JPH06219711A - Method for denitrating and decoloring concentrated sulfuric acid - Google Patents
Method for denitrating and decoloring concentrated sulfuric acidInfo
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- JPH06219711A JPH06219711A JP2764093A JP2764093A JPH06219711A JP H06219711 A JPH06219711 A JP H06219711A JP 2764093 A JP2764093 A JP 2764093A JP 2764093 A JP2764093 A JP 2764093A JP H06219711 A JPH06219711 A JP H06219711A
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- sulfuric acid
- hydrogen peroxide
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Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は濃硫酸の脱硝・脱色方法
に関する。更に詳しくは、ＮＯX および有機化合物を含
有した着色硫酸から着色成分を除去し、高品位の硫酸を
製造する方法に関する。FIELD OF THE INVENTION The present invention relates to a method for denitration and decolorization of concentrated sulfuric acid. More specifically, the present invention relates to a method for producing high-quality sulfuric acid by removing a coloring component from colored sulfuric acid containing NO X and an organic compound.
【０００２】[0002]
【従来の技術】銅、亜鉛、鉛等、非鉄金属精錬の焙焼工
程で発生する亜硫酸ガスを原料として製造された硫酸中
には、窒素酸化物（以下、ＮＯX と略す）および種々の
有機化合物等が不純物として含まれている。硫酸中に溶
存するＮＯX はニトロシル硫酸、亜硝酸、硝酸等に起因
する。ＮＯX と有機化合物が製品硫酸の着色原因等、製
品の品位低下の原因となるため従来より種々の脱硝・脱
色方法が検討されてきた。着色成分の除去は酸化脱色法
によるのが一般的であり、酸化剤として過酸化水素水、
オゾン、過マンガン酸カリウム等が用いられる。一方、
上記ＮＯX を予め尿素で脱硝処理して、その後、過酸化
水素で脱色処理する方法が公知である（特開昭６２−１
０５９０４号公報）。BACKGROUND ART Copper, zinc, during such as lead, sulfuric acid and sulfurous acid gas generated in the roasting step of the non-ferrous metal refining prepared as raw materials, nitrogen oxides (hereinafter, abbreviated as NO X) and various organic Compounds and the like are contained as impurities. NO X dissolved in sulfuric acid originates from nitrosyl sulfuric acid, nitrous acid, nitric acid and the like. Since NO x and organic compounds cause deterioration of product quality such as coloring of product sulfuric acid, various denitration / decolorization methods have been conventionally studied. The removal of the coloring component is generally performed by an oxidative decolorization method, and hydrogen peroxide solution as an oxidant,
Ozone, potassium permanganate, etc. are used. on the other hand,
A method is known in which the above NO x is denitrified with urea in advance and then decolorized with hydrogen peroxide (JP-A-62-1).
No. 05904).
【０００３】[0003]
【発明が解決しようとする課題】酸化剤を用いる酸化脱
色法に関しては過酸化水素水を用いて行う方法が、工業
的には簡易かつ安価である。しかしながら、過酸化水素
水を用いて脱色を行う場合に、着色度は同じであるにも
かかわらず、時として同じ量の過酸化水素水を用いても
脱色が進まなくなる場合がある。この時には、硫酸の着
色が消え難いばかりか、脱色のために多量の過酸化水素
水を加えることになり、硫酸濃度の低下の原因となる。
硫酸の濃度が薄くなると過酸化水素水による酸化脱色が
さらに起こり難くなり、特に硫酸濃度が９８％以下とな
ると脱色速度は著しく低下する。その結果、得られる硫
酸の濃度が薄まり、製品の品質上にも問題を残すことに
なる。Regarding the oxidative decolorization method using an oxidizing agent, a method using hydrogen peroxide solution is industrially simple and inexpensive. However, when decolorization is performed using hydrogen peroxide water, even if the same degree of coloring is used, decolorization may sometimes not progress even though the same degree of coloring is used. At this time, not only the coloring of sulfuric acid is difficult to disappear, but also a large amount of hydrogen peroxide solution is added for decolorization, which causes a decrease in sulfuric acid concentration.
