JP2001276771A - Treatment method for making incineration residue and/or molten fly ash harmless - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a treatment method for making an incineration residue and molten fly ash harmless, capable of conducting a perfect decomposition treatment of dioxins and the like, and low in both initial and running costs. SOLUTION: This treatment method for making an incineration residue and molten fly ash harmless is characterized by adding inexpensive titanium dioxide as a catalyst to the raw materials to be treated composed of an incineration residue and molten fly ash, heating and agitating the dioxins and the like at a predetermined temperature for a predetermined time to decompose it with oxidation catalytic action by titanium dioxide followed by conducting an elution prevention treatment of heavy metals.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detoxifying incineration residues discharged from an incineration facility for municipal waste and / or molten fly ash discharged from a melting facility.

[0002]

2. Description of the Related Art Conventionally, incineration residues (main ash and fly ash) discharged from incineration facilities for municipal garbage and the like and / or molten fly ash discharged from melting facilities are subjected to a treatment for preventing heavy metal elution by a chelating chemical treatment. And disposed at the final disposal site. Recently, a device for decomposing (dechlorinating) dioxins in incineration residues and / or molten fly ash and a chemical for decomposing (dechlorinating) dioxins have been developed.

[0003]

However, in the apparatus for decomposing (dechlorinating) dioxins, it is necessary to heat and agitate the processing raw materials in a low oxygen state, and the sealing structure of the apparatus (mainly a rotary kiln) is required. However, there is a problem that a rapid cooling device for preventing re-synthesis of dioxin is required, and the initial cost is high. When a chemical that decomposes (dechlorinates) dioxins is used, it is possible to operate in a normal oxygen state and the sealing structure of the apparatus can be simplified, but the cost of the chemical is high and the long-term running cost is low. There's a problem. The present invention has been made in view of the above problems,
Incineration residue that can completely decompose dioxins at low initial and running costs and / or
Another object of the present invention is to provide a method for detoxifying molten fly ash.

[0004]

Means for Solving the Problems In order to achieve the above object, the method for detoxifying incineration residues and / or molten fly ash according to the present invention provides a method for treating a raw material comprising incinerated residues and / or molten fly ash with a carbon dioxide. A step of adding titanium as a catalyst, and heating and stirring the processing raw material to which the titanium dioxide is added by a rotary kiln at a temperature of 100 to 500 ° C. for 5 to 60 minutes to thereby dioxins contained in the processing raw material It is characterized by comprising a step of decomposing by the oxidation catalytic action of titanium, and a step of adding and mixing a chemical and water to the processed product obtained by decomposing the dioxins to prevent elution of heavy metals.

[0005]

Embodiments of the present invention will be described below in detail with reference to the drawings. As shown in FIG. 1, a processing raw material composed of incineration residues and / or molten fly ash is quantitatively cut out from a raw material quantitative supply device 1, and titanium dioxide is quantitatively supplied to the cut out processing raw material from a catalyst quantitative supply device 2. At this time, the amount of titanium dioxide added as a catalyst is in the range of 0.5 to 10% by weight of dioxins (here, dioxins are polychlorinated dibenzoparadioxins (PCDDs), polychlorinated dibenzofurans and coplanar-PCB). It is economically advantageous together with the complete decomposition (refers to polychlorinated biphenyl).

Next, the processing raw material to which titanium dioxide has been added is put into a decomposition apparatus 3 composed of a rotary kiln whose temperature is set at 100 to 500 ° C., and is heated and stirred. At this time, the processing raw material stays in the decomposition device (rotary kiln) 3 for 5 to 60 minutes, and the dioxins contained in the processing raw material are decomposed by the oxidation catalytic action of titanium dioxide, and the content of dioxins is reduced. It is discharged from the decomposer 3 as a processed product that has become below the reference value. Exhaust gas containing a small amount of dust generated from the decomposition device 3 is removed by the dust collector 4 so that the dust is removed.
The exhaust gas is returned to an incinerator (not shown) or a secondary combustion furnace, and the collected dust is returned to the discharged processed material.

[0007] The discharged material and dust thus discharged are carried into the heavy metal elution prevention equipment 6 by the transport device 5, where a chemical and water are added and mixed, the heavy metal elution prevention treatment is performed, and the detoxification treatment is performed. The detoxified substances such as the decomposition of dioxins and the prevention of elution of heavy metals are sequentially conveyed to a final disposal site and discarded.

[0008]

As is clear from the above description, according to the present invention, inexpensive titanium dioxide is added as a catalyst to a processing raw material comprising incineration residues and / or molten fly ash, and this is heated at a predetermined temperature for a predetermined time. Since dioxins are agitated to decompose by the catalytic action of oxidation of titanium dioxide and then subjected to a treatment for preventing elution of heavy metals, dioxins can be decomposed at low initial costs and low running costs, resulting in incineration residues and / or melting and flying. There is an effect that the ash can be detoxified at low cost.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of equipment for implementing the present invention.

[Explanation of symbols]

 Reference Signs List 1 raw material fixed supply device 2 catalyst fixed supply device 3 decomposition device 4 dust collector 5 transfer device 6 heavy metal elution prevention equipment

 ────────────────────────────────────────────────── ─── Continued on the front page F-term (reference) 2E191 BA02 BA12 BB00 BC01 BD13 3K061 NA01 NA07 4D004 AA36 AA46 AB03 AB07 CA15 CA22 CB09 CB34 CC03 CC09 CC11 DA02 DA03 DA06 DA10 4G069 AA02 BA04A BA04B BB04A BB0419 CA05 CA07

Claims (2)

[Claims] 1. A process in which titanium dioxide is added as a catalyst to a processing raw material comprising incineration residues and / or molten fly ash, and the processing raw material to which the titanium dioxide is added is heated to 100 to 500 ° C. by a rotary kiln. Heating and stirring for 5 to 60 minutes, thereby decomposing the dioxins contained in the processing raw material by the oxidation catalytic action of titanium dioxide, and adding and mixing a drug and water to the processed product obtained by decomposing the dioxins. A method for detoxifying incineration residues and / or molten fly ash, comprising: 2. The detoxification treatment of incineration residues and / or molten fly ash according to claim 1, wherein the added amount of said titanium dioxide is in the range of 0.5 to 10% by weight based on the raw material to be processed. Method.