JPH0521636B2 - - Google Patents
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- Publication number
- JPH0521636B2 JPH0521636B2 JP62103923A JP10392387A JPH0521636B2 JP H0521636 B2 JPH0521636 B2 JP H0521636B2 JP 62103923 A JP62103923 A JP 62103923A JP 10392387 A JP10392387 A JP 10392387A JP H0521636 B2 JPH0521636 B2 JP H0521636B2
- Authority
- JP
- Japan
- Prior art keywords
- waste liquid
- solution
- tank
- reducing agent
- sulfur
- 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 - Lifetime
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- Treating Waste Gases (AREA)
- Removal Of Specific Substances (AREA)
Description
〔産業上の利用分野〕
この発明は、例えば電気メツキ工程で発生する
Cr6+を含む廃液を確実に、しかも安価に処理する
方法に関するものである。
〔従来の技術〕
電気メツキ工程では、テインフリースチールの
ようなクロム酸の電解による皮膜形成や、亜鉛等
のメツキをした後に化成処理によるクロム酸塩の
皮膜形成を行ない、耐食性、防錆性等を付加する
ことが広く行なわれている。
一方、Cr6+のクロムは、有害元素として取上げ
られており、これを無害にして処理することが厳
重に義務付けられている。
前記のような電気メツキ工程では、その廃液に
Cr6+が含むことが多いことから、確実に無害にし
て処理する方法が厳重にチエツクされながら、実
用的に行なわれている。その方法の一つとして、
表１に示すような還元剤による場合が挙げられ
る。
[Industrial Field of Application] This invention is applicable to
The present invention relates to a method for reliably and inexpensively treating waste liquid containing Cr 6+ . [Conventional technology] In the electroplating process, a film is formed by electrolyzing chromic acid, such as with stain-free steel, or a film of chromate is formed by chemical conversion treatment after plating with zinc, etc., to improve corrosion resistance, rust prevention, etc. It is widely practiced to add On the other hand, chromium (Cr 6+ ) is considered a harmful element, and it is strictly required to treat it in a harmless manner. In the electroplating process as mentioned above, the waste liquid is
Since it often contains Cr 6+ , methods to ensure that it is rendered harmless are being carefully checked and are being put into practical use. As one of the methods,
Examples include the use of reducing agents as shown in Table 1.
しかしながら、電気メツキ工程で発生する廃液
は大量であり、その還元に要する還元剤の量も膨
大である。そのため、電気メツキ設備を有する工
場では、それらの還元剤を安価にして、かつ還元
剤としての機能を充分に発揮出来る代替が得られ
ることを強く要望していた。
本発明の目的は、かかる要望を満足出来る代替
を見出し、Cr6+を含む廃液を確実に無害にし、し
かも安価に処理する方法を提供することにある。
〔問題点を解決するための手段及び作用〕
本発明は、コークス炉発生ガスを脱硫して得ら
れた硫黄又は硫黄化合物を燃焼して得られる亜硫
酸ガスを石灰乳で処理し、そこで得られる重亜硫
酸カルシウムを含む廃液をCr6+を含む廃液に添加
して反応させ、中和後、凝集沈殿処理する廃液の
処理方法を特徴とするものである。
製鉄会社等では、工場内に電気メツキ設備とと
もに、SO3源として考えられるコークス炉ガス脱
硫設備等がある。それにより回収して得られる硫
黄等を燃焼して発生させた亜硫酸ガス（SO2）を
石灰乳で処理し、重亜硫酸カルシウム溶液を得、
それを還元剤の代替に供しようとした。
まず、前記重亜硫酸カルシウム溶液が電気メツ
キ工程で発生するCr6+を含んだ廃液の処理に適す
るかどうかをビーカー実験及びモデル還元槽での
実験によつて確認した。その結果を次に示す。
（ビーカー実験）
(1) 実験方法：電気メツキ工程で発生したCr6+を
含んだ廃液をビーカーに３採取し、硫酸を加
えてPH２に調整し、攪拌しながら、実験用の重
亜硫酸カルシウム溶液を所定量添加し、還元反
応を行なつた後に、石灰乳（Ca（OH）2）でPH
８に中和し、処理した。同様に比較として従来
のNaHSO3溶液により処理した。
(2) 結果：結果を表２に示す。
However, a large amount of waste liquid is generated in the electroplating process, and an enormous amount of reducing agent is required to reduce the waste liquid. For this reason, factories with electroplating equipment have strongly desired an alternative reducing agent that can be used at a lower cost and that can fully perform its function as a reducing agent. An object of the present invention is to find an alternative that can satisfy such demands, and to provide a method for treating waste liquid containing Cr 6+ reliably and at low cost while rendering it harmless. [Means and effects for solving the problems] The present invention treats sulfur dioxide gas obtained by burning sulfur or sulfur compounds obtained by desulfurizing coke oven generated gas with milk of lime, and This method is characterized by adding a waste solution containing calcium sulfite to a waste solution containing Cr 6+ to cause a reaction, neutralizing it, and then subjecting it to coagulation and precipitation treatment. In addition to electroplating equipment, steel manufacturing companies have coke oven gas desulfurization equipment, which can be considered as a source of SO3 , in their factories. The sulfur dioxide gas (SO 2 ) generated by burning the recovered sulfur is treated with milk of lime to obtain a calcium bisulfite solution.
