JP2003190907A - Treatment method of hardly decomposable substance and apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a treatment method of hardly decomposable substances and apparatus capable of removing even hardly decomposable substances existing in fly ashes at a high decomposition efficiency in a short time. <P>SOLUTION: In the treatment apparatus of hardly decomposable substances, for hardy decomposable substances existing in fly ashes contained in a flue gas 20 discharged out of an incinerator which comprises a means for changing a catalyst 20 for hardly decomposable substance removal into the high temperature atmosphere where fly ashes are generated, a bag filter 10 for separating fly ashes internally containing the catalyst 29 from a flue gas 20, a decomposition tank 14 where the hardly decomposable substances contained in the fly ashes 22 are decomposed and removed in the presence of hydroxyl radical by utilizing the catalyst 20 internally contained in the fly ashes after the separated fly ashes 22 are cooled, a magnetic separator 13 for separating and recovering the catalyst 30 remaining in the fly ashes after the hardly decomposable substance removal, and a return route for turning at least a portion of the recovered catalyst 30 back to the high temperature atmosphere. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to treatment of hardly decomposable substances such as dioxins contained in fly ash discharged from a boiler, incinerator, or melting furnace, and more particularly to the treatment of hardly decomposable substance-containing fly ash. The present invention relates to a method for treating a hardly decomposable substance that oxidizes and decomposes ash to render it harmless, and an apparatus therefor.

[0002]

Fly ash discharged from boilers, incinerators, or melting furnaces contains sulfur oxides, nitrogen oxides, hydrogen chloride,
It contains harmful substances such as heavy metals and dioxins that adversely affect the human body and the environment. Among them, persistent substances such as dioxins are highly toxic and have toxicity such as carcinogenicity and teratogenicity, so that they have recently been regulated by strict environmental standards. The dioxins are organic chlorine compounds such as polychlorinated dibenzofuran (PCDF) and polychlorinated dibenzo-para-dioxin (PCDD), which are unintentionally generated in the process of burning the organic compound under the coexistence of chlorine. .

The organic chlorine compounds such as dioxins and PCBs are chemically stable and hardly decomposable substances, and in an incinerator or the like, in a temperature range of about 250 to 350 ° C.,
It may be resynthesized by contact between a precursor substance such as chlorobenzene and fly ash, or contact between inorganic chlorine, air, water and the like with unburned carbon using unburned carbon as a starting material. As a method for suppressing the emission of the hardly decomposable substance, in the combustion process, combustion control is performed to improve the combustion state and prevent re-synthesis of the hardly decomposable substance in the temperature range, and further in the temperature range for decomposable substance decomposition. Reburning and the like can be mentioned, but it is difficult to eliminate the generation of hardly decomposable substances even by these methods.

Therefore, as a method for treating fly ash containing a hardly decomposable substance, a melting method, a gas phase hydrogen reduction method, a reduction heating dechlorination method, a supercritical hydroxylation decomposition method, a metallic sodium dispersion method, a photochemical decomposition method, There are various methods such as oxidative decomposition method, but among them, the oxidative decomposition method using a hydroxy radical having a strong oxidizing power is considered to be a cost effective method because of its high efficiency of removing hardly decomposable substances. To be

As a technique using such a system, the present inventors have proposed a method for treating a hardly decomposable substance in Japanese Patent Application No. 2001-72826 (unknown). Such treatment method, incineration ash containing the hardly decomposable substance discharged from the incinerator is mixed with drainage to form a slurry, and the acid is added to the reaction tank after depositing the hardly decomposable substance on the surface of the incinerator ash. The incineration ash is rendered harmless by oxidatively decomposing the hardly decomposable substance in the presence of hydrogen peroxide and a hydroxy radical generated by an ozone generator. According to such a method, dioxins can be decomposed at room temperature, and by performing oxidative decomposition treatment in an acidic state or in the presence of a surfactant, the dioxins deposited on the surface of the incinerated ash can be decomposed efficiently. be able to.

