JPS609965B2 - Purification method for industrial concentrated sulfuric acid - Google Patents
Purification method for industrial concentrated sulfuric acidInfo
- Publication number
- JPS609965B2 JPS609965B2 JP6051377A JP6051377A JPS609965B2 JP S609965 B2 JPS609965 B2 JP S609965B2 JP 6051377 A JP6051377 A JP 6051377A JP 6051377 A JP6051377 A JP 6051377A JP S609965 B2 JPS609965 B2 JP S609965B2
- Authority
- JP
- Japan
- Prior art keywords
- sulfuric acid
- concentrated sulfuric
- industrial
- concentration
- dope
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Description
【発明の詳細な説明】
本発明は「工業用濃硫酸の精製方法に関するものであり
、詳しくは、工業用濃硫酸中に存在する白い懸濁物を猿
週、除去することによって、長期に百つて放置しても再
び懸濁物を生じることのない濃硫酸に精製する方法であ
る。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for purifying industrial concentrated sulfuric acid. This is a method for purifying concentrated sulfuric acid that does not produce suspension even if it is left to stand.
高強力、高モジュラス芳香族ポリアミド繊維が知られ、
その一つであるポリーパラフェニレンテレフタルアミド
繊維は既に商品化されている。High strength, high modulus aromatic polyamide fibers are known.
One of them, polyparaphenylene terephthalamide fiber, has already been commercialized.
例えば、ポリーパラフェニレンテレフタルアミドの如き
、パラ配合の分子構造をつた芳香族ポリアミドは、溶剤
に対する溶解性に乏しく、実用的な繊維製造技術の開発
が遅れていた。しかし最近に至り、椿開昭４７一３９４
５８号公報等で開示された如く、ポリマーを高濃度の硫
酸や、特殊なフッ素系無機溶剤に溶解した高い濃度の敵
糸ドープを用いること等によって高強力、高ヤング率、
高い耐熱性を有する繊維が実用化された。For example, aromatic polyamides with a para compound molecular structure, such as polyparaphenylene terephthalamide, have poor solubility in solvents, and the development of practical fiber manufacturing techniques has been delayed. However, recently, Tsubaki Kaisho 47-1394
As disclosed in Publication No. 58, etc., high strength, high Young's modulus,
Fibers with high heat resistance have been put into practical use.
実際の工業的規模に於ける繊維製造に際しては、用いる
溶剤はコスト面や取り扱いの容易さから、特殊なフッ素
系溶剤よりも、濃硫酸、それも工業用濃硫酸が好ましい
。本発明者らの研究によると、例えば、ポリーパラフェ
ニレンテレフタルァミド繊維の如く、極めて高い強力、
ヤング率に特徴づけられる繊維は、繊維フィラメント中
にわずかの異物でも存在すれば、繊維に引張り応力を加
えた場合、混入した異物附近に応力の集中が起り、引張
り強力、伸度が著しく低下することが分った。In actual fiber production on an industrial scale, concentrated sulfuric acid, especially industrial concentrated sulfuric acid, is preferable to special fluorinated solvents as the solvent from the viewpoint of cost and ease of handling. According to the research of the present inventors, for example, polyparaphenylene terephthalamide fiber has extremely high strength,
Fibers characterized by Young's modulus are characterized by the presence of even a small amount of foreign matter in the fiber filament, and when tensile stress is applied to the fiber, stress concentration occurs near the mixed foreign matter, resulting in a significant decrease in tensile strength and elongation. I found out.
それ故、高強力の繊維製造に際しては、紡糸ドープ中の
異物の櫨過、又はドープ中に異物を混入させないことが
極めて重要な問題となる。Therefore, in the production of high-strength fibers, it is extremely important to prevent foreign substances from passing through the spinning dope or from mixing them into the dope.
しかし、ポリマーの溶剤として、工業用濃硫酸を用いる
場合、該濃硫酸中には、硫酸製造時、装置材料からの不
純物、異物の溶出等によって、白い懸濁物が混入してい
ることは避け得ない。However, when industrial concentrated sulfuric acid is used as a polymer solvent, it is important to avoid the presence of white suspended matter in the concentrated sulfuric acid due to impurities and foreign substances eluted from equipment materials during sulfuric acid production. I don't get it.
