JPH1144417A - Treatment method of refuse incineration ash - Google Patents

Abstract

PROBLEM TO BE SOLVED: To completely pyrolyze dioxin at a low cost by placing the incineration ash in a heat resistant container in a sealed condition, and heating and melting it in an incinerator. SOLUTION: The incineration ash 3 which is the municipal refuse 1 incinerated in a refuse incinerator 2, is placed in a container 4, and sealed by a lid 4a, and heated and melted in an incinerator 5. The container 4 is a ceramic heat resistant container capable of withstanding high temperature of >=1,700 deg.C, and an aluminum powder is applied to an inner surface of the container. The incineration ash 3 of approximately 0.5 ton is filled in the container 4, and the container is sealed by the lid 4a which is similarly heat resistant to the container body. The incinerator 5 employs a ceramic oven which is fired with LPG, and the container 4 is taken in/out using a charging truck 5a attached to the ceramic oven. The incinerator 5 is heated in advance until the in-furnace temperature reaches approximately 1,300 deg.C. Then, the container 4 filled with the incineration ash 3 and sealed is loaded on the charging truck 5a, and charged in the furnace, and the incineration ash 3 is melted through the heating for approximately 18 hours.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for treating incinerated ash discharged from a refuse incineration plant.

[0002]

2. Description of the Related Art In recent years, dioxin generated during incineration of municipal incineration facilities has become a problem.
Since incineration ash discharged from incineration equipment also contains dioxin, various methods for detoxifying dioxin in incineration ash have been proposed.

[0003] Among them, as a treatment method for melting incineration ash and thermally decomposing dioxin, Japanese Patent Application Laid-Open No. 64-3341 discloses a method.
No. 6 and JP-A-3-232579 disclose a method of melting dioxin-containing ash in a melting furnace to thermally decompose dioxin. JP-A-7-214032 and JP-A-8-145330 disclose waste incineration. A method is described in which ash is dissolved at a high temperature by a combustion burner using fuel and pure oxygen to thermally decompose dioxin.

[0004] It is said that dioxin starts to decompose at a temperature of 600 ° C or higher and almost decomposes at a high temperature of 900 ° C or higher. According to the descriptions of the above publications, dioxin is decomposed in any treatment method. It is said that it can be almost completely detoxified.

[0005]

However, Japanese Patent Application Laid-Open No. 64-33416 and Japanese Patent Application Laid-Open No. 3-2525 are not disclosed.
No. 79 does not describe a specific embodiment of melting of incineration ash such as a type of a melting furnace, a combustion method, and a melting temperature, and the effect of the implementation is not clear.

Further, the processing methods described in JP-A-7-214032 and JP-A-8-145330 are
1600 ° C by using pure oxygen with fuel
It is characterized by obtaining a high temperature of about the same level, and furthermore, silicon incineration ash and soda ash are put into a melting furnace together with refuse incineration ash and the refuse incineration ash that is melted is made into a glass. In order to carry out the method, a considerably large melting furnace or a combustion apparatus is required, and if the throughput is not so large, there is a problem that the processing cost increases.

An object of the present invention is to provide a low-cost means for completely decomposing dioxin when melting incineration ash to thermally decompose dioxin.

[0008]

The method for treating incinerated ash of the present invention is a method for melting incinerated ash discharged from refuse incineration equipment, wherein the incinerated ash is placed in a heat-resistant container and sealed. It is characterized by heating in a combustion furnace and melting incineration ash in the heat-resistant container.

The waste incineration ash targeted in the present invention is:
Incinerated ash after incineration of general municipal waste.
This incineration ash contains dioxin. In the present invention, dioxin is thermally decomposed and made harmless by melting the incineration ash.

In the present invention, the incineration ash is melted by heating in a combustion furnace in a heat-resistant container in a sealed state. As this heat-resistant container, a container having a heat resistance of about 1500 ° C. or more, preferably a ceramic container is used. The heat-resistant container containing the incinerated ash is sealed so that the dioxin contained in the incinerated ash does not leak out of the container, and the incinerated ash in the container is not scattered. This is to prevent heavy metals from volatilizing outside the container.

As the combustion furnace, a combustion furnace using heavy oil, LPG, LNG or other fuel is used. As the small-scale furnace equipment, for example, a kiln for producing ceramics using LPG as a fuel can be used. Into the combustion furnace, a sealed heat-resistant container containing the refuse incineration ash was placed, and the temperature in the furnace was set to 1
When heated at about 300 ° C. for a long time, the refuse incineration ash in the container melts, and in this process, dioxin contained in the refuse incineration ash is thermally decomposed and made harmless.

