JP2013147523A - Dry distillation apparatus and method for recovering metallic resources using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dry distillation apparatus in which the recovery of metallic resources from a metal and organic substance composite raw material can be performed by one rotary kiln.SOLUTION: A dry distillation apparatus includes a cylinder that includes: a feed section of a material to be processed in one end thereof; and a carrying out part of a processed material in the other end thereof, wherein the cylinder is rotatably supported. The cylinder is slightly inclined or horizontal so that the carrying out part side is located downward of the feed section, thereby the material to be processed gradually moves to the carrying out part side by the rotation of the cylinder, the cylinder is partitioned in two or more processing chambers by partition walls that open partially to pass the material to be processed, and the amount of air or supporting gas of the processing chamber that is nearer the carrying-out part is relatively more increased than that of the processing chamber near the feed section among the two or more processing chambers.

Description

  The present invention relates to a dry distillation apparatus effective for recovering metal resources by dry distillation from a raw material in which a metal and an organic substance are in a composite or mixed state.

There are paper or plastic materials, or laminates of these materials in which aluminum foil is laminated or a vapor-deposited composite material.
This kind of aluminum composite material is used in many fields such as containers for various beverages, containers for various liquid foods, packaging materials for foods and confectionery, and packaging materials for pharmaceuticals.
However, the thickness of the aluminum layer is thin, and the incineration of ordinary waste oxidizes the aluminum layer, making it difficult to recover it as metallic aluminum.
Therefore, the present inventors have examined whether or not metal aluminum can be recovered by subjecting these aluminum wastes to dry distillation at a temperature at which aluminum does not melt by heating.

Plastic materials, paper materials, or composite materials with aluminum foil laminated or aluminum deposited on it must generate low-oxygen conditions in the dry distillation chamber because a lot of flammable gas is generated at the heating temperature of 300 to 450 ° C at the initial stage of dry distillation. If it fires, it becomes a combustion state of 800 ° C. or higher.
Then, metal aluminum having a melting point of about 600 ° C. cannot be recovered.
Moreover, after the volatile component was distilled from the composite material, the carbide remained attached to the surface of the aluminum, and high purity aluminum could not be recovered.
Therefore, using the rotary kiln tester, the first dry distillation treatment was performed while keeping the air supply amount relatively low, and then the air supply amount was increased more than the first time, and the second time. The dry distillation treatment was performed.
As a result, a highly pure metal aluminum foil having a silver-white surface was obtained.
However, when two treatments are performed, continuous treatment cannot be performed with one rotary kiln, and connecting two rotary kilns has a problem that not only the equipment becomes large, but also energy consumption increases.

  Patent Document 1 discloses a multistage rotary kiln, which also connects a plurality of rotary kilns.

JP 2001-31412 A

  An object of the present invention is to provide a dry distillation apparatus capable of recovering metal resources from a metal / organic composite raw material with a single rotary kiln.

In the conventional rotary kiln, when the object to be processed moves gradually toward the unloading part in one rotation-supported cylindrical body, air or air is supplied between the supply part side and the unloading part side of the object to be processed in the furnace. It was difficult to make a difference in the amount of auxiliary combustion gas.
The carbonization treatment apparatus according to the present invention is capable of gradual carbonization suitable for each material to be treated, particularly suitable for recovering metals from composite raw materials, having a material supply part at one end, and processing at the other end. A carbonization device comprising a rotation-supported cylindrical body having an object carry-out section, wherein the cylinder body is slightly inclined or horizontal so that the carry-out section side is positioned below the supply section. Due to the rotation of the cylindrical body, the object to be processed is gradually moved toward the unloading part, and is partitioned into a plurality of processing chambers by partially opened partition walls for allowing the object to be processed to pass therethrough. Among the processing chambers, the amount of air or auxiliary combustion gas in the processing chamber close to the unloading unit is relatively larger than that in the processing chamber close to the supply unit.
Here, partitioning into a plurality of processing chambers means that the object to be processed is moved when the inner side of one cylindrical body is gradually moved toward the unloading portion by the rotation of the cylindrical body. It means that it is possible to provide a difference in the amount of air or auxiliary combustion gas in each processing chamber by partitioning with a partition wall partially opened so that an object can pass through.
In addition, the number of treatment chambers is not limited as long as it can be divided into two or more, and the purpose of the dry distillation treatment is multi-stage depending on the moisture content of the object to be treated (raw material) and the blending ratio of organic matter and metal. It is.
Therefore, you may have a preliminary drying apparatus etc. in front of the carbonization apparatus which concerns on this invention.
By dividing the cylindrical body into a plurality of processing chambers, it is possible to efficiently recover the dry distillation gas from the processing chamber in which the dry distillation gas is most generated. Therefore, at least one of the plurality of processing chambers has generated combustible gas. It is preferable to have a means for recovering the combustible liquid and / or combustible gas.
The recovered flammable liquid and / or flammable gas is preferably reused as fuel.