When the concentration of sulfuric acid becomes low, oxidative decolorization by hydrogen peroxide solution becomes more difficult to occur, and especially when the concentration of sulfuric acid becomes 98% or less, the decolorization rate remarkably decreases. As a result, the concentration of sulfuric acid obtained is diminished, leaving a problem in terms of product quality.
【０００４】また、脱硝処理の後に脱色処理する方法と
しては、前記のように例えば特開昭６２−１０５９０４
号公報に開示の方法が挙げられる。この方法によると、
第１ステップとして硫酸に尿素を加えて溶存するＮＯX
成分を除去し、ついで第２ステップとして過酸化水素水
で着色成分を除去する２段階処理にて脱硝・脱色を行っ
ている。しかしながら、第１ステップで硫酸に対して約
１．５ｗｔ％量と多量の尿素を加え、しかも１１０〜１
２０℃の狭い温度範囲にコントロールしながら３０分間
加熱する必要がある。温度がこの範囲より外れると第２
ステップの脱色がうまく進まない。従って、このように
多量の尿素を利用することは経済的に不利というだけで
はなく、硫酸の二次汚染も懸念され、さらに脱硝および
脱色処理が必要となり工程的に煩雑となる。As a method of decolorizing treatment after denitration treatment, as described above, for example, JP-A-62-105904.
The method disclosed in the publication is mentioned. According to this method,
As the first step, NO X dissolved by adding urea to sulfuric acid
Denitration and decolorization are carried out by a two-step treatment of removing the components, and then, as a second step, removing the coloring components with hydrogen peroxide solution. However, in the first step, a large amount of urea, about 1.5 wt% with respect to sulfuric acid, was added, and 110-1
It is necessary to heat for 30 minutes while controlling in a narrow temperature range of 20 ° C. If the temperature is out of this range, the second
Decolorization of steps does not proceed well. Therefore, using such a large amount of urea is not only economically disadvantageous, but also secondary contamination of sulfuric acid is feared, and denitration and decolorization treatment are required, which complicates the process.
【０００５】[0005]
【課題を解決するための手段】そこで本発明者らは、硫
酸（本発明にいう硫酸は濃度９５．０〜９９．９％の濃
硫酸をさす。）中に溶存する着色成分をできるだけ少量
の過酸化水素水を用いて、しかもその使用量の変動を少
なくして確実に着色成分を除去する方法を確立すべく鋭
意検討した。その結果、以下の知見が得られた。 （１）ＮＯX が硫酸中に存在すると過酸化水素水が水と
酸素に分解する。 （２）硫酸中ではＮＯX の一部がニトロシル硫酸（ＮＯ
ＨＳＯ4 ）となって安定化するため、脱硝処理を行った
後もニトロシル硫酸の形で硫酸中に微量残存する。 （３）残存したニトロシル硫酸は時間の経過とともに水
と反応してＮＯX を再生する。 （４）ニトロシル硫酸は過酸化水素水により分解され
る。Therefore, the present inventors have found that as little coloring component as possible is dissolved in sulfuric acid (sulfuric acid in the present invention means concentrated sulfuric acid having a concentration of 95.0 to 99.9%). The inventors have earnestly studied to establish a method for surely removing the coloring component by using a hydrogen peroxide solution and reducing the variation in the amount used. As a result, the following findings were obtained. (1) When NO X is present in sulfuric acid, hydrogen peroxide solution is decomposed into water and oxygen. (2) In sulfuric acid, part of NO X is nitrosyl sulfuric acid (NO
Since it becomes HSO 4 ) and is stabilized, a small amount remains in sulfuric acid in the form of nitrosyl sulfuric acid even after the denitration treatment. (3) The remaining nitrosyl sulfuric acid reacts with water over time to regenerate NO x . (4) Nitrosyl sulfuric acid is decomposed by hydrogen peroxide solution.
