KR20120139638A - Selective fragmentation system and method using high voltage pulse generator - Google Patents

Abstract

PURPOSE: A selective fragmentation system using high voltage pulse and a method for the same are provided to selectively separate and fragmentize expensive metals from a waste printed circuit board and to improve the concentration rate and the separation degree of metals. CONSTITUTION: A selective fragmentation system(100) includes a high voltage generator(110), a discharging electrode(120), and a discharging apparatus(130). The high voltage generator repeatedly implements charging and discharging operations. The discharging electrode applies high voltages from the high voltage generator to a material(140) to be fragmentized. The discharging apparatus immerses the discharging electrode and the material in water and implements dielectric breakdown. The discharging apparatus includes a water bath(131) and a mesh(132). The water bath collects fragmentized materials. The discharging electrode and the material are arranged on the mesh.

Description

Selective fragmentation system and method using high voltage pulse generator

The present invention relates to a selective shredding apparatus and method using a high voltage pulse, and more particularly to a selective shredding apparatus and method capable of selectively separating metal from a closed printed circuit board using a high voltage pulse generator.

The recycling process for recovering valuable metals from waste electricity and electronic devices consists of crushing, sorting, extraction, separation and refining, and recovery.The main technologies used here are mechanical crushing, wet recovery, and hot melt recovery. It is rough. In particular, more than 90% of wastes such as plastic or metal case except valuable metals can be recycled by simple dismantling and sorting process, but in case of printed circuit board (PCB) containing valuable metals Only through the recovery of valuable metals is possible. Among them, PCB contains Cu, Fe, Ni, Al and Au, Ag, Pd, Pt and other precious metals, so the added value is very high.

Currently, wet and dry methods are mainly used to separate valuable metals from PCBs. In the dry method, an oxidant for separating organic substances and a collecting metal for recovering valuable metals are charged together with scrap and reacted at a high temperature to burn the organic substances and to separate the metals from the remaining slag and metals, and then to the separated metals. It is a method of obtaining valuable metals required through secondary separation and purification. In the dry method, it is not easy to separate the valuable metals from the slag, so it takes a long time to separate the valuable metals, or there is a problem that the separation error of the valuable metals is lowered.

In the wet method, the PCB is crushed into powder, dissolved in acid or caustic soda, and the target metal is separated and concentrated by solvent extraction, chemical precipitation, cementation, and ion exchange. Such a wet method has a problem of injecting a leachate which is corrosive and toxic in order to dissolve because many insoluble substances such as plastics are included.

The present invention provides an apparatus and method for selectively separating metal and plastic from waste PCB.

The present invention provides an apparatus and method for sorting and separating only metals in a crushing process.

The present invention is to provide a continuous shredding device capable of shredding the PCB in a large amount.

One aspect of the present invention is a high voltage generator in which charge and discharge are repeated; A discharge electrode configured to apply the high voltage formed by the high voltage generator to the material to be crushed; And a discharge device in which the discharge electrode and the material to be crushed are immersed in water and the dielectric breakdown is performed by a high voltage discharge. The discharge device includes a water tank for collecting the material and the discharge electrode and the material to be shredded. A selective crushing apparatus comprising a crushing net (ground electrode mesh).

In another aspect, the present invention is a high voltage generator that is repeated charging and discharging; Water tank filled with water; A discharge electrode positioned at one side of the water tank and applying a high voltage formed by the high voltage generator to a material to be crushed; Two or more crushing meshes accommodating the material to be shredded and positioned in the tank, and moved to a lower portion of the discharge electrode to perform dielectric breakdown by high voltage discharge; And a rotating unit for rotating the two or more crushing nets in a water tank to perform discharge contact and separation of the crushed material.

In another aspect, the present invention is a high voltage generator that is repeated charging and discharging; Water tank filled with water; A transport belt for receiving the crushed material and transporting the material to the tank; A transfer unit for continuously circulating the transfer belt; A discharge electrode for applying a high voltage formed by the high voltage generator to the material to be crushed when the material to be crushed on the transfer belt is immersed in a water tank; And an electrode reciprocating device configured to move the discharge electrode and the ground to perform discharge contact and separation with the crushing material.

In another aspect, the present invention provides a method for supplying a crushed material to a transport belt; Transferring the material to be crushed to the tank filled with water by the rotation of the crushing belt; Contacting or approaching the discharge electrode and the ground electrode with the material to be crushed using an electrode reciprocating device; Performing a high voltage pulse discharge on the crushed material immersed in water for a predetermined time using a high voltage generator; A continuous crushing method comprising the step of discharging the remaining material crushed by the high voltage pulse discharge.

