JPS5891004A - Production of dithionite - Google Patents
Production of dithioniteInfo
- Publication number
- JPS5891004A JPS5891004A JP18971081A JP18971081A JPS5891004A JP S5891004 A JPS5891004 A JP S5891004A JP 18971081 A JP18971081 A JP 18971081A JP 18971081 A JP18971081 A JP 18971081A JP S5891004 A JPS5891004 A JP S5891004A
- Authority
- JP
- Japan
- Prior art keywords
- dithionite
- crystals
- liquid
- compds
- parts
- 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.)
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- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Epoxy Compounds (AREA)
Abstract
Description
【発明の詳細な説明】 本発明は亜ニチオン酸塩の製造方法に関する。[Detailed description of the invention] The present invention relates to a method for producing dithionite.
水−有機溶媒中においてギ酸化合物、アルカリ化合物お
よび無水亜硫酸から無水亜ニチオン酸塩を製造する方法
では、反応進行中に亜ニチオン酸塩が反応液中に析出す
るので、反応終了とともにp過工程において反応母液か
ら分離することによって亜ニチオン酸塩の結晶を得るこ
とができる。この結晶をそのまま乾燥すると結晶に付着
している母液の影響で製品純度が低下したり、母液に含
まれる水分によって著しく乾燥が遅くなるとともに亜ニ
チオン酸塩の分解が促進される9亜ニチオン酸塩の分解
速度が大きい場合には乾燥装置の中で発火が起こるほど
極めて危険である。したがって通常は結晶から母液をr
別後、亜二千オン酸塩の結晶は有機溶剤(例えばメタノ
ールあるいはエタノール)で十分に洗浄し、結晶に付着
している水分あるいは不純物塩類を含む母液を取除くこ
とが不可欠であり、その後に結晶を乾燥しなければなら
ない。In the method of producing anhydrous dithionite from a formic acid compound, an alkali compound, and anhydrous sulfite in a water-organic solvent, dithionite precipitates in the reaction solution during the reaction, so in the p-filtration step upon completion of the reaction. Crystals of dithionite can be obtained by separation from the reaction mother liquor. If these crystals are dried as they are, the product purity will decrease due to the influence of the mother liquor adhering to the crystals, and the moisture contained in the mother liquor will significantly slow down the drying process and accelerate the decomposition of the dithionite.9 Nithionite If the rate of decomposition is high, it is extremely dangerous and can cause ignition in the drying equipment. Therefore, usually the mother liquor is extracted from the crystals.
After separation, it is essential to thoroughly wash the dithionite crystals with an organic solvent (e.g. methanol or ethanol) to remove the water adhering to the crystals or the mother liquor containing impurity salts. The crystals must be dried.
亜ニチオン酸塩の洗浄操作についでは従来はとんど報告
がなく、通常は濾過後に結晶を有機溶剤で洗浄すること
を記載しているのみである。There have been very few reports on washing operations for dithionite salts, and there are usually only reports on washing the crystals with an organic solvent after filtration.
そして一般には洗浄液は独立しであるいは母液と合体さ
れて蒸留等によって精製処理され、有機溶剤を回収して
いる。例えば特公昭48−68556の明細書中に、反
応に使用したアルコールは蒸留回収して再使用すること
ができることが記載されている。しかしながら蒸留回収
すると蒸留に多大のエネルギーを要するという欠点があ
った。Generally, the cleaning liquid is purified by distillation or the like, either independently or combined with the mother liquor, to recover the organic solvent. For example, in the specification of Japanese Patent Publication No. 48-68556, it is stated that the alcohol used in the reaction can be recovered by distillation and reused. However, distillation recovery has the disadvantage that distillation requires a large amount of energy.
一方、チオ硫酸塩を含有する液をそのまま反応に循環使
用すると亜二千オン酸塩の合成反応に対してチオ硫酸塩
が著しく悪影響を与える結果、亜ニチオン酸塩の生成反
応が阻害されると同時に亜ニチオン酸塩の分解が促進さ
れるという欠点があった。On the other hand, if a solution containing thiosulfate is recycled as it is for the reaction, thiosulfate will have a significant negative effect on the synthesis reaction of dithionite, and the reaction to produce dithionite will be inhibited. At the same time, there was a drawback that the decomposition of dithionite was accelerated.
