JP3321289B2 - Mixed acid analysis method and pickling solution management method - Google Patents
Mixed acid analysis method and pickling solution management methodInfo
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- JP3321289B2 JP3321289B2 JP08691394A JP8691394A JP3321289B2 JP 3321289 B2 JP3321289 B2 JP 3321289B2 JP 08691394 A JP08691394 A JP 08691394A JP 8691394 A JP8691394 A JP 8691394A JP 3321289 B2 JP3321289 B2 JP 3321289B2
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- free
- acid
- concentration
- measured
- iron
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Description
【０００１】[0001]
【産業上の利用分野】本発明はステンレス鋼帯の酸洗液
の分析に用いることができる、鉄イオン、遊離弗酸およ
び遊離硝酸を含んだ混合酸の分析法および該分析法を採
用した酸洗液の管理方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for analyzing a mixed acid containing iron ions, free hydrofluoric acid and free nitric acid, and an acid employing the method, which can be used for analyzing a pickling solution of a stainless steel strip. The present invention relates to a method for managing a washing liquid.
【０００２】熱間加工後のステンレス鋼帯の表面に存在
する酸化物を除去する方法の一つとして酸洗法がある。
この酸洗法において、弗酸および硝酸を含む酸洗液が用
いられる場合が一般的である。このような酸洗液の酸洗
能力は、その中に含まれる遊離弗酸および遊離硝酸の濃
度に依存する。すなわち、ステレンス鋼帯を上記酸洗液
で酸洗を行うにつれて、ステンレス鋼帯表面より鉄イオ
ン、その他の金属イオンが塩基である水酸化物として溶
出し、それと共に遊離弗酸および遊離硝酸の濃度は減少
し、酸洗液の酸洗能力は低下する。従って、酸洗液の遊
離弗酸および遊離硝酸の濃度を常に監視し、合わせてこ
れらの濃度の低下と共に増加する鉄イオン濃度をも監視
することが行われている。One of the methods for removing oxides present on the surface of a stainless steel strip after hot working is an acid pickling method.
In this pickling method, a pickling solution containing hydrofluoric acid and nitric acid is generally used. The pickling ability of such a pickling solution depends on the concentration of free hydrofluoric acid and free nitric acid contained therein. That is, as the stainless steel strip is pickled with the above pickling solution, iron ions and other metal ions are eluted from the surface of the stainless steel strip as hydroxide, which is a base, and the concentration of free hydrofluoric acid and free nitric acid is also increased. And the pickling ability of the pickling solution decreases. Therefore, the concentrations of free hydrofluoric acid and free nitric acid in the pickling solution are constantly monitored, and the concentration of iron ions that increases with a decrease in these concentrations is also monitored.
【０００３】従来、酸洗液の遊離弗酸濃度は弗素イオン
電極で測定されている。遊離硝酸濃度は、拡散透析膜お
よび水素イオン電極を用いた拡散透析法により測定され
た全遊離酸濃度から遊離弗酸濃度を差し引くことにより
求められている。Conventionally, the concentration of free hydrofluoric acid in a pickling solution has been measured with a fluoride ion electrode. The free nitric acid concentration is determined by subtracting the free hydrofluoric acid concentration from the total free acid concentration measured by a diffusion dialysis method using a diffusion dialysis membrane and a hydrogen ion electrode.
【０００４】しかしながら、上記方法は必ずしも精度良
く遊離弗酸および遊離硝酸濃度を測定できる方法ではな
い。[0004] However, the above method is not always a method capable of accurately measuring the concentrations of free hydrofluoric acid and free nitric acid.
