AIST Stories No2

19Into the future AIST!development of the recycling technology had this to say about the difficulty of recovery.“In order to carry out recycling, you need to first strip off the electronic components such as tantalum capacitors*1 from the printed circuit boards before processing in a smelter. Stripping off electronic components that may measure but a few millimeters while retaining their original form is not easy by any stretch of the imagination. And once they have been stripped off, you are then confronted with a mixture of various component from which rare metals cannot be recycled with any degree of efficiency.”Without being able to sort and recover the components containing these important rare metals from this mixture of electronic components, this precious treasure ends up being worthless.Tantalum components separated and recovered in a world firstAIST was the first organization to develop the equipment required for such new resource development and it now possesses world-leading technology. In 2012, AIST succeeded in developing an advanced sorting system that realized rare metal recycling by recovering electronic components such as tantalum condensers based on their type from discarded printed circuit boards. This system was comprised of a double tube pneumatic separator*2 for recovering only specific electronic components such as tantalum capacitors and an inclined and low-intensity magnetic shape separator*3 that pre-sorts component such as aluminum electrolytic capacitors and quartz resonators. Through a combination of these two devices, tantalum capacitors can be recovered in high purity from this group of comingled waste electronic components. While infrastructure for recycling rare metals other than tantalum is starting to be established, this is the first system in the world than enables recovery of tantalum capacitors (located at Re-Tem Corporation’s Mito Plant).Currently, development of the second such system is underway. Until now, relatively large printed circuit boards from personal computers and servers have been targeted for recycling but the second system features enhanced performance enabling the separation and recovery of smaller components found in such devices as laptop ◦Information technology◦Eco products◦‌‌Environment, resources, energy◦IT and telecommunications◦Electronics◦Materialscomputers, cellphones, digital cameras, and smartphones. This is in line with the prevalence of these small domestic appliances and telecommunications devices in the market. “The number of columns (tubes) has been increased compared with the first unit, and the material types that can be separated has been increased. We also succeeded in downsizing the technology in order to avoid a larger unit size accompanying an increased number of columns.”Leading the world in recycling technologyTantalum recycling can only be realized if an unbroken cycle can be put in place such that material is recycled and used in subsequent production. To this end, the Strategic Urban Mining Research Base (SURE)*4 was established and efforts will start to establish a recycling system jointly with AIST, recycling companies, and equipment manufacturers. This is the first such attempt in the world and if it is realized, it is likely that large-scale and furthermore high purity rare metal recovery will be realized.“Moving forward, while establishing recycling technology as a proud specialty of Japan, we aim to simultaneously push ahead with comprehensive technology packaging and standardization, and have Japan lead the world as the founding nation of urban mine development. We do hope that our technology will be used throughout the world to achieve global environmental preservation.”*1 Tantalum capacitor: Tantalum is a rare metal whose price is exceeded only by those of precious metals. Capacitors using this metal are employed as active components that accumulate and discharge electrical charges in the electrical circuits on printed circuit boards. Compared with other capacitors, they are more compact and have better frequency characteristics.*2 Double tube pneumatic separator: A sorting device that utilizes multiple columns (tubes) employing specific upward airflow rates in order to sort particles based on their specific gravities. Heavier particles fall while lighter particles are suspended (Eriez Magnetics Japan).*3 Inclined and low-intensity magnetic shape separator: A sorting device developed for rough sorting of electronic components based on their shape and magnetic properties (Eriez Magnetics Japan).*4 Strategic Urban Mining Research Base (SURE): An organization to promote the industrialization of urban mine technology with the objective of applying AIST research findings in society.Flow of tantalum capacitors recoveryDouble tube pneumatic separator, inclined and low-intensity magnetic shape separator, etc.SortingMetal recoveryTantalum refiningVarious components comingledPrinted circuit board Tantalum capacitor “concentrate”Components stripped from printed circuit board in their original formCrushingMetal recoveryRefining of various metalsImpact in the following fields! Community lifeIndustry