本発明はこれらの欠点を克服すべく洗浄液中のチオ硫酸
塩と選択的に反応する添加剤について研究した結果、チ
オ硫酸塩を無害化し、そのまま反応に再使用しうること
を見出した。本発明はこの知見に基づくものである。In order to overcome these drawbacks, the present invention conducted research on additives that selectively react with thiosulfates in cleaning solutions, and as a result, it was discovered that thiosulfates can be rendered harmless and reused as they are in the reaction. The present invention is based on this knowledge.
すなわち本発明はギ酸化合物、アルカリ化合物および無
水亜硫酸を水−有機溶媒中で反応させて無水亜ニチオン
酸塩を製造する方法において、反応後、無水亜ニチオン
酸塩の結晶を母液から戸別し、結晶に付着している母液
を有機溶剤で洗浄し、排出される洗浄液にエチレンオキ
シドまたはプロピレンオキシドのうち一種以上を添加し
、次いでこの液を前記亜ニチオン酸塩の製造に循環して
再使用することを特徴とする亜ニチオン塩の製造方法で
ある。That is, the present invention provides a method for producing anhydrous dithionite by reacting a formic acid compound, an alkali compound, and anhydrous sulfite in a water-organic solvent. After the reaction, crystals of anhydrous dithionite are separated from the mother liquor, and The mother liquor adhering to the water is washed with an organic solvent, one or more of ethylene oxide or propylene oxide is added to the discharged washing liquid, and this liquid is then recycled and reused in the production of the dithionite salt. This is a characteristic method for producing dinition salts.
本発明に係る亜ニチオン酸ナトリウムの製造方法を詳細
に説明する。先づ、ギ酸ナトリウム法においては通常水
−有機溶媒中でギ酸ナトリウム、アルカリ化合物及び無
水亜硫酸を反応させて亜ニチオン酸ナトリウムを合成し
、反応液を冷却して亜ニチオン酸ナトリウムの結晶を分
離し、結晶に付着している母液を有機溶媒で洗浄し、結
晶を乾燥する。ここで用いられるアルカリ化合物として
は例えば水酸化す) IJウム、炭酸ナトリウム、亜硫
酸ナトリウムなどが挙げられ、有機溶媒としてはメタノ
ール、エタノール、インプロパツールなどで例示される
アルコール類、ジオキサンで例示されるエーテル類、ジ
メチルポルムアミドで例示される酸アミド類が挙げられ
、その中でもアルコール類、特にメタノールが好ましい
。この結晶の洗浄液中には未反応のギ酸ナトリウム及び
亜硫酸水素す) jllラム残存しており、また亜ニチ
オン酸ナトリウムの分解によって副生じたチオ硫酸ナト
リウムが溶存している。本発明ではこの結晶の洗浄液に
チオ硫酸ナトリウムと選択的に反応する化合物を添加し
て液中のチオ硫酸ナトリウムを亜5−
ニチオン酸ナトリウムの生成阻害及び分解1こ何等関与
しない開ば無害物質に転化する。The method for producing sodium dithionite according to the present invention will be explained in detail. First, in the sodium formate method, sodium formate, an alkali compound, and anhydrous sulfite are usually reacted in a water-organic solvent to synthesize sodium dithionite, and the reaction solution is cooled to separate crystals of sodium dithionite. , the mother liquor adhering to the crystals is washed with an organic solvent, and the crystals are dried. Examples of the alkaline compounds used here include hydroxide, sodium carbonate, sodium sulfite, etc., and organic solvents include alcohols such as methanol, ethanol, and impropatol, and dioxane. Examples include ethers and acid amides such as dimethylpolamide, among which alcohols, particularly methanol, are preferred. Unreacted sodium formate and hydrogen sulfite remain in the washing solution for the crystals, and sodium thiosulfate, a by-product of the decomposition of sodium dithionite, is dissolved. In the present invention, a compound that selectively reacts with sodium thiosulfate is added to the crystal washing solution to inhibit the formation of sodium 5-nithionite and decompose the sodium thiosulfate into a harmless substance that does not participate in any way. Transform.