工業用濃硫酸をポリマー溶剤として、例えば、高強力の
ポリーパラフェニレンテレフタルアミド繊維と製造する
場合、いかにして繊維フィラメント中への該濃硫酸中に
存在する懸濁異物の混入を防ぐかが問題となる。その一
つの方法として「懸濁物の存在する工業用濃硫酸とその
ままポリマーの溶剤として使用して紡糸ドープを製造し
、ドープの状態で、該濃硫酸中に存在した懸濁物を、櫨
過等によって除去する手段であるが、ドープの櫨過に際
して濠材の目語りが激しく、猿圧の上昇の為に頻繁に猿
材の取り替えが必要な‘まかりでなく、得られた繊維の
強力も低いものにとどまる。For example, when manufacturing high-strength polyparaphenylene terephthalamide fibers using industrial concentrated sulfuric acid as a polymer solvent, the problem is how to prevent suspended foreign substances present in the concentrated sulfuric acid from being mixed into the fiber filaments. becomes. One method is to produce a spinning dope by using industrial concentrated sulfuric acid containing suspended matter as it is as a solvent for the polymer, and then pass the suspended matter present in the concentrated sulfuric acid in the dope state through filtration. However, when the dope is passed through the dope, the moat material cracks violently, and the moat material needs to be replaced frequently due to the increase in pressure. Stay low.
他の方法として、予め工業用濃硫酸のみを濠過して、該
濃硫酸中の懸濁物を除去し、得られた清澄な濃硫酸をポ
リマー溶剤として使用する手段があるが、工業用濃硫酸
をそのまま猿遇したのでは、櫨過直後は清澄な濃硫酸が
得られるが「短時間のうちに、櫨過した濃硫酸中に再び
白い懸濁物が生じることが分った。Another method is to filter only concentrated industrial sulfuric acid in advance to remove suspended matter in the concentrated sulfuric acid and use the resulting clear concentrated sulfuric acid as a polymer solvent. If the sulfuric acid was used as a monkey, clear concentrated sulfuric acid would be obtained immediately after the sulfuric acid filtration, but it was found that "in a short period of time, a white suspension was formed again in the sulfuric acid filtrated.
又この現象は、繰り返し工業用濃硫酸を猿過してもみら
れる。This phenomenon is also observed even when industrial concentrated sulfuric acid is repeatedly filtered.
さらに不都合なことには、櫨過によって得られた清澄な
工業用濃硫酸に、白い懸濁物が再び発生する前に、ポリ
マーを溶解し得られたドープを織糸した所、櫨遇しない
工業用濃硫酸を溶剤として使用したドープの場合と同じ
く、櫨圧の急激な上昇や強力低下の現象がみられた。Even more inconveniently, when the dope obtained by dissolving the polymer was woven into the clear concentrated industrial sulfuric acid obtained by filtration, before the white suspension re-occurred, the industrial grade sulfuric acid obtained by filtration was not used. Similar to the case of dope using concentrated sulfuric acid as a solvent, a rapid increase in pressure and a decrease in strength were observed.
これは、ドープ中で工業用濃硫酸中にみられたと同じ懸
濁物に相当する異物が生じた為と思われる。This is believed to be due to the formation of foreign matter in the dope that corresponds to the same suspension found in industrial concentrated sulfuric acid.
このように再び白い懸濁物の発生する現象は工業用濃硫
酸とそのまま櫨遇し、一且得られた清澄な濃硫酸に、清
澄な発煙硫酸又は／及び無水硫酸を加えて、硫酸濃度を
高めた時にも見られた。In this way, the phenomenon of white suspension being generated again is directly treated with industrial concentrated sulfuric acid, and clear fuming sulfuric acid or/and sulfuric anhydride is added to the obtained clear concentrated sulfuric acid to increase the sulfuric acid concentration. It was also seen when elevated.
これらの現象は、工業用濃硫酸をポリマーの溶剤として
用いる、例えばポリーパラフェニレンテレフタルアミド
繊維の製造に於ては好ましくない現象である。本発明者
らは、猿過後の清澄な工業用濃硫酸に再び白い懸濁物が
生じない工業用濃硫酸に精製する方法を鋭意検討した結
果、工業用濃硫酸を猿遇するに当って、予め工業用濃硫
酸中に発煙硫酸又は／及び無水硫酸を加え、硫酸濃度を
９＄重量％以上にせしめた後、漣週すれは長期間放置し
ても白い懸濁物が生じない工業用濃硫酸が得られること
が分り、本発明を達成するに至った。These phenomena are undesirable in the production of polyparaphenylene terephthalamide fibers, for example, in which industrial concentrated sulfuric acid is used as a polymer solvent. The inventors of the present invention have intensively studied methods for refining clear industrial concentrated sulfuric acid after sieving into industrial concentrated sulfuric acid that does not produce white suspension again. After adding fuming sulfuric acid or/and sulfuric anhydride to industrial concentrated sulfuric acid in advance to make the sulfuric acid concentration 9% by weight or more, we prepared an industrial concentrated sulfuric acid that does not produce white suspension even if left for a long period of time. It was found that sulfuric acid could be obtained, and the present invention was accomplished.
