JP2000219921A - Method and apparatus for recovering solder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus for recovering a solder from pulverized pieces of waste printed circuit boards, etc. SOLUTION: A solder recovering apparatus comprises a feeder 1 to successively feed solder pieces generated by pulverizing wastes and pulverized pieces of other materials, a belt 5 which is rotated with the solder pieces and pulverized pieces from the feeder 1 placed thereon, a heating part 6 which heats the solder pieces and the pulverized pieces in the upstream of the belt 5 to melt the solder pieces, and deforms the molten solder into spherical solder grains by the surface tension, a cooling part 25 which cools the solder grains 10 in the downstream of the belt 5 and solidifies the spherical solder grains, a belt 7a which receives the spherical solder grains 10 and the pulverized pieces 11 dropping from a tip of the belt 5, and is rotated in an upwardly inclined direction, and a solder recovering container 8 arranged in the vicinity of a lower end of the belt 7a, the pulverized pieces 11 are carried to the upward direction of the belt 7a, and the spherical solder grains 10 are rolled in the downward direction and recovered in the solder recovering container 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for crushing wastes composed of a plurality of materials including solder and electrical components such as boards and elements, such as discarded printed circuit boards, and then removing harmful substances from the crushed pieces. The present invention relates to a method and an apparatus for effectively collecting solder including solder.

[0002]

2. Description of the Related Art Conventionally, waste industrial products in which a mounted printed circuit board including solder such as home electric appliances and personal computers are incorporated are recycled in a recycling system of a processing company or a local government.
It is first crushed and then the iron is recovered by a magnetic separator.
Further, non-ferrous metals such as copper, aluminum and zinc are recovered by an eddy current sorter or the like. However, other crushed pieces mixed with plastics, printed boards, and the like collected on the non-metal side are mostly sent to landfill processing as shredder dust. However, recently, since solder containing harmful lead has adhered to printed circuit boards, shredder dust cannot be landfilled in conventional stable landfills, and landfilling in controlled landfills is obligatory. Have been. However, the lack of managed landfills has made disposal more difficult.

[0003] Therefore, solder containing harmful substances is recovered from these shredder dusts, and other crushed pieces are sorted and recovered by material, thereby promoting the recycling of waste materials, reducing the volume of landfilled dust, and shrinking landfilled shredders. Detoxification of dust becomes possible.

Here, as a method for recovering the solder containing lead, which is a harmful substance, which adheres to the mounting board or the like, after dissolving in a chemical such as hydrochloric acid, the solder is brought into contact with a metal having a higher ionization tendency than lead and tin. There is a method of depositing metallic lead and metallic tin.
There is also a method of separating valuable materials such as copper from resin, glass, and the like by crushing to 0.5 to 5 mm and classifying the particles to a size of 45 to 300 μm. However, in these methods for recovering solder by dissolving in a chemical such as hydrochloric acid, for example, the method for recovering the solder is based on a chemical reaction, so the melting process is slow, and a large amount of processing is performed. Since the capacity of the reaction tank becomes large and equipment such as waste liquid treatment is required, the apparatus becomes large-scale. In addition, there is a problem that the management of the chemical concentration, the temperature, and the like are always required, and the operation and management of the apparatus are very troublesome.

[0005] In the method of pulverizing and classifying according to the particle size, copper and resin / glass can be separated when only a substrate not containing solder is selected, but when solder is further included like a mounting substrate. , Solder and copper have specific gravity (specific gravity of copper 8.9,
Sorting is difficult because there is no great difference in the specific gravity of the solder 8-9). In addition, there is a problem that a large amount of energy is required due to the necessity of fine grinding in processing.

[0006]

SUMMARY OF THE INVENTION According to the present invention, it is possible to easily recover a solder containing a harmful element from a crushed piece of waste including a soldered component such as a mounted printed circuit board. An object of the present invention is to provide a method and an apparatus for collecting solder.

[0007]

In order to achieve the above object, a method of recovering solder according to the present invention is to transport various types of crushed pieces in which crushed pieces of solder and crushed pieces of different materials are mixed together. While heating above the melting point of the solder, the molten solder is deformed into spherical particles by its surface tension, cooled and solidified, and the crushed pieces cooled together with the spherical solder particles are transferred to the inclined plate, and the inclined plate is crushed. The method is characterized in that the piece is operated so as to move upward along the inclined plate, and the spherical solder particles are dropped down along the inclined plate and collected.