【０００５】[0005]
【発明が解決しようとする課題】本発明の目的は、混合
酸中の遊離弗酸、遊離硝酸および鉄イオンの各濃度を精
度よく測定することができる分析方法を提供することで
ある。本発明の他の目的は、ステンレス鋼帯で例示され
る鉄を成分とする金属材の酸洗液に含まれる遊離弗酸、
遊離硝酸および鉄イオンの各濃度を精度よく監視するた
めに用いることができる酸洗液の分析方法を提供するこ
とである。本発明のさらなる他の目的は、上記分析法を
用いた酸洗液の管理方法を提供することである。SUMMARY OF THE INVENTION An object of the present invention is to provide an analytical method capable of accurately measuring the concentrations of free hydrofluoric acid, free nitric acid and iron ions in a mixed acid. Another object of the present invention is to provide free hydrofluoric acid contained in a pickling solution of a metal material containing iron as exemplified by a stainless steel strip,
An object of the present invention is to provide a method for analyzing a pickling solution that can be used to accurately monitor the concentrations of free nitric acid and iron ions. Still another object of the present invention is to provide a method for managing a pickling solution using the above-mentioned analysis method.
【０００６】[0006]
【課題を解決するための手段】本発明によれば、第１
に、遊離弗酸、遊離硝酸および鉄イオンを含んだ混合酸
について、（ａ）鉄サリチル酸錯体吸光度法により鉄イ
オン濃度を測定し、（ｂ）鉄アセチルアセトン錯体退色
吸光度法により遊離弗酸濃度を測定し、そして（ｃ）中
和滴定法により全遊離酸濃度を測定し、測定された全遊
離酸濃度より上記（ｂ）で測定された遊離弗酸濃度を差
し引くことにより遊離硝酸濃度を測定する、ことを特徴
とする混合酸の分析方法が提供される。According to the present invention, there is provided:
Then, for a mixed acid containing free hydrofluoric acid, free nitric acid and iron ions, (a) the iron ion concentration is measured by the iron salicylic acid complex absorbance method, and (b) the free hydrofluoric acid concentration is measured by the iron acetylacetone complex bleaching absorbance method. And (c) measuring the total free acid concentration by a neutralization titration method, and measuring the free nitric acid concentration by subtracting the free hydrofluoric acid concentration measured in (b) from the measured total free acid concentration. A method for analyzing a mixed acid is provided.
【０００７】さらに本発明によれば、第２に、 （Ａ）遊離弗酸、遊離硝酸および鉄イオンを含んだ、鉄
を成分として含有する金属材の酸洗液から採取された試
料について、（ａ）鉄サリチル酸錯体吸光度法により鉄
イオン濃度を測定し、（ｂ）鉄アセチルアセトン錯体退
色吸光度法により遊離弗酸濃度を測定し、そして（ｃ）
中和滴定法により全遊離酸濃度を測定し、測定された全
遊離酸濃度より上記（ｂ）で測定された遊離弗酸濃度を
差し引くことにより遊離硝酸濃度を測定し、 （Ｂ）測定せられた鉄イオン、遊離弗酸および遊離硝酸
の各濃度に相関する信号をコンピューターに入力し、 （Ｃ）コンピューターで、予めコンピューターに設定せ
られた鉄イオン、遊離弗酸および遊離硝酸の許容濃度範
囲と測定された酸洗液中のこれらの濃度とが照合されか
つ演算せられて、出力信号がコンピューターから発っせ
られ、 （Ｄ）コンピューターから発っせられた出力信号に従っ
て、酸洗液中の鉄イオン、遊離弗酸および遊離硝酸の各
濃度が上記許容濃度範囲に維持されるように新しい弗
酸、硝酸および／または水を酸洗液に添加する、ことを
特徴とする酸洗液の管理方法が提供される。Further, according to the present invention, secondly, (A) a sample taken from a pickling solution of a metal material containing iron as a component, containing free hydrofluoric acid, free nitric acid and iron ions, a) measuring the iron ion concentration by the iron salicylic acid complex absorbance method, (b) measuring the free hydrofluoric acid concentration by the iron acetylacetone complex fading absorbance method, and (c)
The total free acid concentration is measured by a neutralization titration method, and the free nitric acid concentration is measured by subtracting the free hydrofluoric acid concentration measured in the above (b) from the measured total free acid concentration. A signal correlating with each concentration of iron ion, free hydrofluoric acid and free nitric acid is input to a computer, and (C) a computer sets a permissible concentration range of iron ion, free hydrofluoric acid and free nitric acid preset in the computer. These measured concentrations in the pickling solution are compared and calculated, and an output signal is generated from the computer. (D) According to the output signal generated from the computer, Adding fresh hydrofluoric acid, nitric acid and / or water to the pickling solution such that the concentrations of free hydrofluoric acid and free nitric acid are maintained within the above allowable concentration ranges. The law is provided.
