JPH09192625A - Alkali fly ash detoxicating treatment - Google Patents
Alkali fly ash detoxicating treatmentInfo
- Publication number
- JPH09192625A JPH09192625A JP8007781A JP778196A JPH09192625A JP H09192625 A JPH09192625 A JP H09192625A JP 8007781 A JP8007781 A JP 8007781A JP 778196 A JP778196 A JP 778196A JP H09192625 A JPH09192625 A JP H09192625A
- Authority
- JP
- Japan
- Prior art keywords
- fly ash
- slurry
- chloride
- solution
- alkali
- 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.)
- Granted
Links
- 239000010881 fly ash Substances 0.000 title claims abstract description 180
- 239000003513 alkali Substances 0.000 title claims abstract description 81
- 229910001385 heavy metal Inorganic materials 0.000 claims abstract description 134
- 239000002002 slurry Substances 0.000 claims abstract description 104
- 239000007788 liquid Substances 0.000 claims abstract description 76
- 238000000605 extraction Methods 0.000 claims abstract description 64
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 claims abstract description 59
- 238000000034 method Methods 0.000 claims abstract description 56
- 239000000284 extract Substances 0.000 claims abstract description 52
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 43
- 230000000087 stabilizing effect Effects 0.000 claims abstract description 17
- 239000003795 chemical substances by application Substances 0.000 claims abstract description 9
- UXVMQQNJUSDDNG-UHFFFAOYSA-L Calcium chloride Chemical compound [Cl-].[Cl-].[Ca+2] UXVMQQNJUSDDNG-UHFFFAOYSA-L 0.000 claims description 35
- 239000001110 calcium chloride Substances 0.000 claims description 29
- 229910001628 calcium chloride Inorganic materials 0.000 claims description 29
- 238000004140 cleaning Methods 0.000 claims description 24
- 230000006641 stabilisation Effects 0.000 claims description 22
- 238000011105 stabilization Methods 0.000 claims description 22
- 238000005406 washing Methods 0.000 claims description 12
- 238000001784 detoxification Methods 0.000 claims description 4
- 230000001376 precipitating effect Effects 0.000 claims description 3
- 238000005660 chlorination reaction Methods 0.000 claims 1
- 239000002738 chelating agent Substances 0.000 abstract description 19
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 abstract description 7
- IXCSERBJSXMMFS-UHFFFAOYSA-N hydrogen chloride Substances Cl.Cl IXCSERBJSXMMFS-UHFFFAOYSA-N 0.000 abstract description 3
- 229910000041 hydrogen chloride Inorganic materials 0.000 abstract description 3
- 239000010813 municipal solid waste Substances 0.000 abstract 1
- 239000002912 waste gas Substances 0.000 abstract 1
- 238000002474 experimental method Methods 0.000 description 22
- 239000000126 substance Substances 0.000 description 19
- 239000002253 acid Substances 0.000 description 15
- 239000000203 mixture Substances 0.000 description 13
- 238000012545 processing Methods 0.000 description 12
- 238000010828 elution Methods 0.000 description 11
- 238000007922 dissolution test Methods 0.000 description 10
- 238000010586 diagram Methods 0.000 description 8
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 6
- 238000004458 analytical method Methods 0.000 description 6
- 239000002244 precipitate Substances 0.000 description 6
- 238000002360 preparation method Methods 0.000 description 6
- 150000003839 salts Chemical class 0.000 description 6
- 239000002956 ash Substances 0.000 description 5
- AXCZMVOFGPJBDE-UHFFFAOYSA-L calcium dihydroxide Chemical compound [OH-].[OH-].[Ca+2] AXCZMVOFGPJBDE-UHFFFAOYSA-L 0.000 description 5
- 239000000920 calcium hydroxide Substances 0.000 description 5
- 229910001861 calcium hydroxide Inorganic materials 0.000 description 5
- 230000007423 decrease Effects 0.000 description 5
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 description 4
- 150000001805 chlorine compounds Chemical class 0.000 description 4
- 150000004696 coordination complex Chemical class 0.000 description 4
- 230000003247 decreasing effect Effects 0.000 description 4
- 238000002156 mixing Methods 0.000 description 4
- 229920000642 polymer Polymers 0.000 description 4
- 229910052979 sodium sulfide Inorganic materials 0.000 description 4
- GRVFOGOEDUUMBP-UHFFFAOYSA-N sodium sulfide (anhydrous) Chemical compound [Na+].[Na+].[S-2] GRVFOGOEDUUMBP-UHFFFAOYSA-N 0.000 description 4
- 238000003756 stirring Methods 0.000 description 4
- 238000007796 conventional method Methods 0.000 description 3
- 230000007613 environmental effect Effects 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- 238000002844 melting Methods 0.000 description 3
- 230000008018 melting Effects 0.000 description 3
- 238000001556 precipitation Methods 0.000 description 3
- 239000000047 product Substances 0.000 description 3
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- 239000011575 calcium Substances 0.000 description 2
- OSGAYBCDTDRGGQ-UHFFFAOYSA-L calcium sulfate Chemical compound [Ca+2].[O-]S([O-])(=O)=O OSGAYBCDTDRGGQ-UHFFFAOYSA-L 0.000 description 2
- 239000000460 chlorine Substances 0.000 description 2
- 229910052801 chlorine Inorganic materials 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 239000000428 dust Substances 0.000 description 2
- 238000001914 filtration Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 2
- RVPVRDXYQKGNMQ-UHFFFAOYSA-N lead(2+) Chemical compound [Pb+2] RVPVRDXYQKGNMQ-UHFFFAOYSA-N 0.000 description 2
- 150000002736 metal compounds Chemical class 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 238000000926 separation method Methods 0.000 description 2
- HYHCSLBZRBJJCH-UHFFFAOYSA-M sodium hydrosulfide Chemical compound [Na+].[SH-] HYHCSLBZRBJJCH-UHFFFAOYSA-M 0.000 description 2
- 238000007711 solidification Methods 0.000 description 2
- 230000008023 solidification Effects 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 1
- BHPQYMZQTOCNFJ-UHFFFAOYSA-N Calcium cation Chemical compound [Ca+2] BHPQYMZQTOCNFJ-UHFFFAOYSA-N 0.000 description 1
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 1
- 235000008733 Citrus aurantifolia Nutrition 0.000 description 1
- CWYNVVGOOAEACU-UHFFFAOYSA-N Fe2+ Chemical compound [Fe+2] CWYNVVGOOAEACU-UHFFFAOYSA-N 0.000 description 1
- PMZURENOXWZQFD-UHFFFAOYSA-L Sodium Sulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=O PMZURENOXWZQFD-UHFFFAOYSA-L 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 235000011941 Tilia x europaea Nutrition 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 229910052793 cadmium Inorganic materials 0.000 description 1
- BDOSMKKIYDKNTQ-UHFFFAOYSA-N cadmium atom Chemical compound [Cd] BDOSMKKIYDKNTQ-UHFFFAOYSA-N 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 229910001424 calcium ion Inorganic materials 0.000 description 1
- 239000004568 cement Substances 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- -1 chlorine ions Chemical class 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 238000007865 diluting Methods 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 238000010169 landfilling Methods 0.000 description 1
- 150000002611 lead compounds Chemical class 0.000 description 1
- PIJPYDMVFNTHIP-UHFFFAOYSA-L lead sulfate Chemical compound [PbH4+2].[O-]S([O-])(=O)=O PIJPYDMVFNTHIP-UHFFFAOYSA-L 0.000 description 1
- 239000004571 lime Substances 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- OTYBMLCTZGSZBG-UHFFFAOYSA-L potassium sulfate Chemical compound [K+].[K+].[O-]S([O-])(=O)=O OTYBMLCTZGSZBG-UHFFFAOYSA-L 0.000 description 1
- 229910052939 potassium sulfate Inorganic materials 0.000 description 1
- 235000011151 potassium sulphates Nutrition 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 229910052938 sodium sulfate Inorganic materials 0.000 description 1
- 235000011152 sodium sulphate Nutrition 0.000 description 1
- 239000003381 stabilizer Substances 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 238000011144 upstream manufacturing Methods 0.000 description 1
Landscapes
- Gasification And Melting Of Waste (AREA)
- Processing Of Solid Wastes (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、ごみ焼却設備やご
み焼却灰の溶融設備から排出する飛灰を廃棄処分するた
めの処理方法であって、特に、乾式集塵機よりも上流の
排ガス流路に水酸化カルシウムなどの石灰含有物質の粉
末を吹き込んで、排ガス中の塩化水素を除去した際に捕
集される飛灰（以下、アルカリ飛灰と言う）を無害化す
る処理方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a treatment method for discarding fly ash discharged from a refuse incineration facility or a refuse incineration ash melting facility, and particularly to an exhaust gas passage upstream of a dry dust collector. The present invention relates to a treatment method for detoxifying fly ash (hereinafter referred to as alkali fly ash) collected when hydrogen chloride in exhaust gas is removed by blowing powder of a lime-containing substance such as calcium hydroxide.
【０００２】[0002]
【従来の技術】ごみ焼却設備やごみ焼却灰の溶融設備か
ら排出するアルカリ飛灰の中には、焼却炉から飛散して
くる通常の灰の他に、塩化水素と水酸化カルシウムの反
応生成物である塩化カルシウムやその複塩、および未反
応の水酸化カルシウムが多量に含まれている。2. Description of the Related Art Alkali fly ash discharged from a refuse incinerator and a refuse incineration ash melting facility includes normal ash scattered from an incinerator as well as reaction products of hydrogen chloride and calcium hydroxide. It contains a large amount of calcium chloride and its double salts, and unreacted calcium hydroxide.
【０００３】また、ごみを焼却したり、ごみ焼却灰を溶
融したりする際には、沸点の低い金属化合物が揮散し、
排ガス中に混入して排出する。そして、排出した金属化
合物は凝縮し、乾式集塵機で捕集される。このため、飛
灰中には、鉛やカドミウムなどの有害重金属も含まれて
いる。In addition, when incinerating refuse or melting incineration ash, metal compounds having a low boiling point are volatilized,
It is mixed with the exhaust gas and discharged. Then, the discharged metal compound is condensed and collected by the dry dust collector. Therefore, harmful heavy metals such as lead and cadmium are also contained in the fly ash.