結晶の洗浄液に添加する化合物としては、エチレンオキ
シドまたはプロピレンオキシドの一種以上を用いる。As the compound added to the crystal washing solution, one or more of ethylene oxide and propylene oxide is used.
上記化合物は何れも洗浄液中においてチオ硫酸す) I
Jウムと選択的に反応し、且つ反応率が良いので液中の
チオ硫酸す) +1ウムをほぼ完全に除去することがで
きる。更に結晶の洗浄液は有機溶媒組成が高いため、な
かでも有機溶媒がメタノールの場合には上記エポキシ化
合物は容易にすばやく溶解拡散するので、反応温度を高
くすることができ、通常30℃以上、好ま1−<は40
°C以上において処理される。この場合、室温で行なう
場合に比べて更に反応速度が増大し、著しく処理時間を
短縮することができろ。All of the above compounds are thiosulfuric acid in the cleaning solution) I
Since it selectively reacts with Jium and has a high reaction rate, it is possible to almost completely remove the thiosulfuric acid in the liquid. Furthermore, since the crystal washing solution has a high organic solvent composition, especially when the organic solvent is methanol, the above-mentioned epoxy compound dissolves and diffuses easily and quickly, so the reaction temperature can be raised, usually 30°C or higher, preferably 1. -< is 40
Processed at temperatures above °C. In this case, the reaction rate is further increased compared to the case where the reaction is carried out at room temperature, and the processing time can be significantly shortened.
また、添加量は液中に含まれるチオ硫酸ナト11ウムに
対して通常1〜3倍モル量が適当であり、好ましくは1
〜2倍モル量である。本発明においては添加後の液の有
機溶媒組成は通常81〕重6−
!B%以上、好ましくは85重N%以上、とくに好まし
くは90重i%以上とし、この液を循環して再使用する
。In addition, the amount added is usually 1 to 3 times the molar amount per 11 um of sodium thiosulfate contained in the liquid, preferably 1 to 3 times the molar amount.
~2 times the molar amount. In the present invention, the organic solvent composition of the liquid after addition is usually 81] heavy 6-! B% or more, preferably 85% by weight or more, particularly preferably 90% by weight or more, and this liquid is circulated and reused.
前記化合物を添加してチオ硫酸す) +1ウムを無害物
質に転化させた液中には亜二千オン酸ナトリウムの生成
阻害或いは分解を起こさせる物質は殆ど含まnておらず
、従ってこの液を亜二手オン酸す1−リウムの製糸に循
環して再使用することができ、この場合純度の高い製品
な高収率でイロろことができる。な8、ギ酸ナトリウム
法による亜二千オン酸すトリウムの製造においては、原
料セル比、溶媒M1成、溶媒量等の条件の影響が大きい
ので洗浄液を循環使用する場合番ま循環液中のギ酸す1
−リウム、亜硫酸水素ナトリウム、有4fiI溶媒、水
等の含有量を測定して次回の反応に使用する各原料の指
を決定し、常に同じ条1′1で79応さlトろ必要があ
る○上述の様に庫発明に係る坩iニチオン酸ナトリウl
、の製造方法においては、結晶の洗浄液中に沼イtする
チオ硫酸す1リウムをほぼ完全に除去することができ、
しかも洗浄液は有機溶媒組成が高いので、添加する化合
物がすばやく溶解拡散するため反応温度を高めて処理時
間を短縮できるばかりではなく、反応に循環使用する際
に循環される水分量が少ないためにギ酸す) IJウム
あるいはアルカリ化合物を水溶液として使用する常法の
場合に、それらの水溶液濃度を極度1こ高める必要がな
く、工業的1こ使用する場合もその取扱いが非常に容易
である。更に、液中のチオ硫酸すl・リウムをほぼ完全
に除去できるので、これらの液を循環使用した場合も純
度の高い製品を高収率で得ることができ、原料を循環使
用するので資源の有効利用が図れる。また、従来は洗浄
液の全量を蒸留してメタノール回収を行なっていたが、
本発明ではこれらの液を循環使用するので循環液につい
てはメタノールの回収蒸留が不要となりエネルギを節約
できる。The solution obtained by converting +1um into a harmless substance contains almost no substances that inhibit the production or decompose sodium dithionite. It can be recycled and reused in the spinning of 1-lium dicarboxylic acid, and in this case, it can be produced with a high yield of a product of high purity. 8. In the production of thorium dithionite by the sodium formate method, conditions such as raw material cell ratio, solvent M1 composition, and amount of solvent have a large effect. Su1
- It is necessary to measure the content of sodium chloride, sodium hydrogen sulfite, 4fiI solvent, water, etc., determine the amount of each raw material to be used in the next reaction, and always add 79 liters in the same column 1'1. ○ As mentioned above, the crucible according to the invention is sodium dithionate.