Further, in Japanese Patent Laid-Open No. 2000-167510,
It proposes a method for treating fly ash, which effectively utilizes heavy metals contained in the incinerated ash. As shown in FIG. 7, such a method comprises a step of extracting heavy metals in fly ash into an acidic solution and a step of bringing the fly ash into contact with an acidic aqueous hydrochloric acid solution containing a reaction catalyst to remove dioxins. It has a decomposition step of decomposing and detoxifying dioxins, and a fly ash stabilization step of stabilizing fly ash by fixing heavy metals remaining in the fly ash. It is possible to detoxify dioxins contained in fly ash and to reliably insolubilize heavy metals without requiring a separate dedicated treatment facility.

[0007]

However, the hardly decomposable substances such as dioxins present in the incinerated ash are
In addition to existing in the state of adhering to the surface of solid matter such as incineration ash, it may be taken in inside the solid matter,
In the prior art such as the Japanese Patent Application No. 2001-72826, it is possible to easily decompose a hardly-decomposable substance which is exposed on the surface or is present near the surface, but it is difficult to remove the hardly-decomposable substance existing in the solid substance. Very difficult to handle.

That is, in the process of producing and growing fly ash containing hardly decomposable substances such as dioxins, the fly ash discharged in the form of containing high-boiling-point solid matter with particulate dioxin is used in the flue. Since it is considered that vaporized dioxins are re-synthesized on the fly ash while being cooled, vaporized dioxins deposited during cooling can be removed by the above-mentioned conventional technique, but they were initially produced. It is difficult to decompose dioxins existing in fly ash, and as a result, it is difficult to achieve a high decomposition rate that satisfies the strict regulation value of dioxins.

Also in the above-mentioned Japanese Patent Application Laid-Open No. 2000-167510, since heavy metals in fly ash are extracted, a hydrochloric acid acidic aqueous solution containing a reaction catalyst in a dissolved state is brought into contact with fly ash for decomposition treatment. The reaction with dioxins near the surface is easy, but as described above, it is very difficult to decompose and remove the hardly decomposable substance present inside the fly ash. Therefore, in view of the problems of the prior art, the present invention is a method for treating a hardly decomposable substance that can be removed with a high decomposition rate in a short time even for a hardly decomposable substance present inside fly ash, and The purpose is to provide the device.

[0010]

SUMMARY OF THE INVENTION Therefore, in order to solve the above-mentioned problems, the present invention according to claim 1 relates to dioxins and the like contained in fly ash contained in exhaust gas from an incinerator or the like. In a treatment method for detoxifying a hardly decomposable substance by oxidizing it, a catalyst and / or an oxidizing agent (hereinafter referred to as a catalyst) is added to the inside of the fly ash in a high-temperature atmosphere in which the fly ash is produced. Etc., and then the fly ash separated from the exhaust gas is put into a decomposition tank for the hardly decomposable substance, and the catalyst etc. in the fly ash are used to remove the hardly decomposable substance in the fly ash. It is characterized by performing decomposition. Then, as in the invention according to claim 2, it is preferable that at least a part of the catalyst or the like used for decomposing the hardly decomposable substance is recovered in a subsequent step.

As described above, about 80 near the outlet of the incinerator.
In the exhaust gas at about 0 ° C., there are a high-boiling-point solid substance containing a particulate persistent substance and a vaporized persistent substance,
The vaporized hardly decomposable substance precipitates on the surface of the solid substance as it is cooled toward the downstream side of the exhaust gas flue. Therefore, as in the first aspect of the present invention, a fly ash containing the catalyst or the like is produced inside by introducing the catalyst or the like in the high-temperature fly ash production process. Then, it is possible to easily decompose and remove the hardly decomposable substance present inside the fly ash by performing oxidative decomposition using such an internal catalyst, and as a result, the hardly decomposable substance in the fly ash is discharged. A high decomposition rate removal can be achieved.

