JP2001050530A - Melting processing method for incinerated residue containing salts and its melting furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a melting processing method for incinerated residue containing salt and its melting furnace capable of reducing the amount of a molten salt on a molten slag layer without permitting molten slag from being mixed in upon the molten salt being taken out. SOLUTION: In a melting furnace for incinerated residue having a discharge outlet for molten slag and for discharge outlet for molten salt, there is provided a perforated structure 20 comprising a refractory containing carbon which has a wetting property for the molten salt while not having wetting property for molten slag on a furnace wall at a position therein in contact with a molten salt layer 51 produced in the furnace upon operation thereof. Hereby, only the molten salt is discharged after transmission through the perforated structure 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for melt-treating incineration residues containing salts such as municipal waste incineration residues and a melting furnace thereof.

[0002]

2. Description of the Related Art Melting treatment of incineration residues is carried out by various methods. Among these methods, in a method using an electric resistance type melting furnace or a method using an induction heating type melting furnace, a furnace is used. A process is performed in which the incineration residue is heated and held while being retained therein, and the incineration residue is charged and melted thereon. For example, operation by a method using an electric resistance melting furnace is performed as follows.

[0003] Electrodes are immersed in a melt retained in a furnace, electricity is generated between the electrodes to generate electric resistance heat, and the incineration residue is charged while heating the melt. When charging incineration residues, always leave unmelted incineration residues in the furnace,
This is performed so that the molten material is covered with the incineration residue. The incineration residue charged in the furnace is heated by the melt and melts sequentially from the lower part in contact with the melt. The generated melt is separated into components while staying in the furnace, and is composed of a layer of molten salt composed of salts such as chloride, a layer of molten slag composed of oxides, and reduced metals. Three layers of the molten metal layer are formed. These layers are formed in order of a molten salt layer, a molten slag layer, and a molten metal layer from above due to a difference in specific gravity.

[0004] For this reason, in the melting furnace, an outlet for molten salt is provided at a level where a molten salt layer at the upper portion is formed, and an outlet for molten metal is provided at the bottom of the furnace, so that a molten metal layer is formed. The outlet of the molten slag is provided at a level higher than a certain level, and the melt of each layer is extracted from another outlet.

[0005]

However, when the molten salt layer is formed in the furnace during the melting treatment by the above method,
Various problems are caused that have a bad influence on equipment and operation.

[0006] First, at the furnace wall in contact with the molten salt, erosion of the refractory by the molten salt becomes severe.
Furnace wall repairs must be made frequently.

In the method using an electric resistance type melting furnace, when a large amount of molten salt is present on the molten slag layer, the electric conductivity of the molten salt is much larger than the value of the molten slag. Therefore, the current flowing between the electrodes immersed in the molten material concentrates on the molten salt layer and flows. For this reason, the heating of the molten slag layer becomes insufficient, so that it cannot be maintained at the predetermined temperature, and the operation of the melting furnace cannot be continued.

When the molten slag is extracted in a state where a large amount of molten salt is present on the molten slag layer, the molten salt is entrained in the molten slag and discharged, and the solidified slag contains salts. included. Such slag cannot be used as a concrete aggregate or as a raw material for cement, so that slag cannot be used effectively.

In order to avoid the above problems, the thickness of the molten salt layer existing on the molten slag must be reduced, but in such a state, the molten slag is not mixed. In order to extract only the molten salt, the level of the interface between the molten salt layer and the molten slag layer must be precisely controlled to a level slightly below the molten salt discharge port. But,
In the operation of the melting furnace for separately discharging the above three layers of molten material in an extremely high temperature state, the level of the interface between the molten salt layer and the molten slag layer is accurately detected, and the level of the interface is set to a predetermined position. Therefore, it is extremely difficult to accurately control the amount of the melt that is withdrawn from each layer in order to maintain the temperature.

When the molten salt is extracted in a state where the thickness of the molten salt layer is reduced, the molten slag is often mixed and discharged. In this way, when the molten slag is discharged from the molten salt discharge port, the molten slag has a very high melting point, so it solidifies at the time of discharge, and narrows or closes the discharge port and the discharge channel, The subsequent operation of removing the molten salt is hindered.

The present invention solves the above-mentioned problems, and can reduce the amount of the molten salt on the molten slag layer without mixing the molten slag at the time of extracting the molten salt. An object of the present invention is to provide a processing method and a melting furnace thereof.

