Solid material comminution or disintegration – Processes – With application of fluid or lubricant material
Reexamination Certificate
2000-06-27
2003-05-27
Rosenbaum, Mark (Department: 3725)
Solid material comminution or disintegration
Processes
With application of fluid or lubricant material
C241S020000, C241S024140, C241S024180, C241S079100, C241SDIG014
Reexamination Certificate
active
06568612
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a method of and an apparatus for recovering valuables which can be recycled from waste, and specifically, a method and an apparatus which are suitable for disposing waste including circuit boards.
RELATED ART
As to a process of recovering variables which can be recycled from waste, various technologies have been proposed in view of kinds of waste or valuables.
For example, Japanese Laid-Open Patent No. H5-147040 discloses a waste disposal method for waste of household appliance such as a refrigerator, wherein metal blocks are separated from waste, and then waste from which the metal blocks are removed, are pulverized into fragments, and then foaming materials are recovered from the fragments from which a gaseous foaming agent is recovered while iron, nonferrous metals and plastics are separated from frozen and pulverized fragments of the metal blocks and the fragments from which the foaming materials are removed, so as to recover the valuables. In order to separate iron, nonferrous metals and plastics, the fragments are subjected to magnetic separation in order to separate iron, and then the remaining fragments are subjected to eddy current separation under the action of eddy current generated by the application of a.c. magnetic fields so as to separate nonferrous metals and plastics. Further, nonferrous metals are then subjected to gravity concentration using difference in specific weight, or wind separation, so as to be sorted into copper, aluminum and other nonferrous metals, and similarly, the plastics are subjected to gravity concentration or wind separation so as to be sorted into different kinds.
Further, Japanese Laid-Open Patent No. H8-318256 proposes such a process that waste is manually disassembled so as to recover reusable parts such as CPU, and the remainder parts are pulverized and then sorted into iron, nonferrous metals and plastics in order to recover reusable parts as valuables. The remainder is further pulverized in order to recover valuables if present, and are finally subjected to innocuous disposal.
However, the waste disposal process disclosed in the Japanese Laid-Open Patent No. H5-147040 is unsatisfactory for disposing OA equipment including a circuit board. There have been offered the following matters which should be improved. That is, OA equipment such as a personal computer, a printer, a copier or a facsimile, includes a circuit board carrying thereon an electronic circuit component such as a CPU, and as well, solder which has been used for connecting electronic circuit components and wiring members, and which contains toxic lead, thereby it is desirable to enhance the recovery rate of solder. However, should OA equipment including such circuit boards be pulverized into fragments, without removing these circuit boards, the fragments would be dispersed around, solder and copper and aluminum wires being stuck thereto. Thus it is impossible to enhance the recovery rate of lead. Further, when copper, aluminum and the like of the nonferrous metal group are sorted by an eddy current classifier, eddy current is induced through solder and wiring stuck to the fragments of the circuit boards, and accordingly, a large volume of fragments of the circuit boards is recovered as nonferrous metal. As a result, a large volume of impurities relating to the circuit boards is mingled in separated nonferrous metals including copper and aluminum, and accordingly, the value of the separated nonferrous metals as valuables is lowered. Similarly, if the fragments of the circuit boards are sorted into plastics, the fragments of the circuit boards which are usually sheet-like, are likely to be sorted into phenol resin having a specific weight of 1.25 to 1.30 or polyvinyl chloride having a specific weight of 1.33 to 1.44 due to the affection by the shapes of the fragments when the fragments are sorted into different kinds of plastics since the specific weight of the circuit boards is in a range from 1.6 to 2.0, and accordingly, there would be caused a risk such that the degrees of purity of sorted plastics are lowered. Further, even after the fragments of the circuit boards are separated from nonferrous metals and other plastics, the remaining fragments are finally collected as dust together with plastic chips, metals chips, wiring chips and other particles, and accordingly, the volume of dust becomes very large so as to increase the costs of reclamation becomes high, resulting in increase in both cost of waste disposal and burden upon the environment.
In order to solve the above-mentioned problems, Japanese Patent No. H8-318256 discloses a method in which OA equipment is manually disassembled or wrecked so as to remove circuit boards, and then, valuables including CPUs are recovered as reusable parts from the circuit boars. However, it is difficult to remove circuit boards from OA equipment in view of its structure since the OA equipment is usually has a compact form. Accordingly, the removable of the circuit boards would require a huge cost and a long working time. Further, in this document, the remaining circuit boards are simply subjected to innocuous disposal for reclamation after valuables are recovered therefrom, that is, this document fails to disclose the separation and recovery of valuables such as lead contained in solder and noble metal from the circuit boards, and the reutilization thereof as resources.
Meanwhile, if a plastics housing which is one of the components of OA equipment is made of ABS resin or the like, plastics having different specific weights in a narrow range would be mingled together. That is, the specific weight of polystyrene is in the range of 1.02 to 1.51 which is substantially equal to the specific weight (1.03 to 1.09) of the ABS resin. There would be a risk such that different kinds of plastics are sorted into one and the same kind, and recovered. Accordingly, the colors and the materials of the recovered plastics are not uniform, and accordingly, the quality of the recycled resources is low.
BRIEF SUMMARY OF THE INVENTION
A first object of the present invention is to enhance the quality of recovered valuables which are obtained by pulverizing waste including circuit boards, and to restrain diffusion of toxic lead included in the circuit board.
A second object of the present invention is provide an automated process for selecting and separating fragments of circuit boards from fragments of waste other than the circuit boards in order to recover valuables are recovered through the disposal of the waste including the circuit boars.
A third object of the present invention is to enhance the quality of recovered plastics, relating to colors and materials thereof.
The first object of the present invention can be achieved by such an arrangement that a circuit board sorting means for sorting and separating fragments of circuit boards from pulverized waste is provided downstream of a pulverizing means for pulverizing waste including circuit boards. That is, although it is difficult to separate fragments of circuit boards from nonferrous metals and plastics through eddy current classification or gravity concentration, with the provision of the circuit board sorting means for sorting and separating fragments of circuit boards, the amount of fragments of circuit boards mingled into nonferrous metals and plastics can be restrained. As a result, the qualities of nonferrous metals and plastics which are valuables to be recovered, can be enhanced. Further, with the provision of the circuit board sorting means, since waste including circuit boards can be directly pulverized by, for example, the pulverizing means, and accordingly, the necessity of handwork for disassembly can be eliminated, thereby it is possible to reduce the processing time for recovering circuit boards and the processing cost.
In this case, it is preferable to arrange the circuit board sorting means upstream of a nonferrous metal sorting means for sorting nonferrous metals. With this arrangement, it is possible to restrain fra
Aoki Toshiyuki
Hasegawa Tsutomu
Hayashi Masakatsu
Antonelli Terry Stout & Kraus LLP
Hitachi , Ltd.
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