The crushing device and method according to the present invention can selectively crush and separate valuable metals from waste PCB. In addition, since the wet treatment and concentration are performed only on the metal separated by the present invention, the concentration and separation are improved as well as the recovery and purity are higher than the conventional method.

The continuous crushing device according to the present invention is economical because it can continuously crush and separate the waste PCB.

1 shows a selective crushing apparatus according to an embodiment of the present invention.
2 illustrates a discharge method in which a separate ground electrode 150 is disposed on the surface of the material to be crushed.
Figure 3 shows a continuous crushing apparatus according to an embodiment of the present invention.
4 shows a continuous crushing apparatus according to another embodiment of the present invention.

The present invention relates to an apparatus and method for selectively separating only metals from a material to be crushed. 1 shows a selective crushing apparatus according to an embodiment of the present invention. Referring to FIG. 1, the selective crushing apparatus 100 according to an embodiment of the present invention includes a high voltage generator 110, a discharge electrode 120, and a discharge device 130.

The high voltage generator 110 is preferably a repetitive high voltage pulse generator in which charge and discharge are automatically controlled. The high voltage generator 110 may have a discharge voltage of 40 to 400 kV, and a discharge time of 0.01 to 1.2 kV, preferably 50 to 500 kV. In more detail, the high voltage generator generates a high voltage discharge pulse of 100 to 500 ns to generate an insulation breakdown of the material to be destroyed, and a repetitive high voltage discharge having a discharge cycle of 0.5 to 20 Hz is required for the continuous processing.

The discharge electrode 120 applies a high voltage formed in the high voltage generator to the material to be crushed.

In the discharge device 130, the discharge electrode and the material to be crushed are immersed in water, and insulation breakdown by high voltage discharge is performed.

The discharge device 130 includes a metal tank 131 for collecting the crushed material and a ground electrode (steel mesh) 132 on which the discharge electrode and the crushed material are placed. The shredding material 140 may be a PCB, a composite material, or a mineral material. The crushed net 132 may be formed of a metal mesh, preferably a wire mesh.

Referring to FIG. 1, the apparatus fills the water tank 131 with a crushing network 132 in which the crushing material 140 is placed in the water tank. In FIG. 1, the shredding network functions as a ground electrode, and as a result, the shredding material is positioned between the discharge electrode and the ground electrode (single point electrode method). When the high voltage formed by the high voltage generator is applied to the material to be crushed through the discharge electrode 120, an electric field is formed on the surface of the material 140 and the interface between the metal sheet and the plastic therein. Since a large current flows back along the electric field formed, insulation breakdown occurs due to thermal expansion and shock waves, which cause the abnormal boundary surface to be destroyed. The distance between the discharge electrode 120 and the shredding network 132 may be in the range of 1 to 200 mm, preferably 10 mm to 200 mm.

2 illustrates a discharge method in which a separate ground electrode 150 is disposed on a surface of the material to be crushed (double point electrode method). In this case, when the high voltage formed by the high voltage generator is applied to the material to be crushed through the discharge electrode 120, an electric field is formed only at the interface between the metal plate and the plastic on the surface of the material to be broken, and a large current flows backward along the electric field, causing thermal expansion and shock waves. This causes insulation breakdown on the abnormal boundary surface. At this time, the distance between the discharge electrode and the ground electrode may be in the range of 5 ~ 50mm.

Figure 3 shows a continuous crushing apparatus according to an embodiment of the present invention. Referring to FIG. 3, the continuous crushing apparatus 200 according to one embodiment of the present invention includes a high voltage generator 210, a water tank 220, a discharge electrode 230, a crushing network 240, and a rotating unit 250. do.

The continuous crushing apparatus 200 of FIG. 3 is a continuous crushing apparatus in which a plurality of crushing nets 240 rotate in a water tank and receive, crush, and discharge the crushing material 260. The high voltage generator 210 and the discharge electrode 230 may refer to the above description.

The tank 220 is filled with water, and breakdown of the insulation by high voltage discharge occurs in the water. The water tank 220 may be a solid non-metallic material, a low corrosive metal or an iron material.

The shredding network 240 accommodates the shredding material and is located in the tank. The shredding net may be provided with one or more, preferably 2-8, more preferably 2-4.