[0008] In order to achieve the above object, a first solder recovery apparatus of the present invention comprises a supply means for sequentially supplying a piece of solder generated by crushing waste and a piece of crushed material different from solder, and A first conveyor belt that rotates with the solder pieces and the crushed pieces from the supply means, and heats the solder pieces and the crushed pieces above the melting point of the solder in an upstream region of the first conveyor belt to melt the solder pieces; Heating means for deforming into spherical solder particles by surface tension of molten solder;
Cooling means for solidifying the spherical solder particles by cooling in the downstream area of the conveyor belt; and receiving the spherical solder particles and crushed pieces falling from the downstream area end of the first conveyor belt and rotating in the upward inclined direction. And a solder collection container disposed near the lower end of the second conveyor belt, and the crushed pieces are conveyed in the upward direction of the second conveyor belt, and the spherical solder particles solidified in the downward direction are removed. It is characterized by falling down. In the first solder collecting device, the crushed pieces having projections and the like are easily retained on the second conveyor belt, and thus are carried above the belt and fall from the upper end of the belt, while the smooth spherical solder particles are removed from the second conveyor belt. It easily falls down and is collected in a solder collection container.

In the above-mentioned solder collecting apparatus, instead of the second conveyor belt rotating in the upwardly inclined direction, a vibration feeder including an inclined table and vibrating means for vibrating the inclined table in the inclined direction may be used. According to this vibration feeder, the crushed pieces having the projections and the like are moved in the upward direction of the inclined table, but the smooth spherical solder particles easily fall down in the downward direction of the inclined table and are collected in the solder collection container.

[0010] The second solder recovery apparatus of the present invention is a supply means for sequentially supplying a solder piece generated by crushing a waste product and a crushed piece of a material different from that of the solder, and a solder piece and a crushed piece from the supply means. A vibrating feeder comprising: a first descending inclined table which is received before descending; a second descending inclined table following the first descending inclined table; and a vibrating means for vibrating the first and second descending inclined tables forward with an upward inclination. Heating means for heating the solder pieces and crushed pieces on the first descending slope above the melting point of the solder to melt the solder pieces and transform them into spherical solder particles by the surface tension of the melted solder; and Cooling means for cooling the crushed pieces and the spherical solder particles conveyed to the second descending inclined table to solidify the spherical solder particles, and receiving the spherical solder particles and the crushed pieces falling from the second descending inclined table and ascending upward. Transport rotating in the direction And a solder collection container arranged near the lower end of the conveyor belt, and conveys crushed pieces in the upward direction of the conveyor belt, and falls down solidified spherical solder particles in the downward direction. . In the second solder collecting device, the solder particles and crushed pieces on the first and second descending inclined platforms are sent downward along each inclined platform by the vibration of the vibration means. The transport belt here has the same configuration as the second transport belt of the first solder collection device.

In the second solder collecting device, instead of the conveyor belt rotating in the upward and inclining direction in order to separate the solidified spherical solder particles and crushed pieces, a third downward inclining table and this third downward inclining table are used. A vibration feeder including vibration means for vibrating the inclined table in the direction of inclination may be used.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a solder collecting apparatus according to the present invention will be described with reference to FIGS. The material to be processed by the solder collecting apparatus of the present invention is obtained by crushing a printed circuit board or the like having a large number of solder joints by a crusher or a crusher (description omitted). Plastic sections, copper sections, aluminum sections, etc.). The crushed pieces have a size (5 mm or less) in which heat can be easily transmitted to the solder inside the crushed pieces in a short time in the heating step in the solder collecting device. The solder pieces are also one kind of crushed pieces, but here, they are handled as solder pieces in order to distinguish between solder and crushed pieces made of different materials.

<First Embodiment> FIG. 1 shows an overall configuration of a solder collecting apparatus according to a first embodiment of the present invention. The solder collecting apparatus according to the first embodiment includes a supply device 1 (supplying means) having a hopper 2 for storing solder pieces and crushed pieces at an upper portion and a supply guide 3 for solder pieces and crushed pieces at a front portion, and a supply guide 3. A belt 5 (first transport belt) for transporting the supplied solder pieces and crushed pieces, a heating unit 6 installed near the belt back surface in an upstream area of the belt 5 and transforming the solder pieces into spherical particles, and a belt 5 In the downstream area, a solder melting and solidifying device 4 which is provided near the back surface of the belt and solidifies spherical solder particles, and receives the solder particles and crushed pieces falling from the tip of the downstream area of the belt 5. A sorting device 7 including a belt 7a (second conveyor belt) that is inclined at an angle θ and rotates above the inclined surface to sort them, and a collection container 8 that is installed below the lower end of the belt 7a and that collects solder particles. ( And Sunda collection container), a collecting container 9 disposed below the belt 7a upper recovering fragments, and a.