[0012] By melting and treating the refuse incineration ash according to the method of the present invention, dioxin is completely decomposed by thermal decomposition and rendered harmless, and at the same time, heavy metal particles in the incineration ash are confined in the melt. Since the incinerated ash is placed in a closed container and heated and melted, the dioxin contained in the incinerated ash does not leak out of the container and the incinerated ash does not scatter during heating, nor is it contained in the incinerated ash. The burning furnace will not be damaged by the heavy metals that are volatilized outside the container. In addition, it is easy to put the container in and out of the combustion furnace. As the combustion furnace can use an existing small furnace such as a pottery kiln, it is possible to reduce equipment costs. The melt can be cooled and then pulverized and used as a raw material for concrete or asphalt.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a view showing a procedure for treating incinerated ash in an embodiment of the present invention.

The refuse incineration ash used in this embodiment is:
This is incineration ash 3 after incineration of municipal waste 1 in a refuse incinerator 2. The incinerated ash 3 is put in a container 4, sealed with a lid 4 a, and heated and melted in a combustion furnace 5.

The container 4 is a heat-resistant container made of ceramics which can withstand a high temperature of 1700 ° C. or more, and alumina powder is applied to the inner surface of the container. This container 4 contains 0.5 tons of incinerated ash 3
And sealed with a lid 4a having the same heat resistance as the container body.

The combustion furnace 5 uses a pottery kiln using LPG as a fuel, and puts the container 4 in and out using a loading cart 5a attached to the pottery kiln. The combustion furnace 5 is preheated until the temperature in the furnace reaches about 1300 ° C., and thereafter, the container 4 filled with the incineration ash 3 and sealed is placed on a loading cart 5a and charged into the furnace. Continue heating for 18 hours.

By this heating, the incineration ash 3 is melted. After the heating, the loading cart 5a is pulled out of the furnace, and is discharged onto the cooling table before the molten material 6 in the container 4 is solidified. Since the alumina powder is applied to the inner surface of the container 4, the entire amount of the melt 6 is discharged without adhering and remaining on the inner surface of the container.
After discharging the molten material 6, the container 4 is air-cooled to about 100 ° C., and then water-cooled to about room temperature. The discharged molten material 6 is cooled and solidified, then crushed into small lumps, and an intermediate product 7 for recycling to concrete or asphalt.
And

In the above-mentioned heating and melting process, dioxin contained in the incineration ash 3 is completely decomposed by heat and detoxified.
At the same time, the heavy metal particles in the incineration ash 3 are confined in the solidified material 7. Since the incineration ash 3 is put into the closed container 4 and melted by heating, the dioxin contained in the incineration ash 3 leaks out of the container at the time of heating, the incineration ash 3 scatters,
The heavy metals contained in the incineration ash 3 do not volatilize out of the container 4 and the combustion furnace 5 is not damaged.
Further, since the container 4 can be quickly taken in and out of the combustion furnace 5 by using the loading cart 5a, the combustion furnace 5 can be operated efficiently. After discharging the melt 6, the container 4 can be used repeatedly.

[0019]

According to the present invention, the following effects can be obtained.

(1) The waste incineration ash is placed in a heat-resistant container and heated and melted in a combustion furnace in a sealed state, so that the dioxin contained in the incineration ash leaks out of the container during heating and the incineration ash is scattered. Also, heavy metals contained in the incineration ash do not volatilize outside the container.

(2) By using a ceramic container as the heat-resistant container, the container after discharging the melt can be used repeatedly.

(3) Since an existing small furnace such as a pottery kiln can be used as the combustion furnace, equipment costs can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing a procedure for treating incineration ash in an embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 municipal solid waste 2 incinerator 3 incineration ash 4 container 4a lid 5 combustion furnace 5a loading cart 6 molten material 7 intermediate product

Claims (2)

[Claims] 1. A method for melting incinerated ash discharged from a refuse incineration plant, wherein the incinerated ash is placed in a heat-resistant container, heated in a combustion furnace in a sealed state, and melted in the heat-resistant container. A method for treating waste incineration ash. 2. The method according to claim 1, wherein the heat-resistant container is a container made of ceramics.