JPH09323077A - Method for recovering metal from plastic / metal laminate waste - Google Patents

Abstract

(57) 【Abstract】 PROBLEM TO BE SOLVED: To recover only metal in a clean state that is not oxidized, from packaging materials in which plastics such as polyester and metals such as aluminum are laminated in a laminate, electronic substrates, wastes such as electric wires. A metal recovery method capable of performing the above is provided. SOLUTION: Waste of plastic / metal laminate i
By indirect contact 7 with the generated gas e from the gasification furnace 1 having a temperature below the melting point of the metal and above the temperature for thermally decomposing and plasticizing the plastic through the heat transfer surface to remove the plastic component and remove the metal. A metal recovery method is characterized by recovering l, and the indirect contact of the waste i with the generated gas e is performed under an oxygen-free atmosphere or under the supply of an oxygen-containing gas to generate the metal. The gas is 4 from the gasifier 1.
The pyrolysis gas of the solid waste a heated to 50 to 700 ° C. is used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for recovering metal from waste of a plastic / metal laminate, and particularly to a packaging material and electric wires in which plastics such as polyester and epoxy and metals such as aluminum and steel and copper are laminated. And a method of heat-treating the waste of a plastic-laminated electronic substrate containing a copper foil to recover only the metal in a clean state without being oxidized.

[0002]

2. Description of the Related Art In recent years, with the widespread use of various retort foods, laminated packaging materials such as toothpaste medicine tubes, beverage cans such as beer and juice, food cans, electronic substrates for electronic computers and controllers, container manufacturing and substrate processes. A large amount of waste such as cut pieces is generated in the above, and with the large amount of waste generated after the use of those containers and electronic devices, it is difficult to process the waste. High-grade aluminum is often used for this type of packaging material, and high-grade copper foil is used for electronic substrates, and most of these are currently subjected to landfill disposal. Its effective use is strongly desired. Therefore, if only the plastic component is removed by heat treatment and the metal is recovered and recycled in a state of maintaining high quality, it is very effective from the viewpoint of effective use of resources or reduction of waste amount. There is an attempt to burn only waste materials such as packaging materials, can materials and substrate materials in which plastics such as polyester and epoxy and aluminum, steel, and copper are laminated in a laminated form to recover only metals such as aluminum. There is a problem that part of the metal is oxidized because it is burned in an oxidizing atmosphere. Further, when a large amount of air is supplied for combustion, the thin foil-shaped metal rises along with the combustion exhaust gas and is deposited on the inside of the flue and the gas treatment device.

[0003]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems and eliminates waste materials such as packaging materials, can materials, electric wires, and substrate materials in which plastics such as polyester and metals such as aluminum are laminated in a laminated form. An object of the present invention is to provide a metal recovery method capable of recovering only metal in a clean state that is not oxidized.

[0004]

In order to solve the above problems, in the present invention, the waste of the plastic / metal laminate is treated at a temperature below the melting point of the metal and above the temperature at which the plastic is pyrolyzed and gasified. The metal recovery method is characterized in that the plastic content is removed and the metal is recovered by indirectly contacting the generated gas from the chemical conversion furnace through the heat transfer surface. In the above method, the indirect contact between the waste and the produced gas is performed in an oxygen-free atmosphere or under the supply of an oxygen-containing gas, and the metal is aluminum, steel, copper, or another laminated body. A metal can be used, the gasification furnace can use a solid waste as a raw material, the generated gas can be a gas heated to 450 to 700 ° C. from the gasification furnace, and recovery of the metal can be performed. It can be carried out by sieving a mixture of the discharged metal and a carbide which is a decomposition product of plastic. Further, since the gas generated by indirect contact with the plastic / metal laminate contains the gasification decomposition product of plastic, it is preferable to combust it in the combustion furnace in the subsequent stage together with the gas generated from the gasification furnace. In the combustion furnace, it is preferable to combust at 1200 to 1400 ° C. to melt slag into slag for discharge from the bottom of the combustion furnace, and the combustion furnace is preferably a swirling melting furnace.