【０００８】以上の発明により、本発明の目的が達成さ
れる。以下、本発明を詳述するが、それにより本発明の
さらなる目的、構成並びにそれに基づく利点および効果
が明らかになろう。The object of the present invention is achieved by the above invention. Hereinafter, the present invention will be described in detail, from which further objects, configurations and advantages and effects based thereon will become apparent.
【０００９】（ａ）鉄イオン濃度の測定 本発明の分析方法の対象である混合酸中の鉄イオン濃度
は鉄サリチル酸錯体吸光度法により測定される。鉄イオ
ン（ＩＩＩ）はサリチル酸と紫色のキレート錯化合物を
作るので、これを利用して波長５２０ｎｍの光を用いて
吸光度法により混合酸中の鉄イオンの濃度を測定するこ
とができる。 (A) Measurement of Iron Ion Concentration The iron ion concentration in the mixed acid which is the object of the analysis method of the present invention is measured by an iron salicylic acid complex absorbance method. Since the iron ion (III) forms a purple chelate complex with salicylic acid, the concentration of the iron ion in the mixed acid can be measured by utilizing this and using a light having a wavelength of 520 nm by an absorbance method.
【００１０】具体的な測定手順の例を下記する。 （１）試料（混合酸）１００μｌを１００ｍｌのポリエ
チレン製メスフラスコに分取する。 （２）ｐＨを４〜８とするための緩衝溶液９０ｍｌと、
弗化鉄イオンを分解するための硝酸アルミニウム溶液
（濃度：８ｇ／ｌ）３ｍｌを加える。 （３）サリチル酸ナトリウム溶液（濃度：１ｇ／ｌ）５
ｍｌを加え、上記緩衝溶液で標線まで薄めた後、よく振
り混ぜる。 （４）１０分後、この溶液の一部を石英ガラス製吸収セ
ル（５ｍｍ）にとり波長５２０ｎｍにおける吸光度を測
定する。 （５）予め作成した検量線により試料中の鉄イオン濃度
（ｇ／ｌ）を求める。[0010] you following the example of a specific measurement procedure. (1) Dispense 100 μl of the sample (mixed acid) into a 100 ml polyethylene volumetric flask. (2) 90 ml of a buffer solution for adjusting the pH to 4 to 8,
3 ml of an aluminum nitrate solution (concentration: 8 g / l) for decomposing iron fluoride ions are added. (3) Sodium salicylate solution (concentration: 1 g / l) 5
ml was added, and diluted with the marked line or above buffer solution, shaking well mixed. (4) After 10 minutes, a part of the solution is placed in a quartz glass absorption cell (5 mm), and the absorbance at a wavelength of 520 nm is measured. (5) The iron ion concentration (g / l) in the sample is determined from a previously prepared calibration curve.
【００１１】（ｂ）遊離弗酸濃度の測定 混合酸中の遊離弗酸濃度は鉄アセチルアセトン錯体退色
吸光度法により測定される。この方法は、（ｉ）アセチ
ルアセトンが鉄と下記式（１） (B) Measurement of Free Hydrofluoric Acid Concentration The free hydrofluoric acid concentration in the mixed acid is measured by an iron acetylacetone complex fading absorbance method. In this method, (i) acetylacetone is combined with iron by the following formula (1)
【００１２】[0012]
【化１】 Embedded image
【００１３】で示される赤色の錯体を形成すること、そ
して（ｉｉ）遊離弗酸を添加すると添加した遊離弗酸の
量に応じて、上記式（１）で示される錯体の量が減少す
ること、を利用して遊離弗酸濃度を測定する方法であ
る。(Ii) the addition of free hydrofluoric acid decreases the amount of the complex represented by the above formula (1) in accordance with the amount of free hydrofluoric acid added; This is a method for measuring the concentration of free hydrofluoric acid using the above method.