【０００６】上記知見を基にして、さらに検討を進めた
結果、脱硝処理に還元剤としてスルファミン酸（Ｈ2 Ｎ
ＳＯ3 Ｈ）を用い、酸化剤として過酸化水素水を用いる
と、脱硝反応と脱色反応を効率よく行うことが可能であ
ることを見出し本発明に到達した。即ち、本発明の要旨
は、（１）ＮＯX を含有する着色硫酸にスルファミン酸
と過酸化水素水を同時に添加することを特徴とする濃硫
酸の脱硝・脱色方法、及び（２）ＮＯX を含有する着色
硫酸にスルファミン酸を添加し、ついで過酸化水素水を
添加することを特徴とする濃硫酸の脱硝・脱色方法に関
する。As a result of further studies based on the above findings, sulfamic acid (H 2 N) was used as a reducing agent for denitration treatment.
The inventors have found that it is possible to efficiently carry out the denitration reaction and the decolorization reaction by using SO 3 H) and hydrogen peroxide solution as the oxidizing agent, and arrived at the present invention. That is, the gist of the present invention is (1) a method for denitration and decolorization of concentrated sulfuric acid, which is characterized by simultaneously adding sulfamic acid and hydrogen peroxide solution to colored sulfuric acid containing NO X , and (2) NO X. The present invention relates to a method for denitration and decolorization of concentrated sulfuric acid, which comprises adding sulfamic acid to the contained colored sulfuric acid and then adding hydrogen peroxide solution.
【０００７】本発明には、スルファミン酸と過酸化水素
水を同時に添加する態様と、スルファミン酸を添加し、
ついで過酸化水素水を添加する態様とが挙げられる。ス
ルファミン酸と過酸化水素の同時添加が可能になった理
由として、以下の反応速度的な関係があるものと推察さ
れる。スルファミン酸によるＮＯX の還元反応≧過酸化
水素によるニトロシル硫酸の分解反応＞＞ＮＯX による
過酸化水素水の分解反応≧過酸化水素水による有機化合
物の酸化分解反応＞＞スルファミン酸による過酸化水素
水の還元反応In the present invention, a mode in which sulfamic acid and hydrogen peroxide solution are added at the same time, and sulfamic acid is added,
Then, an embodiment in which hydrogen peroxide water is added can be mentioned. The reason why the simultaneous addition of sulfamic acid and hydrogen peroxide is possible is presumed to be due to the following reaction rate relationship. Reduction of NO x by sulfamic acid ≧ Decomposition reaction of nitrosylsulfuric acid by hydrogen peroxide >> Decomposition reaction of hydrogen peroxide water by NO x ≧ Oxidative decomposition reaction of organic compounds by hydrogen peroxide water >> Hydrogen peroxide by sulfamic acid Reduction reaction of water
【０００８】スルファミン酸と過酸化水素水を同時に添
加する態様において、用いるスルファミン酸の使用量は
硫酸中に含まれているＮＯX の種類およびその量によっ
て左右されるが、一般的にいって存在が想定されるＮＯ
X のモル数に対して０．２〜１０倍モル、好ましくは１
〜３倍モルを用いる。０．２倍モルより少ないとＮＯ X
の還元が不十分となり、１０倍モルを越えるとそれに伴
う効果がなく、却って過剰のスルファミン酸による二次
汚染の恐れがある。用いる過酸化水素水としては濃度は
特に限定されないが、製品の濃度を考慮すると濃度が高
い方が望ましい。一般的には工業的に供給されている３
５％過酸化水素水が好適に用いられる。過酸化水素水を
加える量は、着色度および有機化合物の含有量による
が、一般的には３５％濃度換算で過酸化水素水を１トン
の硫酸当たり０．２〜１０リットル用いればよい。Sulfamic acid and hydrogen peroxide solution are added at the same time.