The crushing network 240 may be rotated by the rotating unit 250 to move to the lower portion of the discharge electrode. When the crushing net is transferred directly under the discharge electrode, the crushing net is brought into close proximity with the material to be crushed in the crushing net. When the crushing network 240 is located directly under the discharge electrode, high voltage discharge is performed by the discharge electrode, and as a result, insulation breakdown of the crushing material occurs. At this time, the interval between the material to be shredded and the discharge electrode 230 accommodated in the shredding network 240 may be in the range of 0 ~ 200mm.

The crushing network 240 may form a U or V groove 241 through which the lower end of the discharge electrode may pass at a middle or higher height. The groove 241 allows the crushing net to rotate freely in the tank without disturbing the discharge electrode.

The shredding net 240 receives the shredding material from the storage tank 260 while rotating in the water tank, and the shredding net 240 is inverted and shredded on the discharge part 270 after the dielectric breakdown is completed. Can be sent to the storage 280. The discharge part 270 may serve to transfer the crushed residual material to the storage tank 280 by being fixedly positioned in the water tank.

The shredding net 240 has a metal, preferably a wire mesh structure, has sidewalls of a predetermined height so that the shredding material is not separated. The spacing of the wire mesh is not particularly limited, and may be, for example, 1 to 10 mm.

The rotating unit 250 rotates the two or more crushing nets in a water tank to perform contact and separation with the discharge electrode of the crushed material.

The rotating unit 250 rotates and moves the two or more crushing networks continuously. The rotating unit may include a central axis and a driving motor connected to the crushing net 240. In addition, the rotating part may be connected to the ground terminal and serve as a grounding function together with the crushing net 240 having the wire mesh structure.

The apparatus may include a specific gravity sorter 221 in the lower portion of the water tank 220 to classify the crushed matter passing through the crushing network 240 into a high specific gravity and a low specific gravity.

In another aspect, FIG. 4 shows a continuous crushing apparatus according to another embodiment of the present invention. Referring to FIG. 4, the continuous crushing apparatus 300 according to an embodiment of the present invention includes a high voltage generator 310, a crushing network belt 320, a discharge electrode 330, a ground electrode 340, and a transfer unit 350. And a discharge electrode and a ground electrode reciprocating device 360, a storage tank 370, a storage tank 380, and a water pipe 390.

The continuous crushing apparatus 300 according to FIG. 4 is a continuous crushing apparatus in which the crushing net belt 320 circulates to receive, crush, and discharge the crushed material.

The high voltage generator 310 and the discharge electrode 330 may refer to the above description.

Unlike FIG. 3, in the water tank 320 of FIG. 4, the crushing net belt 320 is immersed by receiving the material to be crushed and immersed in the water tank, and moving out of the water tank again to the discharge unit after the discharge reaction.

The crushed mesh belt 320 receives the crushed material from the storage tank 370 while being circulated by the transfer unit 350, and discharges the crushed material by the dielectric breakdown to the storage tank 380.

The conveyer 350 continuously circulates the crushed belt 320. The transfer part 350 may include a metal conveyor belt and a driving motor. In addition, the belt of the transfer unit is connected to the ground terminal may be grounded together with the crushed mesh belt 320 of the wire mesh structure.

The discharge electrode 330 and the ground electrode 340 discharge the high voltage formed by the high voltage generator to the material to be crushed on the crushed mesh belt 320 submerged in the water tank to induce the crushing of the material.

The electrode reciprocating device 360 moves the discharge electrode and the ground electrode to perform contact (proximity approach) with respect to the material to be crushed and separation. That is, when the crushing network is transferred to the tank, the discharge electrode 330 is moved by the discharge electrode reciprocating device 360 to be in contact with or close to the material to be crushed. The discharge electrode reciprocating device 360 may use any known transfer device or reciprocating device without limitation. For example, the discharge electrode may be moved up and down using hydraulic pressure or a spring. A water inlet 390 for injecting water is installed to smoothly flow the crushed target material.

Referring to FIG. 3, when the crushing network is positioned directly under the discharge electrode in the tank, a discharge structure as shown in FIG. 1 is formed. That is, when the discharge electrode is placed in contact with or close to the shredding material, when the high voltage generated by the high voltage generator is applied to the shredding material through the discharge electrodes 230 and 330, the interface between the surface of the target material and the metal thin plate and the plastic therein. An electric field is formed in the. Since a large current flows back along the electric field formed, insulation breakdown occurs due to thermal expansion and shock waves, which cause the abnormal boundary surface to be destroyed.

