JPS6354769B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to an apparatus for recovering metal from resin-coated metal products such as laminated aluminum foil, aluminum sash material, aluminum foil, and coated electric wire.

Note that the resin coating includes not only those whose surfaces are coated with resin as described above, but also those in which a resin such as a sealing material is sandwiched in the grooves of a material such as an aluminum sash.

Prior art and its problems When recovering metal from resin-coated metal products, conventional incineration in the atmosphere was used. However, with this method, the metal itself also oxidizes,
The drawback was that the collection efficiency deteriorated. Therefore, by filling the melting furnace with an inert gas such as Ar gas or _N2 gas, or by reducing the pressure inside the furnace to a vacuum state, the resin coating can be performed while maintaining a non-oxidizing atmosphere inside the furnace. One possible method is to melt the metal product. However, although this method improves metal recovery efficiency, it has the disadvantage that running costs for maintaining the inside of the furnace in a non-oxidizing atmosphere become high. In addition, since a large amount of decomposed tar-like substances are generated in the thermal decomposition gas of the resin that is generated when the metal is melted, equipment for processing this is required, resulting in an increase in cost. Furthermore, since a considerable amount of thermal energy is required to melt the metal, there is also an economical problem in this respect.

This invention has been made in view of the above circumstances, and it is an object of the present invention to provide a metal recovery device from resin-coated metal products that is economical in all respects.

Means for Solving the Problems The apparatus for recovering metal from resin-coated metal products according to the present invention includes a resin-coated metal product melting furnace, and a flame hole disposed outside the melting furnace in close proximity to the melting furnace. a pyrolysis gas supply path that communicates a melting furnace heating burner and a pyrolysis gas combustion burner, and an upper end of the melting furnace and the pyrolysis gas combustion burner;
It consists of an oxygen supply path that supplies oxygen to the pyrolysis gas combustion burner.

Embodiments Hereinafter, the present invention will be explained based on drawings showing embodiments.

The apparatus for recovering metal from resin-coated metal products includes a resin-coated metal melting furnace 1 whose upper end is open, and a furnace 1 which is placed close to the outside of the melting furnace 1 and whose flame holes are directed toward the melting furnace 1. A melting furnace heating burner 2 for heating; a pyrolysis gas combustion burner 3 which is also disposed outside and close to the lower end of the melting furnace 1 and whose flame hole is directed toward the lower end of the melting furnace 1; A pyrolysis gas supply passage 4 is disposed between the upper end of the melting furnace 1 and the pyrolysis gas combustion burner 3 and communicates the interior of the furnace 1 with the burner 3, and supplies oxygen to the pyrolysis gas combustion burner 3. and an oxygen supply path 5.

The melting furnace 1, the pyrolysis gas combustion burner 3, and the pyrolysis gas supply section 4 are housed in a heating chamber 6 made of refractory material.

A molten metal outlet passage 7 is provided at the lower end of the melting furnace 1 and extends outward through the bottom wall of the heating chamber 6.

A plurality of heating burners 2 are attached to the peripheral wall of the heating chamber 6, and each penetrates the peripheral wall from the outside so that the flame hole faces inward.

There is a resin-coated metal product inlet 8 on the top wall of the heating chamber 6.
is provided. This inlet 8 may be closed with a lid 9 as shown in the drawings, or may be kept open at all times. This is because the pyrolysis gas of the resin is heavy, so the pyrolysis gas filling the furnace 1 overflows from the furnace 1 through the supply path 4 to the burner 3, just like liquid overflowing from a container, and reaches the burner 3 through the supply port 8. This is because there is no escape from it. Furthermore, an exhaust port 10 is provided on the top wall of the heating chamber 6 for discharging exhaust gas after combusting the pyrolysis gas.