In the manufacturing method of , monolithium thiosulfate present in the crystal washing solution can be almost completely removed,
Moreover, since the cleaning solution has a high organic solvent composition, the compounds to be added can be quickly dissolved and diffused, which not only increases the reaction temperature and shortens the processing time, but also reduces the amount of water that is recycled during the reaction. In the case of a conventional method in which IJum or an alkali compound is used as an aqueous solution, there is no need to increase the concentration of the aqueous solution to an extreme degree, and even when used industrially, it is very easy to handle. Furthermore, since sulfur and lithium thiosulfate can be almost completely removed from the liquid, even if these liquids are recycled, products with high purity can be obtained at a high yield, and the recycling of raw materials saves resources. It can be used effectively. In addition, conventionally, methanol was recovered by distilling the entire amount of the cleaning solution.
In the present invention, since these liquids are used in circulation, recovery and distillation of methanol is not necessary for the circulating liquid, and energy can be saved.
また更に、未反応のギ酸、す) IIウム及び亜硫酸水
素ナトリウムを廃棄しないので廃液処理負担が軽減され
る。Furthermore, since unreacted formic acid, sodium bisulfite and sodium bisulfite are not disposed of, the burden of waste liquid treatment is reduced.
次Iこ、実施例を挙げて本発明lこ係る亜ニチオン酸ナ
トリウムの製造方法を更に詳細に説明する。Next, the method for producing sodium dithionite according to the present invention will be explained in more detail with reference to Examples.
実施例 1
チオ硫酸ナトリウム 2.9部、亜硫酸水素ナトリウム
18.6部、ギ酸ナトリウム 6゜6部を含む結晶洗
浄液(メタノール組成92%)1000ffi量部を攪
拌機と還流器付フラスコに入れ、温度調整された恒温槽
内1こ静置する。洗浄液温度が平衡に達した後、洗浄液
中のチオ硫酸す) IIウムに対して1.5倍モル量の
表11こ記載される化合物を所定温度のもとに離船して
溶解し、4時間後に液中のチオ硫酸ナトリウム濃度を測
定してチオ硫酸ナトリウムの減少率を求めたつそれらの
結果を表1に示す。Example 1 1000 ffi parts of a crystal washing solution (methanol composition 92%) containing 2.9 parts of sodium thiosulfate, 18.6 parts of sodium bisulfite, and 6.6 parts of sodium formate were placed in a flask equipped with a stirrer and a reflux device, and the temperature was adjusted. Leave it undisturbed in the thermostatic oven. After the temperature of the cleaning solution reaches equilibrium, the compounds listed in Table 11 in an amount of 1.5 times the molar amount of thiosulfate (II) in the cleaning solution are taken off the ship at a predetermined temperature and dissolved. After a period of time, the sodium thiosulfate concentration in the solution was measured and the reduction rate of sodium thiosulfate was determined. The results are shown in Table 1.