【０００４】ところで、ごみ焼却飛灰を埋め立て処分す
る場合には、溶融固化法、セメント固化法、薬剤添加
法、酸その他の溶媒への抽出法（以下、単に酸抽出法と
言う）のうちの何れかの方法によって飛灰を処理し、飛
灰中の重金属を化学的に安定な状態にするか、若しくは
分離しなければならないことが、法令によって義務づけ
られている。By the way, in the case of landfill disposal of refuse incineration fly ash, one of the melt solidification method, the cement solidification method, the chemical addition method, and the extraction method using acid or other solvent (hereinafter, simply referred to as acid extraction method) is used. It is obliged by law that the fly ash must be treated by any method to make the heavy metal in the fly ash chemically stable or separated.
【０００５】上記４方法の飛灰処理法のうち、本発明と
関連する技術である酸抽出法および薬剤添加法は次のよ
うに行われている。Among the above four methods of fly ash treatment, the acid extraction method and the chemical addition method, which are the techniques related to the present invention, are carried out as follows.
【０００６】酸抽出法による飛灰の無害化処理において
は、まず、飛灰に水を加えてスラリーにし、このスラリ
ーに硫酸や塩酸などの酸を加えて酸性にし、重金属を抽
出する。次いで、このスラリーにアルカリを加えて重金
属を水酸化物にして沈澱させるか、あるいは、アルカリ
を加えてｐＨを適正な範囲に調整した後、硫化剤を加え
て重金属を硫化物にして沈澱させるか、あるいは、アル
カリを加えてｐＨを適正な範囲に調整した後、液体キレ
ート剤などの重金属固定剤を加えて重金属を不溶性の高
分子金属錯体にして沈澱させる処理を行う。そして、上
記何れかの処理法で重金属を不溶化させたスラリーを脱
液処理することによって、処分可能な処理飛灰が得られ
る。In the detoxification treatment of fly ash by the acid extraction method, first, water is added to fly ash to form a slurry, and an acid such as sulfuric acid or hydrochloric acid is added to this slurry to make it acidic, and heavy metals are extracted. Then, an alkali is added to this slurry to convert the heavy metal into a hydroxide for precipitation, or an alkali is added to adjust the pH to an appropriate range, and then a sulfidizing agent is added to the heavy metal to form a sulfide for precipitation. Alternatively, after the alkali is added to adjust the pH to an appropriate range, a heavy metal fixing agent such as a liquid chelating agent is added to the heavy metal to form an insoluble polymer metal complex for precipitation. Then, the treated fly ash that can be disposed of can be obtained by subjecting the slurry in which the heavy metal is insolubilized by any one of the above treatment methods to the deliquoring treatment.
【０００７】薬剤添加法による飛灰の無害化処理におい
ては、飛灰に液体キレート剤などの重金属固定剤の溶液
を加えて混練し、飛灰中の重金属を不溶性の高分子金属
錯体にして安定化させることによって、処分可能な処理
飛灰が得られる。In the detoxification treatment of fly ash by the chemical addition method, a solution of a heavy metal fixing agent such as a liquid chelating agent is added to the fly ash and kneaded to make the heavy metal in the fly ash stable as an insoluble polymer metal complex. The treated fly ash that can be disposed of can be obtained.
【０００８】[0008]
【発明が解決しようとする課題】しかし、上記酸抽出法
による処理および薬剤添加法による処理においては、次
のような解決すべき問題がある。However, in the treatment by the above-mentioned acid extraction method and the treatment by the chemical addition method, there are the following problems to be solved.
【０００９】まず、酸抽出法による処理においては、ア
ルカリ飛灰中には１０〜４０％にも及ぶ未反応の水酸化
カルシウムが含まれており、この多量の水酸化カルシウ
ムなどが重金属を抽出するために添加した酸と反応する
ので、添加した酸が目的外の反応に消費されてしまう。
このため、極めて多量の酸を添加しなければならない。
また、この場合、スラリーが強い酸性を示すまで酸を添
加しなければならないので、このスラリー中の重金属を
安定化させる際には、スラリーのｐＨを適正な範囲にす
るために、多量のアルカリを加えなくてはならない。従
って、飛灰を酸抽出法によって処理すると、極めて多量
の酸およびアルカリを要し、処理コストが非常に高くな
る。First, in the treatment by the acid extraction method, 10-40% of unreacted calcium hydroxide is contained in the alkali fly ash, and this large amount of calcium hydroxide or the like extracts heavy metals. Therefore, it reacts with the added acid, so that the added acid is consumed for the reaction other than the purpose.
Therefore, a very large amount of acid must be added.
Further, in this case, since an acid must be added until the slurry exhibits strong acidity, when stabilizing the heavy metal in the slurry, a large amount of alkali is added in order to keep the pH of the slurry within an appropriate range. Must be added. Therefore, when the fly ash is treated by the acid extraction method, an extremely large amount of acid and alkali are required, and the treatment cost becomes very high.
【００１０】また、薬剤添加法による処理においては、
通常、飛灰量に対し数％〜１０％近い量の液体キレート
剤を添加しなくてはならないが、この液体キレート剤は
非常に高価な薬剤であるので、飛灰中の重金属含有率が
非常に高い場合には、その添加量が１０％近くにもなる
と、飛灰の処理コストが非常に高くなると言う問題が発
生する。Further, in the treatment by the chemical addition method,
Normally, it is necessary to add a liquid chelating agent in an amount of several% to 10% with respect to the amount of fly ash, but since this liquid chelating agent is a very expensive chemical, the content of heavy metals in fly ash is extremely high. In the case of a very high amount, if the amount added is close to 10%, the problem arises that the treatment cost of fly ash becomes very high.
【００１１】さらに、上述の２法による処理において
は、飛灰中の重金属を不溶性の化合物にして安定化させ
るだけであって、重金属そのものを取り除いてしまう訳
ではないので、安定化された重金属はそのまま飛灰中に
残留し、廃棄処分される。そして、安定化されたもので
あるとは言え、重金属が含まれている処理飛灰を廃棄処
分すると、廃棄場所における重金属量が増加することに
なり、いわゆる環境負荷が大きくなる。このため、飛灰
の廃棄処分に際しては、その重金属を分離する処理を行
うことが望ましいものとされている。Further, in the treatment by the above-mentioned two methods, only the heavy metal in the fly ash is made into an insoluble compound and stabilized, and the heavy metal itself is not removed. It remains in the fly ash as it is and is discarded. And, although it is stabilized, when the treated fly ash containing heavy metals is disposed of, the amount of heavy metals at the disposal site increases, and so-called environmental load increases. For this reason, when disposing of fly ash, it is desirable to perform a process for separating the heavy metal.
【００１２】本発明は、上記従来技術の問題点を解決し
たものであって、処理コストが安く抑えられ、かつ処理
飛灰中の重金属を大幅に減少させることができるアルカ
リ飛灰の無害化処理方法を提供することを目的とする。The present invention solves the above-mentioned problems of the prior art, in which the treatment cost is kept low, and the heavy metal in the treated fly ash can be greatly reduced. The purpose is to provide a method.
【００１３】[0013]
【課題を解決するための手段】上記の目的を達成するた
めに、本発明においては、重金属を含有するアルカリ飛
灰に、このアルカリ飛灰中の塩化物を溶液にするための
水と、塩化物の溶液を加えてスラリーにし、このスラリ
ーを脱液処理して抽出液と脱液飛灰に分離し、この脱液
飛灰を重金属安定化処理する。In order to achieve the above object, in the present invention, an alkali fly ash containing a heavy metal is mixed with water for converting the chloride in the alkali fly ash into a solution, and a chloride. A solution of the product is added to form a slurry, the slurry is subjected to a deliquoring treatment to separate into an extract and a deliquored fly ash, and the deliquored fly ash is subjected to a heavy metal stabilization treatment.
【００１４】この処理方法においては、重金属を含有す
るアルカリ飛灰に、このアルカリ飛灰中の塩化物を溶液
にするための水と、塩化物の溶液を加えてスラリーにす
る際に、塩化物の溶液として前記スラリーを脱液処理し
た際に分離された抽出液を供給するのがよい。According to this treatment method, water is added to the alkali fly ash containing heavy metal to dissolve the chloride in the alkali fly ash, and a chloride solution is added to form a slurry. As the solution, it is preferable to supply the extract liquid separated when the slurry is subjected to the liquid removal treatment.
【００１５】また、本発明においては、重金属を含有す
るアルカリ飛灰に、このアルカリ飛灰中の塩化物を溶液
にするための水と、塩化物の溶液を加えてスラリーに
し、このスラリーを脱液処理して抽出液と脱液飛灰に分
離し、この脱液飛灰を重金属安定化処理すると共に、抽
出液中の重金属を析出させて分離する処理を行い、この
重金属が分離された処理液を上記塩化物の溶液としてア
ルカリ飛灰をスラリーにする工程へ供給する。Further, in the present invention, water for making chloride in the alkali fly ash into a solution and a solution of the chloride are added to alkali fly ash containing heavy metal to form a slurry, and the slurry is removed. Liquid treatment is performed to separate the extract and the deliquesed fly ash, and the deliquefied fly ash is stabilized with heavy metals, and the heavy metals in the extract are precipitated and separated. The solution is supplied as a solution of the above chloride to the step of making the alkali fly ash into slurry.
【００１６】また、本発明においては、重金属を含有す
るアルカリ飛灰に、このアルカリ飛灰中の塩化物を溶液
にするための水と、塩化物の溶液を加えてスラリーに
し、このスラリーを脱液処理して抽出液と脱液飛灰に分
離し、この脱液飛灰に、抽出液中の重金属を析出させて
分離した処理液を加えて洗浄スラリーにし、この洗浄ス
ラリーを脱液処理して分離液と洗浄脱液飛灰に分離し、
この洗浄脱液飛灰を重金属安定化処理すると共に、上記
処理液を上記塩化物の溶液としてアルカリ飛灰をスラリ
ーにする工程へ供給する。Further, in the present invention, water for making chloride in the alkali fly ash into a solution and a solution of the chloride are added to alkali fly ash containing heavy metal to form a slurry, and the slurry is removed. Liquid treatment is performed to separate the extract liquid and the dewatered fly ash, and the treatment liquid separated by precipitating heavy metals in the extract liquid is added to this dewatered fly ash to form a cleaning slurry, and the cleaning slurry is dewatered. Separated into separated liquid and washed dewatered fly ash,
The washed deliquoring fly ash is subjected to a heavy metal stabilization treatment, and the treatment liquid is supplied to the step of making the alkali fly ash into a slurry by using the chloride solution.