[0012]

The above object is achieved by the following invention.

[0013] In the melting treatment method according to the first invention, the incineration residue is charged and melted while the melt is retained in a furnace;
In a method for melting incineration residues, which separates a molten material into a molten slag and a molten salt and discharges the molten salt, the refractory having a wettability with respect to the molten salt and a wettability with respect to the molten slag. It is characterized in that the porous body is made to permeate and discharged.

The present inventors have proposed various methods for extracting only molten salt without mixing molten slag even when the interface between the molten salt layer and the molten slag layer is fluctuating. Investigations and tests were performed. As a result, the porous body made of a refractory having the above-mentioned wetting characteristics with respect to the molten salt and the molten slag has a function of selectively transmitting only the molten salt and preventing the molten slag from being transmitted. I found it to be. That is, if the porous body is made of a refractory having wettability to the molten salt and not wettable to the molten slag, the molten salt penetrates into the pores of the porous body. However, the molten slag is prevented from penetrating into the pores.

In the present invention, the wettability of the refractory to the molten salt and the molten slag was evaluated based on the results of the following tests. First, a refractory specimen was placed at the bottom of the crucible, and salts or slag was put into the specimen and heated and melted. Next, the state of the melt in the crucible was observed, and FIG.
(A), when the layer of the melt is in contact with the side surface of the refractory, the refractory has wettability to the melt. Further, as shown in FIG. 3B, when the layer of the melt was not in contact with the side surface of the refractory, the refractory was determined not to have wettability to the melt.

According to a second aspect of the present invention, in the first aspect, the porous body made of a refractory material having wettability to molten salt and not wettable to molten slag is used. It is characterized by being a porous body made of a refractory material containing carbon.

In the present invention, the material of the refractory forming the porous body is selected first based on the wettability to the melt. Refractories having wettability to molten salt and not wettability to molten slag include those mainly composed of carbon components, those whose main components are carbides, carbons in carbides or oxides. And the like, all of which contain carbon. Graphite or the like can be used as the carbon component. As a material made of carbide, for example, silicon carbide (Si
C) -based refractories can be used. The one carbon is added to the oxide or carbide, SiC-C system refractories, Al ₂ O ₃ -C refractory material of MgO-C based refractory material, the refractory of the ZrO ₂ -C system Can be used.

The material of the porous body is required to be a material which does not react with molten salt or molten slag and a material which does not fuse with molten slag, in addition to the properties relating to the wettability.
For example, a material that reacts with a molten material in a furnace or that a molten slag adheres to, such as an oxide-based refractory, cannot be used.

A melting furnace according to a third aspect of the present invention is a melting furnace for an incineration residue having a discharge port for molten slag and a discharge port for molten salt in a furnace wall at a portion in contact with a molten salt layer generated in the furnace during operation. A porous body portion made of a refractory material containing carbon is provided so that molten salt permeates through the porous body portion and is discharged.

Since a refractory containing carbon has wettability to molten salt and no wettability to molten slag, a porous body made of a refractory containing carbon is molten salt. Has the function of selectively permeating only molten slag and preventing the permeation of molten slag. For this reason, if a porous body made of a refractory material containing carbon is arranged on the furnace wall in a portion in contact with the molten salt layer and a porous body part is provided on the furnace wall, the molten salt penetrates the pores of the porous body part. Spilled and discharged. At this time, when the molten slag layer exists in the area where the porous body portion is provided, the molten salt is transmitted and discharged in the porous body portion in contact with the molten salt layer, but the molten slag layer In the portion of the porous body in contact with the slag, the infiltration of the molten slag into the interior is prevented, so that the state is the same as that of closing the pores, and the flow of the melt does not occur.

A melting furnace according to a fourth aspect of the present invention is a furnace for melting incineration residue having a discharge port for molten slag and a discharge port for molten salt, wherein a furnace wall at a portion in contact with a molten salt layer generated in the furnace during operation. A porous body portion made of a refractory material containing carbon is provided inside the inside, and an opening reaching the porous body portion is provided outside a furnace wall at a portion where the porous body portion is provided, and the molten salt is provided in the porous body portion. And discharged through the opening.