The temperature range in which the catalyst or the like is charged is preferably
Is above the boiling point of the hardly decomposable substance, about 180 ° C to 800 ° C
Temperature range is good. The catalyst and the like are, for example, Fe
_TwoO_Three, KMnO_Four, Mn (CH_ThreeCO_Two)_Three, MnO
_Two, CrO_Three, K_TwoCr_TwoO₇, K _TwoCrO_Four, Pb
O, PbO_Two, AgO, Ag_TwoO, AgNO_Three, CuC
l_Two, NiO_Two, NaBiO_Three, H_TwoO_Two, Na_TwoO_Two
Etc. have oxidative power themselves and oxidize and decompose persistent substances
Oxidizer, iron, nickel, cobalt, copper, zinc, molybdenum
Ribden, chrome, vanadium, tungsten, cadmium
Um, aluminum, silver, cerium, ruthenium or this
A catalyst that accelerates the oxidative decomposition reaction of these mixtures is applied.
It is possible to use at least one of these oxidants and catalysts.
Shall be included. Of course, multiple oxidants and catalysts were mixed
It can be one. Further, as in claim 2.
In addition, the above-mentioned catalysts, etc. and the catalysts contained in the fly ash, etc.
Hazardous substances by separating and collecting at least a part of
It is not necessary to provide a treatment facility for the catalyst including quality.

Further, the invention according to claim 3 is the treatment method for detoxifying by decomposing the hardly decomposable substances such as dioxins contained in the fly ash contained in the exhaust gas from the incinerator, etc. After the oxidative decomposition treatment of the hardly decomposable substance contained in the fly ash separated from the exhaust gas in the presence of the catalyst present inside the fly ash, the catalyst etc. remaining in the fly ash. At least a part is separated and recovered. Then, as in the invention according to claim 4, it is preferable to return at least a part of the recovered catalyst and the like into a high temperature atmosphere in which the fly ash is generated.

According to the present invention, the hardly decomposable substance existing in the fly ash can be easily removed, and at least a part of the catalyst or the like is returned to the high temperature atmosphere to add the catalyst. It is possible to reduce the discharge amount of the catalyst and the like containing the amount and harmful components to the outside, and further accelerate the decomposition reaction of the hardly decomposable substance.

Further, the invention according to claim 5 is characterized in that the fly ash separated from the exhaust gas is mixed with water to form a slurry and subjected to oxidative decomposition treatment. As in the present invention, by making the fly ash into a slurry, oxidative decomposition at room temperature becomes possible, and the reaction is promoted due to the diffusion of fly ash to obtain a high decomposition rate of the hardly decomposable substance. You can

Further, in the invention according to claim 6, the catalyst and the like are separated from the fly ash by at least one selected from magnetic separation, specific gravity difference separation, electrostatic separation, ion exchange membrane separation and electrolysis. It is characterized by being called. By appropriately selecting the separation method, the catalyst and the like can be efficiently separated from fly ash at low cost.

In the invention according to claim 7, the catalyst and the like are separated from the fly ash by magnetic separation, and the catalyst and the like supplied to the high temperature atmosphere in which the fly ash is generated have magnetism. Is characterized by. As in the invention, the separation of the catalyst and the like from the fly ash is performed by magnetic separation, and Co
By applying O, NiO, Fe ₂ O ₃ , Fe ₃ O ₄ , and a magnetic catalyst such as a ferritic metal,
The catalyst and the like can be separated and recovered easily and reliably.

The invention according to claims 8 to 14 relates to a treatment apparatus, and the invention according to claim 8 is a fly ash separating means for taking out fly ash discharged from an incinerator or the like and containing a catalyst and the like, In a treatment device for a hardly decomposable substance comprising a decomposition means for decomposing and removing a hardly decomposable substance contained in the separated fly ash, the catalyst or the like is removed by separating the catalyst or the like from the effluent after the removal of the hardly decomposable substance. It is characterized by having means for collecting. Then, as in the invention described in claim 9, it is preferable that the recovered catalyst and the like is provided with a return passage for returning the recovered catalyst and the like to the high temperature atmosphere in which fly ash is generated on the inlet side of the fly ash separation means. .