[0005]

Next, the present invention will be described in detail.
In the present invention, the waste of the plastic / metal laminate, for example, the waste of the packaging material, is indirectly contacted with the product gas from the gasification furnace controlled at a predetermined temperature, preferably the fluidized bed gasification furnace, through the heat transfer surface. By doing so, only the plastic component is pyrolyzed and gasified, and the remaining metal is recovered in a clean state without being oxidized. Specifically, quantify the plastic / metal laminate waste that had been finely cut beforehand in the plastic thermal decomposition machine installed in the discharge path of the high-temperature generated gas from the gasification furnace with the air cut off. By supplying it, it is indirectly heated by the high-temperature generated gas via the heat transfer surface, and the plastic component is pyrolyzed and gasified in the absence of oxygen,
Gaseous components such as gas / tar and solid carbide particles. The pyrolysis gas generated by the thermal decomposition of plastic is sent to the combustion furnace in the subsequent stage and burned together with the product gas derived from the gasification furnace extracted from the thermal decomposition machine, and the solid carbide particles are outside the system together with the metal foil. After discharging to, the coarse metal foil is separated from the fine carbides and recovered by sieving.

Alternatively, by supplying air to the plastic thermal decomposition machine, the plastic portion of the shredded plastic / metal laminate waste is partially combusted to be pyrolyzed and gasified, and gas / tar gas is produced. It becomes an ingredient. In this case, the char is gasified into CO or CO ₂ and is hardly mixed in the separated metal. Therefore, only the metal foil is discharged out of the system and collected. When the gasification furnace of the present invention is a fluidized bed furnace, sand such as silica sand and olivine sand, alumina, dolomite, limestone and the like can be used as the fluid medium. In the fluidized bed gasification furnace, air, oxygen-enriched air, or oxygen + steam is appropriately selected, supplied to the gasification furnace, and primary combustion is performed at 450 to 700 ° C. Then, in the present invention, the produced gas obtained by the primary combustion is introduced into the plastic thermal decomposition machine and indirectly contacted with the shredded plastic / metal laminate through the heat transfer surface. For example, in order to recover aluminum as a metal, the temperature of the generated gas is 660 ° C. which is the melting point of aluminum.
It should be lower.

Hereinafter, the present invention will be specifically described with reference to the drawings. 1 is an overall configuration diagram of a combustion apparatus to which the metal recovery method of the present invention is applied, and FIG. 2 is an enlarged view of the plastic thermal decomposition machine of FIG. In FIG. 1 and FIG. 2, 1 is a gasification furnace, 2 is a fluidized bed, 3 is a deaeration damper (quantitative supply, extraction device), 4 is a supply of laminated waste, and a degassing damper for discharge is a vibrating screen. , 6 is a sand conveying elevator, 7 is a plastic thermal decomposition machine, 8 is a crushing material feed conveyer, 9 is a vibrating screen, 10 is a swirl-type melting furnace, 11 is a primary combustion chamber, 12 is a secondary combustion chamber, and 13 is slag separation. Part 14 is a heating tube.

Next, each component of FIG. 1 will be described in detail.
Numeral 1 is a fluidized bed gasification furnace for treating a large amount of combustible materials other than laminated waste, in which sand as a fluid medium and coarse incombustible materials are continuously discharged from the degassing damper 3 at the bottom of the furnace, and the discharged sand The coarse incombustibles are supplied to the vibrating screen 5, and are separated into fine sand and coarse incombustibles. The separated sand is circulated in the gasification furnace 1 by the sand transport elevator 6. On the other hand, from the lower side of the fluidized bed gasification furnace 1, primary air b is fed to form a fluidized bed 2 of sand, and the combustible material a fed above the fluidized bed 2 is heated at 450 to 700 ° C. Promptly pyrolyze and gasify. With the gasification, gas, tar, and carbide are produced, and the carbide is finely pulverized by the disturbing motion of the fluidized bed 2 to become char, which is entrained in the produced gas and discharged from the gasification furnace 1. Further, in order to adjust the temperature of the produced gas, the gasification furnace is provided with an inlet for the secondary air c, and when the temperature of the produced gas is low, the secondary air is blown in to partially burn and raise the temperature. be able to.

The produced gas e discharged from the gasification furnace is introduced into the plastic thermal decomposition machine 7. As shown in the enlarged view of FIG. 2, the plastic thermal decomposition machine 7 has a shell-and-tube heat exchange tube 14 installed in the flow path of the generated gas e, and a crushed material of the plastic / metal laminate. i is supplied by the deaeration damper 4 of the supply device,
While being indirectly heated by the generated gas e, and only the plastic component is pyrolyzed and gasified, it moves by the crushing raw material feed conveyor 8 provided in the tube 14. Metal and char etc. are discharged by the degassing damper 4 for extraction. The vibrating screen 9
Coarse metal 1 is separated by and is recovered in a recyclable and clean state, while a fine solid content containing char is introduced by the char carrying air j into the primary combustion chamber 11 of the swirl-type melting furnace 10. .

