JP2003136035A - Method for treating soot and dust and treatment device for soot and dust - Google Patents
Method for treating soot and dust and treatment device for soot and dustInfo
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- JP2003136035A JP2003136035A JP2001334013A JP2001334013A JP2003136035A JP 2003136035 A JP2003136035 A JP 2003136035A JP 2001334013 A JP2001334013 A JP 2001334013A JP 2001334013 A JP2001334013 A JP 2001334013A JP 2003136035 A JP2003136035 A JP 2003136035A
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- dust
- soot
- flue gas
- mixing
- boron
- Prior art date
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Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、排煙処理方法及び排煙
処理装置に関し、詳しくは、排煙中のばいじんに含まれ
るホウ素、セレン、又はホウ素及びセレンの無害化を容
易に行うことができるばいじんの処理方法及びばいじん
の処理装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flue gas treatment method and a flue gas treatment apparatus, and more specifically, it can easily detoxify boron, selenium, or boron and selenium contained in dust in flue gas. The present invention relates to a dust disposal method and a dust disposal device.
【０００２】[0002]
【従来の技術】従来、火力発電所等に設置される排煙処
理装置としては、排煙からフライアッシュ等のばいじん
を除去する集塵装置（通常、電気集塵機）と、吸収塔内
で吸収剤スラリ（例えば、カルシウム化合物含有スラリ
など）と接触させることにより排煙中の亜硫酸ガスを吸
収除去する湿式排煙脱硫装置などを備えた排煙処理装置
が普及している。ところが、近年、この集塵装置で除去
されたフライアッシュ等のばいじんの扱いが問題となっ
てきており、特に、石炭焚きボイラで使用する石炭中に
は最大で１２０ｍｇ／ｋｇ程度の含有量で含まれるホウ
素（Ｂ）や、最大で１０ｍｇ／ｋｇ程度の含有量で含ま
れるセレン（Ｓｅ）がばいじんに蓄積するため、これら
を無害化して処理することが望まれている。ＢやＳｅは
我が国で新たに規制項目に加わり、Ｂについては排水基
準（陸水域：１０ｍｇ／ｌ、海域：２３０ｍｇ／ｌ）が
制定され、埋立処分に関する溶出基準（３０ｍｇ／ｌ）
も検討中で、また、Ｓｅについては、排水基準（０．１
ｍｇ／ｌ）と埋立処分に関する溶出基準（０.３ｍｇ／
ｌ）が制定された。2. Description of the Related Art Conventionally, as a flue gas treatment device installed in a thermal power plant or the like, a dust collecting device (usually an electric dust collector) for removing dust such as fly ash from flue gas, and an absorbent in an absorption tower. A flue gas treatment apparatus including a wet flue gas desulfurization apparatus that absorbs and removes sulfurous acid gas in flue gas by contacting with a slurry (for example, a calcium compound-containing slurry) is widely used. However, in recent years, the handling of soot and dust such as fly ash removed by this dust collector has become a problem, and in particular, coal used in a coal-fired boiler contains a maximum content of about 120 mg / kg. Since boron (B) contained therein and selenium (Se) contained at a maximum content of about 10 mg / kg accumulate in soot and dust, it is desired to treat them so as to be harmless. B and Se are newly added to the regulation items in Japan, and drainage standards (land water area: 10 mg / l, sea area: 230 mg / l) have been established for B, and elution standards for landfill disposal (30 mg / l).
Is under consideration, and for Se, the drainage standard (0.1
mg / l) and elution standard for landfill disposal (0.3 mg / l)
l) was enacted.
【０００３】図５は、石炭焚きボイラ用の排煙処理にお
いて、従来の排煙処理装置を備えたシステムの一例を示
している。図５において、石炭焚きボイラ１から出る排
煙１０は、ボイラ１に付設された脱硝装置２で窒素酸化
物（ＮＯX）が除去され、エアヒータ３及びガスガスヒ
ータ（ＧＧＨ）の熱回収部４を通過した後、電気集塵機
（ＥＰ）５に導入されてフライアッシュ等のばいじんが
取り除かれる。次いで排煙は、湿式排煙脱硫装置６に導
かれ、この脱硫装置６において亜硫酸ガスを除いた後に
ガスガスヒータ（ＧＧＨ）の再加熱部７を通過した後、
図示省略した煙突に導かれて大気中に放出されるように
構成されている。そして、電気集塵機５で取り除かれた
フライアッシュ等のばいじんはサイロ９に抜き出された
後、一部がセメント原料等として再利用され、残部は灰
捨て場８に捨てられる。しかし、上記従来の排煙処理方
法では、石炭中のＢ及びＳｅのほとんどがエアヒータ３
等の後流側で凝縮し、排煙中のばいじんに含まれた状態
で電気集塵機５により取り除かれて、そのまま灰捨て場
８の廃棄物中又はセメント原料等の中に混在することに
なる。したがって、燃料として使用する石炭の種類にお
いては、ばいじんに含有されるＢ及びＳｅの含有量が多
く、水により溶出して前記の溶出基準値に近い値となる
事態が発生する。FIG. 5 shows an example of a system provided with a conventional flue gas treatment device in flue gas treatment for a coal-fired boiler. In FIG. 5, the flue gas 10 emitted from the coal-fired boiler 1 has nitrogen oxides (NO x ) removed by the denitration device 2 attached to the boiler 1, and the heat recovery part 4 of the air heater 3 and the gas gas heater (GGH). After passing, it is introduced into the electrostatic precipitator (EP) 5 to remove dust such as fly ash. Next, the flue gas is guided to the wet flue gas desulfurization device 6, and after the sulfur dioxide is removed in the desulfurization device 6, after passing through the reheating part 7 of the gas gas heater (GGH),
It is configured to be guided to a chimney (not shown) and discharged into the atmosphere. Then, the dust such as fly ash removed by the electric dust collector 5 is extracted to the silo 9, a part of it is reused as a cement raw material, and the rest is discarded to the ash dump 8. However, in the above conventional flue gas treatment method, most of B and Se in the coal are heated by the air heater 3.
Condensate on the downstream side of the exhaust gas, etc., and is removed by the electrostatic precipitator 5 in a state of being contained in the dust in the smoke exhaust, and is mixed as it is in the waste in the ash dump 8 or the cement raw material. Therefore, in the type of coal used as a fuel, the content of B and Se contained in soot and dust is large, and a situation occurs in which it is eluted by water and becomes a value close to the above-mentioned elution standard value.
【０００４】[0004]
【発明が解決しようとする課題】このような問題点を解
決する方法としては、排煙を３５０℃以下に冷却する冷
却工程と、排煙中のばいじんを分離する集塵工程と、こ
の集塵工程により分離されたばいじんに水及びＳｅの不
溶化処理剤を加えてばいじん中のＳｅを不溶化するＳｅ
処理工程とを備えた排煙処理方法が提案されている（特
開平８-２６６８５６号公報）。この方法によれば、排
煙中のＳｅについては容易に無害化することができる。
しかしながら、分離回収したばいじんに水を加えてスラ
リ化し、不溶化処理剤を添加混合してＳｅを不溶化した
のち固液分離するため、排水処理設備や固液分離装置等
の設備、機器が必要であるという問題があった。As a method for solving such a problem, a cooling step of cooling the exhaust gas to 350 ° C. or less, a dust collecting step of separating dust in the exhaust gas, and this dust collecting step. Se to insolubilize Se in soot and dust by adding water and an insolubilizing agent for Se to the soot and dust separated in the step
A flue gas treatment method including a treatment step has been proposed (Japanese Patent Laid-Open No. 8-266856). According to this method, Se in the flue gas can be easily made harmless.
However, since water is added to the separated dust to make it into a slurry, and an insolubilizing agent is added and mixed to insolubilize Se and then solid-liquid separation is performed, equipment and devices such as wastewater treatment equipment and solid-liquid separation equipment are required. There was a problem.