=9−
表 1
実施例 2
ギ酸ナトリ喝りム 81部を熱水 74部に溶解し、更
にメタノール 105部を加え1こスラリーを攪拌機、
温度計、還流冷却器、低沸点捕集用深冷コンデンサー及
び原料簡[用タンクを有するジャケット付反応器に入れ
、反応器内の液を攪拌しなから1− o K9A、ゼゲ
ージの加圧下で82°Cに加温する。更に、メタノール
276部トギ酸メ千ル 16部からなる液に105部
の無水並値【俊を溶解させた液及び50%苛性ソーダ溶
液 69部を91部分間に亘って並行して滴下し、温度
、圧力を維持して更Iこ15111分間情拌な続けた。=9- Table 1 Example 2 81 parts of sodium formate paste was dissolved in 74 parts of hot water, 105 parts of methanol was added, and the slurry was stirred with a stirrer.
The liquid in the reactor was placed in a jacketed reactor equipped with a thermometer, a reflux condenser, a deep-cooled condenser for collecting low boiling points, and a tank for storing the raw materials, and was heated under pressure using a 1-o K9A zeguage without stirring. Warm to 82°C. Furthermore, 105 parts of an anhydrous solution and 69 parts of a 50% caustic soda solution were added dropwise in parallel over a period of 91 parts to a solution consisting of 276 parts of methanol and 16 parts of methyl formate, and the temperature was increased. The pressure was then maintained and stirring continued for a further 15,111 minutes.
次に、反応液を76℃に冷却し10−
たのち亜ニチオン酸塩の結晶を炭酸カスで加圧濾過して
反応母液と分離した。続いて結晶をメタノール 120
部で洗浄した。結晶はメタノールで浸され、濾過機を炭
酸ガスで加圧して洗浄液 120部を回収した。洗浄後
結晶は減圧下で75〜90°Cに90分間保持して乾燥
した。Next, the reaction solution was cooled to 76°C, and after 10 minutes, the dithionite crystals were filtered under pressure through carbonic acid scum to separate them from the reaction mother liquor. Next, the crystals are mixed with methanol 120
Washed at room temperature. The crystals were soaked in methanol, and the filter was pressurized with carbon dioxide gas to collect 120 parts of the washing liquid. After washing, the crystals were dried by holding at 75-90°C for 90 minutes under reduced pressure.
製品の収着は116−5部で亜二千オン酸ナトリウムの
純度は92.3%であった。The sorption of the product was 116-5 parts and the purity of sodium dithionite was 92.3%.
一方、回収された洗浄液中のメタノール組成は92%で
あったから、洗浄液中のメタノールが反応開始時のメタ
ノールと同量イこなるように洗浄液 114部を循環液
とした。この循環液中に溶解している千オ硫酸ナトリ・
ダム(0,40部)に対して1゜5倍モル量の表2に記
載の化合物を添加し45℃に4時間保持した後、次回の
反応に供用した。なお、この2回目の反応においてはギ
酸ナトリウム、苛性ソーダ及び無水亜硫酸の仕込量は前
記循環液中に溶解しているギ酸ナトリウム 0.9部、
及び亜硫酸水素ナトリリム 2.5部に相当する苛性ソ
ーダ1.0部と無水亜硫酸 1.5部を初回の仕込量か
ら差し引いた量とした。また、循環液中には水が4.3
部存在するため、ギ酸ナトリウムは熱水 69.7部に
溶解した。上記の循環液を用いて前述した初回の場合と
同様にして亜ニチオン酸塩の製造を行なった。On the other hand, since the methanol composition in the recovered cleaning liquid was 92%, 114 parts of the cleaning liquid was used as a circulating liquid so that the methanol in the cleaning liquid was the same amount as the methanol at the start of the reaction. Sodium sulfate dissolved in this circulating fluid
A compound listed in Table 2 was added in an amount of 1.5 times the molar amount based on dam (0.40 parts), and the mixture was kept at 45° C. for 4 hours, and then used for the next reaction. In addition, in this second reaction, the amounts of sodium formate, caustic soda, and anhydrous sulfite were 0.9 parts of sodium formate dissolved in the circulating fluid;
and 1.0 part of caustic soda, which corresponds to 2.5 parts of sodium bisulfite, and 1.5 parts of anhydrous sulfite were subtracted from the initial charge amount. Also, water in the circulating fluid is 4.3
Sodium formate was dissolved in 69.7 parts of hot water. Nithionite was produced in the same manner as in the first case using the above circulating fluid.