Further, the thermal decomposition gas derived from the plastic component discharged from the heat exchange tube of the plastic thermal decomposition machine 7 is combined with the product gas e discharged from the thermal decomposition machine 7 to generate the gas in the swirling melting furnace 10. It is introduced into the primary combustion chamber 11. At this time, the generated gas from the gasification furnace 1 can separate only the char f and introduce it into the thermal decomposition unit 7, and the separated char f
May be introduced directly into the primary combustion chamber. The produced gas e and the char f supplied to the primary combustion chamber 11 of the swirl-type melting furnace 10 are mixed with the char-air mixture k that is preheated tertiary air in a swirl flow while being 1200 to 1400 ° C.
Burns at high speed. Combustion is completed in the next secondary combustion chamber 12,
The combustion exhaust gas g is discharged from the slag separation unit 13. The ash contained in char becomes slag mist due to high temperature,
The centrifugal force of the swirling flow traps the molten slag phase on the furnace wall of the primary combustion chamber 11, flows down the furnace wall into the secondary combustion chamber 12, and is discharged from the bottom of the slag separation unit 13. In addition,
The flue gas g discharged from the swirl-type melting furnace 10 is a waste heat boiler,
It is released into the atmosphere through a series of heat recovery devices such as a economizer and an air preheater.

In the above, the plastic thermal decomposition unit 7
It is also possible to introduce controlled air 15 into the heat exchange tube 14 of the. As a result, the plastic, or the plastic of the laminated waste such as aluminum, is partially burned to accelerate the pyrolysis gasification of the carbide. By supplying the air 15, it becomes possible to achieve smooth and simple plastic pyrolysis gasification process. In the heat exchange tube 14 of the plastic thermal decomposition apparatus 7, oxygen in the air 15 sent in causes a partial oxidation reaction of the plastic, but since the inside of the layer is kept in a reducing atmosphere,
The metal can be taken out without being oxidized.

[0012]

INDUSTRIAL APPLICABILITY In the present invention, a metal laminate of a plastic such as a waste of a packaging material obtained by laminating a plastic such as polyester and a metal such as aluminum in a laminated form, a waste of an electronic substrate, a waste electric wire, etc. This method presents a method of pyrolyzing and gasifying by indirectly contacting with a medium having a temperature lower than the melting point, and recovering only metal in a clean state that is not oxidized, that is, in a recyclable state. By applying the present invention, it is possible to collect the metal in a state in which the quality of the metal is kept higher than that of the waste of the plastic / metal laminate, which is very effective from the viewpoint of effective use of resources or reduction of the amount of waste dumped.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a combustion device to which a metal recovery method of the present invention is applied.

FIG. 2 is an enlarged view of the plastic pyrolyzer of FIG.

[Explanation of symbols]

1: Fluidized bed combustion furnace, 2: Fluidized bed part, 3: Degassing damper,
4: Degassing damper, 5: Vibrating sieve, 6: Sand transport elevator, 7: Plastic thermal decomposition machine, 8: Crushing material feed conveyor, 9: Vibrating sieve, 10: Swirling type melting furnace, 11: Primary combustion chamber, 12: secondary combustion chamber, 13: slag separator, 1
4: heat exchange tube, 15: air, a: waste, b: primary air, c: secondary air, d: incombustible, e: product gas,
f: char, g: combustion exhaust gas, h: slag, i: stack waste, j: char carrier air, k: tertiary air containing char, l: recovered metal

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takio Muramatsu 11-11 Haneda-Asahicho, Ota-ku, Tokyo Inside EBARA CORPORATION

Claims (6)

[Claims] 1. A waste material of a plastic / metal laminate,
By indirectly contacting the generated gas from the gasifier at a temperature below the melting point of the metal and above the temperature at which the plastic is pyrolyzed and gasified through the heat transfer surface, the plastic content is removed and the metal is recovered. Characteristic metal recovery method. 2. Removal of the plastic content of the waste
The metal recovery method according to claim 1, wherein the method is performed in an oxygen-free atmosphere or is performed while supplying an oxygen-containing gas. 3. The metal recovery method according to claim 1, wherein the metal is aluminum, steel, copper, or another metal forming a laminated body. 4. The metal recovery method according to claim 1, wherein the gasification furnace uses solid waste as a raw material. 5. The product gas is generated from the gasifier.
The metal recovery method according to any one of claims 1 to 4, wherein the gas is heated to 50 to 700 ° C. 6. The metal recovery method according to claim 1, wherein the recovery of the metal is performed by sieving a mixture of the discharged metal and a decomposition product of the plastic.