本発明で言う工業用濃硫酸とは、ＪＩＳＫ−１３０２に
て定義されるものである。The industrial concentrated sulfuric acid referred to in the present invention is defined in JISK-1302.
本発明において「工業用濃硫酸に加える発煙硫酸又は／
及び無水硫酸は工業用濃硫酸の硫酸濃度量に対応して硫
酸濃度が９９重量％以上になるように添加することが必
要である。In the present invention, “fuming sulfuric acid added to industrial concentrated sulfuric acid or/
It is necessary to add sulfuric anhydride so that the sulfuric acid concentration is 99% by weight or more, corresponding to the sulfuric acid concentration of industrial concentrated sulfuric acid.
発煙硫酸、無水硫酸は何れを用いてもよく、あるいは両
者を適宜に用いることができる。本発明方法によって櫨
過精製された濃硫酸が長期間放置後も白い懸濁物を生じ
ない理由は明らかではないが、発煙硫酸又は／及び無水
硫酸を加えて調整した工業用硫酸の硫酸濃度が９の重量
％未満であると、猿遇して一且清澄なものが得られても
、再び白い懸濁物が生ずる現象が見られる。Either fuming sulfuric acid or sulfuric anhydride may be used, or both may be used as appropriate. It is not clear why concentrated sulfuric acid purified by the method of the present invention does not form white suspension even after being left for a long time, but the sulfuric acid concentration of industrial sulfuric acid prepared by adding fuming sulfuric acid or/and sulfuric anhydride is If the amount is less than 9% by weight, even if a clear product is obtained, a phenomenon in which a white suspension is generated again is observed.
孫酸濃度９塁重量％以上のものに調製し、濠過すれば白
い懸濁物を生ずることがないのである。長期に亘つて白
い懸濁物の生ずることのない工業用濃硫酸の選定にあた
っては、実際使用に必要な濃度を考慮して本発明方法に
より経済的硫酸濃度をえらぶべきである。If the concentration of Sonate acid is adjusted to 9% by weight or higher and the water is filtered, no white suspension will be produced. When selecting industrial concentrated sulfuric acid that does not produce white suspension over a long period of time, an economical sulfuric acid concentration should be selected by the method of the present invention, taking into consideration the concentration required for actual use.
硫酸濃度９＄重量％以上の所定濃度に調製した硫酸は絶
対櫨過径１０一以下を有する猿材を用いて櫨過し白い懸
濁物ならびに異物を除去する。The sulfuric acid prepared to a predetermined concentration of 9% by weight or more is passed through a sieve to remove white suspended matter and foreign matter using a sieve wood having an absolute sieve diameter of 10 or less.
櫨過に際しては、用いる猿村は当然濃硫酸に耐える材質
であることが必要であるが「その具体的な例としては、
ステンレスを材質とする焼結金属「焼結金網、焼結不織
布や「サンドフィルター、珪藻士をプレコートしたフィ
ルター、ガラスフィルター、テフロンフィルター等であ
るが、本発明の実施に当っては特に限定されるものでは
ない。When filtering, the material used must of course be made of a material that can withstand concentrated sulfuric acid.
Sintered metal meshes made of stainless steel, sintered non-woven fabrics, sand filters, diatom pre-coated filters, glass filters, Teflon filters, etc. are not particularly limited in carrying out the present invention. It's not a thing.
本発明の方法で、工業用濃硫酸に加える発煙硫酸は、例
えば、ＪＩＳＫ−１３０３によって定義されるが如き工
業用濃硫酸発煙硫酸、又はＪＩＳＫ−８７４１で定義さ
れる試薬級の発煙硫酸のいずれであってもよい。In the method of the present invention, the fuming sulfuric acid added to the industrial concentrated sulfuric acid is, for example, either industrial concentrated sulfuric acid or fuming sulfuric acid as defined by JISK-1303, or reagent grade oleum as defined by JISK-8741. There may be.