According to a tenth aspect of the present invention, a means for introducing a catalyst or the like for removing a hardly decomposable substance into a high-temperature atmosphere in which fly ash is generated, and a fly ash having the catalyst or the like internally deposited are separated from exhaust gas. And a means for decomposing and removing the hardly decomposable substance contained in the fly ash by cooling the separated fly ash and then using a catalyst or the like that is internally infused inside the fly ash. And
As in the invention according to claim 11, means for separating and recovering the catalyst and the like remaining in the fly ash after removal of the hardly decomposable substance, and at least a part of the recovered catalyst and the like in the high temperature atmosphere. It is characterized by having a means for returning and returning.

Further, in the invention according to claim 12, the catalyst recovery means is at least one selected from a magnetic separation separator, a specific gravity difference separator, an electrostatic separator, an ion exchange membrane separator and an electrolysis tank. It is characterized by being. Further, claim 1
As in the invention described in 3, it is preferable that the catalyst etc. collecting means is a magnetic separation separator and the catalyst etc. is a magnetic catalyst etc. which can be collected by the magnetic separation separator. Further, it is preferable that the fly ash separating means is a bag filter or a scrubber. According to these inventions, it is possible to obtain the same effects as those of the inventions described in claims 1 to 7.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be exemplarily described in detail below with reference to the drawings. However, the dimensions, materials, shapes, relative positions, etc. of the components described in this embodiment are not intended to limit the scope of the present invention thereto unless specifically stated otherwise, and are merely illustrative examples. Not too much. FIG. 1 is an overall schematic configuration diagram of a treatment apparatus for a hardly decomposable substance according to a first embodiment of the present invention, and FIGS. 2 to 6 are overall second to sixth embodiments which are other embodiments of FIG. It is a schematic block diagram.

As shown in FIG. 1, the apparatus of this embodiment has a bag filter 10 for separating and collecting fly ash from an exhaust gas 20, a scrubber 11 for cleaning the separated exhaust gas, and a scrubber drainage. A fly ash mixing tank 12 that mixes 25 and fly ash 22 to form a slurry, a decomposition tank 14 that oxidatively decomposes the slurry 35, and a magnetic separator 13 that separates and collects a catalyst 30 from the oxidatively decomposed slurry. Consists of. In the present embodiment, the exhaust gas 20 is exhaust gas discharged from an incinerator for general waste, industrial waste, etc., a melting furnace for melting incineration ash, a boiler, etc., but is not particularly limited, but contains a large amount of heavy metals and the like. Melt furnace exhaust gas is suitable.

Further, the bag filter 10 may be any structure as long as it can be combined with the scrubber 11 in the subsequent stage so that the amount of dust emission and the like meet the environmental standard, and an electric dust collector, a bag filter or a multi-cyclone is used. be able to. The scrubber 11 is intended to remove exhaust fly ash, dioxins, hydrogen chloride, etc. in the exhaust gas by allowing exhaust gas to flow from the lower portion and spraying makeup water 24 from the upper portion. At this time, hydrogen chloride, sulfur oxides, etc. in the exhaust gas may be removed by adding caustic soda or the like to the makeup water 24. Further, the fly ash mixing tank 12 is equipped with a mixing means such as a stirring blade and a bubbling means to mix the fly ash 22 with the scrubber wastewater 25 to form a slurry.

