A New Recycling Technology
1. Background
Securing abundant natural resources is an important issue facing every nation.
Securing these needed resources requires a tremendous outlay of capital and the support of mining countries.
Therefore, the idea of Urban-Metal was born.
We feel it is important to make the best use of the resources that are already being utilized. A great amount of precious or rare metals are used in the manufacturing of IC boards. The recovery of these precious metals using high technology has now become an important topic of interest worldwide.
2. Recycling Metals from Circuit boards.
While it is possible to reclaim precious metals from the post-consumer waste of disassembled electronic devices, PC’s, mobile phones, etc., by smelting, or electrical refining, this method is very inefficient requiring a great expenditure of energy and releases a large volume of CO2 gas into the air. What is needed is a technology to recycle metal by a simpler means. So we directed our attention to developing a technology to recycle metal not by smelting, but by heat treatment.
Simple methods of heating the material, that is to say incineration, have been studied, but most were in vain because of the high costs and high energy consumption required. Moreover, simply burning the material causes additional problems because in the process of eliminating the plastic portion of the boards, the melted fiberglass encases the metal making the extraction process even more difficult.
3. Our Method
We developed a heating method at lower temperatures wherein the fiberglass becomes brittle rather than molten.
This is process is part of an applied patent by our company founder, Tetsuyuki Koizumi, entitled “A method to reclaim precious metals from wastes.” (JP-A-2008-144732) The patent details a method to reclaim rare metals from multi-layered circuit boards by heat treatment without smelting. In addition, this low temperature treatment method utilizes much less energy to achieve results.
Dr. Koizumi came to the realization that a dry distillation type of heating would be the most efficient method. So he developed a plan to create a dry distillation furnace.
Several technical developments and rework of equipment were required during the design stage because the output of this process differs from that of a typical incinerator.
4. The Heating Process
Reactions in the First Chamber:
The epoxy resin generates heat with the introduction of low levels of O2.
This phenomenon can also be considered imperfect combustion.
CO is generated instead of CO2 in the oxygen-poor atmosphere.
The heat reaction will make the fiberglass in the multi-layered boards become extremely brittle, but the temperature maintained at a low level.
Reactions in the Second Chamber:
CO, generated in the first chamber, is oxidized with the O2 of inspired air.
CO is burnt and heated up.
The temperature increases to more than 950 degrees centigrade.
This high temperature dissolves hazardous gasses like dioxin.
5. The Advantage of our Heating Process.
5-1 Fuel for continuous heating is not needed.
This system does not require fuel since it is driven by the heat energy contained within the circuit boards themselves. Only a small amount of fuel is required for ignition.
5-2 Environmentally-Friendly
A large volume of air is necessary to burn with a typical burner. In turn, a large volume of air causes a large volume of exhaust gases.
However, our system does not require large amounts of air.
Since the volume of exhaust gas is reduced, the burden to the environment becomes less as well.
5-3 Portability
The equipment needed to create Urban-Metal is compact. Therefore, it is possible to install close to the collection point of electronic scrap.