On the other hand, even in the case of a continuous shredding device, as shown in Figure 2 may be manufactured in a double point electrode structure to place a separate ground electrode on the surface of the material to be shredded.

The continuous crushing apparatus of FIG. 3 and FIG. 4 has a large capacity for treating crushing because the receiving, crushing and discharging of the crushing material is continuously performed, and thus the economical and commercial use possibility is high.

In another aspect the present invention relates to a method of continuous crushing. The method includes supplying the material to be crushed, rotating or transporting the crushed network, contacting with the discharge electrode, performing discharge, and discharging.

Referring to Figure 3, the continuous crushing method comprises the steps of supplying a material to be crushed into the crushing network; Rotating the crushing net in a water filled tank; Contacting or discharging the discharge electrode with the material to be crushed in the crushing network by rotating the crushing network; Performing a high voltage pulse discharge on the crushed material immersed in water for a predetermined time using a high voltage generator; Rotating the crushing net after the high voltage pulse discharge is completed, moving the upper part of the discharge unit, and inverting the crushing net to discharge the crushed residual material.

Referring to Figure 4, the continuous crushing method comprises the steps of supplying the material to be crushed to the conveying belt; Transferring the material to be crushed to the water filled tank by the rotation of the crushing net belt; Contacting or approaching the discharge electrode and the ground electrode with the material to be crushed using an electrode reciprocating device; Performing a high voltage pulse discharge on the crushed material immersed in water for a predetermined time using a high voltage generator; And discharging the remaining material crushed by the high voltage pulse discharge.

For each of the above steps, reference may be made to the continuous crushing apparatus described above.

Example

The high voltage pulse discharge was performed on the waste PCB by setting the equipment of the structure as shown in FIG. High voltage generator (IVG-80) is a device that is impossible to discharge continuously which takes maximum output voltage 80 (variable), high voltage rise time 1.2 (fixed), maximum charging energy 800, and charging time about 3 seconds. The high voltage generated by the high voltage generator is discharged through the discharge copper electrode, and the voltage generated by the discharge is recorded with time through an attenuator on a digital oscilloscope and the current is recorded through a current monitor and an attenuator. The voltage recorded on the digital oscilloscope is attenuated by 1/5 through the Attenuator, and the current is attenuated twice by 1/5 in the Current monitor and 1/5 in the Attenuator. Therefore, the voltage-current graph was prepared by correcting the voltage 5 times and the current 250 times from the measured voltage-current waveform. A copper electrode having a diameter of 4.8 was used as the discharge electrode, and a crushing net was grounded as the ground electrode.

As an initial preliminary discharge to measure the breakdown voltage and breakdown strength, the voltage-current waveform was measured by increasing the charging voltage from 10 to 20 to 60. Breakdown occurred at a minimum charging voltage of 20, measured voltage was about 15, and current was about 0.05. The measured breakdown voltage is the breakdown voltage of the applied voltage sample, and the breakdown strength is calculated by dividing the breakdown voltage by the thickness of the sample. The dielectric breakdown strength of the PCB calculated in this experiment is 15.

Table 1 shows the charging voltage and the maximum applied voltage and current. As the charging voltage increases from 20 to 10, the applied voltage supplied between the electrodes also increases. In addition, it can be seen that the value of the maximum current flowing backward which causes insulation breakdown also increases as the charging voltage increases. In addition, when the charging voltage was 60, the utilization rate was close to 80%, and the applied voltage and generated current of 68 were nearly equal to 60. Therefore, 60 was selected as the best charging voltage for crushing.

Charge voltage (kV) 20 30 40 50 60 68 Applied voltage (kV) 15.7 23.6 22.7 30.7 47.0 46.0 Current value (kA) 0.049 0.082 0.10 0.133 0.155 0.183

Crushing test

As a sample, a PCB separated from PH-K2700C mobile phone model (Polder type) released by Pantech in 2004 was used, and the test was performed by discharging the charging voltage at 60 times 100 times. PCB's weight before shredding was 11.13, width and length were 39.00 and 79.83, respectively, and the weight after shredding was 9.52, about 1.61. The weight of the shredding product (+2) remaining in the shredding net was about 0.89, and the weight of the shredding product (-2) passed through the shredding mesh was about 0.7.

X-ray CT analysis was performed by dividing 0.7 g of -2mm crushed product into two groups, and the metal content calculated from the analysis image was about 27 vol% (30.6 vol%, average value of 24.7 vol%). That is, the weight of the metal component in the −2 mm crushed product was about 0.189 g.