The magnetic separator 13 is a device for adsorbing, capturing and recovering a ferromagnetic catalyst or the like by means of a permanent magnet, an electromagnet or the like. The decomposition tank 14 may be of a batch type or a continuous type, and has a means for decomposing the slurry 35. In this embodiment, by supplying hydrogen peroxide 26 and ozone 28, Hydroxyl radicals having a very strong oxidizing power are generated, and the slurry 35 is vigorously stirred in the presence of the hydroxy radicals to oxidize and decompose dioxins in the slurry.

As the oxidative decomposition means using hydroxy radicals, at least two or more of hydrogen peroxide, ozone, catalyst, photocatalyst or ultraviolet irradiation are used, for example, reaction between hydrogen peroxide and ozone, under high pH. Oxidation in water, ozone oxidation under UV irradiation, UV irradiation in the presence of hydrogen peroxide, UV irradiation in the presence of hypochlorite,
Although it is possible to generate hydroxy radicals by photooxidation in the presence of a photocatalyst, oxidation by a Fenton's reagent, etc., it is difficult to transmit ultraviolet rays in the incinerated ash slurried. Oxidation or ozone oxidation under high pH is suitable. Of course, the present invention is not limited to this, and decomposition treatment with a single oxidizing agent such as hydrogen peroxide or ozone is also possible.

Explaining the flow of processing in the processing apparatus having such a configuration, first, the exhaust gas 20 containing the hardly decomposable substance discharged from the incinerator and harmful substances such as hydrogen chloride is discharged.
Is sprayed with slaked lime 21 for the purpose of removing hydrogen chloride and the like, and a catalyst 29 and the like is added to the bag filter 10 to be guided. The temperature range in which the catalyst or the like is charged is preferably about 180 ° C. to 8 ° C. which is higher than the boiling point of the hardly decomposable substance.
00 ° C is good, and it may be near the exhaust gas outlet in the incinerator. When the catalyst and the like required for the subsequent oxidative decomposition reaction are sufficiently contained in the fly ash component, it is not necessary to add the catalyst and the like here.

The catalyst 29 and the like are preferably oxidants and / or catalysts having ferrite magnetism in the first embodiment, but in addition, for example, Fe ₂ O ₃ , KMnO ₄ , Mn.
_{(CH 3 CO 2) 3,} MnO 2, CrO 3, K 2 Cr 2
O ₇ , K ₂ CrO ₄ , PbO, PbO ₂ , AgO, Ag
₂ O, AgNO ₃ , CuCl ₂ , NiO ₂ , NaBiO
₃ , H ₂ O ₂ , Na ₂ O _{2 and the} like have an oxidizing power to oxidize and decompose persistent substances, and iron, nickel, cobalt, copper, zinc, molybdenum, chromium, vanadium, Tungsten, cadmium, aluminum, silver,
A catalyst or the like that promotes the oxidative decomposition reaction of cerium, ruthenium, or a mixture thereof can be appropriately selected according to the recovery means described later, and at least one of these oxidizing agents and catalysts is included. At this time, the catalyst or the like 29 may be a mixture of a plurality of oxidizing agents and catalysts.

The fly ash contained in the high-temperature exhaust gas at about 800 ° C. and discharged in the form of high-boiling solids containing particulate dioxins incorporates the catalyst and the like while being cooled in the flue. At the same time, vaporized dioxins are re-synthesized on the fly ash to generate and grow. In this way, fly ash existing at a position where the catalyst and the like taken into the fly ash and the dioxins and the like contained in the fly ash are very close to each other is generated. After that, the fly ash is captured by the bag filter 10 and guided to the fly ash mixing tank 12, while the exhaust gas that has passed through the bag filter is sent to the scrubber 11, and the exhaust gas is further cleaned by the makeup water 24 to purify it. The discharged exhaust gas 23 is discharged to the outside or sent to an exhaust gas treatment device (not shown) in the next step.