In such an apparatus, a resin-coated aluminum foil 11 (resin-coated metal product) coated with polyethylene and vinyl acetate is charged into the melting furnace 1 from an input port 8 . Next, melting furnace heating burner 2
When the furnace 1 is heated, the temperature inside the furnace 1 reaches a predetermined temperature, and the resin (polyethylene and vinyl acetate) covering the foil 11 is thermally decomposed and gasified. This pyrolysis gas then fills the furnace 1, creating a non-oxidizing atmosphere inside the furnace 1. Pyrolysis gas is generated even after the furnace 1 is filled, and the excess gas is passed through the pyrolysis gas supply path 4 by the weight of the gas itself to the pyrolysis gas combustion burner, as shown by the arrow in Fig. 1. 3. Here, the oxygen supply path 5 is connected to the burner 3 so that the pyrolysis gas and oxygen have an appropriate mixing ratio.
The pyrolysis gas is combusted by the burner 3. At this time, the pyrolysis tar-like substances contained in the pyrolysis gas are also completely combusted. thus,
When the temperature inside the melting furnace 1 exceeds 300°C, the melting furnace heating burner 2 is turned off and the melting furnace 1 is heated only by the pyrolysis gas combustion burner 3. This is because when the temperature inside the furnace 1 exceeds 300°C, the amount of pyrolysis gas generated increases rapidly.
This is because it can be heated sufficiently. Thereafter, when the temperature inside the furnace 1 exceeds the melting point of aluminum, the aluminum foil 1 is melted, and the molten metal is taken out from the molten metal removal path 7. On the other hand, the exhaust gas generated by burning the pyrolysis gas is discharged from the exhaust port 10.
However, from this exhaust gas,
Only CO ₂ and H ₂ O are detected.

In the above example, the temperature inside the furnace 1 is 300°C.
If the melting furnace heating burner 2 exceeds The heating burner 2 may be used until the In this case as well, the fuel for the heating burner 2 can be significantly saved compared to the case where the heating burner 2 alone is used for heating. In addition, if the amount of pyrolysis gas generated is insufficient and it is not possible to heat the metal product above its melting point using only the energy obtained by burning the pyrolysis gas, heating burner 2 is of course used in combination. However, in this case as well, the fuel for the heating burner 2 can of course be saved.

Effects of the Invention According to the device of this invention, as described above,
After the pyrolysis gas from the resin coating the metal product fills the melting furnace, the pyrolysis gas passes through the pyrolysis gas supply path to the pyrolysis gas combustion burner, where it is burned. The resin-coated metal product can be heated from outside the melting furnace while maintaining a non-oxidizing atmosphere inside with pyrolysis gas. Therefore, it is possible to completely prevent the metal from being consumed by oxidation when melting the metal, and the metal recovery efficiency is improved.

In addition, since a non-oxidizing atmosphere is created using the thermal decomposition gas of the resin that coats the metal product, there is no need to use a separate inert gas or to reduce the pressure in a vacuum. The cost becomes unnecessary. In addition, the heat generated during this process is used by burning the thermal decomposition gas of the resin that coats the metal product as thermal energy for melting the metal. The amount of fuel used can be significantly reduced.Furthermore, when the pyrolysis gas is combusted, the tar-like substances contained in this gas are also combusted, so there is no need for separate equipment to process this tar-like substance. Therefore, that cost can also be omitted. Therefore, the method using the device of this invention is economically superior in all respects.

[Brief explanation of the drawing]

The drawings show an embodiment of the product according to the invention, in which FIG. 1 is a vertical sectional view, and FIG. 2 is a sectional view taken along the line --- in FIG. 1... Melting furnace, 2... Melting furnace heating burner, 3...
...Pyrolysis gas combustion burner, 4...Pyrolysis gas supply path, 5...Oxygen supply path.

Claims (1)

[Claims] 1 Resin coated metal product melting furnace 1 and this melting furnace 1
A melting furnace heating burner 2 and a pyrolysis gas combustion burner 3 are arranged outside and close to the melting furnace 1 and have flame holes directed toward the melting furnace 1, and an upper end inside the melting furnace 1 and the pyrolysis gas combustion burner 3. An apparatus for recovering metals from resin-coated metal products, comprising a pyrolysis gas supply path 4 that communicates with the pyrolysis gas supply path 4 and an oxygen supply path 5 that supplies oxygen to the pyrolysis gas combustion burner 3.