【０００５】また、排煙を３５０℃以下に冷却する冷却
工程と、排煙中のばいじんを分離除去する集塵工程と、
この集塵工程により分離されたばいじんにＳｅ溶出防止
剤と加湿液又はＳｅ溶出防止剤の溶液を添加して混合す
る混合工程と、さらに必要によりこの混合工程でＳｅ溶
出防止剤と加湿液又はＳｅ溶出防止剤の溶液と混合され
たばいじんを塊状化する塊状化工程とを備えた排煙処理
方法が提案されている（特開平８-３２３１３９号公
報）。この方法によれば、排煙中のＳｅを無害化するこ
とができる。しかしながら、Ｂの無害化や、ＢとＳｅを
同時に無害化し効率的な同時処理を達成することができ
ないという問題があった。Further, a cooling step for cooling the flue gas to 350 ° C. or lower, and a dust collecting step for separating and removing the dust in the flue gas,
A mixing step of adding a Se elution inhibitor and a humidifying liquid or a solution of the Se elution inhibitor to the dust separated in the dust collecting step and mixing them, and further, if necessary, in this mixing step, the Se elution inhibitor and the humidifying solution or Se are mixed. A flue gas treatment method has been proposed which includes a lumping step of lumping soot and dust mixed with a solution of an elution inhibitor (Japanese Patent Laid-Open No. 8-323139). According to this method, Se in flue gas can be rendered harmless. However, there is a problem in that it is not possible to render B harmless or render B and Se harmless at the same time to achieve efficient simultaneous processing.
【０００６】本発明は、上記の問題点に鑑み、排煙中の
ばいじんに含まれるホウ素の無害化、さらにはホウ素と
セレンの同時無害化が容易に達成できるばいじんの処理
方法及びばいじんの処理装置を提供することを目的とす
る。In view of the above problems, the present invention provides a method and apparatus for treating soot and dust which can easily achieve detoxification of boron contained in soot and dust in flue gas and further simultaneous detoxification of boron and selenium. The purpose is to provide.
【０００７】[0007]
【課題を解決するための手段】上記の目的を達成するた
め、本発明は、排煙中に含まれるばいじんの処理方法で
あって、該排煙中のばいじんを分離する集塵工程と、該
集塵工程により分離されたばいじんにホウ素の溶出防止
剤としてカルシウム化合物、特に、生石灰（Ｃａ(ＯＨ)
2）又は消石灰（ＣａＯ）を添加して混合する混合工程
とを含むことを特徴とする。これにより、ばいじんに含
有されたＢが不溶性の化合物に変換される。このため、
ばいじんを従来と同様に廃棄処理しても、Ｂの溶出基準
等がクリアでき、面倒な後処理を行わなくてもＢの無害
化が容易に可能となる。In order to achieve the above object, the present invention provides a method for treating dust contained in flue gas, which comprises a dust collection step for separating the dust in flue gas, Calcium compounds, especially quicklime (Ca (OH)) as an elution inhibitor for boron in dusts separated in the dust collection process.
2 ) or slaked lime (CaO) is added and mixed. As a result, B contained in the dust is converted into an insoluble compound. For this reason,
Even if soot and dust are disposed of in the same manner as in the conventional case, the elution standard of B can be cleared, and B can be easily rendered harmless without performing a troublesome post-treatment.
【０００８】前記混合工程で添加するホウ素の溶出防止
剤の量は、以下の式とすることができる。
Ｒ≧０．００５４Ｑ−０．６・・・・・・・・（４）
［式（４）中、Ｒはホウ素の溶出防止剤の添加量（Ｃａ
換算）〔ｗｔ％〕を示し、Ｑはばいじん中のホウ素含有
量〔ｍｇ／ｋｇ−ｄｒｙ〕を示す。］このように、添加
するカルシウム化合物、特に、生石灰又は消石灰の量を
定量化することにより、より経済的にＢの不溶化処理が
可能となる。The amount of the boron elution inhibitor added in the mixing step can be represented by the following formula. R ≧ 0.0054Q−0.6 (4) [In the formula (4), R is the amount of the boron elution inhibitor added (Ca
(Converted) [wt%], and Q represents the boron content in soot and dust [mg / kg-dry]. As described above, by quantifying the amount of the calcium compound to be added, particularly quick lime or slaked lime, the insolubilization treatment of B becomes possible more economically.
【０００９】また、本発明は、排煙中に含まれるばいじ
んの処理方法であって、該排煙中のばいじんを分離する
集塵工程と、該集塵工程により分離されたばいじんに、
ホウ素の溶出防止剤としてカルシウム化合物、特に、生
石灰又は消石灰、及びセレンの溶出防止剤として鉄（３
価）塩、特に、ＦｅＣｌ3又はＦｅ2(ＳＯ4)3を添加して
混合する混合工程とを含むことを特徴とする。これによ
り、ばいじんに含有されたＢとＳｅの両方が不溶性の化
合物に変換される。このため、ばいじんを従来と同様に
廃棄処理しても、Ｂ及びＳｅの溶出基準等が同時にクリ
アでき、面倒な後処理を行わなくても、ＢとＳｅの同時
無害化が容易に可能となる。The present invention also provides a method for treating soot and dust contained in flue gas, comprising a dust collecting step for separating soot and dust in the flue gas, and soot and dust separated by the dust collecting step,
Calcium compounds as elution inhibitors for boron, especially quick lime or slaked lime, and iron (3 as elution inhibitors for selenium).
Valent) salt, in particular FeCl 3 or Fe 2 (SO 4 ) 3 is added and mixed. As a result, both B and Se contained in the soot and dust are converted into insoluble compounds. Therefore, even if the dust is disposed of as in the conventional case, the elution standard of B and Se can be cleared at the same time, and it is possible to easily render B and Se harmless at the same time without performing a troublesome post-treatment. .
【００１０】前記混合工程で添加するホウ素の溶出防止
剤及びセレンの溶出防止剤の量は、以下の式とすること
ができる。
Ｒ≧０．００５４Ｑ−０．６＋１．１Ｙ・・・（５）
［式（５）中、Ｒはホウ素の溶出防止剤の添加量(Ｃａ
換算)〔ｗｔ％〕を示し、Ｑはばいじん中のホウ素含有
量〔ｍｇ／ｋｇ−ｄｒｙ〕を示し、Ｙはセレンの溶出防
止剤の添加量（Ｆｅ換算）〔ｗｔ％〕を示す。］
Ｙ≧０．０３２Ｘ−０．２・・・・・・・・・（６）
［式（６）中、Ｙはセレンの溶出防止剤の添加量（Ｆｅ
換算）〔ｗｔ％〕を示し、Ｘはばいじん中のセレン含有
量〔ｍｇ／ｋｇ−ｄｒｙ〕を示す。］このように、添加
するカルシウム化合物、特に、生石灰又は消石灰と、鉄
（３価）塩、特に、ＦｅＣｌ3又はＦｅ2(ＳＯ4)3の量を
定量化することにより、より経済的にＢとＳｅの不溶化
処理が可能となる。The amounts of the boron elution inhibitor and the selenium elution inhibitor added in the mixing step can be represented by the following formula. R ≧ 0.0054Q−0.6 + 1.1Y (5) [In the formula (5), R is the addition amount of the elution inhibitor of boron (Ca).
(Converted) [wt%], Q represents the boron content in soot and dust [mg / kg-dry], and Y represents the amount of the selenium dissolution inhibitor added (converted to Fe) [wt%]. ] Y ≧ 0.032X-0.2 ... (6) [In the formula (6), Y represents the amount of the selenium dissolution inhibitor added (Fe).
(Converted) [wt%], and X represents the selenium content in soot and dust [mg / kg-dry]. ] Thus, by quantitatively quantifying the amount of the calcium compound to be added, especially quick lime or slaked lime, and the iron (trivalent) salt, especially FeCl 3 or Fe 2 (SO 4 ) 3 , And Se can be insolubilized.
【００１１】また、前記混合工程で前記溶出防止剤と混
合されたばいじんを塊状化する塊状化工程をさらに含む
こともできる。これにより、ばいじんをスラリ化して不
溶化剤を混合し、その後、固液分離して廃棄する場合に
比べて、排水（ろ液）処理設備や固液分離機等の大掛か
りな設備又は機器を設ける必要がなくなるとともに、ば
いじんの廃棄処理等における取り扱いがさらに容易にな
る。また、ばいじんのかさ密度が大きくなって圧密化さ
れるため、灰捨て場の延命化策となる。The method may further include an agglomeration step of agglomerating the dust mixed with the elution inhibitor in the mixing step. This makes it necessary to install large-scale equipment or devices such as wastewater (filtrate) treatment equipment and solid-liquid separators, as compared with the case where the soot and dust is slurried and the insolubilizer is mixed, and then solid-liquid separation is performed and then discarded. And the handling of dust and so on becomes easier. In addition, since the bulk density of dust is increased and consolidated, it is a measure to prolong the life of ash dumps.