【００１７】また、本発明においては、重金属を含有す
るアルカリ飛灰に塩化物の溶液を加えてスラリーにし、
このスラリーを脱液処理して抽出液と脱液飛灰に分離
し、この脱液飛灰に水を加えて洗浄スラリーにし、この
洗浄スラリーを脱液処理して分離液と洗浄脱液飛灰に分
離し、この洗浄脱液飛灰を重金属安定化処理すると共
に、上記抽出液および上記分離液を上記塩化物の溶液と
してアルカリ飛灰をスラリーにする工程へ供給する。Further, in the present invention, a solution of chloride is added to alkali fly ash containing heavy metal to form a slurry,
This slurry is subjected to deliquoring treatment to separate it into an extraction liquid and deliquored fly ash, and water is added to this deliquored fly ash to form a washing slurry. And the washed deliquoring fly ash is subjected to a heavy metal stabilization treatment, and the extract and the separated liquor are supplied as a solution of the chloride to the step of making the alkali fly ash into a slurry.
【００１８】そして、上記の各処理方法においては、ス
ラリーの溶液中に含まれている塩化物は主として塩化カ
ルシウムであるのがよい。In each of the above treatment methods, the chloride contained in the slurry solution is preferably calcium chloride.
【００１９】また、スラリーの溶液中に含まれている塩
化カルシウムの濃度は１０ｗｔ％〜４０ｗｔ％であるの
がよい。The concentration of calcium chloride contained in the slurry solution is preferably 10 wt% to 40 wt%.
【００２０】また、上記スラリーを脱液処理して分離し
た脱液飛灰の重金属安定化処理は、重金属を安定化させ
る薬剤を添加する方法による処理であるのがよい。Further, the heavy metal stabilization treatment of the liquid liquor fly ash separated by subjecting the slurry to the liquid removal treatment is preferably a treatment by a method of adding an agent for stabilizing the heavy metal.
【００２１】また、上記洗浄スラリーを脱液処理して分
離した洗浄脱液飛灰の重金属安定化処理は、重金属を安
定化させる薬剤を添加する方法による処理であるのがよ
い。Further, the heavy metal stabilization treatment of the washed deliquoring fly ash separated by deliquoring the washing slurry is preferably a treatment by a method of adding a chemical for stabilizing the heavy metal.
【００２２】表１はアルカリ飛灰の組成の一例を示す
表、表２はアルカリ飛灰に含まれている重金属類の含有
量を示す表であり、表３は表１および表２に示す組成の
アルカリ飛灰について、本発明者が、環境庁告示１３号
の方法によって、溶出試験を行った結果を記載したもの
である。表３の記載で明らかなように、飛灰に含まれて
いる有害重金属のうち、特に、鉛の溶出濃度が格段に高
く、この鉛の溶出濃度だけが埋め立て処分に関する基準
を大幅に上回っている。このため、現状におけるアルカ
リ飛灰の無害化処理においては、主として、鉛の溶出を
防止することを目的とした処理がなされている。Table 1 is a table showing an example of the composition of alkali fly ash, Table 2 is a table showing the content of heavy metals contained in the alkali fly ash, and Table 3 is a composition shown in Tables 1 and 2. For the alkaline fly ash of No. 3, the present inventor described the result of the dissolution test by the method of the Environmental Agency Notification No. 13. As is clear from the description in Table 3, of the harmful heavy metals contained in fly ash, the lead elution concentration is particularly high, and only this lead elution concentration is significantly higher than the standard for landfill disposal. . Therefore, in the current detoxification process of alkaline fly ash, a process mainly aimed at preventing elution of lead is performed.
【００２３】[0023]
【表１】 [Table 1]
【００２４】[0024]
【表２】 [Table 2]
【００２５】[0025]
【表３】 [Table 3]
【００２６】上述のような状況において、本発明者は、
酸類を使用しない方法によってアルカリ飛灰中の鉛を抽
出し、この鉛を除去してしまう方法について種々の検討
を行った。このような検討の過程において、本発明者
は、鉛が各種の塩化錯体（ＰｂＣｌ+ ，ＰｂＣｌ3 - ，
ＰｂＣｌ4 2-）を形成するものであることに着目し、こ
れらの塩化錯体を生成させれば、その溶解度が大幅に上
昇させることができるものと想定した。そして、その実
験を実施したところ、後述のように、塩化物の溶液中に
おいては、飛灰中の鉛が多量に溶出し、その溶出濃度は
溶液中の塩化物濃度が高くなるに従って大きくなること
を見出した。In the above situation, the present inventor
Various studies were conducted on the method of extracting lead from alkali fly ash by a method that does not use acids and removing this lead. In the process of such investigation, the present inventors have found that lead is mixed with various chloride complexes (PbCl + , PbCl 3 − ,
Focusing on the fact that PbCl 4 2− ) is formed, it was assumed that the solubility of these chloride complexes could be significantly increased by forming these chloride complexes. Then, when the experiment was carried out, as will be described later, in the chloride solution, a large amount of lead in the fly ash was eluted, and the elution concentration increased as the chloride concentration in the solution increased. Found.
【００２７】そこで、本発明においては、アルカリ飛灰
を塩化物の溶液中へ投入し、アルカリ飛灰をスラリーに
してその溶液側へ鉛を抽出し、このスラリーを脱液処理
して鉛などの重金属が含まれている溶液（抽出液）を分
離し、重金属が除去された飛灰を得ることを図ってい
る。Therefore, in the present invention, the alkali fly ash is put into a chloride solution, the alkali fly ash is slurried to extract lead into the solution side, and the slurry is deliquored to remove lead and the like. The solution (extract) containing heavy metals is separated to obtain fly ash from which heavy metals have been removed.
【００２８】ところで、アルカリ飛灰には塩化カルシウ
ムなどの塩類が多量に含まれており、このアルカリ飛灰
に水を加えれば、上記塩類が溶解して塩化カルシウムな
どよりなる塩化物の溶液が生成し、飛灰中の鉛がその塩
化物の溶液中へ抽出されるものと考えられる。By the way, alkali fly ash contains a large amount of salts such as calcium chloride. When water is added to the alkali fly ash, the salts are dissolved to form a chloride solution of calcium chloride or the like. However, it is considered that lead in fly ash is extracted into the chloride solution.
【００２９】しかし、アルカリ飛灰に水を加えただけ
で、鉛を抽出しようとすると、次のようなことが問題に
なる。すなわち、アルカリ飛灰と水を混合することによ
って、鉛を抽出しようとする場合、その混合物を攪拌し
たり、ポンプ輸送したりすることができるような状態に
しなければならないが、これを上記のような状態のスラ
リーにするためには、少なくとも、飛灰量に対し２倍程
度の水を加えなくてはならない。そして、このような多
量の水を加えてスラリーを調製すると、そのスラリー溶
液中の塩化物の濃度が非常に低くなり、その結果、上述
のように、鉛の溶出濃度が低下するので、鉛を効率的に
抽出することができなくなる。However, if lead is to be extracted by simply adding water to the alkali fly ash, the following problems occur. That is, if lead is to be extracted by mixing alkali fly ash and water, the mixture must be in a state in which it can be stirred or pumped. In order to make the slurry in such a state, at least about twice the amount of fly ash must be added. Then, when a slurry is prepared by adding such a large amount of water, the concentration of chloride in the slurry solution becomes extremely low, and as a result, the elution concentration of lead decreases, as described above, It becomes impossible to extract efficiently.
【００３０】アルカリ飛灰に加える水は、アルカリ飛灰
中の可溶性塩化物を溶解させて塩化物の溶液を調製する
ための水であり、従って、その水の添加量は新たに生成
する塩化物溶液を所定濃度範囲にすることができる量に
制限される。そして、上記の制限に基づいた水量だけで
は、攪拌やポンプ輸送ができるような状態のスラリーを
調製することはできない。The water added to the alkali fly ash is water for dissolving the soluble chloride in the alkali fly ash to prepare a chloride solution. Therefore, the amount of water added is the amount of newly formed chloride. It is limited to the amount that can bring the solution into a predetermined concentration range. Then, it is not possible to prepare a slurry in a state in which stirring and pumping are possible only with the amount of water based on the above limit.
【００３１】このため、本発明においては、アルカリ飛
灰のスラリーを調製する際に、新たな塩化物の溶液を調
製するために加える水の他に、別途、塩化物の溶液を添
加し、スラリー中の溶液量を増加させる。塩化物の溶液
を添加してスラリーを調製すれば、スラリー中の溶液量
を適宜増減することができるので、適度な流動性を有す
るスラリーが得られる。また、スラリーの流動性の調整
が塩化物溶液の添加によって行われるので、その溶液中
の塩化物濃度の低下が避けられる。Therefore, in the present invention, when a slurry of alkali fly ash is prepared, in addition to water added to prepare a new chloride solution, a chloride solution is separately added to form a slurry. Increase the amount of solution in. When a chloride solution is added to prepare a slurry, the amount of the solution in the slurry can be appropriately increased or decreased, and thus a slurry having appropriate fluidity can be obtained. Further, since the fluidity of the slurry is adjusted by adding the chloride solution, it is possible to avoid a decrease in the chloride concentration in the solution.