【００１４】遊離弗酸濃度を測定する具体的な手順の１
例を下記する。 （１）硝酸（０.１Ｎ）約６０ｍｌをポリエチレン製メ
スフラスコ（１００ｍｌ）に加える。 （２）鉄イオン水溶液（鉄濃度：１.０ｍｇ／ｍｌ）１
０ｍｌを正確に分取して加える。 （３）アセチルアセトン溶液（濃度：０.６容量％）５
ｍｌを正確に加える。 （４）試料（混合酸）１００μｌを加え、硝酸（０.１
Ｎ）で標線までうすめた後、よく振り混ぜる。 （５）この溶液の一部を吸収セル（１０ｍｍｌ）にと
り、波長４９０ｎｍでの吸光度を測定する。 （６）予め作成した検量線により、試料中の遊離弗酸量
を求める。Specific procedure 1 for measuring the concentration of free hydrofluoric acid
An example is given below. (1) About 60 ml of nitric acid (0.1N) is added to a polyethylene measuring flask (100 ml). (2) Iron ion aqueous solution (iron concentration: 1.0 mg / ml) 1
Aliquot exactly 0 ml and add. (3) Acetylacetone solution (concentration: 0.6% by volume) 5
Add ml exactly. (4) Add 100 μl of the sample (mixed acid), and add nitric acid (0.1
After thinning to the mark in N), shake well. (5) A part of this solution is taken in an absorption cell (10 mm), and the absorbance at a wavelength of 490 nm is measured. (6) The amount of free hydrofluoric acid in the sample is determined from a previously prepared calibration curve.
【００１５】以上の手順によりステンレス鋼帯の酸洗液
について遊離弗酸濃度を繰り返して測定した結果を表１
に示す。表１の従来法は弗素イオン電極法によるもので
ある。また表１のσは標準偏差値である。Table 1 shows the results of repeatedly measuring the concentration of free hydrofluoric acid in the pickling solution of the stainless steel strip according to the above procedure.
Shown in The conventional method shown in Table 1 is based on the fluorine ion electrode method. Further, σ in Table 1 is a standard deviation value.
【００１６】[0016]
【表１】 [Table 1]
【００１７】表１から明らかな如く、本発明で採用する
遊離弗酸の測定法は従来法と比較して測定精度が著しく
高いことが明らかである。As is clear from Table 1, it is clear that the measuring method of free hydrofluoric acid used in the present invention has a remarkably higher measuring accuracy than the conventional method.
【００１８】（ｃ）遊離硝酸濃度の測定 混合酸中の遊離硝酸濃度は、中和滴定法により全遊離酸
濃度を測定し、この値から、上述した方法で測定された
遊離弗酸濃度を差し引いて求める。 (C) Measurement of Free Nitric Acid Concentration The free nitric acid concentration in the mixed acid is determined by measuring the total free acid concentration by a neutralization titration method, and subtracting the free hydrofluoric acid concentration measured by the above method from this value. Ask.
【００１９】全遊離酸濃度を測定するたの具体的手順の
１例を下記する。 （１）試料（混合酸）１ｍｌをポリエチレン製ビーカー
（２５０ｍｌ）に分取する。 （２）弗化カリウム溶液（濃度：５０ｇ／ｌ）１５ｍｌ
および水１０ｍｌを加え、よく混合する。 （３）指示薬としてフェノールフタレインを用い標準水
酸化ナトリウム溶液（０.２Ｎ）で滴定し、終点に到る
滴定量から全遊離酸濃度を計算する。An example of a specific procedure for measuring the total free acid concentration is described below. (1) Dispense 1 ml of a sample (mixed acid) into a polyethylene beaker (250 ml). (2) 15 ml of potassium fluoride solution (concentration: 50 g / l)
And 10 ml of water and mix well. (3) Using phenolphthalein as an indicator, titrate with a standard sodium hydroxide solution (0.2N), and calculate the total free acid concentration from the titer reaching the end point.
【００２０】以上の手順により、ステレンス鋼帯の酸洗
液について、全遊離酸濃度を繰り返して測定した結果を
表２に示す。表２の従来法は拡散透析法によるものであ
る。Table 2 shows the results of repeatedly measuring the total free acid concentration of the pickling liquid of the stainless steel strip according to the above procedure. The conventional method in Table 2 is based on the diffusion dialysis method.
