JPS5844613B2 - Method of oxidizing desulfurization slurry - Google Patents
Method of oxidizing desulfurization slurryInfo
- Publication number
- JPS5844613B2 JPS5844613B2 JP51029433A JP2943376A JPS5844613B2 JP S5844613 B2 JPS5844613 B2 JP S5844613B2 JP 51029433 A JP51029433 A JP 51029433A JP 2943376 A JP2943376 A JP 2943376A JP S5844613 B2 JPS5844613 B2 JP S5844613B2
- Authority
- JP
- Japan
- Prior art keywords
- oxidation
- amount
- desulfurization slurry
- added
- oxidation rate
- 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
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F11/00—Compounds of calcium, strontium, or barium
- C01F11/46—Sulfates
- C01F11/464—Sulfates of Ca from gases containing sulfur oxides
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Inorganic Chemistry (AREA)
- Treating Waste Gases (AREA)
- Treatment Of Water By Oxidation Or Reduction (AREA)
- Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
Description
【発明の詳細な説明】
本発明は、各種燃焼炉や、鉄鉱石の焼結機などから排出
される硫黄酸化物（ＳＯｘ と略記）含有排煙を、Ｃａ
塩を吸収剤として吸収脱硫して得られる脱硫スラリーか
ら容易に石膏を取得する方法に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention aims to convert flue gas containing sulfur oxides (abbreviated as SOx) emitted from various combustion furnaces, iron ore sintering machines, etc.
The present invention relates to a method for easily obtaining gypsum from desulfurization slurry obtained by absorbing and desulfurizing salt using salt as an absorbent.
大気汚染の主要因であるＳＯｘは窒素酸化物（ＮＯｘ
と略記）と異り、被燃物中に８分があれば、その分だけ
は必ず発生する。SOx, the main cause of air pollution, is nitrogen oxide (NOx
(abbreviated as ), if there is 8 minutes in the combustible material, that amount will always be generated.
そのようなＳＯｘを伴った排煙からＳＯｘ を除去（脱
硫と略記）する各種方法のうち現在量も広く使用されて
いるのは、安価な炭酸カルシウムや消石灰ないしは石灰
の単独あるいはそれら２以上の混合物を脱硫剤とし、そ
れらの懸濁液と上記排煙とを接触させることによって脱
硫する方法である。Of the various methods for removing SOx (abbreviated as desulfurization) from such SOx-containing flue gas, the currently widely used method is to use inexpensive calcium carbonate, slaked lime, or lime alone or in a mixture of two or more of them. This is a method of desulfurizing by using a desulfurizing agent as a desulfurizing agent and bringing a suspension thereof into contact with the flue gas.
この方法による反応生成物は、通常亜硫酸カルシウムで
あって、脱硫後の状態はいわゆるスラリー状である（脱
硫スラリーと略記）。The reaction product obtained by this method is usually calcium sulfite, and the state after desulfurization is in the form of a so-called slurry (abbreviated as desulfurization slurry).
こ〜に得られる亜硫酸カルシウムは、用途が狭いので工
業的には、上記脱硫スラリーを酸化処理して石膏の形態
に変え、副産物として回収する。Since the calcium sulfite obtained from this process has a narrow range of uses, industrially, the desulfurization slurry is oxidized to convert it into gypsum form and recovered as a by-product.
そのためには、脱硫スラリーを酸化処理するに先立って
硫酸によりＰＨ３〜４に調整し、該スラリー中に含有さ
れる未反応カルシウムを、欠配（１）、（２）式に従っ
て中和する。For this purpose, prior to oxidizing the desulfurization slurry, the pH is adjusted to 3 to 4 with sulfuric acid, and unreacted calcium contained in the slurry is neutralized according to equations (1) and (2).
亜硫酸カルシウムを酸性亜硫酸カルシウムに変え次工程
たる酸化槽における酸化速度を増大させ、酸化槽容量を
小さくさせる為である。This is to change calcium sulfite to acidic calcium sulfite, increase the oxidation rate in the next step, the oxidation tank, and reduce the oxidation tank capacity.
この場合、ＰＩ（を低くすれば、Ｃａ （Ｈ８Ｏｓ）２
の存在量、即ちＨ８〔とじての存在量が多くなり、従っ
て亜硫酸カルシウムの石膏への転化量が多くなるのであ
る。In this case, if PI is lowered, Ca (H8Os)2
The amount of H8 present increases, and therefore the amount of calcium sulfite converted to gypsum increases.
しかし乍ら、ＰＲがもつと低くなると、（４）式に示す
ように反応は右方へ進行し、
るようになる。However, as PR becomes lower, the reaction proceeds to the right as shown in equation (4).
ＳＯ２を放出す
このことは、折角排煙脱硫したＳＯ２を再び放出せしめ
ることであって、無意味な操作をしたことになる。To release SO2 is to release SO2, which has been painstakingly desulfurized from flue gas, again, which is a meaningless operation.