【００３２】ここで添加する塩化物の溶液は系外から求
めたものであってもよいが、アルカリ飛灰中の重金属を
抽出したスラリーを脱液処理した際には、多量の塩化物
を含む抽出液が分離されて排出するので、この抽出液を
循環させて使用するのが効率的である。その上、鉛を抽
出する際に、溶液中に塩化物として存在させる物質は、
次に述べるように、塩化カルシウムであるのがよく、こ
の点についても、上記抽出液は多量の塩化カルシウムを
含む溶液であるので、好ましい組成になっている。The chloride solution added here may be obtained from the outside of the system, but when the slurry obtained by extracting the heavy metal in the alkali fly ash is subjected to the deliquoring treatment, it contains a large amount of chloride. Since the extract is separated and discharged, it is efficient to circulate and use this extract. Moreover, the substances that are present as chlorides in the solution when extracting lead are
As described below, calcium chloride is preferable, and in this respect as well, the above extract has a preferable composition because it is a solution containing a large amount of calcium chloride.
【００３３】抽出液中の塩化物が塩化カルシウムである
のがよい理由は次の如くである。飛灰中には、硫酸ナト
リウム（Ｎａ2 ＳＯ4 ）や硫酸カリウム（Ｋ2 ＳＯ4 ）
などの可溶性の硫酸塩が含まれており、飛灰と水を混合
したスラリーには上記硫酸塩が溶解している。そして、
スラリーの溶液中には、鉛イオンＰｂ2+と共に多量の硫
酸イオンＳＯ4 2-が存在するので、（１）式によるＰｂ
2+とＳＯ4 2-の平衡が硫酸鉛の溶解度積によって左辺側
へ移行し、鉛イオンＰｂ2+の濃度が非常に低下する。こ
のため、鉛を抽出する際に、多量の塩素イオンを存在さ
せても、硫酸イオンが共存すると、効率的な処理をする
ことができない。The reason why the chloride in the extract is preferably calcium chloride is as follows. In the fly ash, sodium sulfate (Na 2 SO 4 ) and potassium sulfate (K 2 SO 4 )
Soluble sulfate is contained in the slurry, and the sulfate is dissolved in the slurry obtained by mixing fly ash and water. And
Since a large amount of sulfate ion SO 4 2- is present in the solution of the slurry together with lead ion Pb 2+ , Pb according to the equation (1) is used.
The equilibrium between 2+ and SO 4 2− shifts to the left side due to the solubility product of lead sulfate, and the concentration of lead ion Pb 2+ decreases significantly. Therefore, even if a large amount of chlorine ions are present when lead is extracted, efficient processing cannot be performed if sulfate ions coexist.
【００３４】この際、塩化物として存在している物質が
塩化カルシウム（ＣａＣｌ2 ）であると、溶液中に硫酸
イオンＳＯ4 2-と共に多量のカルシウムイオンＣａ2+が
存在するので、（２）式によるＰｂ2+とＳＯ4 2-の平衡
が硫酸カルシウムの溶解度積によって左辺側へ移行し
て、硫酸イオンＳＯ4 2-が減少し、鉛の溶解を阻害する
要因が排除される。At this time, when the substance existing as chloride is calcium chloride (CaCl 2 ), a large amount of calcium ion Ca 2+ is present together with the sulfate ion SO 4 2− in the solution. The equilibrium between Pb 2+ and SO 4 2− according to the formula shifts to the left side by the solubility product of calcium sulfate, the sulfate ion SO 4 2− decreases, and the factor that inhibits the dissolution of lead is eliminated.
【００３５】[0035]
【化１】 Embedded image
【００３６】[0036]
【化２】 Embedded image
【００３７】[0037]
【発明の実施の形態】図１は本発明に係る第１の実施の
形態における処理工程を示す図である。この実施の形態
は、重金属を含有するアルカリ飛灰をスラリーにして重
金属を抽出する抽出工程１０と、重金属を抽出したスラ
リーから抽出液を分離する脱液工程１１と、この脱液工
程から排出された脱液飛灰中の重金属を化学的に安定化
させる重金属安定化工程１２よりなる。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram showing processing steps in a first embodiment according to the present invention. In this embodiment, an extraction step 10 for extracting a heavy metal by making an alkali fly ash containing a heavy metal into a slurry, a deliquoring step 11 for separating an extract from the slurry from which the heavy metal has been extracted, and a deliquoring step are discharged. And a heavy metal stabilization step 12 for chemically stabilizing the heavy metal in the deliquored fly ash.
【００３８】抽出工程１０においては、アルカリ飛灰中
の可溶性塩化物を溶解させて塩化物の溶液にするための
水（溶液調製用の水）と、脱液工程１１で分離された塩
化物を含む抽出液が加えられて攪拌混合され、スラリー
が調製される。このスラリーは、アルカリ飛灰と添加液
（水＋抽出液）の混合比が１：２〜１：１０程度、その
溶液中の塩化カルシウムの濃度が１０％〜４０％程度に
なるように調製される。塩化カルシウム濃度は溶液調製
用水の添加量の増減によって調整され、アルカリ飛灰と
添加液の混合比は抽出液の添加量の増減によって調整さ
れる。そして、スラリーが攪拌されている間に、アルカ
リ飛灰に含まれていた重金属はスラリー中の溶液へ抽出
される。次に、このスラリーは脱液工程１１へ送られ、
例えば、フィルタープレスなどの濾過機、あるいはデカ
ンターなどのような遠心沈降機によって脱液処理され
る。この脱液処理によって、スラリーは、重金属の除去
処理がなされた脱液飛灰と、重金属を含む抽出液に分離
される。この脱液飛灰には、上記抽出液が付着してお
り、未だ若干の重金属が残留しているので、重金属安定
化工程１２において、脱液飛灰に重金属を安定化させる
薬剤である硫化ソーダや水硫化ソーダなどの硫化剤ある
いは液体キレート剤が添加され、脱液飛灰中に残留して
いる重金属は硫化物や高分子金属錯体になって不溶化す
る。In the extraction step 10, water for dissolving the soluble chloride in the alkali fly ash to form a chloride solution (water for solution preparation) and the chloride separated in the deliquoring step 11 are used. The containing extract is added and mixed by stirring to prepare a slurry. This slurry was prepared so that the mixing ratio of the alkali fly ash and the additive liquid (water + extract liquid) was about 1: 2 to 1:10, and the concentration of calcium chloride in the solution was about 10% to 40%. It The calcium chloride concentration is adjusted by increasing or decreasing the addition amount of the solution preparation water, and the mixing ratio of the alkali fly ash and the addition liquid is adjusted by increasing or decreasing the addition amount of the extraction liquid. Then, while the slurry is being stirred, the heavy metal contained in the alkali fly ash is extracted into the solution in the slurry. Next, this slurry is sent to the deliquoring step 11,
For example, the liquid is removed by a filter such as a filter press or a centrifugal settling machine such as a decanter. By this deliquoring process, the slurry is separated into deliquored fly ash from which the heavy metal has been removed, and an extraction liquid containing heavy metal. The extracted liquid adheres to the deliquored fly ash, and some heavy metals still remain. Therefore, in the heavy metal stabilizing step 12, sodium sulfide, which is a chemical for stabilizing heavy metal in the deliquored fly ash, is used. A sulfidizing agent such as or sodium hydrosulfide or a liquid chelating agent is added, and the heavy metal remaining in the dewatered fly ash becomes a sulfide or a polymer metal complex and becomes insoluble.
【００３９】なお、ここで安定化処理される重金属は、
スラリー中の溶液へ抽出された重金属のうち、脱液飛灰
に付着している抽出液が含有しているものが殆どである
ので、その量は僅かである。このため、重金属安定化工
程１２で添加される薬剤の量はごく少量である。重金属
の安定化処理がなされた処理飛灰は、埋め立てなどによ
って処分される。The heavy metal to be stabilized here is
Since most of the heavy metals extracted into the solution in the slurry are contained in the extraction liquid adhering to the dewatered fly ash, the amount thereof is small. Therefore, the amount of the chemical added in the heavy metal stabilization step 12 is very small. The treated fly ash, which has been subjected to stabilization treatment of heavy metals, is disposed of by landfilling.
【００４０】一方、脱液工程１１で分離された抽出液は
アルカリ飛灰中の塩類が溶解した溶液であり、塩化カル
シウムなどの塩化物が多量に含まれている。このため、
分離された抽出液は、その一部を除き、スラリー調製用
の塩化物溶液として抽出工程１０へ送られる。そして、
残りの抽出液は別途処理された後、処分される。On the other hand, the extract separated in the deliquoring step 11 is a solution in which salts in alkali fly ash are dissolved, and contains a large amount of chloride such as calcium chloride. For this reason,
The separated extract is sent to the extraction step 10 as a chloride solution for slurry preparation, except for a part thereof. And
The remaining extract is treated separately and then disposed.
【００４１】なお、抽出工程１０でアルカリ飛灰のスラ
リーを調製する際に、脱液工程１１で分離された抽出液
と共に溶液調製用の水を加えているが、この溶液調製用
の水は、必ずしも別個に加えなくてはならないものでは
ない。抽出工程１０は飛灰と塩化物の溶液よりなるスラ
リーをつくる操作を行う工程であるので、溶液調製用の
水は上記抽出液と混合して加えても差し支えない。When the slurry of alkali fly ash is prepared in the extraction step 10, water for solution preparation is added together with the extraction liquid separated in the deliquoring step 11. The water for solution preparation is It does not necessarily have to be added separately. Since the extraction step 10 is an operation of preparing a slurry composed of a solution of fly ash and a chloride, water for preparing a solution may be added as a mixture with the above-mentioned extraction liquid.
【００４２】図２は本発明に係る第２の実施の形態にお
ける処理工程を示す図である。図２において、図１で説
明した処理工程の操作については、重複を避けるためそ
の説明を省略する。この実施の形態においては、脱液工
程１１で分離された抽出液を重金属除去工程１３へ送っ
て、抽出液中の重金属を析出させて分離し、この重金属
が除去された処理液を抽出工程１０へ送り、スラリーを
調製する。残った処理液については、塩濃度が適度にな
るように希釈した後、放流することもできる。FIG. 2 is a diagram showing processing steps in the second embodiment of the present invention. In FIG. 2, the description of the operation of the processing steps described in FIG. 1 is omitted to avoid duplication. In this embodiment, the extraction liquid separated in the deliquoring process 11 is sent to the heavy metal removing process 13 to deposit and separate the heavy metals in the extraction liquid, and the treatment liquid from which the heavy metals have been removed is extracted in the extraction process 10 And prepare a slurry. The remaining treatment liquid can be discharged after diluting it so that the salt concentration becomes appropriate.