In the addition mode, the amount of sulfamic acid used is
NO contained in sulfuric acidXDepending on the type and amount
However, it is generally assumed to exist NO
X0.2 to 10 times, preferably 1
~ 3 times moles are used. NO if less than 0.2 times mole X
Reduction is insufficient, and if the amount exceeds 10 times the molar amount,
Secondary to excess sulfamic acid
There is a risk of contamination. The concentration of hydrogen peroxide used is
Although not particularly limited, the concentration is high considering the concentration of the product.
Is better. Generally supplied industrially 3
A 5% hydrogen peroxide solution is preferably used. Hydrogen peroxide
The amount added depends on the degree of coloring and the content of organic compounds.
However, in general, 1 ton of hydrogen peroxide solution is converted to 35% concentration.
0.2 to 10 liters may be used for each sulfuric acid.
【０００９】スルファミン酸と過酸化水素水を加えた後
の反応温度は６０〜１５０℃、好ましくは６０〜１１０
℃、反応時間は１〜６０分が好ましい。反応温度が６０
℃より低いと反応時間が長くかかり実用的ではなく、反
応温度が１５０℃より高くても特にメリットはない。ま
た、反応時間が１分より短いと反応が完結しない場合が
多く、反応時間が６０分より長いと反応が完結している
にも拘らず単に加熱しているのみとなる。この処理の結
果、ＮＯX 成分をほとんど完全に除去でき、その量を検
出限界の０．１ｐｐｍ以下に下げることができる。また
着色度も透過率で９０％以上とすることができる。The reaction temperature after the addition of sulfamic acid and aqueous hydrogen peroxide is 60 to 150 ° C., preferably 60 to 110.
The temperature and reaction time are preferably 1 to 60 minutes. Reaction temperature is 60
If it is lower than 0 ° C, the reaction time is long and it is not practical. Even if the reaction temperature is higher than 150 ° C, there is no particular advantage. Further, if the reaction time is shorter than 1 minute, the reaction is often not completed, and if the reaction time is longer than 60 minutes, the heating is simply performed although the reaction is completed. As a result of this treatment, the NO x component can be almost completely removed, and the amount thereof can be lowered to the detection limit of 0.1 ppm or less. Also, the degree of coloring can be 90% or more in terms of transmittance.
【００１０】また、特開昭６２−１０５９０４号公報の
方法と同様に第１ステップでスルファミン酸を加えて脱
硝を行い、第２ステップで過酸化水素水を加えて脱色を
行っても、両者を同時に加えた場合とほぼ同じ結果とな
る。Further, even if sulfamic acid is added in the first step for denitration, and hydrogen peroxide solution is added for decolorization in the second step as in the method disclosed in Japanese Patent Laid-Open No. 62-105904, both are removed. The result is almost the same as when added at the same time.
【００１１】この態様では、スルファミン酸を加えた
後、反応温度６０〜１５０℃、好ましくは６０〜１１０
℃、反応時間１〜６０分で還元反応を行う。反応温度が
６０℃より低いと反応時間が長くかかり実用的ではな
く、反応温度が１５０℃より高くても特にメリットはな
い。また、反応時間が１分より短いと反応が完結しない
場合が多く、反応時間が６０分より長いと反応が完結し
ているにも拘らず単に加熱しているのみとなる。用いる
スルファミン酸の量は前記のスルファミン酸と過酸化水
素水を同時に添加する態様と同様であり、硫酸中のＮＯ
X 量の０．２〜１０倍モル、好ましくは１〜３倍モルが
使用される。In this embodiment, after the sulfamic acid is added, the reaction temperature is 60 to 150 ° C., preferably 60 to 110.