Next, the operation of the solder collecting apparatus according to the first embodiment will be described. The supply device 1 supplies the solder pieces and crushed pieces put into the hopper 2 to the solder melting and solidifying device 4 by a predetermined amount from the supply guide 3 at the tip. In the solder melting and solidifying device 4, the solder pieces and the crushed pieces carried on the belt 5 in the upstream area of the belt 5 are heated to a solder melting point or higher by the heating unit 6 to melt the solder pieces. Further, the molten solder is gradually transformed into spherical solder particles 10 by the surface tension of the molten solder itself, and the belt 5
Of the crushed pieces 11 and the solder particles 10 conveyed on the belt 5 in the downstream region of the
0 solidifies. During this time, since the crushed pieces 11 do not melt, they keep the shape as they are charged. In the sorting device 7,
Among the crushed pieces 11 and the spherical solder particles 10 that have fallen on the conveyor belt 7a rotating above the inclined surface, the spherical solder particles 10 are transferred to the collection container 8 installed below the sorting device 7 in order to roll down the slope. On the other hand, the crushed pieces 11 have a protruding sharp-angled surface while being crushed, so they stop rolling on the transport belt, are transported upward by the rotating transport belt 7a, and are provided below the upper end of the transport belt 7a. Collected in the collected container 9. Here, the inclination direction of the conveying belt 7a inclined by the sorting device 7 is such as shown in FIG.
It may be perpendicular to the transport direction of the coagulation device 4 or may be parallel. An example of the solder heating temperature is as follows.
% -Pb 40%, melting point 190 ° C., specific gravity 8.5, and 270 ° C.

FIG. 2 shows a sketch of each shape of a piece of solder and a crushed piece of another material to be processed by the solder collecting apparatus of the present invention. FIG. 2 (a) shows the solder pieces and crushed pieces (copper pieces,
FIG. 2 (b) shows solder particles and copper pieces after heating and cooling. Before and after heating and cooling, the solder deforms from an uneven or angular shape to a spherical round particle, but the copper crushed piece hardly changes the uneven or angular shape.

Next, the solder melting and solidifying apparatus 4 will be described in detail with reference to FIG. The solder melting / solidifying device 4 is constituted by a belt 5, and performs the melting of the solder in the heating unit 6 and the solidification of the solder in the cooling unit 25 in the conveyance and conveyance of the solder pieces and crushed pieces. Further, a heater 26 (heating means) is provided in the heating section 6.
And generate heat when energized from the power supply 12.
Further, the heating unit 6 is provided with a member having a large heat capacity such as a metal body 27 on the back side of the belt to stabilize the heating temperature,
The efficiency of heat transfer to the belt surface 5 is improved. Auxiliary rollers 17 are provided before and after the heating unit 6, respectively, and furthermore, contact between the surface of the belt 5 and the heating unit 6 and stabilization of the belt conveyance are achieved. Here, the belt 5 can be made of a metal such as nickel or a resin such as silicone rubber or polyimide having good heat conductivity and heat resistance and strength. The cooling unit 25 may be provided with a space to cool the belt 5 by natural cooling as a cooling means. However, in order to increase the belt speed and increase the processing speed, the cooling unit 25 is provided with the cooling fan 13 (cooling). Means) and forcibly cooling is more effective. Further, when the heat insulating cover 15 is provided around the heat generating portion 6 to prevent heat loss of the heating portion 6 due to heat radiation to the surroundings, the heat loss can be minimized. Insulation cover 1
5 is provided with an inlet 16 for crushed pieces.