【００４３】この方法によれば、スラリー調製用の塩化
物溶液として抽出工程１０へ送られる処理液が重金属の
除去処理がなされたものであり、スラリー溶液中の重金
属濃度が低くなるので、脱液工程１１から排出する脱液
飛灰に付着して残留する重金属の量が減少する。このた
め、重金属安定化工程１２で添加される薬剤の量を減ら
すことができる。According to this method, the treatment liquid sent to the extraction step 10 as the chloride solution for slurry preparation has been subjected to the removal treatment of heavy metals, and the concentration of heavy metals in the slurry solution becomes low. The amount of heavy metal remaining attached to the dewatered fly ash discharged from step 11 is reduced. Therefore, the amount of chemicals added in the heavy metal stabilization step 12 can be reduced.
【００４４】なお、上記重金属除去工程１３における抽
出液中の重金属析出方法としては、次の何れかの方法が
採用させれる。As a method of depositing heavy metal in the extract in the heavy metal removing step 13, any one of the following methods can be adopted.
【００４５】 抽出液に硫化ソーダや水硫化ソーダな
どの硫化剤を添加し、抽出液中の重金属を硫化物にして
析出させる。この析出物を濾過機あるいは遠心沈降機な
どによって分離し、抽出液から除去する。A sulfidizing agent such as sodium sulfide or sodium hydrosulfide is added to the extract, and the heavy metal in the extract is converted into a sulfide to be deposited. This precipitate is separated from the extract by separating it with a filter or a centrifugal settler.
【００４６】 抽出液に液体キレート剤を添加し、抽
出液中の重金属を高分子金属錯体にして析出させる。こ
の析出物を濾過機あるいは遠心沈降機などによって分離
し、抽出液から除去する。A liquid chelating agent is added to the extract, and the heavy metal in the extract is converted into a polymer metal complex and deposited. This precipitate is separated from the extract by separating it with a filter or a centrifugal settler.
【００４７】 抽出液に水を加えて塩濃度を１０％以
下に希釈し、必要に応じて若干の酸を加え、そのｐＨを
９〜１１に調整し、重金属を水酸化物にして析出させ
る。この析出物を濾過機あるいは遠心沈降機などによっ
て分離し、抽出液から除去する。Water is added to the extract to dilute the salt concentration to 10% or less, and if necessary, some acid is added to adjust the pH to 9 to 11 to precipitate heavy metal in the form of hydroxide. This precipitate is separated from the extract by separating it with a filter or a centrifugal settler.
【００４８】上記のようにして除去された析出物はその
大部分が鉛の化合物であるので、これを回収すれば、非
鉄金属精錬用の原料源として供給することができる。Since most of the precipitates removed as described above are lead compounds, if they are recovered, they can be supplied as a raw material source for non-ferrous metal refining.
【００４９】図３は本発明に係る第３の実施の形態にお
ける処理工程を示す図である。図３において、図１また
は図２で説明した処理工程の操作については、重複を避
けるためその説明を省略する。この実施の形態において
は、脱液工程１１から排出する脱液飛灰が洗浄工程１４
へ送られ、重金属除去工程１３で抽出液中の重金属を析
出させて分離した処理液が加えられ、脱液飛灰が再びス
ラリーになる。この洗浄スラリーは２回目の脱液処理を
行う脱液工程１５へ送られて洗浄脱液飛灰と分離液に分
離される。分離された洗浄脱液飛灰は重金属安定化工程
１２で重金属の安定化処理がなされた後、処分される。
また、分離液は重金属除去工程１３へ戻され、重金属が
除去される。FIG. 3 is a diagram showing processing steps in the third embodiment according to the present invention. In FIG. 3, the description of the operation of the processing steps described in FIG. 1 or FIG. 2 is omitted to avoid duplication. In this embodiment, the dewatered fly ash discharged from the dewatering step 11 is the cleaning step 14.
The treatment liquid separated from the extracted heavy metal in the heavy metal removing step 13 is added to the heavy metal removing step 13, and the liquid ash is slurried again. This cleaning slurry is sent to a dewatering step 15 for performing a second dewatering process, where it is separated into a cleaning dewatered fly ash and a separated liquid. The separated washed dewatered fly ash is subjected to heavy metal stabilization treatment in the heavy metal stabilization step 12 and then disposed.
Further, the separated liquid is returned to the heavy metal removing step 13 to remove the heavy metal.
【００５０】この方法によれば、洗浄工程１４におい
て、重金属の除去処理がなされた処理液が加えられ、脱
液飛灰が再びスラリーにされるので、脱液飛灰に付着し
ていた溶液が希釈される。このため、脱液工程１５から
排出する洗浄脱液飛灰に付着して残留する重金属の量が
非常に少なくなる。この結果、重金属安定化工程１２で
添加される薬剤の量を一層少なくすることができる。According to this method, in the cleaning step 14, the treatment liquid from which the heavy metals have been removed is added and the deliquored fly ash is slurried again, so that the solution adhering to the deliquored fly ash is removed. Diluted. For this reason, the amount of heavy metals attached to and remaining in the cleaning and dewatering fly ash discharged from the dewatering step 15 is extremely small. As a result, the amount of the chemical added in the heavy metal stabilization step 12 can be further reduced.
【００５１】図４は本発明に係る第４の実施の形態にお
ける処理工程を示す図である。図４において、図１、図
２、または図３で説明した処理工程の操作については、
重複を避けるためその説明を省略する。この実施の形態
においては、脱液飛灰を洗浄する洗浄工程１４で水が加
えられる。洗浄工程１４から排出した洗浄スラリーは２
回目の脱液処理を行う脱液工程１５へ送られて洗浄脱液
飛灰と分離液に分離される。この際に発生する分離液
は、飛灰のスラリーを調製する際に加える溶液調整用水
の代わりに抽出工程１０へ送られる。このため、抽出工
程１０における溶液中の塩化カルシウム濃度は、洗浄工
程１４で加える水量の増減によって調整される。そし
て、洗浄脱液飛灰は重金属安定化工程１２で重金属の安
定化処理がなされた後、処分される。FIG. 4 is a diagram showing processing steps in the fourth embodiment according to the present invention. In FIG. 4, regarding the operation of the processing steps described in FIG. 1, FIG. 2 or FIG.
The description is omitted to avoid duplication. In this embodiment, water is added in the cleaning step 14 for cleaning the dewatered fly ash. The cleaning slurry discharged from the cleaning process 14 is 2
It is sent to a dewatering step 15 in which a liquid removal process is performed for the second time, and is separated into washed dewatered fly ash and a separated liquid. The separated liquid generated at this time is sent to the extraction step 10 instead of the solution adjusting water added when preparing the fly ash slurry. Therefore, the calcium chloride concentration in the solution in the extraction step 10 is adjusted by increasing or decreasing the amount of water added in the washing step 14. Then, the washed and dewatered fly ash is subjected to heavy metal stabilization treatment in the heavy metal stabilization step 12, and then disposed.
【００５２】この方法によれば、洗浄工程１４におい
て、脱液飛灰に水が加えられ、脱液飛灰が再びスラリー
にされるので、脱液飛灰に付着していた溶液が希釈され
る。このため、脱液工程１５から排出する洗浄脱液飛灰
に付着して残留する重金属の量が非常に少なくなる。こ
の結果、重金属安定化工程１２で添加される薬剤の量を
一層少なくすることができる。According to this method, in the washing step 14, water is added to the dewatered fly ash and the deliquefied fly ash is slurried again, so that the solution adhering to the dewatered fly ash is diluted. . For this reason, the amount of heavy metals attached to and remaining in the cleaning and dewatering fly ash discharged from the dewatering step 15 is extremely small. As a result, the amount of the chemical added in the heavy metal stabilization step 12 can be further reduced.
【００５３】[0053]
（実験１）アルカリ飛灰を塩化物の溶液中へ投入して重
金属を抽出する各種実験を実施するに際し、まず、塩化
物溶液の濃度と鉛の抽出率との関係を調べた。(Experiment 1) In conducting various experiments for extracting heavy metals by introducing alkali fly ash into a chloride solution, first, the relationship between the chloride solution concentration and the lead extraction rate was investigated.
【００５４】表４および表５に示す組成のアルカリ飛灰
５０ｇに、薬品の塩化カルシウムを溶解して調製した１
０％の塩化カルシウム溶液３００ｍｌを加えてスラリー
にし、２時間攪拌した後、このスラリーを減圧濾過器に
よって固液分離し、２８０ｍｌの抽出液と、液分が約５
０％の抽出残渣（脱液飛灰）６０ｇを得た。得られた抽
出液中の塩化カルシウム濃度（カルシウム濃度と塩素濃
度からの推算値）および鉛濃度は表６に記載の通りであ
った。1 was prepared by dissolving the chemical calcium chloride in 50 g of alkali fly ash having the composition shown in Tables 4 and 5.
After adding 300 ml of 0% calcium chloride solution to form a slurry and stirring for 2 hours, the slurry was subjected to solid-liquid separation with a vacuum filter, and 280 ml of the extract and about 5
60 g of 0% extraction residue (dehydrated fly ash) was obtained. The calcium chloride concentration (estimated value from the calcium concentration and chlorine concentration) and the lead concentration in the obtained extract were as shown in Table 6.
【００５５】次いで、アルカリ飛灰をスラリーにする際
に加える塩化カルシウム溶液の濃度だけを２０％、３０
％、４０％に種々変えた実験と、塩化カルシウム溶液の
代わりに水を加えた実験を上記と同様に行った。この結
果も、表６に示す。Next, only the concentration of the calcium chloride solution added when making the alkali fly ash into slurry is 20% and 30%.
%, 40% and various experiments in which water was added instead of the calcium chloride solution were conducted in the same manner as above. The results are also shown in Table 6.
