JPS5952695B2 - Method for separating copper components from printed circuit board waste - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention generally relates to printed circuit boards that are produced in the manufacturing process of printed circuit boards in which a thin copper plate is bonded to an insulating laminate made of a phenolic resin molding material, or that are disposed of as part of industrial waste. This invention relates to a method for separating copper components from substrate waste.

There is a considerable amount of waste printed circuit boards (hereinafter simply referred to as raw materials) produced as a part of defective products and uncut parts resulting from the printed circuit board manufacturing process, or as part of industrial waste generated from home appliances and other forms. Conventionally, these raw materials were incinerated to recover only the copper component, but incineration poses a risk of generating secondary pollution sources such as air pollution and bad odors. Due to the incineration, the copper component became contaminated and deteriorated, and the quality of the recovered copper component significantly deteriorated.

In another conventional technique, a separate known pulverizer and a known classifier/separator are combined to separate the copper component from the raw material, which is pulverized to an appropriate particle size and then passed through a separately equipped classifier/separator.

However, in this case, since there is a conveyance distance between the crusher and the classifier, extra energy is required for conveyance, and particularly important substances such as copper components are transported at the bottom of the pneumatic pipe in the conveyance route. In addition, excessive amounts of equipment and power were wasted to solve these problems, and the separation of the printed circuit board and copper component was extremely inefficient.

Therefore, the present invention attempts to eliminate the above-mentioned drawbacks of the conventional method by using a highly efficient crusher and classifier and a foreign matter discharge port attached thereto that is effective for copper sorting. explain. In FIG. 1, 29 is a crusher/classifier, and a feeder 32 is connected to the upper part of the supply port 3 provided on one side of the crusher/classifier 29, and a raw material hopper 33 is connected to the upper part of the feeder 32. The crusher and classifier 29
A pipe 36 communicating with a separator 30 is connected to the fine powder outlet 8 provided on the other side, and the exhaust from the separator 30 is sent to a wind turbine 31.
The gas is connected by a pipe 37 forming a circulation path so that the gas is circulated through a flow rate control valve 34 and back to the supply port 3 of the crusher/classifier 29, and 35 is a flow rate control valve that controls a part of the gas flow in the circulation path. This is for adjusting the amount of gas passing through the exhaust pipe 38 for release outside the circulation path. Reference numeral 21 attached to the crusher/classifier 29 is a foreign matter discharge port, which is connected to the feeder 32.
is a screw type or other known feeder, and separator 3
0 is a cyclone, a bag filter, or the like for separating the fine powder particles carried out with the airflow from the fine powder outlet 8 and taking them out of the circulation path.

Note that the crusher/classifier is rotationally driven by an electric motor or the like (not shown). Next, in FIGS. 2 to 4, reference numeral 1 denotes a rotating crushing impeller, and a disk-shaped rotating holding arm 11 fixed to the rotating shaft 10.
2 is a crushing chamber formed in an annular shape that includes the rotation locus of the rotary crushing impeller 1; A liner 12 having a serrated crushing surface 12a is provided on the wall surface. Reference numeral 13 denotes a casing which includes the rotation shaft 10, rotation holding arm 11. It is integrally constructed to surround the rotary crushing impeller 1, and is connected to a feed port 3 for raw materials and the like.

Reference numeral 4 denotes a partition wall, one side of which faces the grinding chamber 2 via a movable plate 17, which will be described later, and the other side of which faces the centrifugal classification chamber 7, which will be described later. A passage 5 is formed between the centrifugal classification chamber 7 and the crushing chamber 2.
are concentrically adjacent to each other, the axial center of which is connected to the fine powder outlet 8, and the outer end of the guide vane 6 is communicated with the passage 5 through guide vanes 6 arranged at regular intervals around the outer periphery. The diameters of the outer periphery of the crushing chamber 2 and the passage 5 and the outer end portion of the guide vane 6 are formed to be approximately the same size, and the inclined guide surface 6a of the guide vane 6 is set at a certain arbitrary angle θ with respect to the axial direction. It is configured to be easy to use.