<Second Embodiment> A solder recovery device according to a second embodiment of the present invention includes a supply device 1, a solder melting and solidifying device 4, a sorting device 7, and a solder particle constituting the solder recovery device of the first embodiment. In this embodiment, the solder melting / solidifying device 4 is replaced with a device having another structure. As shown in FIG. 4, the solder melting and solidifying apparatus 4 used in the second embodiment includes a metal descending ramp board 14 (first descending ramp) and a heater 26 installed on the back side of the descending ramp board 14. Heating section 6 composed of (heating means)
A cooling unit 25 including a cooling guide 24 (second downward inclined table) installed at the same inclination following the downwardly inclined road plate 14 and a cooling fan 13 (cooling means) installed behind the cooling guide 24; The vibration feeder 20 is configured to vibrate the descending inclined road plate 14, the cooling guide 24 together with the heater 26 and the cooling fan 13 forward and incline upward. Above the ramp board 14, a heat insulating bar 15 is provided.

In this solder melting and solidifying device 4,
After the solder pieces and the crushed pieces supplied from the supply device 1 shown in FIG. 1 fall on the downward sloped road plate 14, they are conveyed below the inclined surface by the vibration of the vibration feeder 20 while being heated by the heater 26. During this time, the solder pieces and crushed pieces are heated to a temperature equal to or higher than the melting point of the solder, and the solder pieces are melted. The melted solder rolls down the inclined surface while becoming spherical by its own surface tension. In addition, since the crushed pieces 11 of other materials remain in a crushed projection shape without melting, they are not rolled by the inclined heating section 6 and are sent along the downwardly inclined surface by the feed of the vibration feeder. Next, when the cooling guide 2 passes through the heating unit 6, the cooling guide 2 is provided with a gap in front thereof.
On 4, the solder 10 solidifies in a spherical or spherical shape. Thereafter, the solder 10 is sent to the sorting device 7 in the same manner as in FIG. 1, and the solder 10 is separated from the crushed pieces 11 of other materials. Also,
When the heat insulating cover 15 is provided in the heating unit 6, heat loss can be prevented. Further, if the cooling fan 13 is provided in the cooling unit 25, the cooling effect is increased, and high-speed processing can be performed. The reason why the gap is provided between the heating unit 6 and the cooling guide 24 is to prevent heat conduction between the two units and increase the heating efficiency of the heating unit and the cooling efficiency of the cooling unit.

<Third Embodiment> A solder collecting device according to a third embodiment of the present invention includes a supply device 1, a solder melting / solidifying device 4, a sorting device 7, and a solder particle constituting the solder collecting device of the first embodiment. The sorting device 7 is replaced with a device having another structure among the collecting container 8 and the crushed piece collecting container 9 described above. As shown in FIG. 5, the sorting device 7 used in the third embodiment includes a guide plate 19 (third downwardly inclined table) that is inclined downward at an angle θ and a vibrator 21 that vibrates the guide plate 19 in the inclination angle direction. (Vibration means)
And a base for supporting the vibration feeder 20 from below via a spring 22.

In this sorting device 7, the solder melting and melting
The spherical solder particles 10 and the crushed pieces 11 are conveyed on the belt 5 of the coagulating device 4, and the inclined guide plate 19 on the vibrating feeder 20 is sequentially moved by a predetermined amount by the inclined guide 18.
Fall on. The guide plate 19 inclined downward is provided with a vibrator 21.
Vibrates in an oblique vertical direction with respect to the inclined surface, that is, in the direction of the arrow shown on the vibrator 21. The guide surface 19 of the vibrating feeder is provided with, for example, a V-shaped groove in the longitudinal direction, and when the solder particles and the crushed pieces fall on the guide surface 19 of the vibrating feeder 20 that vibrates obliquely up and down, a spherical solder particle is formed. 10 bounces on the guide plate 19, then rolls down on the guide plate 19 and is collected in the collection container 8 provided below. On the other hand, the crushed pieces 11 having projections made of other materials drop or fall upon the guide plate 19 of the vibrating feeder 20, but they eventually stop in the groove, and thereafter are fed by the vibrating feeder 20. The slant is sent upward, and is collected in the collection container 9 installed below the end above the inclined guide 19.

[0021]

According to the present invention, the solder collecting method or apparatus is heated while conveying the solder pieces generated by the crushing of the waste and the crushed pieces of other materials from the solder, so that the solder pieces are melted, cooled and solidified. In the process, the molten solder is deformed into spherical particles by the surface tension of the molten solder, the cooled spherical solder particles and crushed pieces are transferred to the inclined plate, and the crushed pieces are moved upward along the inclined plate by the conveying operation of the inclined plate. Spherical solder particles are configured to fall down along the inclined plate and collected, so that smooth spherical solder particles and non-slip crushed pieces having protrusions and the like can be easily separated due to their difference in shape, and the solder particles can be easily separated. Can be easily collected. In addition, by utilizing the shape difference according to the present invention, it is possible to easily separate both solder and copper having a specific gravity close to each other in the form of spherical solder particles and crushed pieces of copper.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram illustrating a solder recovery device according to a first embodiment of the present invention.