【００５６】この表６に記載されている鉛の抽出率は、
飛灰５０ｇ中の鉛含有量に対する、抽出液に含まれてい
た鉛の総量（分離された抽出液中の鉛含有量と残渣に付
着している抽出液中の鉛含有量の合計）の割合を示す値
である。The lead extraction rates listed in Table 6 are:
Ratio of the total amount of lead contained in the extract to the lead content in 50 g of fly ash (the total of the lead content in the separated extract and the lead content in the extract adhering to the residue) Is a value indicating.
【００５７】また、表６に記載されている鉛の抽出率と
塩化カルシウム濃度の関係を図５に示す。この図によれ
ば、鉛の抽出率は塩化カルシウム濃度が高くなるに従っ
て大きる。そして、塩化カルシウム濃度が濃度が１０％
付近までは急激に高くなり、その濃度が１０％になる
と、約８０％の値が得られている。しかし、塩化カルシ
ウム濃度が約２０％を超えると、鉛の抽出率は約９０％
で略頭打ちの状態になる。FIG. 5 shows the relationship between the lead extraction rate and calcium chloride concentration shown in Table 6. According to this figure, the lead extraction rate increases as the calcium chloride concentration increases. And the concentration of calcium chloride is 10%
The value rapidly increases up to the vicinity, and when the concentration reaches 10%, a value of about 80% is obtained. However, when the calcium chloride concentration exceeds about 20%, the lead extraction rate is about 90%.
It will be almost capped at.
【００５８】このように、抽出液の塩化カルシウム濃度
あまり高くしても、鉛の抽出率は上がらないことが分か
った。また、さらに塩化カルシウム濃度をあまり高くす
ると、抽出液の粘度が大きくなり、スラリーの脱液操作
における飛灰と抽出液の分離効率が低下する。この分離
操作の効率からすると、抽出液の塩化カルシウム濃度は
４０％程度を上限とすべきものと思われる。As described above, it was found that the lead extraction rate does not increase even if the calcium chloride concentration of the extract is too high. Further, if the calcium chloride concentration is too high, the viscosity of the extract becomes large, and the efficiency of separating fly ash from the extract in the deliquoring operation of the slurry decreases. Considering the efficiency of this separation operation, it seems that the calcium chloride concentration of the extract should have an upper limit of about 40%.
【００５９】従って、抽出液の塩化カルシウム濃度は１
０％〜４０％程度にするのがよい。Therefore, the calcium chloride concentration of the extract is 1
It is preferable to set it to about 0% to 40%.
【００６０】[0060]
【表４】 [Table 4]
【００６１】[0061]
【表５】 [Table 5]
【００６２】[0062]
【表６】 [Table 6]
【００６３】（実験２）表４および表５に示す組成のア
ルカリ飛灰１０ｋｇに、薬品の塩化カルシウムを溶解し
て調製した１４％の塩化カルシウム溶液５０ｋｇを加え
てスラリーにし、３時間攪拌した後、このスラリーをフ
ィルタープレスによって分離し、抽出液と抽出残渣を得
た。次いで、上記抽出液３８．５ｋｇに水１１．５ｋｇ
を加えて、再び、塩化カルシウム濃度が１４％に相当す
る溶液５０ｋｇを調整し、この溶液に、表４および表５
に示す組成のアルカリ飛灰１０ｋｇを投入してスラリー
にした後、上同様の処理をし、抽出液と抽出残渣に分離
した。(Experiment 2) 50 kg of a 14% calcium chloride solution prepared by dissolving calcium chloride as a chemical was added to 10 kg of alkali fly ash having the composition shown in Tables 4 and 5 to make a slurry, and after stirring for 3 hours. The slurry was separated by a filter press to obtain an extract and an extraction residue. Next, 18.5 kg of water was added to 38.5 kg of the above extract.
Was added again to prepare 50 kg of a solution having a calcium chloride concentration of 14%. Table 4 and Table 5 were added to this solution.
After 10 kg of alkali fly ash having the composition shown in (1) was added to form a slurry, the same treatment as above was performed to separate an extract and an extraction residue.
【００６４】そして、上記のようにして得られた抽出液
を順次５回繰り返して使用し、アルカリ飛灰中の重金属
を抽出した。この際に得られた抽出液は４６．４ｋｇ、
抽出残渣は１３．６ｋｇであった。この抽出液を分析
し、その化合物組成を求めたところ、表７の通りであっ
た。また、抽出残渣を分析したところ、水分含有率は３
９．０％で、鉛の含有率は０．２９％であった。この抽
出残渣の分析値から、抽出残渣に残留していた鉛の量の
割合を算出したところ、その残留率は元のアルカリ飛灰
の鉛含有量に対し、約４６％であった。The extract obtained as described above was repeatedly used 5 times in succession to extract heavy metals in the alkali fly ash. The extract obtained at this time was 46.4 kg,
The extraction residue was 13.6 kg. This extract was analyzed and its compound composition was determined. The results are shown in Table 7. Moreover, when the extraction residue was analyzed, the water content was 3
The lead content was 9.0% and 0.29%. When the ratio of the amount of lead remaining in the extraction residue was calculated from the analysis value of this extraction residue, the residual ratio was about 46% with respect to the lead content of the original alkali fly ash.
【００６５】次いで、上記抽出残渣に液体キレート剤
（日本鋼管（株）製、商品名Ａ２００）を３％添加して
混練し、重金属の安定化処理を行った。この混練物を２
４時間放置した後、環境庁告示１３号溶出試験を実施し
た。この試験においては、試料であるアルカリ飛灰と溶
媒（純水を塩酸でｐＨ５．８〜６．３に調整したもの）
を１：１０の割合で混合し、６時間振盪した後、濾過分
離して溶出液を得た。そして、この溶出液に含まれてい
る重金属類の分析を行った。この分析値は表８に示す。Next, 3% of a liquid chelating agent (manufactured by Nippon Kokan Co., Ltd., trade name A200) was added to the above extraction residue and kneaded to stabilize the heavy metal. 2 this kneaded mixture
After standing for 4 hours, the Environmental Agency Notification No. 13 dissolution test was performed. In this test, a sample of alkali fly ash and solvent (pure water adjusted to pH 5.8-6.3 with hydrochloric acid)
Were mixed at a ratio of 1:10, shaken for 6 hours, and then separated by filtration to obtain an eluate. Then, the heavy metals contained in this eluate were analyzed. The analytical values are shown in Table 8.
【００６６】この表８の記載のように、重金属の安定化
処理をした抽出残渣（処理飛灰）の重金属溶出濃度は、
Ｐｂが０．０５mg／ｌ未満（埋め立て処分に関する基準
は０．３mg／ｌ未満）で、基準値を十分に満足している
外、他の重金属の溶出濃度も基準値を十分に満足してい
る。従って、この実験２においては、重金属の安定化に
支障が生ずることなく、抽出残渣に対する液体キレート
剤の添加量を３％まで低減することができた。この液体
キレート剤の添加量は、次に記すように、従来の薬剤添
加法による場合の約１／３に相当する値である。As shown in Table 8, the heavy metal elution concentration of the extraction residue (treated fly ash) obtained by stabilizing the heavy metal was
Pb is less than 0.05 mg / l (the standard for landfill disposal is less than 0.3 mg / l), which fully satisfies the standard value, and the elution concentrations of other heavy metals also fully satisfy the standard value. . Therefore, in this Experiment 2, the addition amount of the liquid chelating agent to the extraction residue could be reduced to 3% without causing any trouble in stabilizing the heavy metal. The addition amount of this liquid chelating agent is a value corresponding to about 1/3 of that in the case of the conventional chemical addition method, as described below.
【００６７】なお、アルカリ飛灰に直接液体キレート剤
を添加する従来の薬剤添加法による場合、一般に、Ｐｂ
の含有量１０００mg／kg当たり１％の液体キレート剤が
添加されており、表５に示す鉛の含有量（８６００mg／
kg）の飛灰を処理する際には、約９％の液体キレート剤
を添加量しなければならない。In the conventional chemical addition method of directly adding a liquid chelating agent to alkali fly ash, Pb is generally used.
1% of liquid chelating agent is added per 1000 mg / kg, and the lead content shown in Table 5 (8600 mg / kg
When treating (kg) fly ash, about 9% of liquid chelating agent must be added.
【００６８】[0068]
【表７】 [Table 7]
【００６９】[0069]
【表８】 [Table 8]
【００７０】（実験３）実験２の場合と同様にして抽出
液を循環使用し、その抽出液と表４および表５に示す組
成のアルカリ飛灰を混合してスラリーにし、このスラリ
ーを脱液処理して抽出残渣と抽出液に分離した。そし
て、この抽出液に硫化ソーダ溶液を加えて重金属類（主
として鉛）の硫化物を析出させ、これを濾過して処理液
と析出物に分離した。この重金属除去処理がなされた処
理液中の鉛濃度は０．０５mg／ｌ未満であった。(Experiment 3) In the same manner as in Experiment 2, the extract was circulated and used, and the extract and the alkali fly ash having the composition shown in Tables 4 and 5 were mixed to form a slurry. It processed and isolate | separated into the extraction residue and the extract. Then, a sodium sulfide solution was added to this extract to precipitate a sulfide of heavy metals (mainly lead), which was filtered to separate into a treatment liquid and a precipitate. The lead concentration in the treatment liquid subjected to this heavy metal removal treatment was less than 0.05 mg / l.
【００７１】次いで、上記処理液３８．５ｋｇに水１
１．５ｋｇを加えて塩化カルシウム濃度１４％の溶液５
０ｋｇを調製し、この溶液に、表４および表５に示す組
成のアルカリ飛灰１０ｋｇを投入してスラリーにし、こ
のスラリーをフィルタープレスによって分離し、４６．
１ｋｇの抽出液と、１３．６ｋｇの抽出残渣（脱液飛
灰）を得た。Next, 18.5 of water was added to 38.5 kg of the above treatment solution.
Solution with 1.5kg calcium chloride concentration 14% 5
0 kg was prepared, 10 kg of alkali fly ash having the composition shown in Tables 4 and 5 was added to this solution to make a slurry, and this slurry was separated by a filter press.
1 kg of extract and 13.6 kg of extraction residue (dehydrated fly ash) were obtained.