The porous portion provided on the furnace wall plays a role of selectively transmitting only the molten salt when the interface between the molten salt layer and the molten slag layer fluctuates. It is not necessary, and if it is thicker than necessary, the resistance when the molten salt permeates increases, and the permeation flow rate of the molten salt decreases. Therefore, in the present invention,
The porous body is provided only in the inner part of the furnace wall, and the opening is provided in the furnace wall outside the porous body, so that the molten salt is discharged.

The melting furnace according to a fifth aspect of the present invention is the melting furnace according to the third or fourth aspect, wherein an insert made of an oxide-based refractory and having a through hole is disposed in an opening provided outside the furnace wall. It is characterized by doing.

The opening provided outside the furnace wall serves as a flow path for discharging the molten salt that has passed through the porous body. If the outside of the porous body is open, the high-temperature porous body is exposed to the outside air, and is oxidized and worn because the material is a refractory material containing carbon. For this reason, in the present invention, an insert made of an oxide-based refractory, for example, an alumina-based refractory is arranged in the opening so that the inflow of outside air into the porous body is blocked. Since this insert has a through-hole, even if the insert is arranged, discharge of the molten salt is performed without any trouble.

[0025] The melting furnace according to the sixth aspect of the present invention is the third aspect of the present invention.
A fifth aspect of the present invention is characterized in that a pressure reducing means is connected to the molten salt discharge flow path, and the pressure on the discharge side of the porous body portion is lower than the pressure on the molten salt layer side.

Since the permeation flow rate of the molten salt is increased by lowering the pressure on the discharge side of the porous body, the installation area of the porous body can be reduced.

According to a seventh aspect of the present invention, there is provided a method for melting incineration residues using a melting furnace according to the third to sixth aspects, wherein the temperature of the molten salt discharge passage is set at 700 ° C.
It is characterized in that the temperature is maintained at １０００1000 ° C.

The molten salt produced when the incineration residue containing salts such as the incineration residue of municipal solid waste is melt-processed is mainly composed of chlorides of alkali metals such as NaCl and KCl.
Alternatively, these are mainly composed of an alkali metal salt and calcium chloride, and have a melting point of 700 ° C to 1000 ° C. Further, when the alkali metal chloride exceeds 1000 ° C., the vapor pressure increases and vaporization occurs. By maintaining the temperature of the molten salt in the above range, the molten salt can be discharged from the furnace without coagulation and without vaporization.

[0029] The melting furnace according to the eighth invention is the third invention-
A sixth aspect of the invention is characterized in that a heating means is provided in the molten salt discharge channel.

When the molten salt is discharged, the temperature of the molten salt must be kept above the above range. However, since the molten salt that has passed through the porous body is continuously discharged, the flow rate is relatively small. Temperature drop is easy to occur. For this reason, it is necessary to heat the discharge channel of the molten salt from the vicinity of the outside of the porous body portion to the molten salt discharge port, and keep the outflowing molten salt at a predetermined temperature or higher.

[0031]

FIG. 1 is a plan view showing an example of an embodiment of a melting furnace according to the present invention. FIG. 2 is a sectional view taken along the line AA in FIG. In FIG. 2, reference numeral 50 denotes an incineration residue charged into the furnace, 51 denotes a molten salt layer, 52 denotes a molten slag layer, and 53 denotes a molten metal layer. The melting furnace shown in FIGS. 1 and 2 is an electric resistance type furnace, 10 is a melting furnace main body,
Numeral 11 denotes a charging pipe for incineration residues, 12 denotes an electrode, 13 denotes a molten salt discharge section, 14 denotes a molten slag discharge port, 15 denotes a molten metal discharge port, and 16 denotes an exhaust gas discharge port.

The molten salt layer 51 at the upper part of the furnace body is formed.
The bell and the inner wall near it are permeable to molten salt.
A porous body portion 20 is provided. Porous body part 2
0 is made of graphite or the like, SiC refractory, Si
C-C refractory, Al_TwoO _Three-C refractory, MgO
-C refractory, ZrO_Two-Carbon such as C-based refractories
It is made of refractory material and contains several mm or less
Are provided in large numbers. This porous body part 20 is a furnace wall
Are arranged in a strip along an arc.

Even if the diameter of the pores provided in the porous body portion 20 is about several mm, the permeation of the molten slag is prevented. This is due not only to the wetting characteristics of the refractory forming the porous body portion 20 but also to the difference in the viscosity of the molten slag and the molten salt. That is, the viscosity at each melting point of the molten salt is about 1 mPa · s, while that of the molten slag is about 10 ⁴ mPa · s. For this reason, the molten slag has a significantly lower fluidity than the molten salt, and cannot flow through the pores.