The reduction reaction is carried out at a temperature of 1 to 60 minutes. If the reaction temperature is lower than 60 ° C, the reaction time is long and it is not practical, and if the reaction temperature is higher than 150 ° C, there is no particular advantage. Further, if the reaction time is shorter than 1 minute, the reaction is often not completed, and if the reaction time is longer than 60 minutes, the heating is simply performed although the reaction is completed. The amount of sulfamic acid used is the same as in the above-described embodiment in which sulfamic acid and hydrogen peroxide solution are added at the same time.
The amount used is 0.2 to 10 times mol, preferably 1 to 3 times mol.
【００１２】第２ステップとして過酸化水素水による脱
色を行う。用いる過酸化水素水としては濃度は特に限定
されないが、製品の濃度を考慮すると濃度が高い方が望
ましい。一般的には３５％過酸化水素水が好適に用いら
れる。過酸化水素水を加える量は着色度および有機化合
物の含有量によるが、前記のスルファミン酸と過酸化水
素水を同時に添加する態様と同様であり、一般的には３
５％濃度換算で過酸化水素水を１トンの硫酸当たり０．
２〜１０リットル用いればよい。脱色反応を完結させる
ためには過酸化水素水を加えた後、一般的には６０〜１
５０℃で１０〜６０分間加熱すればよい。このようにし
て、第１ステップ、第２ステップの処理を経た硫酸は無
色透明であり、ＮＯX は０．１ｐｐｍ以下、透過率は９
０％以上となる。As a second step, decolorization with hydrogen peroxide solution is performed. The concentration of the hydrogen peroxide solution to be used is not particularly limited, but it is desirable that the concentration be high considering the concentration of the product. Generally, 35% hydrogen peroxide solution is preferably used. The amount of the hydrogen peroxide solution added depends on the degree of coloring and the content of the organic compound, but is similar to the above-described mode of simultaneously adding sulfamic acid and the hydrogen peroxide solution, and generally 3
The hydrogen peroxide solution was converted to 0.5% per ton of sulfuric acid at a concentration of 5%.
It is sufficient to use 2 to 10 liters. In order to complete the decolorization reaction, generally 60 to 1 is added after adding hydrogen peroxide solution.
It may be heated at 50 ° C. for 10 to 60 minutes. In this way, the sulfuric acid that has undergone the treatments of the first step and the second step is colorless and transparent, NO x is 0.1 ppm or less, and the transmittance is 9
It becomes 0% or more.
【００１３】以上述べたように、還元剤としてスルファ
ミン酸を用いるとＮＯX の還元と過酸化水素水による着
色成分の酸化を同時に行うことが可能となるなど、効率
の良い処理が可能となった。この時スルファミン酸の使
用条件は、従来技術に示されている尿素を用いる場合に
比べて広い温度範囲で使用可能となる。またその使用量
も特開昭６２−１０５９０４号公報に記載の実施例と比
較すると約１／１００の還元剤の使用量となり、工業的
に有利である。As described above, when sulfamic acid is used as a reducing agent, it is possible to reduce NO x and oxidize a coloring component with hydrogen peroxide solution at the same time, which enables efficient treatment. . At this time, the sulfamic acid can be used in a wider temperature range as compared with the case of using urea shown in the prior art. The amount of the reducing agent used is about 1/100 of that of the examples described in JP-A-62-105904, which is industrially advantageous.
【００１４】[0014]
【実施例】以下、実施例および比較例により本発明をさ
らに詳しく説明するが、本発明はこれらの実施例等によ
りなんら限定されるものではない。 実施例１ 亜鉛精錬の焙焼ガスを用いて接触法で合成した９８．５
％濃度の着色硫酸の脱硝・脱色を行った。用いた硫酸中
にはＮＯX およびニトロシル硫酸が合計で２９ｐｐｍ
（硝酸換算値）含まれていた。着色度は分光光度計（Ｈ
ＩＴＡＣＨＩ Ｕ−３２１０型）を用いて測定した結
果、４００ｎｍにおける透過率で２０％であった。この
硫酸１リットルに１００℃でスルファミン酸０．１ｇと
３５％過酸化水素水２ｍｌを同時に添加して３０分間加
熱した。その結果、透過率は９５％、ＮＯX は０．１ｐ
ｐｍ以下（硝酸換算値）となった。EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. Example 1 98.5 synthesized by a contact method using a roasting gas for zinc refining
Denitration and decolorization of the coloring sulfuric acid having a concentration of% were performed. The total amount of NO x and nitrosyl sulfuric acid in the sulfuric acid used was 29 ppm.