【００１２】さらに、前記集塵工程では、ばいじんを分
離回収する回収部が排煙の入口側から出口側に向って複
数設けられており、排煙の入口側の回収部から回収され
るばいじんと出口側から回収されるばいじんとを別個に
分離回収し、出口側で分離回収されたばいじんのみを、
前記混合工程に導入することもできる。このように、集
塵工程における排煙の出口側の特定の回収部から分離回
収されたばいじんのみを混合工程に導入して不溶化処理
することで、不溶化剤の必要量や混合工程及び塊状化工
程の容量等が低減でき、ＢとＳｅの無害化をより容易か
つ安価に行うことができる。すなわち、本発明者らの研
究によれば、出口側の特定の回収部から分離回収される
ばいじんは、入口側で回収されるばいじんよりも粒径が
小さく、よって表面積が大きいので、ＢやＳｅがより多
量に付着・含有されていることが判明した。したがっ
て、この粒径の小さいばいじんに対してのみ不溶化処理
を施す方法によれば、処理対象とするばいじんの量を少
なくして、効率的な処理を行うことができ、全体として
ＢとＳｅの無害化が可能となる。Further, in the dust collecting step, a plurality of collecting portions for separating and collecting soot and dust are provided from the inlet side of the flue gas toward the outlet side, and the soot and dust collected from the collecting portion on the flue gas inlet side. Separately collects soot and dust collected from the outlet side, and only soot and dust separated and collected at the outlet side
It can also be introduced into the mixing step. In this way, by introducing only the soot and dust separated and recovered from the specific recovery part on the side of the exhaust gas in the dust collecting process into the mixing process and insolubilizing the mixture, the required amount of the insolubilizing agent and the mixing process and the agglomeration process are performed. The capacity and the like can be reduced, and B and Se can be made harmless more easily and at a lower cost. That is, according to the research conducted by the present inventors, the soot and dust separated and recovered from the specific recovery unit on the outlet side have a smaller particle size and thus a larger surface area than the soot and dust recovered on the inlet side. Was found to be attached and contained in a larger amount. Therefore, according to the method of insolubilizing only soot and dust having a small particle size, the amount of soot and dust to be treated can be reduced and efficient treatment can be carried out, and B and Se are harmless as a whole. Can be realized.
【００１３】[0013]
【発明の実施の形態】以下、本発明の実施の形態を添付
図面に基づいて説明する。第１の実施の形態
図１は、本発明に係るばいじんの処理方法の一実施の形
態の要部構成を示した図である。この排煙処理方法は、
図１に示すように、石炭焚きボイラ（図示省略）から出
る排煙２０を電気集塵機２１に導き、排煙２０中のフラ
イアッシュ等のばいじんを集塵除去する。ばいじんを除
去した排煙２２は後工程の脱硫装置（図示省略）に導入
される。電気集塵機２１は、ばいじんを分離回収する複
数のホッパ２３〜２６を有しており、これらホッパ２３
〜２６が排煙の入口側（上流側）から出口側（後流側）
に向って順次形成されている。このような構成により、
入口側のホッパからより大粒径のばいじんが回収され、
出口側のホッパからより小粒径のばいじんが回収できる
ようになっている。そしてこの場合、電気集塵機２１に
おける複数のホッパ２３〜２６のうち、排煙の出口側の
特定のホッパ２５、２６から分離回収されたばいじん２
７のみを混合機３１に導入する。BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. First Embodiment FIG. 1 is a diagram showing a main configuration of an embodiment of a method for treating dust according to the present invention. This flue gas treatment method is
As shown in FIG. 1, flue gas 20 emitted from a coal-fired boiler (not shown) is guided to an electric dust collector 21 to remove dust such as fly ash in the flue gas 20. The flue gas 22 from which dust has been removed is introduced into a desulfurization device (not shown) in a post process. The electric dust collector 21 has a plurality of hoppers 23 to 26 for separating and collecting soot and dust.
~ 26 is the flue gas inlet side (upstream side) to the outlet side (wake side)
Are formed in sequence toward. With this configuration,
Larger particle size dust is collected from the hopper on the inlet side,
Dust with a smaller particle size can be collected from the hopper on the outlet side. In this case, the dust 2 separated and collected from the specific hoppers 25 and 26 on the smoke exhaust outlet side among the plurality of hoppers 23 to 26 in the electrostatic precipitator 21.
Only 7 is introduced into the mixer 31.
【００１４】混合機３１では、Ｂの溶出防止剤としてカ
ルシウム化合物２９を添加し、Ｂを不溶化処理した後、
Ｓｅの溶出防止剤として鉄（３価）塩３０を添加し、Ｓ
ｅを不溶化処理して、混合機３１の排出口から不溶化処
理されたばいじん３２を排出する。Ｂの溶出防止剤であ
るＣａ化合物２９としては、生石灰又は消石灰が好まし
い。他のＣａ化合物、例えば、炭酸カルシウム等も使用
可能であるが、ｐＨが低いため、添加量を多くする必要
がある。なお、Ｂの溶出防止剤として添加する生石灰又
は消石灰により、ばいじん中のフッ素（Ｆ）の溶出も副
次的に防止できる。すなわち、ばいじん中のＦは添加さ
れる生石灰又は消石灰により、難溶解性のＣａＦ2が生
成し、Ｆの不溶化が図れる。Ｓｅの不溶化剤である鉄
（３価）塩３０としては、ＦｅＣｌ3又はＦｅ2(ＳＯ4)3
が好ましい。ＦｅＣｌ3又はＦｅ2（ＳＯ4）3の他に、キ
レート剤や、高分子重金属捕集剤等を使用することもで
きるが、高価となる。In the mixer 31, a calcium compound 29 is added as an elution inhibitor for B, and the B is insolubilized.
Iron (trivalent) salt 30 is added as an elution inhibitor for Se, and S
The e is insolubilized, and the insolubilized dust 32 is discharged from the discharge port of the mixer 31. As the Ca compound 29 which is the elution inhibitor of B, quick lime or slaked lime is preferable. Other Ca compounds, such as calcium carbonate, can be used, but since the pH is low, the addition amount needs to be increased. In addition, quick lime or slaked lime added as an elution inhibitor for B can secondarily prevent elution of fluorine (F) in soot and dust. That is, the F in the soot and dust can be made insoluble by the addition of quick lime or slaked lime, which makes it difficult to dissolve CaF 2 . Examples of the iron (trivalent) salt 30 which is an insolubilizing agent for Se include FeCl 3 or Fe 2 (SO 4 ) 3
Is preferred. In addition to FeCl 3 or Fe 2 (SO 4 ) 3 , a chelating agent, a heavy polymer heavy metal scavenger or the like can be used, but it is expensive.
【００１５】この不溶化処理されたばいじん３２は、一
度サイロ（図示省略）に貯えられ、セメント原料に再利
用するか又は灰捨て場（図示省略）に廃棄される。ここ
でサイロを省略し、直接灰捨て場に廃棄しても何ら問題
ない。また、残りのばいじん２８を廃棄処理等する構成
としている。混合機３１は、この場合、投入されたばい
じんや、Ｂの溶出防止剤として添加する生石灰又は消石
灰、Ｓｅの溶出防止剤として添加する鉄（３価）塩（Ｆ
ｅＣｌ3又はＦｅ2(ＳＯ4)3）を混合して排出する機能を
有するもので、例えば、投入物を撹拌しつつ排出側に送
り出す撹拌羽根を内部に有するものである。The insolubilized soot and dust 32 is once stored in a silo (not shown) and reused as a cement raw material or discarded at an ash dump (not shown). There is no problem if you omit the silo here and discard it directly at the ash dump. Further, the remaining dust 28 is configured to be discarded. In this case, the mixer 31 includes a quick-drying lime or slaked lime added as an elution inhibitor for B or E, an iron (trivalent) salt (F) added as an elution inhibitor for Se.
It has a function of mixing and discharging eCl 3 or Fe 2 (SO 4 ) 3 ), and has, for example, a stirring blade inside which stirs the charged material and sends it to the discharge side.
【００１６】ばいじん中のＢは一般的にＨ3ＢＯ3として
溶出するので、ばいじんにＢの溶出防止剤として生石灰
又は消石灰を混合することにより、生成した混合物から
のＢ溶出が極めて少なくなり、溶出基準を十分満足さす
ことができる。本発明者らは、このメカニズムを解明す
べく、混合物をＸ線回折にて詳細に調査した結果、ばい
じんのみでは確認されなかった化合物として、３ＣａＯ
・Ａｌ 2Ｏ3・２Ｃａ（ＯＨ）2・Ｃａ［Ｂ（ＯＨ）4］2
・３６Ｈ2Ｏが新しく生成しているのを確認した。この
化合物は難溶解性であり、この化合物の生成によりＢの
不溶化が図れる。但し、弱い回折ピークとして、Ｃａ6
Ａｌ12Ｂ2Ｏ6（ＯＨ）12・３６Ｈ2Ｏ、Ｃａ6Ｆｅ2（Ｓ
Ｏ4）2［Ｂ（ＯＨ）4］（ＯＨ）12・２６Ｈ2Ｏも存在す
る。３ＣａＯ・Ａｌ2Ｏ3・２Ｃａ（ＯＨ）2・Ｃａ［Ｂ
（ＯＨ）4］2・３６Ｈ2ＯのＸ線回折パターンのうち、
最も強度の高い２θ＝９°付近のピーク強度とＢ溶出濃
度の関係を調べたが、ピーク強度の増加とともにＢ溶出
濃度は低下しており、本化合物の含有量が多い混合物で
はＢ溶出濃度が低くなることが判明した。B in dust is generally H3BO3As
As it elutes, quick lime is used as an elution inhibitor for B in the dust.