Further, a reducing passage 9 communicating with the axial center of the grinding chamber 2 is provided in the partition wall 4 near the inner periphery on the axial center side of the guide vane 6 in a uniform state over the entire circumference, and 17 is a movable plate with a handle. The degree of opening of the annular passage 9 can be adjusted from outside the machine by means of a shaft 19 and a handle 18. 20 is a groove having a uniform depth d1 all around the liner 12 near the passage 5;
Alternatively, it is provided in the casing 13, a foreign matter discharge port 21 is bored in a part of the groove 20, and connected to the foreign matter removal mechanism 25, and in the drawing, it is connected to the screw outer cylinder 23, and foreign matter is discharged by rotation of the screw 22. The foreign particles guided to the outlet 21 can be taken out of the machine, and the damper 24 is a screw type as shown in the figure, or an electromagnet can be used to open/close the foreign particle outlet 21 or adjust the opening. It is considered possible.

Further, reference numeral 16 is used to arbitrarily adjust the angle θ of the guide vane 6 by rotating the ring 15 with an operation stick. (The arrows in the drawings indicate the flow direction of airflow and raw materials, and the movement of the main components.) In the above embodiments,
First, a raw material coarsely crushed by a separately prepared known crusher or the like is prepared so as to be supplied to the crusher/classifier 29, and is introduced into the hopper 33.

Next, the crusher/classifier 29 and the windmill 31 are operated, and the feeder 32
is operated to quantitatively supply the raw material through the supply port 3 to the crusher and classifier 29 together with the gas flow in the circulation path. In the crushing chamber 2 of the crusher and classifier 29, the raw material is first crushed by the rotary crushing impeller 1, and then the raw material is crushed by the crushing surface 12a.
The raw material is subjected to secondary pulverization by being hit by a pulverizer, and by repeatedly undergoing these pulverizing actions, the raw material becomes a fine powder.

On the other hand, the rotation of the rotary crushing impeller 1 causes the air in the crushing chamber 2 to swirl, and as a result of the centrifugal force, the axial center becomes negative pressure and the outer circumference becomes positive pressure, which is sucked together with the raw material from the supply port 3. Air is pushed out of the machine from a passage 5 through a guide vane 6 and a classification chamber 7 through a fine powder outlet 8, but some of the air passes through a return passage 9 and is returned to the axial center of the crushing chamber 2. Therefore, the normal pulverized raw material is pushed out from the passage 5 in the direction of the guide vane 6, and is guided by the inclined guide surface 6a of the guide vane 6, and the rotational movement is braked, and at the same time, it is rotated in a predetermined rotation direction and speed. A centripetal velocity component is imparted to it and sent to the classification chamber 7. In this state, the rotational centrifugal force of the airflow and the centripetal force toward the center are balanced, and a classification action occurs with a certain particle size (limit particle size) as the boundary, and the coarse particles have a force that moves them toward the outer circumference. The particles are given a force to move toward the center. Then, the coarse particles are returned to the grinding chamber 2 along with the circulating air flowing toward the grinding chamber 2 through the reduction passage 9 and are re-pulverized, and the fine particles are removed from the fine powder outlet 8 provided in the center of the classification chamber 7. taken out to the outside. In a crushing/classifying machine that performs the crushing and classifying functions at the same time as described above, a foreign matter discharge port 2 is provided between the crushing mechanism and the classifying mechanism.
1 is provided to take out the copper component mixed in the raw material out of the system, and this will be explained in detail below. Due to the rotation of the rotary crushing impeller 1, coarse particles subjected to a large centrifugal force rotate around the radially outermost end of the crushing chamber 2, but copper component particles having a high specific gravity are moved by the guide vanes 6 or the inclined guide surface 6a. Therefore, it is difficult to apply a centripetal component with a predetermined rotation direction and speed, and even if a centripetal component is applied, it is classified in the centrifugal classification chamber 7 and circulated back into the crushing chamber 2, so the passage 5 It will be mostly distributed around .