それで現実には、酸化速度を上げて装置を小さくし、か
つＳＯ２の再発生も出来るだけ抑える兼ね合いとしてＰ
Ｈを３〜４に設定するのである。Therefore, in reality, P
H is set to 3 to 4.
したがってスラリーのＰＨをそのように低くすることな
く酸化速度を増大せしめ得れば石膏取得という後処理工
程は著しい工業的な利便が得られることになる。Therefore, if the oxidation rate could be increased without lowering the pH of the slurry to such a low level, the post-treatment step of obtaining gypsum would have significant industrial advantages.
本発明は、このような観点に立って為されたものであっ
て、排煙脱硫スラリーにＮＯ２を添加した酸化ガスを吹
き込むことを特徴とするものである。The present invention was developed based on this viewpoint, and is characterized by blowing an oxidizing gas to which NO2 is added into the flue gas desulfurization slurry.
こ又に酸化ガスというのは、亜硫酸カルシウムを石膏に
酸化するためのガスであって空気もしくは酸素である。Here, the oxidizing gas is a gas for oxidizing calcium sulfite to gypsum, and is air or oxygen.
これに添加するＮＯ２の量は多い方が好ましい。It is preferable that the amount of NO2 added to this is large.
空気を酸化ガスとするとき、ＮＯ２を１０ｐｐｍ程度添
加すれば酸化速度は無添加の場合の約１．２倍となる。When air is used as an oxidizing gas, if about 10 ppm of NO2 is added, the oxidation rate will be about 1.2 times that of the case without the addition.
添加量を３倍量の３０ｐｐｍ以上にすると酸化速度も急
上昇し、無添加の場合の２倍以上の速度となるが、５０
ｐｐｍ以上の添加では添加量の増大はどには酸化速度は
向上しない。When the amount added is three times the amount of 30 ppm or more, the oxidation rate increases rapidly, becoming more than twice the rate when no additive is added, but 50 ppm or more.
If the addition amount exceeds ppm, the oxidation rate will not improve as much as the amount added.
例えば、５０ｐｐｍ添加のときの酸化速度を１とすれば
、１０倍の５００ｐｐｍの添加で酸化速度は１０％程度
しか向上しない。For example, if the oxidation rate when 50 ppm is added is 1, then when 500 ppm is added, which is 10 times the oxidation rate, the oxidation rate increases by only about 10%.
その様な事実から見て、ＮＯ２の添加量は、その効果が
顕著にあられれる３０〜１５０ｐｐｍ程度であることが
適当とされる。In view of such facts, it is considered appropriate that the amount of NO2 added is about 30 to 150 ppm, at which the effect is noticeable.
この際、微量に添加されたＮＯ２は（５）式に示される
反応により、Ｎ２にまで還元されるのでＮＯ２添加によ
る二次公害の発生の心配はない。At this time, the trace amount of NO2 added is reduced to N2 by the reaction shown in equation (5), so there is no concern that secondary pollution will occur due to the addition of NO2.
酸化工程におけるＰＨは、従来法のそれは３〜４である
が、それ以上では亜硫酸カルシウムの酸化される速度が
極端に低下し、必然的に酸化処理槽の容量を増大しなげ
ればならなくなる為であったからである。The pH in the oxidation process is 3 to 4 in the conventional method, but if it is higher than that, the rate of oxidation of calcium sulfite will be extremely reduced, and the capacity of the oxidation treatment tank will inevitably have to be increased. This is because it was.
本発明法にあってもＰＨ４以上となると、酸化速度は、
それ以下の場合に比して低下するとは云うもの工、従来
法に比べれば、なお十分に犬であるので、ＰＨ４以上と
いう条件で実用に供することができる。Even in the method of the present invention, when the pH is higher than 4, the oxidation rate is
Although it is lower than when the pH is lower than that, it is still much better than the conventional method, so it can be put to practical use under the condition of pH 4 or higher.
そのようなＰＨであれば、スラリーの腐食性が減じ、容
器材料の選択が容易となると同時に、ＰＨ調整の為に使
用する硫酸消費量も少くてすむから、総体としてのラン
ニングコストは安くなるのである。With such a pH, the corrosiveness of the slurry will be reduced, the selection of container materials will be easier, and at the same time, the amount of sulfuric acid used for pH adjustment will be less, resulting in lower overall running costs. be.
