Innovative High Performance Cell Phone Recycling Technology

Development of a Small- Scale, Simple “Urban Ore” Recycling System Suitable for Decentralized Treatment of Used Electronic Devices

Abstract

1. A team led by Dr. Kohmei Halada, Managing Director of the Center for Strategic Natural Resources of the National NIMS, in cooperation with Oshigane Ltd. and Nagao System Ltd., developed a simple system for producing “urban ore” containing a high concentration of rare metals, etc. by crushing used small-scale electronic devices.
2. The developed system consists of two components, a “small-scale electronic device crusher” which makes it possible to expose and separate the board and other parts containing rare metals by crushing and dismantling the body cases of used small-scale electronic devices, and a “3-dimensional ball mill” which efficiently degrades the chips and other parts recovered from the crushed devices to a powdered form. Because both components of the system are small in scale, the system is suitable for decentralized type treatment, for example, by local governments. These two components represent a large advance toward the practical application of urban ore production.
3. The“small-scale electronic device crusher” is a device which decomposes electronic devices into smaller pieces, taking advantage of the fact that the mechanical strength of such devices differs in various parts, by applying torsional force to used small-scale electronic products such as cell phones. We named it a “crusher” because it reduces the internal parts of the products being recycled to a decomposed state by crushing the body case as if it were dismantled by hand.
4. The crusher is capable of reducing cell phones to pieces in several seconds, and makes it possible to expose the main parts of electronic equipment in small home electrical appliances without using a large-scale unbalanced crusher. It does not require operation by a person with experience in disassembly work. In addition to producing urban ore by using the ball mill method, etc., it is also possible to extract designated parts by human identification of the desired parts following crushing.
5. The “3-dimensional ball mill” is a ball mill with two rotating shafts (vertical, horizontal) like a gyro-top. Because random motion of the balls inside the container can be secured by adjusting the rotation of the two shafts, it is possible to efficiently separate and degrade chips and other parts to powder when crushed electronic devices are placed in the mill. In the case of cell phones, production of urban ore requires only several minutes of treatment time. In comparison with planetary mills, this mill features stable, high speed rotation because the two rotating shafts intersect in its center. Furthermore, because the objects being treated are subjected to impact by the balls in the entire interior of the container, chips and platings can be separated from boards and pulverized at high speed with low energy consumption. Thanks to the short treatment time, the remaining fragments of plastics and other materials receive little damage and can be recovered in a condition which enables easy plastic recycling.
6. Patent applications for an urban ore production method using the above-mentioned “crusher” and “3-dimensional ball mill” have already been filed jointly with Oshigane Ltd. and Nagao Systems Ltd., respectively. Details of these results will be reported at the “Urban Ore Workshop III” at the Ecomaterial Forum, which is to be held on December 21, and demonstrations of the devices will also be presented.

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small-scale electronic device crusher

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3-dimensional ball mill

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