As described above, since the inside of one cylindrical body is divided into a plurality of processing chambers, it is suitable for dry distillation of the object to be processed in stages. In particular, the metal / organic composite raw material is supplied as the object to be processed, and is supplied to the supply unit side. A combustible liquid and a gas component are distilled off in a nearby processing chamber and decarburized in a processing chamber close to the carrying-out side, thereby recovering metal resources with less carbides and organic impurities.
Here, a metal / organic composite material is a composite of a metal component and an organic material such as paper, plastic, wood, etc., and the composite form is such as lamination, mixing, dispersion in a matrix, etc. Any type.
Among them, it is particularly effective for recovering low-melting metals such as aluminum and its alloys, magnesium and its alloys, and metals that are easily oxidized such as titanium and its alloys.
Furthermore, it is effective for recovering aluminum and its alloys from aluminum-based composite waste of packaging materials such as paper and / or plastic laminated with aluminum foil or deposited with aluminum.
These metals have a high affinity with oxygen, and when the metal is thin like a foil, a process of carbonizing paper and plastic without burning, and a process of decarburizing impurities adhering to the metal as carbides The feature of the present invention is that the above is realized by one kiln.

  In the rotary body such as a rotary kiln adopting a reducing atmosphere heating system using an external heat or internal heat system, the present invention divides the inside of one cylindrical body into a plurality of processing chambers along the rotation axis direction. Without using a rotary kiln, stepwise carbonization conditions and decarburization conditions can be set according to the processing state of the workpiece, so that it is possible to share a cylindrical rotation drive device, heating device, etc. It is a dry distillation device that is compact and saves energy.

In addition, by using such a carbonization device, for example, when aluminum composite waste discarded after being used for packaging materials is processed, air supplied in the initial stage of carbonization where a large amount of organic components such as plastic is generated or It is possible to prevent ignition by reducing the amount of the auxiliary combustion gas or by heating in a state where supply of air or the like is stopped, and it is possible to suppress the oxidation loss of the aluminum foil or the like.
In this state, brown carbon impurities remain on the surface of the aluminum foil or the like, but even if the supply amount of air or auxiliary combustion gas is relatively increased in the subsequent processing chamber, the carbon impurities do not ignite. Since decarburization is performed, high-purity aluminum with few impurities and an aluminum foil made of an alloy thereof can be obtained.

The structural example of the carbonization apparatus which concerns on this invention is shown typically.

As schematically shown in FIG. 1, a dry distillation apparatus 10 according to the present invention has a cylindrical body 11 having a supply part 11b for supplying an object to be processed (raw material) and an unloading part 11c for unloading the processed object. Is rotatably supported by the roller support portions 16a and 16b via the two front and rear ring bodies 15a and 15b.
The cylindrical body 11 is supported in a state where the supply portion 11b and the carry-out portion 11c are horizontal or inclined by 0.1 to 2 ° so that the carry-out portion 11c is lower than the supply portion 11b. The rotation is controlled by a rotary drive device such as a sprocket drive or a gear drive.
The inside of the cylindrical body 11 is partitioned into a plurality of processing chambers by a partition wall 12 along the rotation axis direction.
In this embodiment, the cylindrical body 11 is divided into two processing chambers, a front chamber 13 on the supply unit side and a rear chamber 14 on the unloading unit side, by the partition wall 12, but the number of processing chambers is limited. Absent.
Further, in this embodiment, the paddle 11a is attached while providing a predetermined interval along the rotation direction inside the cylindrical body 11 so that the object to be processed moves toward the carry-out portion 11c while stirring.
The outer peripheral side of the cylindrical body 11 is an external heating type rotary kiln having a hot air heating unit 30.

The partition wall 12 is attached to the inside of the cylindrical body 11 so as to rotate together with the cylindrical body 11, and the object to be processed passes through it, but the outer peripheral side is partially opened so as to suppress the movement of air and generated gas. It has the opening part 12a and the piping insertion hole 12b for letting piping pass in the center part.
The central pipe insertion hole 12b is also a small opening so that movement of air and exhaust gas between the front chamber 13 and the rear chamber 14 is reduced.
The area of the combined opening of the passage opening 12a and the pipe insertion hole 12b is preferably in the range of 5 to 15% with respect to the inner cross-sectional area of the cylindrical body.