実施例 １
固形分中の亜硫酸カルシウムが約７０％であり、残余が
硫酸カルシウムおよび炭酸カルシウムである固形分濃度
的１０％で、ＰＨ８，５の脱硫スラリーを、ＰＨ調整槽
に入れて、硫酸によりＰＨ３，３に調整したのち、これ
を容量１ｍの酸化槽に移し、８０ｐｐｍになるようにＮ
Ｏ２を添加した空気を毎分１ｍＦの割合で劇しくバブリ
ングさせることによって酸化反応を遂行した。Example 1 A desulfurization slurry with a solid content concentration of 10%, in which calcium sulfite in the solid content is about 70% and the remainder is calcium sulfate and calcium carbonate, and a pH of 8.5, is placed in a pH adjustment tank and treated with sulfuric acid. After adjusting the pH to 3.3, transfer it to an oxidation tank with a capacity of 1 m, and add N to 80 ppm.
The oxidation reaction was carried out by vigorously bubbling O2-doped air at a rate of 1 mF per minute.
このときの亜硫酸カルシウムの酸化速度は３５ｋｇ／時
であったが、他方、ＮＯ２を添加しない空気を、他の条
件を同一にしてバブリングさせた場合のそれは１１ｋｇ
／時にすぎなかった。The oxidation rate of calcium sulfite at this time was 35 kg/hour, but on the other hand, when air without NO2 was bubbled under the same conditions, it was 11 kg/hour.
/ It was just a moment.
実施例 ２
脱硫スラリーのＰＨ条件が異る以外は実施例と同一条件
である。Example 2 The conditions were the same as in Example except that the PH conditions of the desulfurization slurry were different.
ＰＨを５．０に設定してＮＯ２８０ｐｐｍを含有せしめ
た空気を吹込んで酸化させたところ、亜硫酸カルシウム
の酸化速度は１８ｋｇ／時であったが、ＮＯ２を含有し
ない空気を用いた場合のそれは３ｋｇ／時にすぎなかっ
た。When the pH was set to 5.0 and air containing 80 ppm of NO2 was blown in for oxidation, the oxidation rate of calcium sulfite was 18 kg/hour, but when air containing no NO2 was used, the oxidation rate was 3 kg/hour. It was just a moment.
実施例 ３
実施例１と異るところは、設定ＰＨを３．３としたこと
、およびＮＯ２の添加量を３５０ｐｐｍとした点にある
。Example 3 The difference from Example 1 was that the set pH was 3.3 and the amount of NO2 added was 350 ppm.
この場合の亜硫酸カルシウムの酸化速度は３７ｋｇ１時
であった。The oxidation rate of calcium sulfite in this case was 37 kg/hour.
以上詳述し、実施例で示した通り本発明方法によるとき
は、亜硫酸カルシウムの酸化速度が極めて増大するので
工業的価値大なるものがある。As detailed above and shown in the examples, the method of the present invention has great industrial value because the oxidation rate of calcium sulfite is greatly increased.
この場合、ＰＨを下げることにより、酸化槽容量や腐食
性あるいは硫酸使用量の増大を認容して酸化速度の増大
を図るか、または酸化速度の若干の低下を認容して、酸
化槽容量や腐食性あるいは硫酸使用量の減少を図るかは
、それが実施せらるべき設置場所、設備費用、ランニン
グコストなど綜合勘案して採択すべき事柄である。In this case, by lowering the pH, the oxidation rate can be increased by accepting an increase in the oxidation tank capacity, corrosiveness, or the amount of sulfuric acid used, or by allowing a slight decrease in the oxidation rate and increasing the oxidation tank capacity and corrosion. Deciding whether to reduce the amount of sulfuric acid used or the amount of sulfuric acid used should be decided after comprehensively taking into consideration factors such as the installation location, equipment costs, and running costs.
Claims (1)
を添加した酸化ガスを吹き込むことを特徴とする脱硫ス
ラリーを酸化する方法。I NO2 is added to the flue gas desulfurization slurry using Ca salt as the desulfurization agent.
A method of oxidizing desulfurization slurry, characterized by blowing in oxidizing gas added with.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP51029433A JPS5844613B2 (en) | 1976-03-17 | 1976-03-17 | Method of oxidizing desulfurization slurry |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP51029433A JPS5844613B2 (en) | 1976-03-17 | 1976-03-17 | Method of oxidizing desulfurization slurry |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS52111877A JPS52111877A (en) | 1977-09-19 |
| JPS5844613B2 true JPS5844613B2 (en) | 1983-10-04 |
Family
ID=12275992
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP51029433A Expired JPS5844613B2 (en) | 1976-03-17 | 1976-03-17 | Method of oxidizing desulfurization slurry |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5844613B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007181756A (en) * | 2006-01-05 | 2007-07-19 | Japan Energy Corp | Wastewater treatment method for flue gas desulfurization equipment |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS515286A (en) * | 1974-07-03 | 1976-01-16 | Tokico Ltd | KYUCHAKUZAINOSEIZOHO |
-
1976
- 1976-03-17 JP JP51029433A patent/JPS5844613B2/en not_active Expired
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS515286A (en) * | 1974-07-03 | 1976-01-16 | Tokico Ltd | KYUCHAKUZAINOSEIZOHO |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS52111877A (en) | 1977-09-19 |
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