While the above has been described in detail with reference to a preferred embodiment of the present invention, this description is merely to describe and disclose an exemplary embodiment of the present invention. Those skilled in the art will readily recognize that various changes, modifications and variations can be made from the above description and the accompanying drawings without departing from the scope and spirit of the invention.

100: crushing device 110: high voltage generator
120: discharge electrode 130: discharge device
140: crushing network 150: grounding electrode
200: continuous crushing device 210: high voltage generator
220: water tank 230: discharge electrode
240: shredding network 250: rotating part
260: material to be shredded
300: continuous shredding device 310: high voltage generator
320: crushing net belt 330: discharge electrode
340: ground electrode 350: transfer unit
360: reciprocating device 370: reservoir
380: storage tank 390: water pipe

Claims (14)

High voltage generator with repeated charging and discharging;
A discharge electrode configured to apply the high voltage formed by the high voltage generator to the material to be crushed; And
And a discharge device for immersing the discharge electrode and the material to be crushed in water and performing dielectric breakdown by a high voltage discharge, wherein the discharge device includes a water tank for collecting the material to be crushed and a crushed material in which the discharge electrode and the material to be crushed are placed. Crushing device comprising a mesh (mesh). High voltage generator with repeated charging and discharging;
Water tank filled with water;
A discharge electrode positioned at one side of the water tank and applying a high voltage formed by the high voltage generator to a material to be crushed;
Two or more crushing meshes accommodating the material to be shredded and positioned in the tank, and moved to a lower portion of the discharge electrode to perform dielectric breakdown by high voltage discharge;
And a rotating unit rotating the two or more crushing nets in a water tank to perform discharge contact and separation of the crushed material. High voltage generator with repeated charging and discharging;
Water tank filled with water;
Two or more crushing meshes for receiving the crushed material and transporting the crushed material to the tank;
A transfer unit for continuously circulating the two or more crushing nets;
A discharge electrode configured to apply a high voltage formed by the high voltage generator to the material to be crushed when the crushing network is immersed in a water tank;
A discharge electrode reciprocating device which moves the discharge electrode to perform discharge contact and separation with the material to be crushed;
Crushing apparatus comprising a. The crushing device of any one of claims 1 to 3, wherein the high voltage generator has a discharge voltage of 4 kV to 400 kV, a voltage rise time of 0.01 to 1.2 kV, and a discharge period of 0.5 to 20 Hz. The crushing device according to any one of claims 1 to 3, wherein the material to be crushed is a printed circuit board (PCB), concrete or rock material. The crushing apparatus according to any one of claims 1 to 3, wherein the crushing net is formed of a wire mesh. The method of claim 2, wherein the shredding net is supplied from the reservoir to the material to be shredded while rotating in the tank, and the shredding net is inverted at the top of the discharge part after the breakdown of the insulation is completed to send the remaining shredded material to the storage tank. Crushing device made. 4. The crushing apparatus according to claim 2 or 3, wherein the apparatus includes a specific gravity sorter at the bottom of the water tank for classifying the crushed matter that has passed through the crushing network into a high specific gravity and a low specific gravity. The crushing apparatus according to claim 3, wherein the crushing net receives the crushed material from the storage tank while being circulated by the conveying unit, and discharges the crushed material by the dielectric breakdown into the storage tank. The crushing device of claim 2, wherein the rotating part comprises a rod of metal, and the rod is connected to a ground terminal. 4. The crushing apparatus according to claim 3, wherein the conveying part is a metal belt, and the conveying part belt is connected to a ground terminal. Supplying the material to be shredded into a shredding network;
Rotating the crushing net in the water filled tank;
Rotating the crushing network to bring a discharge electrode into proximity with the crushed material in the crushing network;
Performing a high voltage pulse discharge on the crushed material immersed in water for a predetermined time using a high voltage generator;
Rotating the crushing net after the high voltage pulse discharge is completed, moving the upper part of the discharge unit, and inverting the crushing net to discharge the crushed residual material. The method of claim 12, wherein the shredding network is a wire mesh structure having a side wall of a predetermined height so that the material to be shredded off, and the distance between the wire mesh is 1 ~ 200mm, characterized in that the continuous shredding method. 13. The method of claim 12, wherein the high voltage generator has a discharge voltage of 4 kV to 400 kV, a voltage rise time of 0.01 to 1.2 kV, and a discharge period of 0.5 to 20 Hz.

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