JPH06228667A - Method for separating and recovering valuables from printed board - Google Patents

Abstract

PURPOSE:To recover valuables from the printed board. CONSTITUTION:A printed board is coarsely crushed and then finely crushed, and the crushed material is separated by gravity into the part having a high content of metallic components such as copper and the part consisting of resin, filler, etc., and recovered. The printed board, parts carrying board and the forming residue generated in the production of the board are efficiently pulverized in this way, and the metals such as copper, resin and filler are efficiently separated and recovered. Consequently, the metals such as copper are effectively utilized as precious metal resources, and the crushed resin and filler are recycled as the filler of the structural material, construction material, insulating material, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention efficiently crushes a molding board such as a printed circuit board used in an electric device, a printed circuit board on which components are mounted, and a frame material generated in the manufacturing process of these, and separates by gravity. In this way, the present invention relates to a method for efficiently separating and recovering these constituent metals such as copper and other components such as resins and fillers.

[0002]

2. Description of the Related Art A printed circuit board containing fillers, resins, metals, etc. as its main constituents and a circuit board on which electronic parts are mounted (hereinafter referred to as "component mounting circuit board") are recycled by incineration. Some methods of energy recovery are implemented. Further, as a method for recovering valuable materials from composite materials such as printed circuit boards, there is a method of heating and carbonizing a resin component in these composite materials, and then classifying and separating and recovering valuable materials such as copper. is there. (JP-A-2-88725)

In the incineration process and carbonization process of the printed circuit board and the component mounting board as described above, various waste gases are generated, and therefore an advanced waste gas treatment service must be installed. In addition, the valuable metal component contained in the printed circuit board or the component mounting board is likely to be oxidized, and there is a concern that the added value when recovered is reduced. As another method for recycling, etching copper or the like on a printed circuit board can be considered, but it is not practical because large-scale equipment is required for wastewater treatment and copper recovery. As described above, a method of efficiently separating and recovering valuable materials such as metals from a printed circuit board, a component mounting board, and a molding residue in the manufacturing process thereof at low cost has been a big problem.

[0003]

A method of recovering a valuable material from a printed circuit board according to the present invention separates and recovers a valuable material from a printed circuit board, a printed circuit board on which components are mounted, and a molding residue generated in the manufacturing process thereof. A method in which the printed board is crushed in a coarse crushing step and a fine crushing step, and the obtained crushed product is a portion containing a large amount of a metal component such as copper in a specific gravity separation step and a portion made of a resin or a filler. Separated into
It is characterized by collecting.

Further, in the method of recovering a valuable material from a printed circuit board of the present invention, during the coarse crushing step, a shearing force is applied to the object to be crushed by a cutter rotating below the charging part and a fixed blade installed on the inner wall of the chamber. In addition, it is characterized by using a coarse crusher having a mechanism for crushing an object to be crushed by applying a shearing force and an impact force with a rotating rotary blade, a fixed blade installed on the inner wall of the chamber, and / or a screen of a discharge part. .

Further, in the method of recovering a valuable material from a printed circuit board of the present invention, during the fine pulverization step, the object to be crushed is moved by an air flow in the axial direction of the rotating rotary blade so that the rotary blade and the inner wall of the chamber are moved. A mechanism that adds impact force and shearing force to the object to be crushed by the fixed blade installed and crushes it further, and then selectively takes out crushed products of a predetermined particle size or less by the air flow and returns the crushed product of a predetermined particle size or more to the chamber again. Characterized by using a fine crusher with.

[0006]

EXAMPLES The printed circuit boards and component mounting boards to which the present invention is applied and molding residues in the manufacturing process thereof are those usually used in electrical equipment. The printed circuit board is composed of a resin component, a filler component, and a metal component such as a circuit. Examples of the resin include epoxy resin, phenol resin, and polyimide resin, and examples of the filler include glass fiber, paper, carbon fiber, and the like. Examples of the metal include copper, aluminum, iron, nickel, solder (copper and lead), and the like. Further, the component mounting board here is an electronic component such as an IC package mounted on the printed board. The molding residue refers to a defective frame material or a copper-clad prepreg during the production of a printed circuit board, a heat-cured body of these, and the like, and has substantially the same constituent components as the printed circuit board of the product.