Or by mixing slaked lime, from the mixture produced
B elution of B is extremely small, and the elution standard is sufficiently satisfied.
be able to. We elucidate this mechanism
Therefore, as a result of detailed examination of the mixture by X-ray diffraction,
3CaO as a compound not confirmed by dust alone
・ Al 2O3・ 2Ca (OH)2・ Ca [B (OH)Four]2
・ 36H2It was confirmed that O was newly generated. this
The compound is sparingly soluble and the formation of this compound
Can be insolubilized. However, as a weak diffraction peak, Ca6
Al12B2O6(OH)12・ 36H2O, Ca6Fe2(S
OFour)2[B (OH)Four] (OH)12・ 26H2O also exists
It 3CaO / Al2O3・ 2Ca (OH)2・ Ca [B
(OH)Four]2・ 36H2Of the X-ray diffraction patterns of O,
Peak intensity around 2θ = 9 °, which is the highest intensity, and B elution concentration
The relationship between the degrees was examined, but B elutes as the peak intensity increases.
The concentration is low, and the mixture containing a large amount of this compound
Was found to have a low B elution concentration.
【００１７】また、ばいじん中にＢ以外にＳｅも含有
し、その不溶化処理が必要となる場合には、ばいじんに
Ｂの溶出防止剤として生石灰又は消石灰を添加した後、
Ｓｅの溶出防止剤として鉄（３価）塩（ＦｅＣｌ3又は
Ｆｅ2(ＳＯ4)3）３０を添加し混合する。ばいじん中に
４価のＳｅ(主形態：亜セレン酸ＳｅＯ3 2-)が存在する
場合には、添加するＦｅＣｌ3又はＦｅ2(ＳＯ4)3によ
り、以下の式に示すように、難溶解性の亜セレン酸鉄
(Ｆｅ2（ＳｅＯ3）3)が生成し、不溶化処理される。
ＦｅＣｌ3 → Ｆｅ3+＋３Ｃｌ-・・・・・・・・・・（７）
２Ｆｅ3+＋３ＳｅＯ3 2- → Ｆｅ2（ＳｅＯ3）3↓・・・（８）
Ｆｅ2（ＳＯ4）3 → ２Ｆｅ3+＋３ＳＯ4 2-・・・・・・（９）
２Ｆｅ3+＋３ＳｅＯ3 2- → Ｆｅ2（ＳｅＯ3）3↓・・・（１０）When Se is contained in the soot and dust in addition to B and insolubilization is required, quick lime or slaked lime is added to the soot and dust as an elution inhibitor for B, and
An iron (trivalent) salt (FeCl 3 or Fe 2 (SO 4 ) 3 ) 30 is added as an Se elution inhibitor and mixed. When tetravalent Se (main form: selenous acid SeO 3 2− ) is present in soot and dust, it is difficult to dissolve as shown in the following formula by adding FeCl 3 or Fe 2 (SO 4 ) 3. Sex iron selenite
(Fe 2 (SeO 3 ) 3 ) is produced and is insolubilized. FeCl 3 → Fe 3+ + 3Cl - ·········· (7) 2Fe 3+ + 3SeO 3 2- → Fe 2 (SeO 3) 3 ↓ ··· (8) Fe 2 (SO 4) 3 → 2Fe 3+ + 3SO 4 2 --- (9) 2Fe 3+ + 3SeO 3 2-- > Fe 2 (SeO 3 ) 3 ↓ ... (10)
【００１８】なお、ばいじん中に６価のＳｅ(主形態：
セレン酸ＳｅＯ4 2-)が存在し、これも不溶化する必要が
ある場合には、処理剤として、この６価のＳｅを４価の
Ｓｅにする還元剤を上記薬剤と共に投入すればよい。還
元剤としては、例えば、ＳＯ 2を水に吹き込んで得られ
る亜硫酸水などが好適に使用できる。なお、湿式脱硫装
置が併設されている場合、脱硫装置でＳＯ2を吸収し未
反応の亜硫酸を含むスラリあるいは、循環水を抜き出し
使用するのが好都合である。但し、電気集塵機２１は通
常湿式脱硫装置（図示省略）の前流側に設置されてお
り、排煙中に亜硫酸ガスを多く含んでいるのでばいじん
中に含まれるＳｅの形態も４価のＳｅが多く存在する。Hexavalent Se in the dust (main form:
Selenate SeOFour 2-) Is present and also needs to be insolubilized
In some cases, this hexavalent Se can be used as a treating agent
A reducing agent for Se may be added together with the above-mentioned agent. Return
As the active ingredient, for example, SO 2Obtained by blowing
Sulfite water and the like can be preferably used. Wet desulfurization equipment
If the equipment is installed side by side, SO2Absorbed
Extraction of slurry containing reaction sulfurous acid or circulating water
It is convenient to use. However, the electrostatic precipitator 21 is not
It is installed on the upstream side of the normal wet desulfurization unit (not shown).
However, since the flue gas contains a large amount of sulfurous acid gas, soot and dust
As for the form of Se contained therein, there are many tetravalent Se.
【００１９】第２の実施の形態
図２は、この本発明に係るばいじんの処理方法の一実施
の形態の要部構成を示した図である。図１と同じ構成に
ついては同じ符号を付し、説明を省略する。図２に示す
ように、ばいじん中のＢ及びＳｅを第１の実施の形態と
同様に不溶化処理した後、混合機３１から排出される不
溶化処理灰３２を、ブリケッティングマシン３３により
塊状に圧密化処理する（以下、塊状ばいじんという）。
そして、この塊状ばいじんを取り扱いに適した大きさに
砕くグラニュレータ３４と、このグラニュレータ３４に
より砕かれた塊状ばいじんのうち、適正な大きさのもの
のみをふるい分けするスクリーン３５とが順に設けられ
ている。スクリーン３５で分級された塊状ばいじんのう
ち、適正な大きさの塊状ばいじん３８は、そのまま廃棄
又は再利用され、小さすぎる塊状ばいじん３６はブリケ
ッティングマシン３３に戻され、大きすぎる塊状ばいじ
ん３７は再度グラニュレータ３４に送られる構成となっ
ている。この様に塊状ばいじんとすることにより、ばい
じんの取り扱いが容易となるばかりでなく、ばいじんの
かさ密度が通常０．８〜１．０ｇ／ｃｍ3から１．４〜
１．６ｇ／ｃｍ3に圧密化されるため、灰捨て場の延命
化策となる。なお、ブリケッティングマシン３３により
塊状にした段階で廃棄し、次段階のグラニュレータ３４
とスクリーン３５を省略してもよい。Second Embodiment FIG. 2 is a diagram showing a configuration of essential parts of an embodiment of the method for treating dust according to the present invention. The same components as those in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted. As shown in FIG. 2, after B and Se in the dust are insolubilized in the same manner as in the first embodiment, the insolubilized ash 32 discharged from the mixer 31 is compacted into a block by the briquetting machine 33. It is processed (hereinafter referred to as lumpy dust).
Then, a granulator 34 for crushing the lumped dust into a size suitable for handling, and a screen 35 for sieving only the lumped dust crushed by the granulator 34 in an appropriate size are provided in order. There is. Of the lumps and dusts classified by the screen 35, the lumps and dusts 38 having an appropriate size are discarded or reused as they are, the lumps and dusts 36 which are too small are returned to the briquetting machine 33, and the lumps and dusts 37 which are too large are reused. It is configured to be sent to the granulator 34. In this way, not only the handling of soot and dust becomes easy by making the lumpy soot and dust, but the bulk density of soot and dust is usually 0.8 to 1.0 g / cm 3 to 1.4 to
Since it is consolidated to 1.6 g / cm 3 , it is a measure to prolong the life of the ash dump. It is to be noted that the briquetting machine 33 discards the lumps at the stage where they are lumped, and the granulator 34 at the next stage is used.