【００２１】[0021]
【表２】 [Table 2]
【００２２】表２から明らかな如く、本発明で採用する
全遊離酸の測定法は従来法と比較して測定精度が著しく
高いことが明らかである。そして、前述の如く、本発明
で使用する遊離弗酸濃度の測定精度は高いのであるか
ら、本発明で採用する遊離硝酸濃度の測定法によって精
度高く遊離硝酸濃度を測定できることも自ずと理解され
よう。As is clear from Table 2, it is clear that the measuring method of total free acid used in the present invention has a remarkably higher measuring accuracy than the conventional method. As described above, since the measurement accuracy of the concentration of free hydrofluoric acid used in the present invention is high, it will be understood that the concentration of free nitric acid can be measured with high accuracy by the method of measuring the concentration of free nitric acid used in the present invention.
【００２３】以上説明した方法に従って、混合酸中の鉄
イオン、遊離弗酸および遊離硝酸の各濃度を測定する際
して、混合酸が酸洗液の場合にはその中にスラッジが含
まれているので、予め濾過などの手段によりスラッジを
除去することが好ましい。When measuring the concentrations of iron ions, free hydrofluoric acid and free nitric acid in the mixed acid according to the method described above, when the mixed acid is a pickling solution, sludge is contained therein. Therefore, it is preferable to remove sludge by means such as filtration in advance.
【００２４】このような混合酸の分析法をステンレス鋼
帯の酸洗液の管理に適用する１例につき以下に述べる。An example of applying such a mixed acid analysis method to the control of a pickling solution for a stainless steel strip will be described below.
【００２５】図１は、本発明の分析方法を使用したステ
ンレス鋼帯の酸洗液の管理方法を模式的に示した図であ
る。図１において、酸洗槽１でステンレス鋼帯５が連続
的に酸洗されている。酸洗液の一部はライン６を通って
循環槽２へ送られライン７を通って酸洗槽１へ戻され
る。ライン７の途中からサンプルライン８が設けられ、
サンプルライン８の途中からバルブ９を経由して、酸洗
液が試料として分析計３へ送られる。分析計３には前述
した鉄イオン濃度、遊離弗酸濃度および遊離硝酸濃度を
測定する方法を自動的に行うための装置が装備されてい
る。FIG. 1 is a diagram schematically showing a method for controlling a pickling solution for a stainless steel strip using the analysis method of the present invention. In FIG. 1, a stainless steel strip 5 is continuously pickled in a pickling tank 1. A part of the pickling liquid is sent to the circulation tank 2 through the line 6 and returned to the pickling tank 1 through the line 7. A sample line 8 is provided in the middle of the line 7,
The pickling solution is sent to the analyzer 3 as a sample from the middle of the sample line 8 via the valve 9. The analyzer 3 is equipped with an apparatus for automatically performing the above-described method for measuring the iron ion concentration, free hydrofluoric acid concentration and free nitric acid concentration.
【００２６】分析計３で測定された鉄イオン濃度、遊離
弗酸濃度および遊離硝酸濃度に相関する信号は各々電気
入力信号１２ａ、１２ｂ、１２ｃとしてコンピューター
４へ入力される。コンピューター４では、予め入力され
ている鉄イオン濃度、遊離弗酸濃度および遊離硝酸濃度
の許容範囲と、測定された酸洗液中のこれらの値とを照
合しかつ演算し、酸洗液の各濃度が許容範囲内に維持さ
れるように出力信号１３および１４として原液（新しい
弗酸と硝酸の混合酸）ライン１５のバルブ１０および浄
水ライン１６のバルブの開閉を行う。Signals correlated with the iron ion concentration, free hydrofluoric acid concentration and free nitric acid concentration measured by the analyzer 3 are input to the computer 4 as electric input signals 12a, 12b and 12c, respectively. The computer 4 collates and calculates the allowable ranges of the iron ion concentration, the free hydrofluoric acid concentration and the free nitric acid concentration which have been input in advance, and these measured values in the pickling solution, and calculates each of the pickling solutions. Opening and closing of the valve 10 of the stock solution (new mixed acid of hydrofluoric acid and nitric acid) line 15 and the valve of the water purification line 16 are performed as the output signals 13 and 14 so that the concentration is maintained within the allowable range.