In the coarse crushing step of the present invention, as a crusher, a shearing force is applied to the object to be crushed by a cutter that rotates below the charging section and a fixed blade installed on the inner wall of the chamber. A coarse crusher having a mechanism for crushing an object to be crushed by applying a shearing force and an impact force to the object to be crushed by a fixed blade installed and / or a screen of a discharge part is used. An example of this is the Orient Mill manufactured by Orient Co., Ltd. Further, by connecting several crushers and gradually making the screen finer, it is possible to reduce the load on each crusher and take measures against wear. Further, it can be used in combination with other coarse crushers, and examples thereof include a combination with a twin-screw rotary shearing machine usually called a shredder.

In the fine crushing process, the object to be crushed is moved by the air flow in the axial direction of the rotating rotary blade, and an impact force and a shearing force are applied to the object to be crushed by the rotary blade and the fixed blade installed on the inner wall of the chamber. A pulverizer having a mechanism for selectively taking out a pulverized product having a predetermined particle size or less by an air stream and returning the pulverized product having a predetermined particle size or more to the chamber again is used. An example of this is an impeller mill manufactured by Seishin Enterprise Co., Ltd. Also, even with this crusher, several crushers can be connected to gradually reduce the crushed particle size to reduce the load on each crusher and take measures against wear. Further, it can be used in combination with other fine pulverizers.

When the printed circuit board is pulverized in such a process, the metal such as copper is hardly pulverized, and the filler and the resin are easily pulverized. It is possible to separate into a coarse powder containing a high content of the above metal and a fine powder containing almost no such metal, such as a resin or a filler. On this occasion,
If the pulverization is insufficient, the fracture separation of the interface between the metal such as copper and the resin will be insufficient, and the separation rate of the metal and other components will be reduced when the specific gravity separation is performed. On the other hand, if the metal is pulverized too much, the metal such as copper will not be pulverized together with other components, and the separation ratio of these components will also decrease when the specific gravity is separated. Therefore, the average particle size of the pulverized material of the printed circuit board is 0.03 mm (3
It is preferably 0 μm or more) and less than 0.4 mm (400 μm).

The specific gravity separation in the present invention is to separate the powders by specific gravity by a specific gravity separator, but dry specific gravity separation is preferable since the treatment after the separation of the powders is easy and practical. For example, a centrifugal classifier that classifies particles by swirling or mechanical rotation of an air flow, an inertia classifier that classifies particles by a horizontal non-traveling distance, and a gravity classifier that classifies particles by the difference in their falling speeds and positions. However, centrifugal classification of a type in which classification is performed by swirling an air stream is particularly preferable. For example, Micron Classifier manufactured by Senshin Enterprise Co., Ltd. may be mentioned. Depending on the separation conditions such as the flow velocity of the air flow of the dry gravity separator and the shape of the device at this time, the ratio of the coarse powder and the fine powder to be recovered is different, and if the ratio of the coarse powder is extremely large, the concentration of the metal contained in this will be It is reduced, and it takes time and effort to refine the metal thereafter. Further, if the proportion of fine powder is extremely large, the amount of residual metal components in the fine powder increases, and it becomes difficult to effectively use this fine powder for applications such as fillers such as structural materials and building materials. Therefore, the ratio of the coarse powder to be separated to the whole is preferably 20% by weight or more and less than 70% by weight. It is also possible to combine with a classification operation using an ordinary sieve as a pretreatment or a posttreatment of the specific gravity separation step.

Metals such as copper that can be separated in this way are
Since it is not oxidized, it can be reused as a metal resource with high added value, and the remaining filler such as glass fiber and finely pulverized resin can be effectively used as a filler such as building materials and structural materials.

Experimental data according to the present invention will be described below.