本発明の方法によって得られた工業用濃硫酸は、そのま
ま使用するか必要なら希釈し、あるいは、さらに発煙硫
酸又は／及び無水硫酸を添加して濃度を高めて使用する
。The industrial concentrated sulfuric acid obtained by the method of the present invention can be used as is, diluted if necessary, or further added with fuming sulfuric acid or/and sulfuric anhydride to increase its concentration.
例えば、工業的に高強力のポリーパラフェニレンテレフ
タルアミド繊維製造の為には、ポリマー重合度、ドープ
濃度にもるが、熔解性やドープ粘度等の点から一般に９
塁重量％以上の工業用濃硫酸をポリマー溶剤として用い
ることが好ましい為、工業用濃硫酸中に、発煙硫酸又は
／及び無水硫酸を必要濃度になる様に加え、吸湿に注意
しながら濠過された濃硫酸をそのまま使用する。For example, in order to industrially produce high-strength polyparaphenylene terephthalamide fibers, it depends on the degree of polymerization and dope concentration, but in general from the viewpoint of solubility and dope viscosity, 9.
Since it is preferable to use concentrated industrial sulfuric acid with a concentration of 1% or more by weight as a polymer solvent, add fuming sulfuric acid or/and sulfuric anhydride to the industrial concentrated sulfuric acid to the required concentration, and then filter it while paying attention to moisture absorption. Use concentrated sulfuric acid as is.
本発明の方法によって得られた工業用濃硫酸は、長期間
に亘っても白い懸濁物を生じることはなく、例えば、ポ
リーパラフェニレンテレフタルアミドポリマーの溶剤と
して使用して溶剤中の懸濁異物に起因するドープ濠過圧
の急激な上昇や、強力の低下等がみられない。The industrial concentrated sulfuric acid obtained by the method of the present invention does not produce white suspensions even over a long period of time, and can be used, for example, as a solvent for polyparaphenylene terephthalamide polymers to eliminate suspended foreign matter in the solvent. There is no sudden increase in dope moat overpressure or decrease in strength caused by this.
本発明の方法によって得られた工業用硫酸の用途は、例
として高強力繊維製造の溶剤をあげたが「それに限定さ
れるものではなく、他に肥料工業、無機薬品工業「食料
品工業等の分野にも用いられる。The industrial sulfuric acid obtained by the method of the present invention can be used as an example of a solvent for producing high-strength fibers, but is not limited thereto. Also used in the field.
次に本発明の効果を実施例にて具体的に示す。Next, the effects of the present invention will be specifically shown in Examples.
実施例中で濁りの尺度として用いたＴ％は、波長４２仇
吻で測定した透過率を示す。又、濃硫酸の濃度及びドー
プ濃度は特にことわらぬ限り重量％で表わした濃度であ
る。実施例 １
白濁した濃度９８．２％の工業用濃硫酸（Ｔ％：２６％
）に、工業用発煙硫酸（Ｓ０３分として６５％含有）を
加えて９９．９％の濃硫酸を調製した。T% used as a measure of turbidity in the examples indicates transmittance measured at a wavelength of 42 nm. Further, the concentration of concentrated sulfuric acid and the concentration of dope are expressed in weight % unless otherwise specified. Example 1 Cloudy industrial concentrated sulfuric acid with a concentration of 98.2% (T%: 26%
) and industrial fuming sulfuric acid (containing 65% as SO3) to prepare 99.9% concentrated sulfuric acid.
この９９．９％濃硫酸を吸湿に注意しながら、細孔の大
きさが５〜１０仏であるグレードＧ−４（ＪＩＳ規格Ｒ
−３５０３一１９５８）のガラスフィルターで猿遇した
。得られた濃硫酸は清澄で、Ｔ％は９９．７％を有して
いた。この櫨週濃硫酸を密閉容器中で１０日間保存し再
びＴ％を測定した所９９．３％を有しており、肉眼でみ
ても全く濁りはなかった。比較の為に「上記の９８．２
％の工業用濃硫酸を、そのままグレードＧ−４のガラス
フィルターで櫨過して得られた濃硫酸は、漣過直後は９
９．１％のＴ％を有していたが、１時間後には７８％の
Ｔ％となり肉眼でみてもかなり白濁していた。Using this 99.9% concentrated sulfuric acid, grade G-4 (JIS standard R
-3503-1958) glass filter. The concentrated sulfuric acid obtained was clear and had a T% of 99.7%. This concentrated sulfuric acid was stored in an airtight container for 10 days and the T% was measured again, and it was found to be 99.3%, and there was no turbidity at all when viewed with the naked eye. For comparison, the above 98.2
% of industrial concentrated sulfuric acid was directly filtered through a grade G-4 glass filter.