Therefore, by providing the foreign matter discharge port 21 in this part, the copper component particles guided here are not affected by the swirling airflow in the crushing chamber 2, and can be taken out of the system one by one, making it extremely easy to remove them. Copper component particles can be separated. In FIG. 4, a groove 20 having a uniform depth is provided along the entire circumference of the inner peripheral wall of the crushing chamber 2 near the passage 5, and a foreign matter discharge port 21 is provided in a lower part of the groove 20, so that a foreign matter discharge port 21 is provided in a lower part of the groove 20. This effectively guides the copper component particles, which tend to twist and swirl, to the foreign matter discharge port 21. Although not shown, in consideration of the influence of gravity, the depth of these grooves is made shallower in the upper part.
It is also effective to make the lower part deeper and provide the foreign matter discharge port 21 at the deepest part. Further, as shown in FIG. 5, the copper component can be effectively separated by providing grooves 20a that gradually become deeper in the direction of rotation of the airflow shown by the arrows only in the vicinity of the foreign matter discharge port 21. Note that the damper 24 is adjusted to open and close as appropriate depending on the proportion of copper component in the raw material, the degree of difficulty of crushing, and other conditions, but it can be opened and closed intermittently, such as when the amount of copper component is small. can also achieve that purpose.

As detailed above, according to the present invention, the contamination of copper components and the inability to recover phenolic resin due to incineration, which was performed to separate copper components from printed circuit board waste materials, have been improved, and the contamination caused by incineration has been completely eliminated. It is now possible to recover high-purity copper components, which are rare, and the phenolic resin can be recovered.Moreover, since the phenolic resin is recovered in the form of a fine powder, post-processing such as blending for recycling is easy, and it is easy to incinerate. In addition to not being a source of secondary pollution, the product has a high recovery rate for both phenolic resin and copper components, and has excellent separation effects.
The equipment is compact, saving unnecessary power, and has excellent power efficiency.Since the crushing and classifier are operated all at once, the crushing and separation operations are stable, and the entire device is very easy to operate. The present invention is industrially extremely useful.

[Brief explanation of the drawing]

Fig. 1 is a schematic explanatory diagram of an embodiment of the present invention, Fig. 2 is a sectional view of the main part of Fig. 1, Fig. 3 is a sectional view taken along line AA'' in Fig. 2, and Fig. 4 is a sectional view taken along line BB in Fig. 2. "Cross-sectional view" FIG. 5 is a cross-sectional view showing another embodiment of the portion C in FIG. 4. In the figure, 1... Rotating crushing impeller, 2...
... Grinding chamber, 3 ... Supply port, 5 ... Passage, 6 ... Guide vane, 8 ... Fine powder outlet, 9 ... - Ring source passage, 21... Foreign matter discharge port, 24... Damper 29... Pulverizer and classifier.

Claims (1)

[Claims] 1. When separating copper components from printed circuit board waste, a crushing section consisting of a crushing chamber 2 equipped with a supply port 3 on one side and a built-in rotary crushing impeller 1 rotatably supported, and a crushing section adjacent to the crushing section are used. Fine powder outlet 8 provided, guide vane 6 around the outer periphery
, an annular passage 9 around the inner axial center of the guide vane 6 communicating with the axial center of the grinding chamber 2, and a passage communicating with the outer periphery inner wall of the grinding chamber 2 around the outer periphery of the guide vane 6. 5
This method uses a crusher and classifier 29 comprising a centrifugal classifier equipped with a centrifugal classifier and a foreign matter discharge port 21 equipped with a damper 24 that can be opened and closed at will near the passage 5. How to separate.