Fly ash 22 introduced into the fly ash mixing tank 12
Is mixed with water such as the scrubber drain 25 from the scrubber 11 in the mixing tank 12 and sent to the decomposition tank 13 as a slurry 35, where it is oxidatively decomposed and detoxified by the strong oxidizing power of the hydroxy radicals. At this time, since a catalyst or the like, that is, a catalyst that promotes oxidative decomposition or / and an oxidant that itself has an oxidizing power is internally present inside the fly ash, the oxidation reaction is promoted and The decomposition process will be carried out for a long time and at a high decomposition rate.

The decomposed slurry is separated from the catalyst 30 by the magnetic separator 13 and at least a part of the slurry is returned to the upstream side of the bag filter 10 for reuse. As a result, oxidative decomposition can be smoothly carried out at a high decomposition rate as described above by further blowing a catalyst or the like without discharging harmful substances such as heavy metals out of the system more than necessary.

In the second embodiment shown in FIG. 2, a plurality of scrubbers 11 arranged in series, a decomposition tank 14 equipped with an oxidation decomposition means and a strong stirring means, and a magnetic separator 13 for separating and recovering a catalyst and the like. And the exhaust gas 20 discharged from the incinerator or the like and containing dioxins, etc., as in the first embodiment,
The smoke is introduced into the scrubber 11 and washed with makeup water 24 containing activated carbon 31. Hazardous substances such as hydrogen chloride contained in the exhaust gas 20 are discharged out of the system as the exhaust gas 23 detoxified by being absorbed and removed by the activated carbon 31.
On the other hand, the fly ash captured by the scrubber wastewater 25 ′ by the makeup water 24 is introduced into the decomposition tank 14.

The scrubber wastewater 25 'introduced into the decomposition tank 14 is oxidatively decomposed by hydroxy radicals as in the first embodiment, and then the magnetic separator 13 removes the catalyst 30 from the scrubber wastewater 25'. The separated wastewater 27 from which dioxins have been removed is discharged to the outside of the system, and the separated catalyst and the like are returned to the upstream side of the scrubber 11. As a result, in addition to the effect similar to that of the first embodiment, it is not necessary to install the fly ash mixing tank 12 by providing a plurality of scrubbers 11 and directly capturing the fly ash by the makeup water 24, which saves space. Energy saving can be achieved.

The third embodiment shown in FIG. 3 has substantially the same structure as the first embodiment, but the decomposition tank 1 is used.
A specific gravity difference separator 15 is provided in place of the magnetic separator 13 in the subsequent stage. Then, the aggregating agent 32 is added to the slurry discharged from the decomposition tank 14, and the agglomerated catalyst etc. 30 is separated and collected by the specific gravity difference separator 15. Bug filter 1
Catalyst etc. to be supplied into the exhaust gas high temperature atmosphere on the upstream side of 0
It is advisable to use a chemical which is easily aggregated by the aggregating agent 32 and is easily separated from other components by the specific gravity difference separation. According to such an embodiment, it is not necessary to use a ferromagnetic material for the catalyst or the like as in the first or second embodiment, and a non-ferrous metal or the like can be used for the catalyst or the like.

The fourth embodiment shown in FIG. 4 has substantially the same structure as that of the first embodiment, except that an electrostatic separator 18 is provided as a catalyst separating means, and a solid state is provided at the rear stage of the decomposition tank 14. A liquid separator 16 is provided, a dryer 17 is installed in parallel with the solid-liquid separator 16, and an electrostatic separator 18 is provided at the subsequent stage. The electrostatic separator 18 may use any method such as an electrostatic type, a corona discharge type, a combination type of both types, and a triboelectric charging type depending on a charging method of particles. It is preferable to use one having a large difference between the conductivity and the electrical conductivity of the fly ash to be treated.