The screen 35 may be omitted.
【００２０】[0020]
【実施例】実施例１
図１に示す方法に従い、Ｂ及びＳｅの含有量の異なる各
種石炭を２５ｋｇ／ｈで燃焼炉に供給し、燃焼炉から排
出される２００ｍ3Ｎ／ｈの排煙を１５０℃まで冷却し
て電気集塵機に導入し、電気集塵機の出口側ホッパでば
いじんを捕集した。この捕集したばいじん１ｋｇを３Ｌ
容量のコンクリートミキサに入れ、工業用の生石灰をば
いじんの５ｗｔ％（Ｃａ換算）になる様に添加した後、
１分間撹拌した。次いで工業用ＦｅＣｌ3溶液をばいじ
んの１ｗｔ％（Ｆｅ換算）になる様に添加し、３分間撹
拌してばいじんの不溶化処理試験を実施した。不溶化処
理前後のばいじんは環境庁告示１３号に準拠した溶出試
験を実施して、溶出液中のＢをプラズマ発光分析法又は
吸光光度法で、Ｓｅを水素化物原子吸光法で分析した。
その際、不溶化処理前のばいじん中Ｂ及びＳｅの分析を
実施し含有量を求めた。According to the method shown in EXAMPLE 1 FIG. 1, B and Se various different coal of content is supplied to the combustion furnace at 25 kg / h, the flue gas of 200m 3 N / h discharged from the combustion furnace It was cooled to 150 ° C. and introduced into an electrostatic precipitator, and the dust was collected by the outlet side hopper of the electrostatic precipitator. 1 L of this collected dust is 3 L
After putting it in a concrete mixer of capacity and adding quicklime for industrial use to 5 wt% of soot and dust (calculated as Ca),
Stir for 1 minute. Then, an industrial FeCl 3 solution was added so as to be 1 wt% of soot and dust (calculated as Fe), and stirred for 3 minutes to conduct a soot and dust insolubilization treatment test. The soot and dust before and after the insolubilization treatment were subjected to an elution test in accordance with Notification No. 13 of the Environment Agency, and B in the eluate was analyzed by plasma emission spectrometry or absorptiometry and Se by hydride atomic absorption spectrometry.
At that time, B and Se in the soot and dust before the insolubilization treatment were analyzed to determine the contents.
【００２１】同様にして、各種石炭を燃焼して得られた
ばいじんに生石灰又は消石灰及びＦｅＣｌ3又はＦｅ
2（ＳＯ4）3の添加量を種々変化させ、Ｂ及びＳｅの不
溶化処理試験を実施し、埋立処分に関する溶出基準（Ｂ
については３０ｍｇ／ｌ、Ｓｅについては０．３ｍｇ／
ｌ）を充分に満足する条件を鋭意探索した。その結果、
図３に示す通り、ばいじん中Ｂ含有量に対して溶出基準
を満足するための最適なカルシウム添加量の関係が得ら
れた。また、図４に示す通り、ばいじん中Ｓｅ含有量に
対して溶出基準を満足するための最適な鉄（３価）塩添
加量の関係が得られた。これらの関係を式化すると以下
の通りとなる。Similarly, soot and dust obtained by burning various coals, quick lime or slaked lime and FeCl 3 or Fe
2 (SO 4 ) 3 addition amount was changed variously, insolubilization test of B and Se was conducted, and elution standard (B
For 30 mg / l and for Se 0.3 mg / l
The conditions for sufficiently satisfying l) were eagerly searched. as a result,
As shown in FIG. 3, the relationship between the B content in the soot and dust and the optimum calcium addition amount for satisfying the elution standard was obtained. Further, as shown in FIG. 4, the relation of the optimum addition amount of iron (trivalent) salt for satisfying the elution standard was obtained with respect to the Se content in the dust. The formula of these relationships is as follows.
【００２２】 Ｒ＝０．００５４Ｑ−０．６・・・・・・・・・・（１１） Ｒ：Ｃａ添加量（Ｃａ換算）〔ｗｔ％〕 Ｑ：ばいじん中のＢ含有量〔ｍｇ／ｋｇ−ｄｒｙ〕 Ｙ＝０．０３２Ｘ−０．２・・・・・・・・・・・（１２） Ｙ：鉄（３価）塩添加量（Ｆｅ換算）〔ｗｔ％〕 Ｘ：ばいじん中のＳｅ含有量〔ｍｇ／ｋｇ−ｄｒｙ〕[0022] R = 0.0054Q-0.6 (11) R: Ca addition amount (calculated as Ca) [wt%] Q: B content in soot and dust [mg / kg-dry] Y = 0.032X-0.2 ... (12) Y: Iron (trivalent) salt addition amount (Fe conversion) [wt%] X: Se content in soot and dust [mg / kg-dry]
【００２３】一方、鉄（３価）塩の添加により、以下の
式に従ってカルシウム化合物が消費されてしまう。
２Ｆｅ3+＋３ＣａＯ＋３Ｈ2Ｏ→２Ｆｅ（ＯＨ）3＋３Ｃａ2+・・（１３）
よって、ＢとＳｅの同時無害化をする場合は、この消費
分を上積みしてカルシウム化合物を添加する必要があ
る。理論的には、消費するＣａ（ｒ）とＦｅ（Ｙ）の反
応の関係は以下の式である。
（ｒ／４０）×２＝（Ｙ／５６）×３・・・・・・（１４）
したがって、このｒ≒１．１Ｙを上記の式（１１）に加
えた以下の式が、ＢとＳｅを同時無害化する場合の最適
Ｃａ添加量ということになる。
Ｒ＝０．００５４Ｑ−０．６＋１．１Ｙ・・・・・（１５）On the other hand, the addition of the iron (trivalent) salt consumes the calcium compound according to the following formula. 2Fe 3+ + 3CaO + 3H 2 O → 2Fe (OH) 3 + 3Ca 2+ ··· (13) Therefore, when simultaneously detoxifying B and Se, it is necessary to add this consumption amount and add a calcium compound. Theoretically, the relationship of the reaction between Ca (r) and Fe (Y) to be consumed is the following formula. (R / 40) × 2 = (Y / 56) × 3 (14) Therefore, the following equation in which this r≈1.1Y is added to the above equation (11) is B and Se. This means the optimum amount of Ca added when simultaneously detoxifying. R = 0.0054Q-0.6 + 1.1Y (15)
【００２４】但し、これらの不溶化剤の添加量は、埋立
処分に関する溶出基準を満足さすための最適な添加量を
算出するために定めた値であり、もちろん最適値以上の
添加量を加えることができるとともに、状況によっては
これらの添加量を増減することも可能である。However, the addition amount of these insolubilizers is a value determined in order to calculate the optimum addition amount for satisfying the elution standard for landfill disposal, and, of course, the addition amount above the optimum value may be added. In addition to this, it is possible to increase or decrease the amount of these added depending on the situation.
【００２５】実施例２
図１に示す方法に従い、石炭を２５ｋｇ／ｈで燃焼炉に
供給し、燃焼炉から排出される２００ｍ3Ｎ／ｈの排煙
を１５０℃まで冷却して電気集塵機に導入した。電気集
塵機により９９％以上のばいじんが捕集され、各ホッパ
から回収されたばいじんの量は３．７ｋｇ／ｈであっ
た。そして、入口側ホッパ（図１の２３、２４）及び出
口側ホッパ（図１の２５、２６）で回収されるばいじん
（回収灰）の搬出量、平均粒径、回収灰のＢ及びＳｅの
含有量、回収灰のＢ及びＳｅの溶出濃度は、それぞれ表
１に示すとおりであった。なお、ここでいう溶出Ｂ濃度
及び溶出Ｓｅ濃度は、環境庁告示１３号に準拠した溶出
試験により、Ｂについてはプラズマ発光分析法又は吸光
光度法、Ｓｅについては水素化物原子吸光法で分析した
ものである。 Example 2 According to the method shown in FIG. 1, coal is supplied to a combustion furnace at 25 kg / h, and 200 m 3 N / h of smoke discharged from the combustion furnace is cooled to 150 ° C. and introduced into an electrostatic precipitator. did. 99% or more of dust was collected by the electric dust collector, and the amount of dust collected from each hopper was 3.7 kg / h. Then, the carry-out amount of soot and dust (recovered ash) collected by the inlet side hopper (23, 24 in FIG. 1) and the outlet side hopper (25, 26 in FIG. 1), the average particle size, and the content of B and Se in the recovered ash. The amounts and the elution concentrations of B and Se in the recovered ash were as shown in Table 1, respectively. In addition, the elution B concentration and elution Se concentration here are those analyzed by the elution test according to the Environmental Agency Notification No. 13, B for plasma emission analysis or absorptiometry, and Se for hydride atomic absorption method. Is.
