムドレイン １ ポンプ ２ 蒸発（濃縮）塔 ３ スチ−ムドレインタンク ４ No.1コンデンセ−トタンク ５ No.2コンデンセ−トタンク ６ スチ−ムエジェクタ−M Raw material tank P Product tank S 1 , S 2 Steam W Clean water D 1 , D 2 Steam drain 1 Pump 2 Evaporation (concentration) tower 3 Steam drain tank 4 No. 1 Condensate tank 5 No. 2 Condensate -Totank 6 Steam ejector-
Claims (3)
有機溶媒抽出法等で処理し、得られた回収酸を蒸発、濃
縮することを特徴とする酸洗廃液より硝酸と弗酸の混合
酸又は硝酸、弗酸を回収する方法。1. A diffusion dialysis method using a pickling waste solution containing nitric acid and hydrofluoric acid,
A method for recovering a mixed acid of nitric acid and hydrofluoric acid or nitric acid and hydrofluoric acid from a pickling waste liquid, characterized by evaporating and concentrating the recovered acid obtained by treating with an organic solvent extraction method or the like.
テフロン耐蝕性材料で内張りした塔を用いることを特徴
とする請求項１に記載の酸洗廃液より硝酸と弗酸の混合
酸又は硝酸、弗酸を回収する方法。2. The evaporation (concentration) column is a column made of carbon or lined with a Teflon anticorrosion material, and the mixed acid of nitric acid and hydrofluoric acid from the pickling waste liquid according to claim 1 is used. A method of recovering nitric acid and hydrofluoric acid.
有機溶媒抽出法等で処理し、得られた回収酸を蒸発、濃
縮して硝酸と弗酸の混合酸を回収し、さらに該混合酸を
有機溶媒を用いて硝酸及び弗酸の各単酸を回収すること
を特徴とする酸洗廃液より硝酸及び弗酸を回収する方
法。3. A nitric acid / hydrofluoric acid-containing pickling waste solution is subjected to a diffusion dialysis method,
The recovered acid is treated by an organic solvent extraction method and the like, and the obtained recovered acid is evaporated and concentrated to recover a mixed acid of nitric acid and hydrofluoric acid. A method for recovering nitric acid and hydrofluoric acid from a pickling waste liquid, characterized by recovering.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23291292A JPH0657466A (en) | 1992-08-07 | 1992-08-07 | Method for recovering mixed acid of nitric acid with hydrofluoric acid or nitric acid, hydrofluoric acid from pickling waste water |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23291292A JPH0657466A (en) | 1992-08-07 | 1992-08-07 | Method for recovering mixed acid of nitric acid with hydrofluoric acid or nitric acid, hydrofluoric acid from pickling waste water |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0657466A true JPH0657466A (en) | 1994-03-01 |
Family
ID=16946789
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP23291292A Pending JPH0657466A (en) | 1992-08-07 | 1992-08-07 | Method for recovering mixed acid of nitric acid with hydrofluoric acid or nitric acid, hydrofluoric acid from pickling waste water |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0657466A (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6375915B1 (en) * | 1996-11-15 | 2002-04-23 | Keramchemie Gmbh | Method of regenerating a spent pickling solution |
| JP2006028556A (en) * | 2004-07-13 | 2006-02-02 | Nippon Refine Kk | Apparatus for regenerating metal-containing waste liquid acid |
| JP2006512478A (en) * | 2002-07-10 | 2006-04-13 | ウーファウカー・エンジニアリング・ゲゼルシャフト・ミト・べシュレンクテル・ハフツング | Method and apparatus for recycling metal pickling baths |
| CN104225956A (en) * | 2014-09-27 | 2014-12-24 | 安徽金禾实业股份有限公司 | Forced circulating extraction method in production of acesulfame |
| CN104310690A (en) * | 2014-10-28 | 2015-01-28 | 中冶南方工程技术有限公司 | Process of regenerating metal nitric acid and hydrofluoric acid pickling wastewater and recycling metal elements |
| CN104498974A (en) * | 2015-01-23 | 2015-04-08 | 黄健 | Method for recycling mixed acid from cold-rolling stainless steel acid washing waste liquid |
| CN104711617A (en) * | 2015-04-09 | 2015-06-17 | 南通晨光石墨设备有限公司 | Regeneration method of acid washing waste acids |
-
1992
- 1992-08-07 JP JP23291292A patent/JPH0657466A/en active Pending
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6375915B1 (en) * | 1996-11-15 | 2002-04-23 | Keramchemie Gmbh | Method of regenerating a spent pickling solution |
| JP2006512478A (en) * | 2002-07-10 | 2006-04-13 | ウーファウカー・エンジニアリング・ゲゼルシャフト・ミト・べシュレンクテル・ハフツング | Method and apparatus for recycling metal pickling baths |
| JP2006028556A (en) * | 2004-07-13 | 2006-02-02 | Nippon Refine Kk | Apparatus for regenerating metal-containing waste liquid acid |
| CN104225956A (en) * | 2014-09-27 | 2014-12-24 | 安徽金禾实业股份有限公司 | Forced circulating extraction method in production of acesulfame |
| CN104310690A (en) * | 2014-10-28 | 2015-01-28 | 中冶南方工程技术有限公司 | Process of regenerating metal nitric acid and hydrofluoric acid pickling wastewater and recycling metal elements |
| CN104498974A (en) * | 2015-01-23 | 2015-04-08 | 黄健 | Method for recycling mixed acid from cold-rolling stainless steel acid washing waste liquid |
| CN104711617A (en) * | 2015-04-09 | 2015-06-17 | 南通晨光石墨设备有限公司 | Regeneration method of acid washing waste acids |
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