It had a T% of 9.1%, but after one hour, the T% was 78%, which was quite cloudy even when viewed with the naked eye.
実施例 ２
９８．０％の白濁した工業用濃硫酸（Ｔ％：３７％）に
、清澄な試薬発煙硫酸（Ｓ０３分として３０％含有）を
添加して、濃度９９．１％の濃硫酸を調整した。Example 2 Clear reagent fuming sulfuric acid (containing 30% as S03) was added to 98.0% cloudy industrial concentrated sulfuric acid (T%: 37%) to produce concentrated sulfuric acid with a concentration of 99.1%. It was adjusted.
この調整濃硫酸のＴ％は３１％であった。The T% of this adjusted concentrated sulfuric acid was 31%.
これをフルィドタぐィナミックス社製の焼結ステンレス
不織布フィルター、ダィナロィ（フルィドタ′ィナミッ
クス社登録商標）のグレード×−４（カタログ値によれ
ば絶対櫨過径５仏）を用いて櫨過した。得られた濃硫酸
は清澄で、３０日間放置も何ら異常は認められなかった
。さらに３０日放置後の清澄な濃硫酸に蒸留水を加えて
、９８．０％の濃度に調製した濃硫酸は、１０日放置後
も清澄であった。This was filtered using a sintered stainless steel non-woven fabric filter manufactured by FluidoDynamics Co., Ltd., Dynaroy (registered trademark of Fluidodynamics Co., Ltd.) grade x-4 (according to the catalog value, absolute diameter of 5 French). The concentrated sulfuric acid obtained was clear and no abnormality was observed even after being left for 30 days. Further, the concentrated sulfuric acid prepared by adding distilled water to the clear concentrated sulfuric acid after being left for 30 days to have a concentration of 98.0% remained clear even after being left for 10 days.
比較として、９８．０％工業用濃硫酸を、ダィナロィＸ
−４フィルターを用いて櫨過した濃硫酸に、試薬発煙硫
酸を加えて、９９．１％濃度にした所、直ちに白濁した
。For comparison, 98.0% industrial concentrated sulfuric acid was
When the reagent fuming sulfuric acid was added to the concentrated sulfuric acid filtered through a -4 filter to give a concentration of 99.1%, it immediately became cloudy.
この白濁した９９．１％濃硫酸を、再びダイナロイＸ−
４フィルターにて炉遇したところ、得られた濃硫酸は清
澄であり、又、放置によっても濁りを発生させないこと
が認められた。This cloudy 99.1% concentrated sulfuric acid was poured into Dynalloy
When heated through a filter, the obtained concentrated sulfuric acid was found to be clear and did not become cloudy even when left standing.
これは、本発明の方法の一つの応用例とも言えるもので
あり、本発明の効果の追証に他ならない。実施例 ３
濃度９８。This can be said to be one application example of the method of the present invention, and is nothing but additional proof of the effects of the present invention. Example 3 Concentration 98.
１％の白濁した工業用濃硫酸に発煙硫酸を加えて、１０
０．１％の濃硫酸を調製した。Add fuming sulfuric acid to 1% cloudy industrial concentrated sulfuric acid,
0.1% concentrated sulfuric acid was prepared.
この濃硫酸を、実施例２と同じフィルターで猿過し、得
られた濃硫酸に、蒸留水を加えて、再び９８．１％の濃
硫酸とした。次いで、再び９８．１％に調製した濃硫酸
に、固有粘度５．７のポリーパラフェニレンテレフタル
アミドを熔解し、ポリマー濃度２０％のドープを得た。
このドープを渡過面積３．１４流の焼結ステンレス不織
布フィルター、ダィナロィ、グレード×−５（絶対猿過
径ｌｏｗ）を用いて漁遇し繊維を製造した。ドープの漣
過差圧は、櫨過開始時は、２０ｋｇ／めであったが、１
時間後は２８ｋ９′めであった。又、得られた繊維は、
強度２３．１タノｄ、伸度３．２％、ヤング率５２７夕
／ｄを有していた。比較の為に、濃度９８．１％の白濁
した工業用濃硫酸を、そのまま、実施例２と同じフィル
ターで櫨過し、直ちに、固有粘度５．７のポリーパラフ
ェニレンテレフタルアミドを溶解して、ポリマ−濃度２
０％のドープを得た。このドープを実施例３と同様の方
法で紡糸したところ、ドープの猿過差圧は、櫨過開始時
１９ｋｇ′のであったが、１時間後は４７ｋ９／地と急
上昇した。又、得られた繊維の物性は「強度１９．７タ
ゾｄ、伸度３．０％、ヤング率５０７夕／ｄであった。
実施例 ４
濃度９７．７％の白濁した工業用濃硫酸（Ｔ％：４９％
）に、無水硫酸を加えて９９．５％の濃硫酸を調製した
。This concentrated sulfuric acid was filtered through the same filter as in Example 2, and distilled water was added to the obtained concentrated sulfuric acid to make 98.1% concentrated sulfuric acid again. Next, polyparaphenylene terephthalamide having an intrinsic viscosity of 5.7 was dissolved in concentrated sulfuric acid again adjusted to 98.1% to obtain a dope with a polymer concentration of 20%.