The fifth embodiment shown in FIG. 5 has substantially the same structure as the first embodiment, and has an ion exchange membrane 19 as a catalyst separating means. In addition to this, FIG.
The electrolysis tank 19 as in the sixth embodiment shown in FIG. 6, a magnetic fluid sorter, a load current sorter, and the like, depending on the components of fly ash, the respective component ratios, the catalysts used, the installation conditions of the device, and the like. It is advisable to appropriately select the separating means. Incidentally, in the second to sixth embodiments, the description of the same components as those of the first embodiment is omitted. With these configurations, the catalyst etc. 30 can be efficiently recovered, and
By supplying the catalyst 30 and the like to a high-temperature atmosphere in which fly ash is generated, it becomes possible to perform oxidative decomposition in the decomposition tank 14 in a short time with a high decomposition rate.

[0036]

As described above, according to the present invention, by introducing a catalyst or the like in the high-temperature fly ash generation process, fly ash containing the catalyst or the like is generated inside, and the catalyst which is internally infused It is possible to easily decompose and remove the hardly decomposable substances present in the fly ash by carrying out oxidative decomposition using, and achieve a high decomposition rate removal of the hardly decomposable substances in the fly ash discharged as a result. can do. Further, it is not necessary to provide a treatment facility for the catalyst or the like containing a harmful substance by separating and recovering at least a part of the charged catalyst or the like and the catalyst or the like contained in the fly ash.

Further, by returning at least a part of the catalyst or the like into the high temperature atmosphere, it is possible to reduce the discharge amount of the catalyst or the like containing a harmful component to the outside, and further to decompose the hardly decomposable substance. The reaction can be accelerated.
Further, separation of the catalyst and the like from the fly ash is performed by magnetic separation, and CoO, NiO, Fe ₂ O ₃ , Fe ₃ O ₄ ,
By applying a magnetic catalyst such as ferritic metal, it is possible to separate and collect the catalyst easily and reliably.

[Brief description of drawings]

FIG. 1 is an overall schematic configuration diagram of a treatment device for a hardly decomposable substance according to a first embodiment of the present invention.

FIG. 2 is an overall schematic configuration diagram of a second embodiment which is another embodiment of FIG.

FIG. 3 is an overall schematic configuration diagram of a third embodiment which is another embodiment of FIG.

FIG. 4 is an overall schematic configuration diagram of a fourth embodiment which is another embodiment of FIG.

5 is an overall schematic configuration diagram of a fifth embodiment which is another embodiment of FIG. 1. FIG.

FIG. 6 is an overall schematic configuration diagram of a sixth embodiment which is another embodiment of FIG. 1.

FIG. 7 is a schematic process diagram of a fly ash treatment method in the related art.

[Explanation of symbols]

10 Bug filter 11 scrubber 12 Fly ash mixing tank 13 magnetic separator 14 Decomposition tank 15 Specific gravity difference separator 16 Solid-liquid separator 18 Electrostatic separator 19 ion exchange membrane 25 scrubber drainage 25 'scrubber drain (including fly ash) 29 Catalyst, etc. 30 Recovery catalyst 34 Electrolysis tank

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI Theme Coat (reference) F23J 15/00 F23J 15/00 Z B01D 53/36 G (72) Inventor Yusuke Kawasaki Kazuoura Kazuzawa, Kanazawa-ku, Yokohama-shi 8-chome 1 Mitsubishi Heavy Industries, Ltd. Yokohama Research Laboratory (72) Inventor Kotoshi Kose 1-8-1, Koura, Kanazawa-ku, Yokohama-shi F-term in Mitsubishi Heavy Industries Yokohama Research Laboratory (reference) 2E191 BA12 BC01 BD13 BD17 3K070 DA05 DA07 DA15 DA26 DA29 DA30 DA32 DA40 4D004 AA37 AB07 AC05 CA07 CA09 CA10 CA36 CA43 CC09 CC11 4D048 AA11 AB03 AC10 BA03Y BA16Y BA19Y BA23Y BA25Y BA26Y BA27Y BA32Y BA34Y BA35Y BA36Y BA37Y BA38Y

Claims (14)