【００２７】必要に応じて廃液ライン１７のバルブ１８
をコンピューターの出力信号（図示せず）によって開閉
することもできる。If necessary, the valve 18 of the waste liquid line 17
Can be opened and closed by a computer output signal (not shown).
【００２８】分析計３においては、試料採取後、鉄イオ
ン濃度の分析、遊離弗酸濃度の分析および遊離硝酸濃度
の分析の順序で行われる。試料採取後、分析が終了し、
次の試料を受け入れる状態となるまでに１時間以内とな
るように分析計を組立てることは容易である。従って、
１時間に少なくとも一度の回数で酸洗液を試料として受
入れ、分析に付すことができる。In the analyzer 3, after sampling, the analysis of iron ion concentration, the analysis of free hydrofluoric acid concentration, and the analysis of free nitric acid concentration are performed in this order. After sampling, the analysis is finished,
It is easy to assemble the analyzer so that it takes less than one hour to accept the next sample. Therefore,
The pickling solution can be received as a sample at least once per hour and submitted for analysis.
【００２９】以上のような酸洗液の監視方法によれば、
酸洗液が一定の酸液能力を保持するようにすることが可
能である。According to the method for monitoring the pickling liquid as described above,
It is possible for the pickling liquid to maintain a constant pickling capacity.
【００３０】しかも極めて重要なこととして、本発明の
分析方法によれば、精度よく鉄イオン、遊離弗酸および
遊離硝酸の各濃度を測定できるので、本発明の分析方法
を採用した上述の管理方法によれば、従来の管理方法と
比較して、より少ない硝酸および弗酸の補給で、酸洗液
の酸洗能を一定に保持することができる。It is extremely important that the analysis method of the present invention can accurately measure each concentration of iron ion, free hydrofluoric acid and free nitric acid. Therefore, the above-described management method employing the analysis method of the present invention. According to this method, the pickling ability of the pickling solution can be kept constant with less replenishment of nitric acid and hydrofluoric acid as compared with the conventional management method.
【００３１】即ち、酸洗に必要な弗酸および硝酸の原単
位は表３に示されるように従来と比べて激減し、合わせ
て酸洗後のステンレス鋼帯のスケール残りによる不良品
の発生率も著しく低下する。In other words, the basic units of hydrofluoric acid and nitric acid required for pickling are drastically reduced as compared with the prior art as shown in Table 3, and the rate of occurrence of defective products due to scale residue of the stainless steel strip after pickling. Is also significantly reduced.
【００３２】[0032]
【表３】 [Table 3]
【００３３】なお、表３で従来の管理方法の欄の各値は
ある年の１〜６月の実績値の平均である。その年の７月
に、従来の監視方法から本発明方法を採用した管理方法
に切り換え、７〜１２月の実績値の平均を本発明方法を
採用した管理方法の欄に記載した。Each value in the column of the conventional management method in Table 3 is an average of the actual values in a certain year from January to June. In July of that year, the monitoring method was switched from the conventional monitoring method to the management method employing the method of the present invention, and the average of the actual values from July to December was described in the column of the management method employing the method of the present invention.
【発明の効果】本発明の分析方法により、ステンレス鋼
帯で代表される鉄を成分とする金属材の酸洗液中の鉄イ
オン、遊離弗酸および遊離硝酸を精度よく、しかも迅速
に測定できるようになった。その結果、本発明の分析方
法を酸洗液管理方法に採用することにより、低原単位で
かつ不良率の発生を低くして該金属材の酸洗工程を行う
ことが可能となった。According to the analysis method of the present invention, iron ions, free hydrofluoric acid and free nitric acid in a pickling solution of a metal material containing iron as represented by a stainless steel strip can be accurately and rapidly measured. It became so. As a result, by adopting the analysis method of the present invention as a pickling liquid management method, the pickling step of the metal material can be performed with a low unit consumption and a low occurrence of a defective rate.
【図１】図１は、本発明の分析方法を採用した酸洗液の
管理方法の１例を示すフローチャートである。FIG. 1 is a flowchart showing an example of a method for managing a pickling solution employing an analysis method of the present invention.