【００７２】抽出残渣を分析したところ、水分含有率は
３９．０％で、鉛の含有率は０．０８％であった。この
抽出残渣の分析値から、抽出残渣に残留していた鉛の量
の割合を算出したところ、その残留率は元のアルカリ飛
灰の鉛含有量に対し、約１２％であった。When the extraction residue was analyzed, the water content was 39.0% and the lead content was 0.08%. When the ratio of the amount of lead remaining in the extraction residue was calculated from the analysis value of this extraction residue, the residual ratio was about 12% with respect to the lead content of the original alkali fly ash.
【００７３】そして、実験２の場合と同様に、抽出残渣
に液体キレート剤（日本鋼管（株）製、商品名Ａ２０
０）を１％添加して重金属の安定化処理を行った後、そ
の溶出試験を実施した。この溶出試験で得られた値は、
表８の示す実験２の溶出試験結果と全く同様であり、重
金属の安定化処理をした抽出残渣（処理飛灰）の重金属
溶出濃度は、何れの重金属についても、埋め立て処分に
関する基準を十分に満足していた。従って、この実験３
においては、重金属の安定化に支障が生ずることなく、
抽出残渣に対する液体キレート剤の添加量を１％（従来
技術の約１／７）まで低減することができた。Then, as in the case of Experiment 2, a liquid chelating agent (manufactured by Nippon Kokan Co., Ltd., trade name A20) was added to the extraction residue.
After 1% of 0) was added to stabilize the heavy metal, the dissolution test was carried out. The value obtained in this dissolution test is
The elution test results of Experiment 2 shown in Table 8 are exactly the same, and the heavy metal elution concentration of the extraction residue (treated fly ash) after stabilization treatment of heavy metals sufficiently satisfies the criteria for landfill disposal for any heavy metal. Was. Therefore, this experiment 3
In, without hindering the stabilization of heavy metals,
The amount of the liquid chelating agent added to the extraction residue could be reduced to 1% (about 1/7 of the conventional technique).
【００７４】また、抽出液に硫化ソーダ溶液を加えて重
金属類を析出させ、これを濾過分離したものを分析した
ところ、この析出物はＰｂの含有率が７０％以上であ
り、非鉄金属精錬の原料として供給することができるも
のであった。Further, a sodium sulfide solution was added to the extract to precipitate heavy metals, which was separated by filtration. The precipitate was analyzed and found to have a Pb content of 70% or more. It could be supplied as a raw material.
【００７５】（実験４）実験３と同様の抽出処理、脱液
処理、重金属除去処理をして得た処理液３８．５ｋｇに
水１１．５ｋｇを加えて塩化カルシウム濃度１４％の溶
液５０ｋｇを調製し、この塩化カルシウム溶液に、表４
および表５に示す組成のアルカリ飛灰１０ｋｇを投入し
てスラリーにし、このスラリーをフィルタープレスで分
離し、１３．６ｋｇの抽出残渣（脱液飛灰）を得た。次
いで、抽出残渣に実験３と同様の処理をして得た処理液
１０ｋｇを加えてスラリー（洗浄スラリー）にし、上記
同様の脱液処理をして洗浄残渣（洗浄脱液飛灰）を得
た。洗浄残渣を分析したところ、水分含有率は３８％
で、鉛の含有率は０．０３％であった。この抽出残渣の
分析値から、抽出残渣に残留していた鉛の量の割合を算
出したところ、その残留率は元のアルカリ飛灰の鉛含有
量に対し、約４％であった。(Experiment 4) 11.5 kg of water was added to 38.5 kg of the treatment solution obtained by the same extraction treatment, deliquoring treatment and heavy metal removal treatment as in Experiment 3 to prepare 50 kg of a solution having a calcium chloride concentration of 14%. Then, add this calcium chloride solution to Table 4
And 10 kg of alkali fly ash having the composition shown in Table 5 was charged into a slurry, and the slurry was separated by a filter press to obtain 13.6 kg of an extraction residue (liquified fly ash). Next, 10 kg of the treatment liquid obtained by performing the same treatment as in Experiment 3 was added to the extraction residue to form a slurry (washing slurry), and the same deliquoring treatment was performed to obtain a washing residue (washing liquor fly ash). . Analysis of the washing residue shows a water content of 38%
The lead content was 0.03%. When the ratio of the amount of lead remaining in the extraction residue was calculated from the analysis value of this extraction residue, the residual ratio was about 4% with respect to the lead content of the original alkali fly ash.
【００７６】そして、上記洗浄残渣に液体キレート剤
（日本鋼管（株）製、商品名Ａ２００）を０．５％添加
し、上記実験２の場合と同様に、重金属の安定化処理を
行った後、その溶出試験を実施した。この溶出試験で得
られた値は、表８の示す実験２の溶出試験結果と全く同
様であり、重金属の安定化処理をした洗浄残渣（処理飛
灰）の重金属溶出濃度は、何れの重金属についても、埋
め立て処分に関する基準を十分に満足していた。従っ
て、この実験４においては、重金属の安定化に支障が生
ずることなく、洗浄残渣に対する液体キレート剤の添加
量を０．５％（従来技術の約１／１３）まで低減するこ
とができた。Then, 0.5% of a liquid chelating agent (manufactured by Nippon Kokan Co., Ltd., trade name A200) was added to the above-mentioned washing residue, and the heavy metal was stabilized in the same manner as in the case of Experiment 2 above. , The dissolution test was carried out. The values obtained in this dissolution test are exactly the same as the results of the dissolution test in Experiment 2 shown in Table 8, and the heavy metal elution concentration of the cleaning residue (treated fly ash) after stabilization treatment of heavy metals is for any heavy metal. However, they were fully satisfied with the standards for landfill disposal. Therefore, in this Experiment 4, the addition amount of the liquid chelating agent to the cleaning residue could be reduced to 0.5% (about 1/13 of the conventional technique) without causing any trouble in stabilizing the heavy metal.
【００７７】（実験５）上記実験２と同様の抽出処理お
よび脱液処理をして得た抽出残渣（脱液飛灰）１３．６
ｋｇに水１０ｋｇを加えてスラリーにし、このスラリー
をフィルタープレスによって分離し、１３．４ｋｇの洗
浄残渣（洗浄脱液飛灰）を得た。洗浄残渣を分析したと
ころ、水分含有率は４２．３％で、鉛の含有率は０．０
２％であった。この洗浄残渣の分析値から、洗浄残渣に
残留していた鉛の量の割合を算出したところ、その残留
率は元のアルカリ飛灰の鉛含有量に対し、約３％であっ
た。(Experiment 5) Extraction residue (deliquesed fly ash) obtained by the same extraction and deliquoring treatment as in Experiment 2 13.6.
10 kg of water was added to kg to make a slurry, and this slurry was separated by a filter press to obtain 13.4 kg of a washing residue (washed dewatered fly ash). Analysis of the cleaning residue showed a water content of 42.3% and a lead content of 0.0
2%. When the ratio of the amount of lead remaining in the cleaning residue was calculated from the analysis value of this cleaning residue, the residual ratio was about 3% with respect to the lead content of the original alkali fly ash.
【００７８】そして、上記洗浄残渣に液体キレート剤
（日本鋼管（株）製、商品名Ａ２００）を０．３％添加
し、上記実験２の場合と同様に、重金属の安定化処理を
行った後、その溶出試験を実施した。この溶出試験で得
られた値は、表８の示す実験２の溶出試験結果と全く同
様であり、重金属の安定化処理をした洗浄残渣（処理飛
灰）の重金属溶出濃度は、何れの重金属についても、埋
め立て処分に関する基準を十分に満足していた。従っ
て、この実験５においては、重金属の安定化に支障が生
ずることなく、洗浄残渣に対する液体キレート剤の添加
量を０．３％（従来技術の約１／２２）まで低減するこ
とができた。Then, 0.3% of a liquid chelating agent (manufactured by Nippon Steel Tube Co., Ltd., trade name A200) was added to the above-mentioned washing residue, and the heavy metal was stabilized in the same manner as in Experiment 2 above. , The dissolution test was carried out. The values obtained in this dissolution test are exactly the same as the results of the dissolution test in Experiment 2 shown in Table 8, and the heavy metal elution concentration of the cleaning residue (treated fly ash) after stabilization treatment of heavy metals is for any heavy metal. However, they were fully satisfied with the standards for landfill disposal. Therefore, in this Experiment 5, it was possible to reduce the amount of the liquid chelating agent added to the cleaning residue to 0.3% (about 1/22 of the conventional technique) without causing any trouble in stabilizing the heavy metal.
【００７９】[0079]
【発明の効果】本発明によれば、アルカリ飛灰中の重金
属が塩化物の溶液に抽出され、この重金属を含有する抽
出液の大半が脱液処理の際に分離されてしまうので、大
部分の重金属が除去された飛灰が得られる。このため、
飛灰の廃棄処分に際して添加しなければならない重金属
安定化剤の量が極めて少なくて済み、アルカリ飛灰の無
害化処理を低コストで実施することができる。EFFECTS OF THE INVENTION According to the present invention, the heavy metals in the alkali fly ash are extracted into the chloride solution, and most of the extraction liquid containing the heavy metals is separated during the deliquoring process. The fly ash from which the heavy metals are removed is obtained. For this reason,
The amount of the heavy metal stabilizer that must be added when the fly ash is disposed of is extremely small, and the alkali fly ash can be detoxified at low cost.
【図１】本発明に係る第１の実施の形態における処理工
程を示す図である。FIG. 1 is a diagram showing a processing step in a first embodiment according to the present invention.
【図２】本発明に係る第２の実施の形態における処理工
程を示す図である。FIG. 2 is a diagram showing a processing step according to a second embodiment of the present invention.
【図３】本発明に係る第３の実施の形態における処理工
程を示す図である。FIG. 3 is a diagram showing processing steps in a third embodiment of the present invention.
【図４】本発明に係る第４の実施の形態における処理工
程を示す図である。FIG. 4 is a diagram showing a processing step in a fourth embodiment according to the present invention.
【図５】塩化カルシウム濃度と鉛抽出率の関係を示す図
である。FIG. 5 is a graph showing the relationship between calcium chloride concentration and lead extraction rate.