[Claims] 1. A treatment method for detoxifying detoxifying substances such as dioxins contained in fly ash contained in exhaust gas from an incinerator, etc., in a high-temperature atmosphere in which the fly ash is produced. A catalyst and / or an oxidant (hereinafter referred to as a catalyst) is charged below to inject the catalyst or the like inside the fly ash, and then the fly ash separated from the exhaust gas is charged to the decomposition tank for the hardly decomposable substance, A method for treating a hardly-decomposable substance, characterized in that the hardly-decomposable substance in the fly-ash is decomposed by utilizing a catalyst or the like inscribed in the fly-ash. 2. The method for treating a hardly decomposable substance according to claim 1, wherein at least a part of the catalyst used for decomposing the hardly decomposable substance is recovered in a subsequent step. 3. In a treatment method for detoxifying by decomposing a hardly decomposable substance such as dioxins contained in fly ash contained in exhaust gas from an incinerator or the like, inside the fly ash separated from the exhaust gas. After the oxidative decomposition treatment of the hard-to-decompose substance contained in the fly ash in the presence of the catalyst etc. present inside the fly ash, at least a part of the catalyst etc. remaining in the fly ash is separated and recovered. A method for treating a hardly decomposable substance, which comprises: 4. The method for treating a hardly decomposable substance according to claim 2, wherein at least a part of the recovered catalyst or the like is returned into a high temperature atmosphere in which the fly ash is produced. 5. The treatment of the hardly decomposable substance according to any one of claims 1 to 3, wherein the fly ash separated from the exhaust gas is mixed with water to form a slurry and subjected to oxidative decomposition treatment. Method. 6. The separation of the catalyst or the like from the fly ash is performed by at least one selected from magnetic separation, specific gravity difference separation, electrostatic separation, ion exchange membrane separation, and electrolysis. 6. The method for treating a persistent substance according to any one of 2 to 5. 7. The catalyst or the like is separated from the fly ash by magnetic separation, and the catalyst or the like supplied to the high temperature atmosphere in which the fly ash is generated has magnetism. 7. The method for treating a hardly decomposable substance according to any of 6. 8. A fly ash separating means for taking out fly ash discharged from an incinerator or the like and containing a catalyst and the like from exhaust gas, and a decomposing means for decomposing and removing hardly decomposable substances contained in the separated fly ash. A treatment device for a hardly decomposable substance, comprising a means for recovering the catalyst, etc. by separating the catalyst, etc. from the discharge after removing the hardly decomposable substance. 9. The incombustible passage according to claim 8, further comprising a return passage for returning the recovered catalyst and the like to a high temperature atmosphere in which fly ash is generated on the inlet side of the fly ash separating means. Material processing equipment. 10. A means for introducing a catalyst or the like for removing a hardly decomposable substance into a high-temperature atmosphere in which fly ash is produced, a means for separating fly ash in which the catalyst or the like has been inscribed from exhaust gas, and a means for separating the fly ash. After cooling the fly ash, it is provided with a means for decomposing and removing the hardly decomposable substance contained in the fly ash by a catalyst or the like that has been internally infused inside the fly ash. 11. A means for separating and recovering the catalyst and the like remaining in the fly ash after removing the hardly decomposable substance, and a returning means for returning at least a part of the recovered catalyst and the like to the high temperature atmosphere. The treatment device for a hardly decomposable substance according to claim 10. 12. The magnetic separation separator is used as the catalyst recovery means.
At least one selected from a specific gravity difference separator, an electrostatic separator, an ion exchange membrane separator, and an electrolysis tank, wherein the hardly decomposable substance according to claim 8, 9, or 10. Processing equipment. 13. The catalyst collecting device is a magnetic separator, and the catalyst is a magnetic catalyst recoverable by the magnetic separator. A treatment device for a hardly decomposable substance according to claim 1. 14. The apparatus for treating a hardly decomposable substance according to claim 8 or 10, wherein the fly ash separating means is a bag filter or a scrubber.