１ 酸洗槽 ２ 循環槽 ３ 分析計 ４ コンピューター ６ 循環ライン ７ 循環ライン ８ サンプルライン ９ バルブ １０ バルブ １１ バルブ １２ 入力信号 １３ 出力信号 １４ 出力信号 １５ 原液ライン １６ 浄水ライン １７ 廃液ライン １８ バルブ DESCRIPTION OF SYMBOLS 1 Pickling tank 2 Circulation tank 3 Analyzer 4 Computer 6 Circulation line 7 Circulation line 8 Sample line 9 Valve 10 Valve 11 Valve 12 Input signal 13 Output signal 14 Output signal 15 Raw liquid line 16 Water purification line 17 Waste liquid line 18 Valve
───────────────────────────────────────────────────── フロントページの続き (72)発明者 山本 準一 千葉県千葉市中央区川崎町１番地 川崎 製鉄株式会社 千葉製鉄所内 (72)発明者 磯部 敏樹 千葉県千葉市中央区川崎町１番地 川崎 製鉄株式会社 千葉製鉄所内 (56)参考文献 特開 平１−234582（ＪＰ，Ａ) 特開 平５−263279（ＪＰ，Ａ) 特開 昭51−133079（ＪＰ，Ａ) 特開 昭54−69526（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) G01N 31/00 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Junichi Yamamoto 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba Kawasaki Steel Corporation Chiba Works (72) Inventor Toshiki Isobe 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba Kawasaki (56) References JP-A-1-245882 (JP, A) JP-A-5-263279 (JP, A) JP-A-51-133079 (JP, A) JP-A-54-69526 (JP, A) (58) Fields investigated (Int. Cl. 7 , DB name) G01N 31/00
Claims (5)
んだ混合酸について、（ａ）鉄サリチル酸錯体吸光度法
により鉄イオン濃度を測定し、（ｂ）鉄アセチルアセト
ン錯体退色吸光度法により遊離弗酸濃度を測定し、そし
て（ｃ）中和滴定法により全遊離酸濃度を測定し、測定
された全遊離酸濃度より上記（ｂ）で測定された遊離弗
酸濃度を差し引くことにより遊離硝酸濃度を測定する、
ことを特徴とする混合酸の分析方法。1. A mixed acid containing free hydrofluoric acid, free nitric acid and iron ions is measured for (a) iron ion concentration by iron salicylic acid complex absorbance method, and (b) free hydrofluoric acid by iron acetylacetone complex fading absorbance method. The concentration of the free nitric acid is determined by measuring the concentration of the free acid, and (c) measuring the total free acid concentration by a neutralization titration method, and subtracting the free hydrofluoric acid concentration measured in (b) from the measured total free acid concentration. Measure,
A method for analyzing a mixed acid, comprising:
洗液である請求項１に記載の混合酸の分析方法。2. The method for analyzing a mixed acid according to claim 1, wherein the mixed acid is a pickling solution of a metal material containing iron as a component.
に記載の混合酸の分析方法。3. The metal material is a stainless steel strip.
The method for analyzing a mixed acid according to the above.