The front chamber 13 is provided with a front chamber air supply pipe 18a and a front chamber exhaust gas pipe 17a, and the supply amount of air and the amount of exhaust gas are controlled.
The combustible gas recovered by the front chamber exhaust pipe 17a can be recovered as fuel.
The rear chamber 14 is provided with a rear chamber air supply pipe 18b and a rear chamber exhaust pipe 17b, and the supply amount of air and the amount of exhaust gas are controlled.
If the amount of air or auxiliary combustion gas can be controlled in each processing chamber, it is not necessary to provide both the air supply pipe and the exhaust gas pipe in each processing chamber.

The cylindrical body 11 has a supply device 20 connected to the supply unit 11b side while suppressing air from entering from the outside.
This embodiment they become an example with a built-in screw 21, the member to be processed M ₁ is adapted to be conveyed supplied by the rotation of the screw 21.
The discharge portion 11c side of the cylindrical body 11 has a resource collection unit 19 connected while preventing the air from the outside entering, metal resources M ₂ the process is completed here is recovered.

Using the carbonization apparatus 10 as described above, an experiment was conducted to recover metallic aluminum from aluminum-based waste.
In the experiment, a cylindrical body 11 having an inner diameter of about 600 mm, a heating part with an overall length of about 1700 mm, and a partition wall 12 attached to the central part in the axial direction was used.
Accordingly, the heating areas of the front chamber 13 and the rear chamber 14 are each about 1.6 m ² .
In the case of plastic waste laminated aluminum, the air supply amount in the front chamber is preferably in the range of 0.5-6 Nm ³ / plastic-kg, and the air supply amount in the rear chamber is 10-30 Nm ³ / Al-kg. Is preferred.

The cylindrical body 11 is heated with hot air from the outside so that the temperatures of the processing chambers of the front chamber 13 and the rear chamber 14 are 580 to 620 ° C., and 5 kg of packaging waste consisting of PET: 80% and aluminum: 20% / H input.
Carbonization and decarburization treatment in a state of supplying air to be treated material 1kg per 5 Nm ^3, air was supplied so that the aluminum 1kg per 30 Nm ³ contained in the treated material in the rear chamber 14 into the front chamber 13 As a result, metallic aluminum having impurities of 1% or less could be recovered.

In the same heating conditions as in Example 1, Example The same workpiece is 25 kg / h introduced using the 1, prechamber 13 1 Nm ³ / treatment object 1kg an air supply, the air supply amount of the rear chamber 14 10 Nm ³ / aluminum content 1 kg.
As a result, metal aluminum having an impurity content of 5% or less was recovered.

(Comparative Example 1)
With the partition wall 12 of the cylindrical body 11 removed, the material to be treated was charged at 25 kg / h and the dry distillation treatment was performed in one chamber under the conditions of a heating temperature of 580 to 620 ° C., an air supply amount of 1 Nm ³ / a material to be treated of 1 kg. However, the surface of aluminum was brown and the amount of impurities was 23%.

  From the results of Example 2 and Comparative Example 1 described above, it was revealed that high-purity metallic aluminum can be recovered from aluminum-based waste when the dry distillation apparatus according to the present invention is used.

DESCRIPTION OF SYMBOLS 10 Carbonization apparatus 11 Cylindrical body 11a Paddle 11b Supply part 11c Unloading part 12 Partition wall 12a Passing opening part 13 Front chamber 14 Rear chamber 15a Ring body 15b Ring body 16a Roller support part 16b Roller support part 17a Front chamber exhaust pipe 17b Rear chamber exhaust gas Tube 18a Front chamber air supply tube 18b Rear chamber air supply tube 19 Resource recovery unit 30 Heating unit

Claims (4)

It is a dry distillation apparatus comprising a rotation-supported cylindrical body having a workpiece supply part at one end and a delivery part for the treatment object at the other end,
The cylindrical body is slightly inclined or horizontal so that the unloading part side is located below the supply part, so that the workpiece is gradually moved to the unloading part side by the rotation of the cylindrical body. It is partitioned into a plurality of processing chambers by a partially opened partition wall for passing the object to be processed,
A dry distillation apparatus characterized in that, among the plurality of processing chambers, the amount of air or auxiliary combustion gas in the processing chamber close to the carry-out portion is relatively larger than the processing chamber close to the supply portion.   2. The dry distillation apparatus according to claim 1, wherein at least one of the plurality of processing chambers has a means for recovering the generated combustible liquid and / or combustible gas. Using the carbonization apparatus according to claim 1 or 2, supplying a metal / organic composite raw material as an object to be treated,
A method for recovering a metal resource, characterized in that a combustible liquid and a gas component are distilled off in a processing chamber close to the supply unit, and the metal resource is recovered by decarburizing in the processing chamber close to the unloading unit. .   4. The method for recovering a metal resource according to claim 3, wherein the metal / organic composite material is aluminum composite waste, and the recovered metal is aluminum and its alloy.

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