They tried to use it as a substitute for a reducing agent. First, whether the calcium bisulfite solution is suitable for treating waste liquid containing Cr 6+ generated in the electroplating process was confirmed by a beaker experiment and a model reduction tank experiment. The results are shown below. (Beaker experiment) (1) Experimental method: Three samples of waste liquid containing Cr 6+ generated in the electroplating process were collected in a beaker, and sulfuric acid was added to adjust the pH to 2. While stirring, a calcium bisulfite solution for the experiment was prepared. After adding a predetermined amount of
8 and processed. Similarly, a conventional NaHSO 3 solution was treated as a comparison. (2) Results: The results are shown in Table 2.
【表】
表２から明らかなように、従来のNaHSO3溶
液の場合と同様にCr6+は検出されず、還元剤とし
ての効果がある。
（モデル還元槽での実験）
(1) 実験方法：実設備の約１／（1000）モデルの
還元槽（容量約35）を用い、電気メツキ工程
で発生するCr6+を含んだ廃液をその還元槽に連
続的に送入し、そこで硫酸を加えてPH２に調整
し、攪拌しながら、実験用の重亜硫酸カルシウ
ム溶液を所定量添加し、還元反応を行なつた後
に、それらの溶液を順次配設した中和槽で石灰
乳（Ca（OH）2）を加えてPH８に中和し、処理
した。同様に比較として従来のNaHSO3溶液
により処理した。
(2) 結果：結果を表３に示す。[Table] As is clear from Table 2, Cr 6+ was not detected as in the case of the conventional NaHSO 3 solution, and it is effective as a reducing agent. (Experiment in a model reduction tank) (1) Experimental method: Using a model reduction tank (capacity approximately 35), which is approximately 1/(1000) of the actual equipment, the waste liquid containing Cr 6+ generated in the electroplating process was Continuously feed the solution into a reduction tank, add sulfuric acid there to adjust the pH to 2, add a predetermined amount of experimental calcium bisulfite solution while stirring, perform a reduction reaction, and then sequentially add the solutions. Milk of lime (Ca(OH) 2 ) was added to the neutralization tank provided to neutralize to pH 8, and the mixture was processed. Similarly, a conventional NaHSO 3 solution was treated as a comparison. (2) Results: The results are shown in Table 3.
【表】
表３から明らかなように、従来のNaHSO3溶
液の場合と同様にCr6+は検出されず、還元剤とし
ての効果があることが確認出来た。ここでは、連
続的に実験用の重亜硫酸カルシウムを使用し、つ
いて従来のNaHSO3溶液を使用し、そして実験
用の重亜硫酸カルシウム溶液を使用したが、どち
らの場合もCr6+は検出されなかつた。
以上の実験結果から、硫黄又は硫黄化合物を燃
焼して得られる亜硫酸ガスを石灰乳で処理し、そ
こで得られた重亜硫酸カルシウム溶液は、電気メ
ツキ工程で発生するCr6+を含む廃液の還元剤とし
て使用されている重亜硫酸ソーダ溶液
（NaHSO3）と同程度の効果があり、充分還元剤
の代替として使用出来ることを確認した。
本発明の方法では、硫黄等を燃焼して得られる
亜硫酸ガスを石灰乳で処理して得られる重亜硫酸
カルシウムを含む廃液を還元剤として使用するこ
と、特に連続的に使用することに特徴がある。特
にコークス炉発生ガス等を水酸化アンモニウム等
で脱硫して得られた硫黄を燃焼して発生させた亜
硫酸ガスは不純物がほとんどなく、それを石灰乳
で処理して得られた重亜硫酸カルシウムを含む廃
液も表４に示すように不純物がほとんどないもの
である。[Table] As is clear from Table 3, Cr 6+ was not detected as in the case of the conventional NaHSO 3 solution, confirming that it was effective as a reducing agent. Here, we sequentially used experimental calcium bisulfite, followed by conventional NaHSO 3 solution, and then used experimental calcium bisulfite solution, and in both cases no Cr 6+ was detected and Ta. From the above experimental results, sulfur dioxide gas obtained by burning sulfur or sulfur compounds is treated with milk of lime, and the calcium bisulfite solution obtained is a reducing agent for waste liquid containing Cr 6+ generated in the electroplating process. It was confirmed that this solution has the same effect as sodium bisulfite solution (NaHSO 3 ), which is used as a reducing agent, and can be used as a sufficient substitute for a reducing agent. The method of the present invention is characterized in that a waste liquid containing calcium bisulfite obtained by treating sulfur dioxide gas obtained by burning sulfur etc. with milk of lime is used as a reducing agent, particularly in that it is used continuously. . In particular, the sulfur dioxide gas generated by burning the sulfur obtained by desulfurizing coke oven gas etc. with ammonium hydroxide has almost no impurities, and contains calcium bisulfite obtained by treating it with milk of lime. As shown in Table 4, the waste liquid also contains almost no impurities.