ンを含んだ、鉄を成分として含有する金属材の酸洗液か
ら採取された試料について、（ａ）鉄サリチル酸錯体吸
光度法により鉄イオン濃度を測定し、（ｂ）鉄アセチル
アセトン錯体退色吸光度法により遊離弗酸濃度を測定
し、そして（ｃ）中和滴定法により全遊離酸濃度を測定
し、測定された全遊離酸濃度より上記（ｂ）で測定され
た遊離弗酸濃度を差し引くことにより遊離硝酸濃度を測
定し、 （Ｂ）測定せられた鉄イオン、遊離弗酸および遊離硝酸
の各濃度に相関する信号をコンピューターに入力し、 （Ｃ）コンピューターで、予めコンピューターに設定せ
られた鉄イオン、遊離弗酸および遊離硝酸の許容濃度範
囲と測定された酸洗液中のこれらの濃度とが照合されか
つ演算せられて、出力信号がコンピューターから発っせ
られ、 （Ｄ）コンピューターから発っせられた該出力信号に従
って、酸洗液中の鉄イオン、遊離弗酸および遊離硝酸の
各濃度が上記許容濃度範囲に維持されるように新しい弗
酸、硝酸および／または水を酸洗液に添加する、ことを
特徴とする酸洗液の管理方法。4. A sample obtained from a pickling solution of a metal material containing iron as a component, containing (A) free hydrofluoric acid, free nitric acid and iron ions, is obtained by (a) iron salicylic acid complex absorption spectrometry. The ion concentration was measured, (b) the concentration of free hydrofluoric acid was measured by the iron acetylacetone complex fading absorbance method, and (c) the total free acid concentration was measured by the neutralization titration method. The concentration of free nitric acid is measured by subtracting the concentration of free hydrofluoric acid measured in (b). (B) A signal correlating with the measured iron ion, free hydrofluoric acid and free nitric acid concentrations is input to a computer. (C) The computer compares the permissible concentration ranges of iron ions, free hydrofluoric acid and free nitric acid preset in the computer with the measured concentrations in the pickling solution and calculates them. An output signal is generated from the computer. (D) According to the output signal generated from the computer, the concentrations of iron ions, free hydrofluoric acid and free nitric acid in the pickling solution are maintained in the above-mentioned allowable concentration range. Adding fresh hydrofluoric acid, nitric acid and / or water to the pickling solution.
に１回採取する請求項４に記載の管理方法。5. The management method according to claim 4, wherein the sample is collected at least once an hour from the pickling solution.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP08691394A JP3321289B2 (en) | 1994-04-25 | 1994-04-25 | Mixed acid analysis method and pickling solution management method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP08691394A JP3321289B2 (en) | 1994-04-25 | 1994-04-25 | Mixed acid analysis method and pickling solution management method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH07294509A JPH07294509A (en) | 1995-11-10 |
| JP3321289B2 true JP3321289B2 (en) | 2002-09-03 |
Family
ID=13900093
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP08691394A Expired - Fee Related JP3321289B2 (en) | 1994-04-25 | 1994-04-25 | Mixed acid analysis method and pickling solution management method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3321289B2 (en) |
Cited By (1)
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|---|---|---|---|---|
| WO2012133869A1 (en) | 2011-03-28 | 2012-10-04 | Ｊｆｅスチール株式会社 | Method and device for producing si-containing cold rolled steel sheet |
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|---|---|---|---|---|
| IT1303814B1 (en) * | 1998-12-02 | 2001-02-23 | Henkel Kgaa | APPARATUS AND METHOD TO CONTROL PERACCIAIO PICKLING PROCESSES. |
| JP2001021548A (en) * | 1999-07-06 | 2001-01-26 | Kawasaki Steel Corp | Analytical method and device for free fluorine in solution containing hydrofluoric acid |
| KR20010064358A (en) * | 1999-12-29 | 2001-07-09 | 이구택 | A method for controlling inhibitor concentration by free concentration of hydrochloric acid in pickling tank |
| US20060270050A1 (en) * | 2005-05-24 | 2006-11-30 | Texaco Development Corporation | Method and test kit for the determination of iron content of in-use lubricants |
| KR101641736B1 (en) * | 2009-12-23 | 2016-07-21 | 주식회사 포스코 | Automatic measuring apparatus and method of concentration mixed acid |
| KR102031316B1 (en) * | 2017-12-26 | 2019-10-11 | 주식회사 포스코 | Analysis method of metal in pickling solution |
| CN113759073A (en) * | 2021-09-26 | 2021-12-07 | 山西沁新能源集团股份有限公司 | Analysis and detection method for multiple components in waste liquid or recovery liquid of mixed acid |
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-
1994
- 1994-04-25 JP JP08691394A patent/JP3321289B2/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2012133869A1 (en) | 2011-03-28 | 2012-10-04 | Ｊｆｅスチール株式会社 | Method and device for producing si-containing cold rolled steel sheet |
| US9243334B2 (en) | 2011-03-28 | 2016-01-26 | Jfe Steel Corporation | Method and apparatus for manufacturing Si-containing cold rolled steel sheets |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH07294509A (en) | 1995-11-10 |
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