This dope was filtered using a sintered stainless steel nonwoven fabric filter with a flow area of 3.14, Dynalloy, grade x-5 (low absolute diameter) to produce fibers. The differential pressure of the dope was 20 kg/m at the beginning of the filtration, but 1
Hours later, it was 28k9'. In addition, the obtained fibers are
It had a strength of 23.1 mm/d, an elongation of 3.2%, and a Young's modulus of 527 mm/d. For comparison, cloudy industrial concentrated sulfuric acid with a concentration of 98.1% was directly filtered through the same filter as in Example 2, and immediately polyparaphenylene terephthalamide with an intrinsic viscosity of 5.7 was dissolved. Polymer concentration 2
A doping of 0% was obtained. When this dope was spun in the same manner as in Example 3, the differential pressure of the dope was 19 kg' at the start of spinning, but rapidly increased to 47 kg' after 1 hour. The physical properties of the obtained fiber were as follows: strength: 19.7 tazod, elongation: 3.0%, and Young's modulus: 507/d.
Example 4 Cloudy industrial concentrated sulfuric acid with a concentration of 97.7% (T%: 49%
) to prepare 99.5% concentrated sulfuric acid by adding sulfuric anhydride.
この９９．５％濃硫酸をタトィナロィ、グレート×−３
（絶対櫨過径３〆）にて漣過した。得られた猿液はＴ％
９８．８％を有しており、３０日間放置後も何ら異常は
認められなかった。実施例 ５
実施例４の９７．７％工業用濃硫酸に、無水硫酸を加え
て９８．６％濃硫酸とした。Add this 99.5% concentrated sulfuric acid to Tatina Roi, Great x-3
(Absolute diameter 3〆) The obtained monkey fluid was T%
98.8%, and no abnormality was observed even after being left for 30 days. Example 5 Sulfuric anhydride was added to the 97.7% industrial concentrated sulfuric acid of Example 4 to obtain 98.6% concentrated sulfuric acid.
Claims (1)
えて、硫酸濃度を９９重量％以上にせしめた後、該濃硫
酸を濾過することを特徴とする工業用濃硫酸の精製方法
。1. A method for purifying industrial concentrated sulfuric acid, which comprises adding fuming sulfuric acid or/and sulfuric anhydride to industrial concentrated sulfuric acid to make the sulfuric acid concentration 99% by weight or more, and then filtering the concentrated sulfuric acid.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6051377A JPS609965B2 (en) | 1977-05-26 | 1977-05-26 | Purification method for industrial concentrated sulfuric acid |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6051377A JPS609965B2 (en) | 1977-05-26 | 1977-05-26 | Purification method for industrial concentrated sulfuric acid |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS53146295A JPS53146295A (en) | 1978-12-20 |
| JPS609965B2 true JPS609965B2 (en) | 1985-03-14 |
Family
ID=13144460
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6051377A Expired JPS609965B2 (en) | 1977-05-26 | 1977-05-26 | Purification method for industrial concentrated sulfuric acid |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS609965B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6339259Y2 (en) * | 1985-12-27 | 1988-10-14 |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101905873B (en) * | 2010-07-29 | 2011-12-21 | 杨锐雄 | Energy-saving high efficiency step temperature difference distillation production method of high purity sulphuric acid |
-
1977
- 1977-05-26 JP JP6051377A patent/JPS609965B2/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6339259Y2 (en) * | 1985-12-27 | 1988-10-14 |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS53146295A (en) | 1978-12-20 |
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