以下本発明により電気メツキ廃液を処理する方
法を図によつて説明する。
第１図は、電気メツキ廃液を処理するフローシ
ートである。SO3源としてのコークス炉発生ガス
２１は脱硫塔２２で脱硫液（水酸化アンモニウ
ム）２３と触媒とで処理され、脱硫ガスは燃焼用
ガス２４に供される。ここで回収された硫黄２５
は、燃焼炉２６で燃焼されて亜硫酸ガス２７とし
てSO2吸収塔２８に送入される。
ここで石灰乳２９を加えて反応し、重亜硫酸カ
ルシウムを含む廃液３０を得る。それは重亜硫酸
カルシウム廃液タンク３１に貯留され、還元剤タ
ンク３５に送入される。還元剤に使用しない重亜
硫酸カルシウム廃液３０は、酸化塔３２に送ら
れ、そこで空気により石膏スラリーとし、脱水機
３３で脱水して石膏３４として回収される。
電気メツキ工程で発生したCr6+を含む廃液１は
クロム還元槽２に送入され、硫酸タンク３から硫
酸４を加えてPH２〜３に調整される。その溶液に
還元剤タンク３５から重亜硫酸カルシウム廃液３
６が添加され、還元反応が行なわれる。ここでは
廃液は攪拌機７により充分に攪拌され、還元反応
は瞬時に終了する。
還元反応の終了した溶液８は中和槽９にオーバ
ーフローして送られ、そこで石灰乳タンク１０か
ら石灰乳１１の添加によりPH８に中和された後、
その中和溶液１２は、凝集沈殿槽１３に送られ、
そこで高分子凝集剤等が加えられて水酸化クロ
ム、硫酸カルシウムとして沈殿し、沈殿物１４を
除去し、上澄液１５は排水される。ここにおいて
１６はスラツジ排出槽である。
次に本発明方法により実験した結果を表５に示
す。
DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for treating electroplating waste liquid according to the present invention will be explained below with reference to the drawings. FIG. 1 is a flow sheet for treating electroplating waste liquid. Coke oven generated gas 21 as an SO 3 source is treated in a desulfurization tower 22 with a desulfurization liquid (ammonium hydroxide) 23 and a catalyst, and the desulfurization gas is provided as combustion gas 24 . 25 sulfur recovered here
is combusted in the combustion furnace 26 and sent to the SO 2 absorption tower 28 as sulfur dioxide gas 27. Here, milk of lime 29 is added and reacted to obtain a waste liquid 30 containing calcium bisulfite. It is stored in the calcium bisulfite waste liquid tank 31 and sent to the reducing agent tank 35. The calcium bisulfite waste liquid 30 that is not used as a reducing agent is sent to an oxidation tower 32, where it is made into gypsum slurry with air, dehydrated in a dehydrator 33, and recovered as gypsum 34. A waste liquid 1 containing Cr 6+ generated in the electroplating process is sent to a chromium reduction tank 2, and sulfuric acid 4 is added from a sulfuric acid tank 3 to adjust the pH to 2 to 3. Calcium bisulfite waste liquid 3 is added to the solution from the reducing agent tank 35.
6 is added and a reduction reaction takes place. Here, the waste liquid is sufficiently stirred by the stirrer 7, and the reduction reaction is completed instantaneously. After the reduction reaction, the solution 8 overflows and is sent to the neutralization tank 9, where it is neutralized to pH 8 by adding milk of lime 11 from the milk of lime tank 10.
The neutralized solution 12 is sent to a coagulation sedimentation tank 13,
Then, a polymer flocculant or the like is added to precipitate chromium hydroxide and calcium sulfate, the precipitate 14 is removed, and the supernatant liquid 15 is drained. Here, 16 is a sludge discharge tank. Next, Table 5 shows the results of experiments conducted using the method of the present invention.