【００２６】[0026]
【表１】 [Table 1]
【００２７】表１に示すように、排煙の出口側ホッパか
ら分離回収されたばいじんは、搬出量が１．４ｋｇ／ｈ
と少ないが、溶出Ｂ濃度は２６ｍｇ／ｌ、溶出Ｓｅ濃度
は０．２９ｍｇ／ｌと埋立処分に関する溶出基準（Ｂに
ついては３０ｍｇ／ｌ、Ｓｅについては０．３ｍｇ／
ｌ）に近い値となっていた。しかし、排煙の入口側ホッ
パから分離回収されたばいじんは、搬出量が２．３ｋｇ
／ｈと多いが溶出Ｂ濃度は８．２ｍｇ／ｌ、溶出Ｓｅ濃
度は０．０９ｍｇ／ｌと低く、溶出基準を下回ってい
た。このため、排煙の入口側ホッパから分離回収された
ばいじんは、そのまま廃棄処理等できることが分かる。
つまり、搬出量が約２倍多い排煙の入口側のばいじんの
Ｂ及びＳｅの不溶化処理が不要となるから、溶出防止剤
の必要量や混合機等の容量が格段に節約できることが明
らかである。なお、このような溶出Ｂ濃度、溶出Ｓｅ濃
度の違いは、ばいじんの粒径に起因しているものと考え
られる。すなわち、石炭焚き燃焼炉から排出されたガス
状のＢ及びＳｅが凝縮して、ばいじんを構成する灰の表
面に付着する際、小さな粒径の灰は単位重量当りの比表
面積が大きいから、より多くのＢ及びＳｅが付着するこ
ととなる。したがって、排煙の出口側で捕集されたばい
じんを不溶化処理すればより経済的となる。As shown in Table 1, the amount of soot and dust separated and collected from the flue gas exit side hopper has an output of 1.4 kg / h.
However, the elution B concentration was 26 mg / l, the elution Se concentration was 0.29 mg / l, and the elution standard for landfill disposal was 30 mg / l for B and 0.3 mg / l for Se.
It was a value close to l). However, the amount of soot and dust separated and collected from the flue gas inlet hopper is 2.3 kg.
However, the elution B concentration was 8.2 mg / l and the elution Se concentration was as low as 0.09 mg / l, which were below the elution standard. Therefore, it is understood that the dust collected and separated from the flue gas inlet side hopper can be directly disposed of.
In other words, it is clear that the insolubilization treatment of soot and dust B and Se on the inlet side of the flue gas, which is about twice as large as the carry-out amount, is not required, so that the required amount of the elution inhibitor and the capacity of the mixer can be significantly saved. . It is considered that such a difference in the concentration of eluted B and the concentration of eluted Se is caused by the particle size of soot and dust. That is, when the gaseous B and Se discharged from the coal-fired combustion furnace are condensed and adhere to the surface of the ash that constitutes the soot and dust, the ash having a small particle size has a large specific surface area per unit weight. A large amount of B and Se will be attached. Therefore, it becomes more economical to insolubilize the dust collected on the exit side of the smoke exhaust.
【００２８】次いで、排煙の出口側ホッパから分離回収
されたばいじんを１．４ｋｇ／ｈで混合機に導入し、ば
いじん中のＢに対し、カルシウム添加量が３．５ｗｔ％
（Ｃａ換算）となる様に工業用の生石灰粉末（純度９８
％）を０．０７ｋｇ／ｈで添加した。そして、ばいじん
中のＳｅに対し、鉄（３価）塩添加量が１．０ｗｔ％
（Ｆｅ換算）となるように、工業用ＦｅＣｌ3溶液（Ｆ
ｅＣｌ3 ３９％溶液）を０．０５８ｋｇ／ｈで添加
し、ばいじんと不溶化剤とを混合した。混合機は６０ｒ
ｐｍの回転数で撹拌しながら、不溶化処理後のばいじん
を排出した。この排出された不溶化処理後のばいじんの
Ｂ及びＳｅの溶出濃度を表２に示す。表２に示すよう
に、不溶化処理後のばいじんのＢ溶出濃度は９ｍｇ／
ｌ、Ｓｅ溶出濃度は０．０８ｍｇ／ｌと埋立処分に関す
る溶出基準濃度を十分満足していた。Next, the soot and dust separated and collected from the flue gas outlet side hopper was introduced into the mixer at 1.4 kg / h, and the amount of calcium added was 3.5 wt% with respect to B in the soot and dust.
Industrial quicklime powder (purity 98)
%) Was added at 0.07 kg / h. The amount of iron (trivalent) salt added is 1.0 wt% with respect to Se in the dust.
Industrial FeCl 3 solution (F
eCl 3 39% solution) was added at 0.058 kg / h, and the dust and the insolubilizer were mixed. Mixer 60r
The soot and dust after the insolubilization treatment was discharged while stirring at a rotation speed of pm. Table 2 shows the elution concentrations of B and Se in the discharged soot and dust after the insolubilization treatment. As shown in Table 2, the B elution concentration of the soot and dust after the insolubilization treatment was 9 mg /
The l and Se elution concentrations were 0.08 mg / l, which sufficiently satisfied the elution standard concentration for landfill disposal.
【００２９】[0029]
【表２】 [Table 2]
【００３０】実施例３
石炭の種類、Ｂの溶出防止剤及びＳｅの溶出防止剤の種
類を変えた以外は、実施例２と同様にして、不溶化試験
を実施した。石炭を２５ｋｇ／ｈで燃焼炉に供給し、燃
焼炉から排出される２００ｍ3Ｎ／ｈの排煙を１５０℃
まで冷却して電気集塵機に導入した。電気集塵機の出口
側ホッパから分離回収されたばいじんを採取し分析し
た。その結果を表３に示す。表３に示すように、溶出Ｂ
濃度は２８ｍｇ／ｌ、溶出Ｓｅ濃度は０．２５ｍｇ／ｌ
と埋立処分に関する溶出基準（Ｂについては３０ｍｇ／
ｌ、Ｓｅについては０．３ｍｇ／ｌ）に近い値となって
いた。 Example 3 An insolubilization test was conducted in the same manner as in Example 2 except that the types of coal, B elution inhibitor and Se elution inhibitor were changed. Coal is supplied to the combustion furnace at 25 kg / h, and 200 m 3 N / h of smoke emitted from the combustion furnace is heated to 150 ° C.
Cooled down and introduced into an electrostatic precipitator. Dust separated and collected from the outlet hopper of the electric dust collector was collected and analyzed. The results are shown in Table 3. As shown in Table 3, elution B
The concentration is 28 mg / l, the elution Se concentration is 0.25 mg / l
And elution standard for landfill disposal (B: 30 mg /
The values of 1 and Se were close to 0.3 mg / l).
【００３１】[0031]
【表３】 [Table 3]
【００３２】この分離回収されたばいじんを１．６ｋｇ
／ｈで混合機に導入し、ばいじん中のＢに対し、カルシ
ウム添加量が５．０ｗｔ％（Ｃａ換算）となる様に工業
用の消石灰粉末（純度９９％）を０．１５ｋｇ／ｈで添
加した。次いで、ばいじん中のＳｅに対し、鉄（３価）
塩添加量が０．５ｗｔ％（Ｆｅ換算）となるように、工
業用Ｆｅ2（ＳＯ4）3溶液（Ｆｅ2（ＳＯ4）3 ４１％溶
液）を０．０５ｋｇ／ｈで添加し、ばいじんと不溶化剤
とを混合した。不溶化処理後のばいじんのＢ及びＳｅの
溶出濃度を表４に示す。表４に示すように、不溶化処理
後のばいじんのＢ溶出濃度は８ｍｇ／ｌ、Ｓｅ溶出濃度
は０．０５ｍｇ／ｌと埋立処分に関する溶出基準濃度を
十分余裕を持って満足しており、Ｂの溶出防止剤として
消石灰、Ｓｅの溶出防止剤としてＦｅ2（ＳＯ4）3を使
用しても十分不溶化処理効果があることを確認した。1.6 kg of the separated and collected dust
Introduced into the mixer at 0.15 / h, 0.15 kg / h of industrial slaked lime powder (purity 99%) is added so that the added amount of calcium is 5.0 wt% (calculated as Ca) with respect to B in dust. did. Next, for Se in the dust, iron (trivalent)
Industrial Fe 2 (SO 4 ) 3 solution (Fe 2 (SO 4 ) 3 41% solution) was added at 0.05 kg / h so that the amount of salt added would be 0.5 wt% (Fe equivalent), and dust And the insolubilizer were mixed. Table 4 shows the elution concentrations of B and Se in the soot and dust after the insolubilization treatment. As shown in Table 4, the B elution concentration of the soot and dust after the insolubilization treatment was 8 mg / l, the Se elution concentration was 0.05 mg / l, and the elution standard concentration for landfill disposal was satisfied with sufficient margin. It was confirmed that even if slaked lime was used as an elution inhibitor and Fe 2 (SO 4 ) 3 was used as an elution inhibitor for Se, the effect of insolubilizing treatment was sufficient.