The furnace wall in the molten salt discharge section 13 includes:
An opening 21 that reaches the porous body portion is provided at a location where the porous body portion 20 is provided, and the molten salt that has passed through the porous body portion 20 is collected in the opening portion 21 and discharged. I have. In the figure, reference numeral 22 denotes an outlet for molten salt, and reference numeral 23 denotes an inspection port. Reference numeral 24 denotes a heating means for maintaining the inside of the molten salt discharge section at a predetermined temperature, and a heating method using a heater having a silicon carbide heating element or the like is applied.

FIG. 3 is an enlarged view of a molten salt discharge section in the melting furnace shown in FIG. 25 is an insert, not shown in FIGS. 1 and 2, which is disposed in the opening. The insert 25 is made of an oxidation-resistant oxide-based refractory and has many through holes. The insert 25 is provided to cover the outside of the porous body portion 20 to prevent the outside air from entering, and to prevent the porous body portion 20 made of a refractory material containing carbon from being oxidized.

The porous body portion 20 is arranged with a slight space between the porous body portion 20 and the furnace wall, and a strip-shaped space 26 is provided. Due to the presence of the space 26, the molten salt that has passed through the porous body portion 20 flows out to the space 26, and is discharged outside the furnace through the insert 25. For this reason, the space 26 functions as a liquid collecting gutter for collecting the molten salt that has flowed out through the band-shaped porous body portion 20 and guiding the molten salt to the insert 25.

When the incineration residue containing salts is melted by the melting furnace having the above configuration, the generated molten salt is discharged by:
It is performed as follows. The incineration residue is charged from the charging pipe 11 into the melting furnace in which the incineration residue melt is retained, and is sequentially melted. The molten incineration residue is separated into three layers: a molten salt layer 51, a molten slag layer 52, and a molten metal layer 53.
Then, while adjusting the discharge amount, the molten slag and the molten metal are extracted so that the molten salt layer 51 comes into contact with the porous body portion 20. Thus, the molten salt layer 5
When 1 is located at a position in contact with porous body portion 20, only the molten salt permeates porous body portion 20 and flows down to the lower part of space 26 between the furnace wall. The molten salt that has flowed down overflows the insert 2 sequentially.
5 enters the place where it is arranged, and is discharged outside the furnace.

As described above, according to this embodiment, since only the molten salt is selectively discharged by the porous body portion 20, even if only a small amount of the molten salt is present on the molten slag layer 52, In addition, only the molten salt can be discharged. or,
Since the molten salt is constantly discharged, the molten salt layer 51 is maintained in a very thin state.

When the incineration residue containing salts is melted by the melting furnace having the above configuration, the generated molten salt is discharged by:
It is performed as follows. The incineration residue is charged from the charging pipe 11 into the melting furnace in which the incineration residue melt is retained, and is sequentially melted. The molten incineration residue is separated into three layers: a molten salt layer 51, a molten slag layer 52, and a molten metal layer 53.
Then, while adjusting the discharge amount, the molten slag and the molten metal are extracted so that the molten salt layer 51 comes into contact with the porous body portion 20. Thus, the molten salt layer 5
When 1 is at a position in contact with porous body portion 20, only the molten salt permeates porous body portion 20 and flows down to the lower part of space 26 between the furnace wall. The molten salt that has flowed down overflows the insert 25 one after another.
Is discharged to the outside of the furnace.

As described above, according to this embodiment, since only the molten salt is selectively discharged by the porous body portion 20, even if only a small amount of the molten salt is present on the molten slag layer 52, In addition, only the molten salt can be discharged. or,
Since the molten salt is constantly discharged, the molten salt layer 51 is maintained in a very thin state.

FIG. 4 is a diagram showing another configuration of the molten salt discharge section in the melting furnace shown in FIG. In FIG. 4, portions having the same configuration as in FIG. 3 are denoted by the same reference numerals, and description thereof is omitted. In this molten salt discharge section, the molten salt discharge section 13 has a closed structure, so that the internal pressure can be reduced. For this reason, an exhaust port 27 for decompression is provided above the molten salt discharge section 13, and the exhaust port 27 is connected to a decompression means 28. According to this configuration, the pressure on the discharge side of the porous body portion 20 is lower than the pressure on the molten salt layer side, and the permeation flow rate of the molten salt increases, so that the installation area of the porous body portion can be reduced. In the molten salt discharge section having this configuration, the porous body section 2
The molten salt that has passed through zero stays at the bottom and is discharged sequentially.