本発明方法によれば、工場内で発生する硫黄等
を燃焼して得られる亜硫酸ガスを石灰乳で処理し
た重亜硫酸カルシウムを含む廃液を還元剤として
使用することによつて、従来の重亜硫酸ソーダ溶
液の還元剤と同程度の効果を挙げることが出来、
Cr6+を無害にすることが出来る。この場合重亜硫
酸カルシウムを含む廃液は工場内で容易に、安価
に得ることが出来るので、本発明方法は産業上利
用価値の非常に大きな発明である。
According to the method of the present invention, by using as a reducing agent a waste liquid containing calcium bisulfite obtained by treating sulfur dioxide gas obtained by burning sulfur etc. generated in a factory with milk of lime, It can be as effective as a solution reducing agent,
Can make Cr 6+ harmless. In this case, the waste liquid containing calcium bisulfite can be easily obtained in a factory at a low cost, so the method of the present invention is an invention of great industrial value.
第１図は本発明方法の一実施例を示すフローシ
ート図、第２図は従来の廃水処理の説明図であ
る。
２６……燃焼炉、２７……亜硫酸ガス、２８…
…SO2吸収塔、２９……石灰乳、３０……重亜硫
酸カルシウムを含む廃液、３１……重亜硫酸カル
シウム溶液貯留槽、３５……還元剤タンク、１…
…廃液、２……クロム還元槽、９……中和槽、１
３……凝集沈殿槽。
FIG. 1 is a flow sheet diagram showing one embodiment of the method of the present invention, and FIG. 2 is an explanatory diagram of conventional wastewater treatment. 26... Combustion furnace, 27... Sulfur dioxide gas, 28...
... SO 2 absorption tower, 29 ... milk of lime, 30 ... waste liquid containing calcium bisulfite, 31 ... calcium bisulfite solution storage tank, 35 ... reducing agent tank, 1 ...
...Waste liquid, 2...Chromium reduction tank, 9...Neutralization tank, 1
3...Coagulation sedimentation tank.
Claims (1)
又は硫黄化合物を燃焼して得られる亜硫酸ガスを
石灰乳で処理し、それによつて得られた重亜硫酸
カルシウムを含む廃液をCr6+を含む電気めつき廃
液に添加して、反応させ、中和後、凝集沈殿処理
することを特徴とする六価クロムを含む廃液の処
理方法。1. Sulfur dioxide gas obtained by burning sulfur or sulfur compounds obtained by desulfurizing coke oven gas is treated with milk of lime, and the resulting waste liquid containing calcium bisulfite is treated with electricity containing Cr 6+ . A method for treating waste liquid containing hexavalent chromium, which comprises adding it to plating waste liquid, reacting it, neutralizing it, and then coagulating and precipitating it.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62103923A JPS63267494A (en) | 1987-04-27 | 1987-04-27 | Treatment method for waste liquid containing hexavalent chromium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62103923A JPS63267494A (en) | 1987-04-27 | 1987-04-27 | Treatment method for waste liquid containing hexavalent chromium |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63267494A JPS63267494A (en) | 1988-11-04 |
| JPH0521636B2 true JPH0521636B2 (en) | 1993-03-25 |
Family
ID=14366946
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62103923A Granted JPS63267494A (en) | 1987-04-27 | 1987-04-27 | Treatment method for waste liquid containing hexavalent chromium |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63267494A (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100345296B1 (en) * | 1998-12-11 | 2002-11-18 | 재단법인 포항산업과학연구원 | Treatment method of waste water containing hexavalent chromium compound_ |
| CN102758080B (en) * | 2012-07-25 | 2014-01-15 | 福建省双旗山矿业有限责任公司 | Method for microwave roasting and non-cyanogen gold leaching of sulfur-bearing gold mineral |
| CN102758081B (en) * | 2012-07-25 | 2013-12-18 | 福建省双旗山矿业有限责任公司 | Method for microwave plasma roasting and non-cyanogen gold leaching of sulfur-bearing gold mineral |
| JP2017121604A (en) * | 2016-01-06 | 2017-07-13 | 日新製鋼株式会社 | Treatment method of hexavalent chromium-containing waste liquid |
| CN105776466B (en) * | 2016-03-14 | 2018-06-15 | 湖北徐风环保科技有限公司 | A kind of purification method of sodium sulfate wastewater |
| JP7316817B2 (en) * | 2019-03-28 | 2023-07-28 | Ｕｂｅ三菱セメント株式会社 | Method for producing sulfur-based composition and cement composition, and production system for cement composition |
| JP7406994B2 (en) * | 2020-01-08 | 2023-12-28 | Ｕｂｅ三菱セメント株式会社 | Method for manufacturing cement composition |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS575598A (en) * | 1980-06-13 | 1982-01-12 | Hitachi Ltd | Operation controller for turborefrigerator |
| JPS57204289A (en) * | 1981-06-09 | 1982-12-14 | Showa Denko Kk | Removal of metallic component |
-
1987
- 1987-04-27 JP JP62103923A patent/JPS63267494A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS63267494A (en) | 1988-11-04 |
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