１０ 抽出工程 １１ 脱液工程 １２ 重金属安定化工程 １３ 重金属除去工程 １４ 洗浄工程 １５ ２回目の脱液工程 10 Extraction Step 11 Deliquation Step 12 Heavy Metal Stabilization Step 13 Heavy Metal Removal Step 14 Cleaning Step 15 Second Deliquification Step
Claims (9)
アルカリ飛灰中の塩化物を溶液にするための水と、塩化
物の溶液を加えてスラリーにし、このスラリーを脱液処
理して抽出液と脱液飛灰に分離し、この脱液飛灰を重金
属安定化処理することを特徴とするアルカリ飛灰の無害
化処理方法。1. An alkali fly ash containing a heavy metal, water for making chloride in the alkali fly ash into a solution and a solution of the chloride are added to form a slurry, and the slurry is subjected to deliquoring treatment for extraction. A method for detoxifying alkali fly ash, which comprises separating the liquid liquor and the liquor fly ash, and stabilizing the liquor fly ash.
アルカリ飛灰中の塩化物を溶液にするための水と、塩化
物の溶液を加えてスラリーにする際に、前記塩化物の溶
液として前記スラリーを脱液処理した際に分離された抽
出液を供給することを特徴とする請求項１に記載のアル
カリ飛灰の無害化処理方法。2. A solution of chloride when the slurry for adding chloride and a solution of chloride in the alkali fly ash is added to the alkali fly ash containing heavy metal to form a slurry. The method for detoxifying alkali fly ash according to claim 1, wherein the extraction liquid separated when the slurry is dewatered is supplied.
アルカリ飛灰中の塩化物を溶液にするための水と、塩化
物の溶液を加えてスラリーにし、このスラリーを脱液処
理して抽出液と脱液飛灰に分離し、この脱液飛灰を重金
属安定化処理すると共に、前記抽出液中の重金属を析出
させて分離する処理を行い、この重金属が分離された処
理液を前記塩化物の溶液としてアルカリ飛灰をスラリー
にする工程へ供給することを特徴とするアルカリ飛灰の
無害化処理方法。3. An alkali fly ash containing a heavy metal, water for making chloride in the alkali fly ash into a solution, and a solution of the chloride are added to form a slurry, and the slurry is subjected to liquid removal treatment for extraction. Separated into liquid and liquor fly ash, and subjecting the liquor fly ash to a heavy metal stabilization treatment, a treatment for precipitating and separating heavy metals in the extraction liquid, and treating the treatment liquid from which the heavy metals have been separated into the chlorination A method for detoxifying alkali fly ash, which comprises supplying the alkali fly ash as a slurry solution to a step of making it into a slurry.
アルカリ飛灰中の塩化物を溶液にするための水と、塩化
物の溶液を加えてスラリーにし、このスラリーを脱液処
理して抽出液と脱液飛灰に分離し、この脱液飛灰に抽出
液中の重金属を析出させて分離した処理液を加えて洗浄
スラリーにし、この洗浄スラリーを脱液処理して分離液
と洗浄脱液飛灰に分離し、この洗浄脱液飛灰を重金属安
定化処理すると共に、前記処理液を前記塩化物の溶液と
してアルカリ飛灰をスラリーにする工程へ供給すること
を特徴とするアルカリ飛灰の無害化処理方法。4. An alkali fly ash containing a heavy metal, water for making chloride in the alkali fly ash into a solution and a solution of the chloride are added to form a slurry, and the slurry is subjected to deliquoring treatment for extraction. Liquid and deliquesed fly ash, and the treated liquid separated by precipitating heavy metals in the extracted liquid to this deliquefied fly ash is used as a cleaning slurry. Alkaline fly ash, characterized in that the fly ash is separated into liquid fly ash, and the washed and dewatered fly ash is subjected to heavy metal stabilization treatment, and the treatment liquid is supplied to the step of making the alkali fly ash into a slurry as the chloride solution Detoxification treatment method.
の溶液を加えてスラリーにし、このスラリーを脱液処理
して抽出液と脱液飛灰に分離し、この脱液飛灰に水を加
えて洗浄スラリーにし、この洗浄スラリーを脱液処理し
て分離液と洗浄脱液飛灰に分離し、この洗浄脱液飛灰を
重金属安定化処理すると共に、前記抽出液および前記分
離液を前記塩化物の溶液としてアルカリ飛灰をスラリー
にする工程へ供給することを特徴とするアルカリ飛灰の
無害化処理方法。5. A solution of chloride is added to alkali fly ash containing heavy metals to form a slurry, and the slurry is subjected to a deliquoring process to separate an extract and a deliquored fly ash. In addition, it is made into a cleaning slurry, and the cleaning slurry is deliquored to separate into a separated liquid and a cleaning dewatered fly ash. A method for detoxifying alkali fly ash, which comprises supplying the alkali fly ash as a chloride solution to a step of making it into a slurry.
が主として塩化カルシウムであることを特徴とする請求
項１〜請求項５に記載のアルカリ飛灰の無害化処理方
法。6. The method for detoxifying alkali fly ash according to claim 1, wherein the chloride contained in the solution of the slurry is mainly calcium chloride.
ルシウムの濃度が１０ｗｔ％〜４０ｗｔ％である請求項
１〜請求項６に記載のアルカリ飛灰の無害化処理方法。7. The method for detoxifying alkali fly ash according to claim 1, wherein the concentration of calcium chloride contained in the solution of the slurry is 10 wt% to 40 wt%.
灰の重金属安定化処理が、重金属を安定化させる薬剤を
添加する方法による処理であることを特徴とする請求項
１〜請求項３に記載のアルカリ飛灰の無害化処理方法。8. The method for stabilizing heavy metal of the dewatered fly ash separated by subjecting the slurry to deliquefaction treatment is a treatment by a method of adding an agent for stabilizing heavy metal. 4. The method for detoxifying alkali fly ash according to item 3.
浄脱液飛灰の重金属安定化処理が、重金属を安定化させ
る薬剤を添加する方法による処理であることを特徴とす
る請求項４または請求項５に記載のアルカリ飛灰の無害
化処理方法。9. The method for stabilizing heavy metals in the washed deliquoring fly ash separated by deliquoring the washing slurry is a treatment by a method of adding an agent for stabilizing heavy metals. The method for detoxifying alkali fly ash according to claim 5.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP00778196A JP3309689B2 (en) | 1996-01-19 | 1996-01-19 | Detoxification treatment method of alkali fly ash |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP00778196A JP3309689B2 (en) | 1996-01-19 | 1996-01-19 | Detoxification treatment method of alkali fly ash |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH09192625A true JPH09192625A (en) | 1997-07-29 |
| JP3309689B2 JP3309689B2 (en) | 2002-07-29 |
Family
ID=11675226
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP00778196A Expired - Fee Related JP3309689B2 (en) | 1996-01-19 | 1996-01-19 | Detoxification treatment method of alkali fly ash |
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| Country | Link |
|---|---|
| JP (1) | JP3309689B2 (en) |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000000546A (en) * | 1998-06-17 | 2000-01-07 | Tsukishima Kikai Co Ltd | Recovering method for heavy metal component |
| JP2005177755A (en) * | 2003-12-23 | 2005-07-07 | Kuen-Sen Chang | Removing method of fly ash heavy metal produced in incineration of waste |
| JP2007301502A (en) * | 2006-05-12 | 2007-11-22 | Kurita Water Ind Ltd | Method and device for treating trash incineration main ash |
| JP2009226279A (en) * | 2008-03-21 | 2009-10-08 | Taiheiyo Cement Corp | Method of treating microdust containing calcium component and lead component |
| JP2010051869A (en) * | 2008-08-27 | 2010-03-11 | Taiheiyo Cement Corp | Method and system for washing incineration ash and dust extracted from cement kiln combustion gas with water |
| JP2010051868A (en) * | 2008-08-27 | 2010-03-11 | Taiheiyo Cement Corp | Method and system for washing incineration ash and dust extracted from cement kiln combustion gas with water |
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| CN111014228A (en) * | 2019-10-31 | 2020-04-17 | 华能国际电力股份有限公司大连电厂 | Device and method for removing ammonia from boiler fly ash |
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-
1996
- 1996-01-19 JP JP00778196A patent/JP3309689B2/en not_active Expired - Fee Related
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000000546A (en) * | 1998-06-17 | 2000-01-07 | Tsukishima Kikai Co Ltd | Recovering method for heavy metal component |
| JP2005177755A (en) * | 2003-12-23 | 2005-07-07 | Kuen-Sen Chang | Removing method of fly ash heavy metal produced in incineration of waste |
| JP2007301502A (en) * | 2006-05-12 | 2007-11-22 | Kurita Water Ind Ltd | Method and device for treating trash incineration main ash |
| JP2009226279A (en) * | 2008-03-21 | 2009-10-08 | Taiheiyo Cement Corp | Method of treating microdust containing calcium component and lead component |
| JP2010051869A (en) * | 2008-08-27 | 2010-03-11 | Taiheiyo Cement Corp | Method and system for washing incineration ash and dust extracted from cement kiln combustion gas with water |
| JP2010051868A (en) * | 2008-08-27 | 2010-03-11 | Taiheiyo Cement Corp | Method and system for washing incineration ash and dust extracted from cement kiln combustion gas with water |
| JP2011083687A (en) * | 2009-10-14 | 2011-04-28 | Sumitomo Osaka Cement Co Ltd | Method of treating waste, and method of converting waste into resources |
| CN111014228A (en) * | 2019-10-31 | 2020-04-17 | 华能国际电力股份有限公司大连电厂 | Device and method for removing ammonia from boiler fly ash |
| CN112893416A (en) * | 2021-02-05 | 2021-06-04 | 南京理工大学 | Recycling method of fly ash and fly ash hydrothermal treatment fluid |
| CN112893416B (en) * | 2021-02-05 | 2022-07-19 | 南京理工大学 | Recycling method of fly ash and fly ash hydrothermal treatment fluid |
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| Publication number | Publication date |
|---|---|
| JP3309689B2 (en) | 2002-07-29 |
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