FIG. 1 shows experimental data 1 to 8 and FIG. 2 shows comparative data 1 to 7. As a sample, a printed circuit board made of glass fiber reinforced epoxy resin with a copper pattern (abbreviated as glass epoxy) (composition: copper; 30% by weight, glass fiber;
20% by weight, epoxy resin; 50% by weight), and solder plating on the copper pattern surface of this substrate, and paper with a copper pattern-phenolic resin (paper-abbreviated as phenol) printed circuit board (composition: copper; 30% by weight) %, Paper; 20
% By weight, phenolic resin; 50% by weight, and a component mounting board (the above-mentioned glass epoxy board with a copper pattern and an IC
A package equipped with electronic parts such as a package and a connector (composition: copper; 33% by weight, others: epoxy resin, glass fiber, silica, etc.) was used. As the crusher for the crushing process of these samples, in the Examples, a coarse crusher having a combination of the above-mentioned Orient mill and two-stage Orient mill,
Also, a combination of a shredder and an orient mill was used, and an impeller mill and a two-stage combination of impeller mill were used as a fine pulverizer. Further, in the comparative example, as the coarse crusher, a hammer mill having a mechanism for impact crushing by a rotating hammer, a fixed blade in the chamber and a screen of the discharge part, a combination of the shredder and the hammer mill, and the orient mill are used. As the fine crusher, the above impeller mill,
A ball mill with a mechanism that crushes by dropping balls in a rotating cylindrical chamber, a disk mill that has a mechanism that crushes with opposing pin or groove of a rotating disk, and a vibration mill that has a mechanism that crushes by the vibration of balls in the chamber. Using. All crushers are capable of crushing 100 kg of plastics per hour in a standard manner. Tungsten carbide was used as the material of the crushing section of these crushers. However, the ball mill and vibration mill used alumina balls and chambers, and the shredder used ordinary steel.

The capabilities of the coarse crushers were compared by the time required to crush a 100 kg sample to less than 10 mm. The capacity of the fine pulverizer was compared by the average particle size of the finely pulverized product when the coarsely pulverized sample was pulverized as much as possible under the condition of 100 kg per hour. Abrasion resistance is 100
Tungsten contained in the fine powder after coarsely pulverizing a sample of kg by the combination of the above-mentioned pulverizers and then finely pulverizing was quantitatively compared. The results are shown in Tables 1 and 2.

As the separating step, the centrifugal classifier, the gravity classifier, and the inertia classifier described above are used in the examples. In the comparative example, a mechanism for separating by the generation of eddy current when a magnetic field is applied is used in addition to the centrifugal classifier. We used a normal eddy current separator that we have, and a normal electrostatic separator that has a mechanism to separate by utilizing the difference in charging rate. 1 and 2 show the weight ratio of coarse powder / fine powder and the content ratio of copper in the coarse powder and the fine powder when the crushed sample was separated into coarse powder and fine powder by a separator. As the copper recovery rate, the ratio of the copper content in the coarse powder to the copper content of the entire printed circuit board is shown. These were compared with experimental data and comparative data.

As is clear from the comparison between the experimental data and the comparative data, when the printed circuit board is crushed and the specific gravity is separated in the coarse crushing step and the fine crushing step of the present invention, copper is concentrated in the coarse powder and recovered with high efficiency. In addition, since the amount of copper remaining in the fine powder can be extremely reduced, it can be effectively reused as a filler such as a structural material, a building material, and an insulating material.

[0017]

According to the present invention, the metal and other components can be efficiently separated and recovered from the printed circuit board, the component mounting board, and the molding residue generated at the time of manufacturing these, which has been difficult until now, and is effective as a resource. Can be used effectively.

[Brief description of drawings]

FIG. 1 Experimental data according to the present invention.

FIG. 2 Comparative data.

Claims (3)

[Claims] 1. A printed circuit board, a printed circuit board on which parts are mounted, and a method for separating and recovering valuable materials from a molding residue generated in the manufacturing process thereof, wherein the printed circuit board is crushed in a coarse crushing step and a fine crushing step. Then, by separating the obtained pulverized product into a portion containing a large amount of metal components such as copper by a specific gravity separation step and a portion composed of resin, filler, etc. Recovery method. 2. During the coarse crushing step, a shearing force is applied to the object to be crushed by a cutter that rotates below the charging part and a fixed blade that is installed on the inner wall of the chamber, and the rotating blade that rotates further and the fixing that is installed on the inner wall of the chamber. The separation and recovery of valuables from a printed circuit board according to claim 1, characterized in that a coarse crusher having a mechanism for crushing an object to be crushed by a blade and / or a screen of a discharge part by applying a shearing force and an impact force is used. Method. 3. An object to be ground is moved by an air flow in the axial direction of a rotating rotary blade during the fine grinding step, and impact force and shearing force are ground by the rotary blade and a fixed blade installed on the inner wall of the chamber. A fine crusher having a mechanism of crushing in addition to the product, selectively extracting a pulverized product having a predetermined particle size or less by an air stream, and returning the pulverized product having a predetermined particle size or more to the chamber again is used. Item 1. A method for separating and recovering valuable materials from a printed circuit board according to Item 1.