(Nitric acid conversion value) was included. Coloring degree is spectrophotometer (H
As a result of measurement using ITACHI U-3210 type), the transmittance at 400 nm was 20%. To 100 g of this sulfuric acid, 0.1 g of sulfamic acid and 2 ml of 35% hydrogen peroxide solution were added at the same time and heated for 30 minutes. As a result, the transmittance of 95%, NO X is 0.1p
It became pm or less (nitric acid conversion value).
【００１５】実施例２ 実施例１と同じ着色硫酸を１リットル用いた。１００℃
でスルファミン酸０．５ｇと３５％過酸化水素水１０ｍ
ｌを同時に添加して３０分間加熱した。その結果、透過
率は９７％、ＮＯX は０．１ｐｐｍ以下（硝酸換算値）
となった。Example 2 1 liter of the same colored sulfuric acid as in Example 1 was used. 100 ° C
With sulfamic acid 0.5g and 35% hydrogen peroxide water 10m
1 was added simultaneously and heated for 30 minutes. As a result, the transmittance is 97%, NO X is 0.1 ppm or less (nitric acid conversion value)
Became.
【００１６】実施例３ 実施例１と同じ着色硫酸を１リットル用いた。スルファ
ミン酸０．１ｇを加えて９０℃で１０分間加熱した後、
３５％過酸化水素水２ｍｌを加えて同温度で３０分間加
熱した。その結果、透過率は９５％、ＮＯX は０．１ｐ
ｐｍ以下（硝酸換算値）となった。Example 3 1 liter of the same colored sulfuric acid as in Example 1 was used. After adding 0.1 g of sulfamic acid and heating at 90 ° C. for 10 minutes,
2 ml of 35% hydrogen peroxide solution was added and the mixture was heated at the same temperature for 30 minutes. As a result, the transmittance of 95%, NO X is 0.1p
It became pm or less (nitric acid conversion value).
【００１７】比較例１ 実施例１と同じ着色硫酸を１リットル用いた。１００℃
で過酸化水素水７ｍｌを添加して３０分間加熱したが着
色は消えなかった。そこで、さらに７ｍｌの３５％過酸
化水素水を加えて同温度で３０分間加熱すると透過率は
５５％となった。ＮＯX の量は２１ｐｐｍ（硝酸換算
値）であった。Comparative Example 1 1 liter of the same colored sulfuric acid as in Example 1 was used. 100 ° C
Then, 7 ml of hydrogen peroxide water was added and heated for 30 minutes, but the coloring did not disappear. Then, when 7 ml of 35% hydrogen peroxide solution was further added and heated at the same temperature for 30 minutes, the transmittance became 55%. The amount of NO x was 21 ppm (nitric acid conversion value).
【００１８】比較例２ 実施例１と同じ着色硫酸を１リットル用いた。スルファ
ミン酸０．１ｇを加えて１００℃で３０分間加熱した。
その結果、透過率は２０％、ＮＯX は８ｐｐｍ（硝酸換
算値）となった。Comparative Example 2 1 liter of the same colored sulfuric acid as in Example 1 was used. 0.1 g of sulfamic acid was added and heated at 100 ° C. for 30 minutes.
As a result, the transmittance was 20% and NO x was 8 ppm (nitric acid conversion value).