FIG. 5 is a plan view showing another example of the embodiment of the melting furnace of the present invention. FIG. 6 is a sectional view taken along the line BB in FIG. In FIGS. 5 and 6, parts having the same configuration as those in FIGS. 1 and 2 are denoted by the same reference numerals, and description thereof is omitted. In this embodiment,
A part of the melting furnace body 10 has a protruding shape,
The molten salt receiving portion 30 is provided in this portion. This portion has a double wall structure, and an outer wall 32 is provided so as to surround the inner wall 31. The inner wall 31 is a partition wall that partitions the inside of the melting furnace main body into a portion for performing a melting process and a portion for receiving the extracted molten salt.
However, the inner wall 31 is formed with an interval between the inner wall 31 and the furnace lid, and the gas phase portions of the two sections can be circulated.

In the main body of the melting furnace, the porous body portion 20 through which the molten salt permeates is formed at the level where the molten salt layer 51 is formed, the inner wall located near the level, and the upper portion of the inner wall 31.
Is provided. In addition, the porous body portion 20 is slightly spaced from the furnace wall, and draws an arc along the furnace wall,
They are arranged in a band. The porous body portion 20 is formed of a refractory made of a carbonaceous material, and has a large number of pores having a diameter of about several mm or less.

In the upper part of the inner side wall 31, the porous body part 20 is arranged inside, and the reinforcing body 3
3 are arranged. Since the porous body portion 20 does not need to be so thick, the strength of the upper portion of the inner wall 31 is ensured by arranging the reinforcing body 33 on the outside thereof. The reinforcing body 33 is provided with a relatively large through-hole, and the through-hole serves as a flow path for the molten salt. The refractory material forming the reinforcing member 33 needs to be hardly damaged by the molten salt, and for example, a refractory material containing carbon is used.

In the drawing, reference numeral 34 denotes a molten salt discharge port, and 35 denotes a heating means for heating the molten salt receiving section 30 to maintain the retained molten salt at a temperature higher than the melting point.

The discharge of the molten salt in the melting furnace having the above configuration is performed as follows. Only molten salt is porous body 2
0 and flows down to the lower part of the space 26 between the furnace wall.
The molten salt that has flowed down overflows and collects at the upper portion of the inner wall 31, passes through the reinforcing member 33, and flows into the molten salt receiving portion 30. The molten salt is heated by the heating means 35 and maintained at a temperature equal to or higher than the melting point, and is appropriately extracted.

According to this embodiment, as in the case of the melting furnace shown in FIGS. 1 and 2, only the molten salt can be discharged, and the molten salt layer 51 is maintained in a very thin state. be able to. Further, since all of the porous body portions 20 are disposed in the high-temperature furnace, there is no need to heat the porous body portion at the portion from which the molten salt is discharged.

FIG. 7 is a plan view showing still another example of the embodiment of the melting furnace of the present invention. FIG. 8 is a sectional view taken along the line CC in FIG. 7 and 8, the portions having the same configuration as those in FIGS. 1 to 6 are denoted by the same reference numerals, and description thereof is omitted. In this embodiment, two types of incineration residues are charged from two places. 11a is a charging pipe for charging incineration residues having a low content of salts such as incineration ash discharged during incineration of municipal waste, and 11b is for charging incineration residues including a large amount of salts such as fly ash. It is a charging pipe. Further, a partition wall 36 surrounding the charging pipe 12b for the incineration residue is provided at the upper part of the melting furnace main body, and the upper part of the melting furnace main body is divided into two sections. 37 is a flow port provided in the gas phase part.

In this embodiment, since the incineration residue containing a large amount of salts is charged into the section partitioned by the partition wall 36, most of the molten salt is generated in this section. Then, the molten salt is discharged from this section.

[0050]

According to the present invention, the molten salt formed on the molten slag layer is made of carbon, which has a property of having wettability with respect to molten salt and not having wettability with respect to molten slag. Since the porous body made of a refractory material containing is permeated and discharged, only the molten salt is selectively discharged. For this reason, even if only a small amount of the molten salt is present, no molten slag is mixed into the molten salt. Also, since the molten salt is constantly discharged, the molten salt layer is maintained in a very thin state,
No equipment or operational problems occur.