【００３３】[0033]
【表４】 [Table 4]
【００３４】[0034]
【本発明の効果】上記したように、本発明のばいじんの
処理方法によれば、排煙中のＢ及びＳｅは凝縮し、ばい
じんに含まれた状態で集塵工程により除去される。そし
て、この集塵工程により分離されたばいじんには、混合
工程により、Ｂの溶出防止剤としてカルシウム化合物、
例えば、生石灰又は消石灰が加えられ、次で、Ｓｅの溶
出防止剤である鉄(３価)塩、例えば、ＦｅＣｌ3又はＦ
ｅ2（ＳＯ4）3が加えられて、そのばいじん中のＢやＳ
ｅの存在形態が不溶性の化合物に変換される。このた
め、ばいじんを従来と同様に廃棄処理しても、Ｂ及びＳ
ｅの溶出基準等がクリアされ、面倒な後処理を行わなく
とも、Ｂの無害化、さらにはＢ及びＳｅの同時無害化が
容易に可能となる。また、集塵工程における排煙の出口
側の回収部から分離回収されたばいじんのみを混合工程
に導入して不溶化処理すれば、Ｂ及びＳｅの溶出防止剤
の必要量や混合手段等の容量が低減でき、より経済的に
行うことができる。また、不要化処理後のばいじんを塊
状化することにより、ばいじんの取り扱いが容易となる
ばかりでなく、ばいじんのかさ密度が大きくなって圧密
化されるため、灰捨て場の延命化策となる。As described above, according to the method for treating soot and dust of the present invention, B and Se in the flue gas are condensed and removed in the dust collecting step while being contained in the soot and dust. Then, the soot and dust separated in the dust collecting step are mixed with a calcium compound as a B elution inhibitor in the mixing step.
For example, quicklime or slaked lime is added, and then an iron (trivalent) salt that is an elution inhibitor for Se, such as FeCl 3 or F.
e 2 (SO 4 ) 3 is added, and B and S in the dust are added.
The existing form of e is converted to an insoluble compound. Therefore, even if the dust is discarded as in the conventional case, B and S
The elution standard and the like of e are cleared, and it becomes possible to easily detoxify B, and further simultaneously detoxify B and Se without performing a troublesome post-treatment. Further, if only the soot and dust separated and collected from the collecting section on the side of the exhaust gas in the dust collecting step is introduced into the mixing step and subjected to the insolubilization treatment, the required amount of the elution inhibitor for B and Se and the capacity of the mixing means and the like are reduced. It can be reduced and can be performed more economically. In addition, not only is the handling of the soot and dust easy by making the soot and dust after the unnecessary treatment into a lump, but the bulk density of the soot and dust is increased and the dust is consolidated, which is a measure to prolong the life of the ash dump.
【図１】本発明に係るばいじんの処理方法の第１の実施
の形態の要部構成を示す図である。FIG. 1 is a diagram showing a main configuration of a first embodiment of a method for treating dust and dirt according to the present invention.
【図２】本発明に係るばいじんの処理方法の第２の実施
の形態の要部構成を示す図である。FIG. 2 is a diagram showing a main part configuration of a second embodiment of a method for treating dust and dirt according to the present invention.
【図３】本発明に係るＢの不溶化処理を行うためのばい
じん中Ｂ含有量に対する最適Ｃａ添加量の関係を示す図
である。FIG. 3 is a diagram showing the relationship between the optimum Ca addition amount and the B content in soot and dust for performing the insolubilization treatment of B according to the present invention.
【図４】本発明に係るＳｅの不溶化処理を行うためのば
いじん中Ｓｅ含有量に対する最適鉄（３価）塩添加量の
関係を示す図である。FIG. 4 is a diagram showing a relationship between the optimum iron (trivalent) salt addition amount with respect to the Se content in dust for performing the Se insolubilization treatment according to the present invention.
【図５】従来の排煙処理システムの概要を示す図であ
る。FIG. 5 is a diagram showing an outline of a conventional flue gas treatment system.
１ ボイラ ２ 脱硝装置 ３ エアヒータ ４ 熱回収部 ５ 電気集塵機（ＥＰ） ６ 湿式排煙脱硫装置 ７ 再加熱部 ８ 灰捨て場 ９ サイロ １０、２０ 排煙 １１ 石炭 １２ クリンカアッシュ １３ フライアッシュ １４ 排水 １５ 石膏 ２１ 電気集塵機（集塵工程） ２２ 除塵された排煙（電気集塵機の出口側の排煙） ２３〜２６ ホッパ（回収部） ２７ 分離回収されたばいじん ２９ カルシウム化合物（Ｃａ） ３０ 鉄（３価）塩（Ｆｅ） ３１ 混合機（混合工程） ３３ ブリケッティングマシン（塊状化工程） ３４ グラニュレータ ３５ スクリーン ３６〜３８ 塊状ばいじん 1 boiler 2 Denitration equipment 3 Air heater 4 Heat recovery section 5 Electric dust collector (EP) 6 Wet flue gas desulfurization equipment 7 Reheating section 8 ash dump 9 silos 10, 20 smoke emission 11 coal 12 Clinker Ash 13 fly ash 14 drainage 15 plaster 21 Electric dust collector (dust collecting process) 22 Exhausted smoke (smoke on the outlet side of the electrostatic precipitator) 23-26 Hopper (collection section) 27 Soot and dust separated and collected 29 Calcium compound (Ca) 30 Iron (trivalent) salt (Fe) 31 Mixer (Mixing process) 33 Briquetting machine (lumping process) 34 Granulator 35 screen 36-38 massive dust
フロントページの続き (72)発明者 平田 琢也 広島県広島市西区観音新町四丁目６番22号 三菱重工業株式会社広島研究所内 (72)発明者 千代丸 勝 広島県広島市西区観音新町四丁目６番22号 三菱重工業株式会社広島研究所内 (72)発明者 高品 徹 広島県広島市西区観音新町四丁目６番22号 三菱重工業株式会社広島研究所内 (72)発明者 沖野 進 東京都千代田区丸の内二丁目５番１号 三 菱重工業株式会社内 (72)発明者 岩下 浩一郎 東京都千代田区丸の内二丁目５番１号 三 菱重工業株式会社内 Ｆターム(参考） 4D004 AA37 AB03 BA02 CA14 CA15 CA34 CB28 CB43 CC11 CC12 DA02 DA10 DA11 Continued front page (72) Inventor Takuya Hirata 4-6-22 Kannon Shinmachi, Nishi-ku, Hiroshima City, Hiroshima Prefecture Mitsubishi Heavy Industries Ltd. Hiroshima Research Center (72) Inventor Masaru Chiyomaru 4-6-22 Kannon Shinmachi, Nishi-ku, Hiroshima City, Hiroshima Prefecture Mitsubishi Heavy Industries Ltd. Hiroshima Research Center (72) Inventor Toru Koshin 4-6-22 Kannon Shinmachi, Nishi-ku, Hiroshima City, Hiroshima Prefecture Mitsubishi Heavy Industries Ltd. Hiroshima Research Center (72) Inventor Susumu Okino 2-5-3 Marunouchi, Chiyoda-ku, Tokyo Hishi Heavy Industries Ltd. (72) Inventor Koichiro Iwashita 2-5-3 Marunouchi, Chiyoda-ku, Tokyo Hishi Heavy Industries Ltd. F-term (reference) 4D004 AA37 AB03 BA02 CA14 CA15 CA34 CB28 CB43 CC11 CC12 DA02 DA10 DA11
Claims (10)
あって、該排煙中のばいじんを分離する集塵工程と、該
集塵工程により分離されたばいじんにホウ素の溶出防止
剤としてカルシウム化合物を添加して混合する混合工程
と、を含むことを特徴とするばいじんの処理方法。1. A method for treating soot and dust contained in flue gas, comprising a dust collecting step for separating the soot and dust in the flue gas, and calcium as an elution inhibitor for boron in the soot and dust separated by the dust collecting step. A method for treating soot and dust, comprising the step of adding a compound and mixing the mixture.