【００１９】比較例３ 実施例１と同じ着色硫酸を１リットル用いた。尿素１ｇ
と３５％過酸化水素水７ｍｌを加えて１００℃で３０分
間加熱した。その結果、透過率は５０％、ＮＯX は８ｐ
ｐｍ（硝酸換算値）となった。Comparative Example 3 1 liter of the same colored sulfuric acid as in Example 1 was used. Urea 1g
And 7 ml of 35% hydrogen peroxide water were added and heated at 100 ° C. for 30 minutes. As a result, the transmittance 50%, NO X is 8p
It became pm (nitric acid conversion value).
【００２０】[0020]
【発明の効果】本発明の方法によると、スルファミン酸
と過酸化水素水によるＮＯX の還元、着色成分の酸化に
よる脱色を同時に行うことができる等、工程の簡略化が
可能となった。また、過酸化水素水による酸化脱色のみ
の場合に比べて、その使用量を大幅に減らすことができ
た。According to the method of the present invention, the steps can be simplified, such as the reduction of NO x by sulfamic acid and aqueous hydrogen peroxide, and the decolorization by the oxidation of the coloring component. In addition, compared with the case where only oxidative decolorization with hydrogen peroxide solution was used, the amount used could be greatly reduced.
Claims (4)
ン酸と過酸化水素水を同時に添加することを特徴とする
濃硫酸の脱硝・脱色方法。1. A method for denitration and decolorization of concentrated sulfuric acid, which comprises simultaneously adding sulfamic acid and aqueous hydrogen peroxide to colored sulfuric acid containing NO X.
ン酸を添加し、ついで過酸化水素水を添加することを特
徴とする濃硫酸の脱硝・脱色方法。2. A method for denitration and decolorization of concentrated sulfuric acid, which comprises adding sulfamic acid to colored sulfuric acid containing NO X , and then adding hydrogen peroxide solution.
ＮＯX 量の０．２〜１０倍モルである請求項１又は２記
載の方法。3. The method according to claim 1, wherein the amount of sulfamic acid used is 0.2 to 10 times the molar amount of NO X in the colored sulfuric acid.
で着色硫酸１トン当たり０．２〜１０リットルである請
求項１又は２記載の方法。4. The method according to claim 1, wherein the amount of hydrogen peroxide solution used is 0.2 to 10 liters per ton of colored sulfuric acid in terms of 35% concentration.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2764093A JPH0798647B2 (en) | 1993-01-23 | 1993-01-23 | Denitration and decolorization method of concentrated sulfuric acid |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2764093A JPH0798647B2 (en) | 1993-01-23 | 1993-01-23 | Denitration and decolorization method of concentrated sulfuric acid |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH06219711A true JPH06219711A (en) | 1994-08-09 |
| JPH0798647B2 JPH0798647B2 (en) | 1995-10-25 |
Family
ID=12226543
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2764093A Expired - Lifetime JPH0798647B2 (en) | 1993-01-23 | 1993-01-23 | Denitration and decolorization method of concentrated sulfuric acid |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0798647B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5955050A (en) * | 1994-10-25 | 1999-09-21 | Marsulex Inc. | Nox destruction in sulphuric acid |
| CN105967151A (en) * | 2015-03-10 | 2016-09-28 | 纳幕尔杜邦公司 | Process for producing sulfuric acid with low levels of niter |
-
1993
- 1993-01-23 JP JP2764093A patent/JPH0798647B2/en not_active Expired - Lifetime
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5955050A (en) * | 1994-10-25 | 1999-09-21 | Marsulex Inc. | Nox destruction in sulphuric acid |
| CN105967151A (en) * | 2015-03-10 | 2016-09-28 | 纳幕尔杜邦公司 | Process for producing sulfuric acid with low levels of niter |
| US9499405B2 (en) | 2015-03-10 | 2016-11-22 | Ei Du Pont De Nemours And Company | Process for producing sulfuric acid with low levels of niter |
| CN105967151B (en) * | 2015-03-10 | 2021-04-09 | 梅克斯公司 | Process for producing sulfuric acid with low content of niter |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0798647B2 (en) | 1995-10-25 |
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