FIG. 2 is a sketch diagram showing solder grains and copper crushed pieces before and after processing by the solder recovery apparatus of the present invention.

FIG. 3 is a view showing a solder melting and solidifying apparatus constituting the solder collecting apparatus according to the first embodiment of the present invention.

FIG. 4 is a view showing another solder melting and solidifying apparatus constituting a solder collecting apparatus according to a second embodiment of the present invention.

FIG. 5 is a diagram showing a sorting device constituting a solder collecting device according to a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Supply apparatus 2 ... Hopper 3 ... Supply guide 4 ... Solder melting and solidification apparatus 5 ... Belt 6 ... Heating part 7 ... Sorting apparatus 8 ... Collection container, 9 ... Collection container, 10 ... Solder 11 ... Fragment of other material DESCRIPTION OF SYMBOLS 13 ... Cooling fan 14 ... Downward slope road plate 18 ... Inclination guide 19 ... Guide plate 20 ... Vibration feeder 21 ... Exciter 24 ... Cooling guide 25 ... Cooling part 26 ... Heater

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tetsuro Miyamoto 502, Kandate-cho, Tsuchiura-shi, Ibaraki Pref. Machinery Research Laboratory, Hitachi, Ltd. Inside the Machinery Division

Claims (5)

[Claims] 1. While heating a solder piece and a crushed piece of solder and another material generated by crushing of a waste product, the solder piece is heated to a temperature equal to or higher than the melting point of the solder, and the molten solder is deformed into spherical particles by its surface tension. The crushed pieces cooled together with the spherical solder particles are transferred to an inclined plate, and the inclined plate is operated so that the crushed pieces move upward along the inclined plate, and the spherical solder particles are moved along the inclined plate. A method of recovering solder by dropping and collecting. 2. A supply means for sequentially supplying solder pieces generated by the crushing of waste products, solder and crushed pieces of another material, and a first means for rotating with the solder pieces and crushed pieces from the supply means placed thereon.
The solder pieces and the crushed pieces are heated above the melting point of the solder in the upstream area of the conveyor belt and the first conveyor belt to melt the solder pieces, and are deformed into spherical solder particles by the surface tension of the melted solder. Heating means, cooling means for cooling in a downstream area of the first conveyor belt to solidify spherical solder particles, and receiving spherical solder particles and crushed fragments falling from the end of the downstream area of the first conveyor belt. And a second conveyor belt rotating in the upwardly inclined direction, and a solder collection container disposed near the lower end of the second conveyor belt. The crushed pieces are transported in the upward direction of the second conveyor belt, and solidified in the downward direction. A solder collection device characterized by falling down spherical solder particles. 3. The vibration feeder according to claim 2, wherein a vibration feeder comprising an inclined table and a vibration means for vibrating the inclined table in the inclined direction is used instead of the second conveyor belt rotating in the upward inclined direction. Solder recovery equipment. 4. A supply means for sequentially supplying a piece of solder generated by crushing of a waste product and a piece of crushed solder and another material,
A first descending ramp descending before receiving the solder pieces and crushed pieces from the supply means, a second descending ramp following the first descending ramp, and the first and second descending ramps are upwardly inclined forward. A vibrating feeder comprising vibrating means, and a solder piece and a crushed piece on the first descending inclined table are heated above the melting point of the solder to melt the solder piece and deformed into spherical solder particles by the surface tension of the melted solder. Heating means for cooling, and cooling means for cooling the crushed pieces and the spherical solder particles conveyed from the first descending inclined table to the second descending inclined table to solidify the spherical solder particles,
The conveyor belt is configured to receive a spherical solder particle and crushed pieces falling from the second descending inclined table and rotate in an ascending and inclining direction, and a solder collection container disposed near a lower end of the conveyer belt. A solder recovery device, which transports crushed pieces in a downward direction and drops spherical solder particles solidified in a downward direction. 5. A vibration feeder comprising a third downwardly inclined table and a vibrating means for vibrating the third downwardly inclined table in the inclined direction is used instead of the transport belt rotating in the upwardly inclined direction. The solder recovery device according to claim 4.