反応終了後、常法に従って亜二千オン酸ナト11ウムの
結晶を反応液から分離し、続いて結晶をメタノール 1
20部で洗浄し、結晶を減圧下で乾燥1−だ。製品の収
量及び亜ニチオン酸ナトリウムの純度は表2のとおりで
ある。After the reaction is completed, crystals of 11 um of sodium dithionite are separated from the reaction solution according to a conventional method, and then the crystals are mixed with methanol 1
The crystals were washed with 20 parts and dried under reduced pressure. The product yield and purity of sodium dithionite are shown in Table 2.
表 2
実施例 3
実施例2に記載された初回の反応を行ない、反応で生成
した亜ニチオン酸ナトリウムの結晶を反応液から分離し
、続いて結晶メタノール120部で洗浄した。結晶はメ
タノールで浸され、濾過機を炭酸ガスで加圧して洗浄液
120部を回収した。Table 2 Example 3 The initial reaction described in Example 2 was carried out, and the crystals of sodium dithionite produced in the reaction were separated from the reaction solution and subsequently washed with 120 parts of crystalline methanol. The crystals were soaked in methanol, and the filter was pressurized with carbon dioxide gas to collect 120 parts of the washing liquid.
回収された洗浄液 120部はチオ硫酸ナトリウム 0
.42部、亜硫酸水素ナトリウム266部、ギ酸ナトリ
ウム 0.9部を含み、メタノール組成は92%であっ
た。この洗浄液中に含まれるチオ硫酸ナトリウム1こ対
して1゜5倍モル値の表6に記載の化合物を添加し、4
5℃に4時間保持した後、次回の反応において無水亜硫
酸を溶解する液の一部とした。120 parts of the recovered cleaning solution is sodium thiosulfate 0
.. 42 parts, sodium bisulfite 266 parts, and sodium formate 0.9 parts, and the methanol composition was 92%. A compound listed in Table 6 was added in an amount of 1.5 times the molar value per 1 piece of sodium thiosulfate contained in this washing solution, and 4
After being maintained at 5° C. for 4 hours, it was used as part of the solution in which sulfite anhydride was dissolved in the next reaction.
次に、初回の反応において無水亜硫酸を溶解させろため
に用いたメタノール 276部のかわりに上記のチオ硫
酸ナトリウムを無害化した洗浄液全量とメタノール 1
65.6部およびギ酸メチル 15部からなる液に10
3.4部の無水亜硫酸を溶解させた液、50%苛性ソー
ダ溶液 69部のかわりに56%苛性ソーダ16−
63.5部及びギ酸ナトリウム 81部のかわりにギ酸
ナトリウム 80.1部を使用することを除き、初回と
同様な反応を行ない、常法にしたがって亜ニチオン酸ナ
トリウムの結晶を反応液から分離し、結晶をメタノール
で洗浄し、結晶を減圧下で乾燥した。製品の収量及び亜
ニチオン酸す) 11ウムの純度は表6のとおりである
。Next, instead of the 276 parts of methanol used to dissolve the anhydrous sulfite in the first reaction, the entire amount of the washing solution in which the sodium thiosulfate was rendered harmless and 1 part of methanol were added.
10 in a solution consisting of 65.6 parts and 15 parts of methyl formate.
3.4 parts of anhydrous sulfite dissolved therein, 16-63.5 parts of 56% caustic soda instead of 69 parts of 50% caustic soda solution, and 80.1 parts of sodium formate instead of 81 parts of sodium formate. The reaction was carried out in the same manner as the first time, and the crystals of sodium dithionite were separated from the reaction solution according to a conventional method, the crystals were washed with methanol, and the crystals were dried under reduced pressure. The yield of the product and the purity of 11 um of dithionite are shown in Table 6.