止剤の量を、以下の式とすることを特徴とする請求項１
記載のばいじんの処理方法。 Ｒ≧０．００５４Ｑ−０．６・・・・・・・・（１） ［式（１）中、Ｒはホウ素の溶出防止剤の添加量（Ｃａ
換算）〔ｗｔ％〕を示し、Ｑはばいじん中のホウ素含有
量〔ｍｇ／ｋｇ−ｄｒｙ〕を示す。］2. The amount of the boron elution inhibitor added in the mixing step is represented by the following formula:
How to dispose of the dust described. R ≧ 0.0054Q−0.6 (1) [In the formula (1), R is the addition amount of the elution inhibitor of boron (Ca
(Converted) [wt%], and Q represents the boron content in soot and dust [mg / kg-dry]. ]
あって、該排煙中のばいじんを分離する集塵工程と、該
集塵工程により分離されたばいじんに、ホウ素の溶出防
止剤としてカルシウム化合物、及びセレンの溶出防止剤
として鉄（３価）塩を添加して混合する混合工程と、を
含むことを特徴とするばいじんの処理方法。3. A method for treating soot and dust contained in flue gas, comprising a dust collecting step for separating soot and dust in the flue gas, and a boron elution inhibitor for the soot and dust separated by the dust collecting step. And a mixing step of adding and mixing a calcium compound and an iron (trivalent) salt as an elution inhibitor for selenium, and a method for treating soot and dust.
止剤及びセレンの溶出防止剤の量を、以下の式とするこ
とを特徴とする請求項３記載のばいじんの処理方法。 Ｒ≧０．００５４Ｑ−０．６＋１．１Ｙ・・・（２） ［式（２）中、Ｒはホウ素の溶出防止剤の添加量(Ｃａ
換算)〔ｗｔ％〕を示し、Ｑはばいじん中のホウ素含有
量〔ｍｇ／ｋｇ−ｄｒｙ〕を示し、Ｙはセレンの溶出防
止剤の添加量（Ｆｅ換算）〔ｗｔ％〕を示す。］ Ｙ≧０．０３２Ｘ−０．２・・・・・・・・・（３） ［式（３）中、Ｙはセレンの溶出防止剤の添加量（Ｆｅ
換算）〔ｗｔ％〕を示し、Ｘはばいじん中のセレン含有
量〔ｍｇ／ｋｇ−ｄｒｙ〕を示す。］4. The method for treating soot and dust according to claim 3, wherein the amounts of the boron elution inhibitor and the selenium elution inhibitor added in the mixing step are represented by the following formulas. R ≧ 0.0054Q−0.6 + 1.1Y (2) [In the formula (2), R is the addition amount of the elution inhibitor of boron (Ca
(Converted) [wt%], Q represents the boron content in soot and dust [mg / kg-dry], and Y represents the amount of the selenium dissolution inhibitor added (converted to Fe) [wt%]. ] Y ≧ 0.032X-0.2 ... (3) [In the formula (3), Y represents the amount of the selenium dissolution inhibitor added (Fe).
(Converted) [wt%], and X represents the selenium content in soot and dust [mg / kg-dry]. ]
れたばいじんを塊状化する塊状化工程を、さらに含むこ
とを特徴とする請求項１〜４のいずれか記載のばいじん
の処理方法。5. The method for treating soot and dust according to claim 1, further comprising an agglomerating step of agglomerating the soot and dust mixed with the dissolution preventive agent in the mixing step.
する回収部が排煙の入口側から出口側に向って複数設け
られており、排煙の入口側の回収部から回収されるばい
じんと出口側から回収されるばいじんとを別個に分離回
収し、出口側で分離回収されたばいじんのみを、前記混
合工程に導入することを特徴とする請求項１〜５のいず
れか記載のばいじんの処理方法。6. In the dust collecting step, a plurality of collecting parts for separating and collecting soot and dust are provided from an inlet side of the flue gas toward an outlet side, and the soot and dust collected from the collecting portion on the flue gas inlet side. The soot and dust collected from the outlet side is separately separated and collected, and only the soot and dust separated and collected at the outlet side is introduced into the mixing step, and the soot and dust treatment according to any one of claims 1 to 5. Method.
あって、該排煙中のばいじんを分離する集塵手段と、該
集塵手段により分離されたばいじんにホウ素の溶出防止
剤としてカルシウム化合物を添加して混合する混合手段
と、を備えてなることを特徴とするばいじんの処理装
置。7. A device for treating soot and dust contained in flue gas, comprising dust collecting means for separating soot and dust in the flue gas, and calcium as an elution inhibitor for boron in the soot and dust separated by the dust collecting means. A device for treating soot and dusts, comprising: a mixing means for adding and mixing a compound.
あって、該排煙中のばいじんを分離する集塵手段と、該
集塵手段により分離されたばいじんに、ホウ素の溶出防
止剤として生石灰又は消石灰、及びセレンの溶出防止剤
として鉄（３価）塩を添加して混合する混合手段と、を
備えてなることを特徴とするばいじんの処理装置。8. A device for treating soot and dust contained in flue gas, comprising dust collecting means for separating soot and dust in the flue gas, and a boron elution inhibitor for the soot and dust separated by the dust collecting means. A soot and dust treatment apparatus comprising: quick lime or slaked lime; and a mixing means for adding and mixing an iron (trivalent) salt as a selenium elution inhibitor.
れたばいじんを塊状化する塊状化手段をさらに備えてな
ることを特徴とする請求項７又は８記載のばいじんの処
理装置。9. The apparatus for treating soot and dust according to claim 7, further comprising an agglomerating means for agglomerating the soot and dust mixed with the elution preventing agent in the mixing device.
する回収部を排煙の入口側から出口側に向って複数備え
ており、排煙の入口側の回収部から回収されるばいじん
と出口側から回収されるばいじんとを別個に分離回収
し、出口側で分離回収されたばいじんのみを、前記混合
手段に導入する構成としたことを特徴とする請求項７〜
９のいずれか記載のばいじんの処理装置。10. The dust collecting means is provided with a plurality of collecting portions for separating and collecting soot and dust from an inlet side of the smoke exhaust toward an outlet side, and the soot and dust collected from the collecting portion on the inlet side of the smoke exhaust and the outlet. The soot and dust collected from the side are separately separated and collected, and only the soot and dust separated and collected at the outlet side is introduced into the mixing means.
9. The dust-disposal device according to any one of 9 above.
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|---|---|---|---|
| JP2001334013A JP3901986B2 (en) | 2001-10-31 | 2001-10-31 | Dust processing method and dust processing apparatus |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001334013A JP3901986B2 (en) | 2001-10-31 | 2001-10-31 | Dust processing method and dust processing apparatus |
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| Publication Number | Publication Date |
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| JP2003136035A true JP2003136035A (en) | 2003-05-13 |
| JP3901986B2 JP3901986B2 (en) | 2007-04-04 |
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| JP2001334013A Expired - Lifetime JP3901986B2 (en) | 2001-10-31 | 2001-10-31 | Dust processing method and dust processing apparatus |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006026511A (en) * | 2004-07-15 | 2006-02-02 | Oji Paper Co Ltd | Method for treating boron-containing combustion ash |
| JP2007255809A (en) * | 2006-03-24 | 2007-10-04 | Chugoku Electric Power Co Inc:The | Control device |
| JP2008170111A (en) * | 2007-01-12 | 2008-07-24 | Chugoku Electric Power Co Inc:The | Method of inhibiting elution of harmful trace element |
| JP2016125031A (en) * | 2015-01-08 | 2016-07-11 | 株式会社トクヤマ | Method for effectively utilizing coal ash |
-
2001
- 2001-10-31 JP JP2001334013A patent/JP3901986B2/en not_active Expired - Lifetime
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006026511A (en) * | 2004-07-15 | 2006-02-02 | Oji Paper Co Ltd | Method for treating boron-containing combustion ash |
| JP2007255809A (en) * | 2006-03-24 | 2007-10-04 | Chugoku Electric Power Co Inc:The | Control device |
| JP2008170111A (en) * | 2007-01-12 | 2008-07-24 | Chugoku Electric Power Co Inc:The | Method of inhibiting elution of harmful trace element |
| JP2016125031A (en) * | 2015-01-08 | 2016-07-11 | 株式会社トクヤマ | Method for effectively utilizing coal ash |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3901986B2 (en) | 2007-04-04 |
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