[Brief description of the drawings]

FIG. 1 is a plan view showing an example of an embodiment according to a melting furnace of the present invention.

FIG. 2 is a sectional view taken along the line AA in FIG.

FIG. 3 is an enlarged view of a molten salt discharge section in the melting furnace shown in FIG.

FIG. 4 is a diagram showing another configuration of the molten salt discharge section in the melting furnace shown in FIG.

FIG. 5 is a plan view showing another example of the embodiment of the melting furnace of the present invention.

FIG. 6 is a sectional view taken along the line BB in FIG. 5;

FIG. 7 is a plan view showing still another example of the embodiment of the melting furnace of the present invention.

8 is a cross-sectional view taken along the line CC in FIG.

FIG. 9 is an explanatory diagram of a method for evaluating the wettability of a refractory to a melt.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Melting furnace main body 11 Charging pipe for incineration residue 11a Charging pipe for charging incineration residue with a low salt content 11b Charging pipe for charging incineration residue containing a large amount of salts 12 Electrode 13 Molten salt discharge section 14 Discharge port of molten slag 16 Discharge port of exhaust gas 20 Porous body 21 Opening 22 Discharge port of molten salt 23 Inspection port 24 Heating means 25 Insert 26 Strip-shaped space 27 Exhaust port for decompression 28 Decompression means 30 Molten salt receiving section 30 31 Inner side wall 31 32 Outer side wall 32 33 Reinforcement body 33 34 Molten salt discharge port 35 Heating means 36 Partition wall 37 Gas phase part 50 Incineration residue charged into furnace 51 Molten salt layer 52 Molten slag layer 53 Molten metal layer

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F23G 5/00 ZAB F23J 1/00 B 115 F27B 3/19 F23J 1/00 3/20 F27B 3/193 / 08 3/20 B09B 3/00 303K // F27B 3/08 5/00 L (72) Inventor Takuya Shinagawa 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd. (72) Inventor Yabuta Kazuya F-term (reference) 1-2-1 Marunouchi, Chiyoda-ku, Tokyo 3K061 AA23 AB03 AC03 BA05 CA12 DB11 DB20 NB02 NB10 NB21 NB27 NB28 4D004 AA36 AB05 CA29 CA50 CB32 CB43 DA03 DA06 4K045 AA04 BA10 CA10 RA12 RA16 RB04

Claims (8)

[Claims] An incineration residue is charged and melted while the melt is retained in a furnace, and the molten salt is separated into a molten slag and a molten salt. A method for melting incineration residues containing salts, wherein a porous body made of a refractory material having wettability to salt and not wettable to molten slag is allowed to pass therethrough and discharged. 2. A porous body made of a refractory material having wettability to a molten salt and not wettable to a molten slag is a porous body made of a refractory material containing carbon. A method for melting incineration residues containing salts according to claim 1. 3. A furnace for melting an incineration residue having an outlet for molten slag and an outlet for molten salt, wherein the furnace wall at a portion in contact with the molten salt layer generated in the furnace during operation is made of a refractory containing carbon. A melting furnace for incineration residues containing salts, wherein a porous body is provided, and molten salt is transmitted through the porous body and discharged. 4. An incineration residue melting furnace having a molten slag discharge port and a molten salt discharge port, a refractory containing carbon inside a furnace wall at a portion in contact with a molten salt layer generated in the furnace during operation. A porous body portion is provided, and an opening is provided outside the furnace wall at a portion where the porous body portion is provided to reach the porous body portion, and molten salt is discharged through the porous body portion and the opening portion. A melting furnace for incineration residues containing salts, characterized in that the furnace is configured as follows. 5. The salt according to claim 3, wherein an insert made of an oxide-based refractory and having a through-hole is disposed in an opening provided outside the furnace wall. Melting furnace for incineration residues. 6. A pressure reducing means is connected to a discharge path of the molten salt, and the pressure on the discharge side of the porous body is configured to be lower than the pressure on the molten salt layer side. ~
A melting furnace for the incineration residue containing the salts according to claim 5. 7. The method for melting incineration residues using a melting furnace according to claim 3, wherein the temperature of the molten salt discharge channel is maintained at 700 ° C. to 1000 ° C. For melting incineration residues, including: 8. The melting furnace for incineration residues containing salts according to claim 3, wherein a heating means is provided in the discharge path of the molten salt.