表 6
特許出願人 三菱瓦斯化学株式会社
代表者長野和吉
14−
手続補正書
昭和57年4月 (日
ニー
特許庁長官 殿
1 事件の表示
昭和56年特許願第189710号
2 発明の名称
亜二チオノ酸塩の製造方法
6 補正をする者
事件との関係 特お出願人
4、補正の対象
明細書の「発明の詳細な説明」の欄
5 補正の内容
明細書の発明の詳細な説Q14を以下のように補正する
。Table 6 Patent Applicant Mitsubishi Gas Chemical Co., Ltd. Representative Kazuyoshi Nagano 14- Procedural Amendment April 1980 (Japanese Patent Office Commissioner) 1 Indication of Case 1989 Patent Application No. 189710 2 Name of Invention A2 Process for producing thiono acid salts 6 Relationship with the case of the person making the amendment Special applicant 4, “Detailed explanation of the invention” column 5 of the specification subject to amendment Q14 Correct as shown below.
頁 行 補正前 補正後Page line Before correction After correction
Claims (4)
水−有機溶媒中で反応させて無水亜ニチオン酸塩を製造
する方法において、反応後、無水亜ニチオン酸塩の結晶
を母液から炉別し、結晶に付着している母液を有機溶剤
で洗浄し、排出される洗浄液にエチレンオキシドまたは
プロピレンオキシドのうち一種以上を添加し、次いでこ
の液を前記亜ニチオン酸塩の製造に循環して再使用する
ことを特徴とする亜ニチオン酸塩の製造方法(1) In a method for producing anhydrous dithionite by reacting a formic acid compound, an alkali compound, and anhydrous sulfite in a water-organic solvent, after the reaction, the crystals of anhydrous dithionite are separated from the mother liquor in a furnace, and the crystals are The mother liquor adhering to the water is washed with an organic solvent, one or more of ethylene oxide or propylene oxide is added to the discharged washing liquid, and this liquid is then recycled and reused in the production of the dithionite salt. Characteristic manufacturing method of dithionite
とし循環して再使用する特許請求の範囲第1項記載の製
造方法(2) The manufacturing method according to claim 1, wherein the organic solvent composition of the liquid after addition is 80% by weight or more and is recycled and reused.
シドのうち一種以上を洗浄液温度が60℃以上において
添加する特許請求の範囲第1項記載の製造方法(3) The manufacturing method according to claim 1, wherein one or more of ethylene oxide or propylene oxide is added to the cleaning liquid at a temperature of 60°C or higher.
レンオキシドまたはブaビ【/ンオキントのうち一種以
上を1〜3倍モル量添加する特許請求の範囲第1項記載
の製造方法(4) The manufacturing method according to claim 1, wherein one or more of ethylene oxide and abioxide is added in an amount of 1 to 3 times the molar amount of thiosulfuric acid salt contained in the cleaning solution.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP18971081A JPS5891004A (en) | 1981-11-26 | 1981-11-26 | Production of dithionite |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP18971081A JPS5891004A (en) | 1981-11-26 | 1981-11-26 | Production of dithionite |
Publications (1)
Publication Number | Publication Date |
---|---|
JPS5891004A true JPS5891004A (en) | 1983-05-30 |
Family
ID=16245890
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP18971081A Pending JPS5891004A (en) | 1981-11-26 | 1981-11-26 | Production of dithionite |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS5891004A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4622216A (en) * | 1985-08-06 | 1986-11-11 | Virginia Chemicals, Inc. | Treatment of sodium dithionite reaction mixture |
US5283046A (en) * | 1989-05-23 | 1994-02-01 | Hoechst Celanese Corporation | Method for re-use of aqueous co-product from manufacture of sodium dithionite |
-
1981
- 1981-11-26 JP JP18971081A patent/JPS5891004A/en active Pending
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4622216A (en) * | 1985-08-06 | 1986-11-11 | Virginia Chemicals, Inc. | Treatment of sodium dithionite reaction mixture |
EP0211648A2 (en) * | 1985-08-06 | 1987-02-25 | Hoechst Celanese Corporation | Treatment of sodium dithionite reaction mixture |
US5283046A (en) * | 1989-05-23 | 1994-02-01 | Hoechst Celanese Corporation | Method for re-use of aqueous co-product from manufacture of sodium dithionite |
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