Saturday, April 18, 2015

No. 145: Urban mine is growing its presence as a source of rare metals (April18, 2015)

Since the law to purchase renewable energy at a fixed price was enacted in 2012, photovoltaic generation has been growing popular quite rapidly. A solar panel has a life between 20 and 30 years. The Ministry of the Environment estimates that used photovoltaic generation equipment will amount up to 700,000 tons in 2030. A solar battery contains various metals including rare metals like iridium and has the possibility of becoming prospect in the future.  

DOWA Holdings has been developing technologies to recover metals like gold, silver, and copper from black ores since the Meiji Period, and it is working on solar panels to establish a technology to recycle them with a view to recovering rare metals. It is urgent and important to establish a recycling technology to eliminate a large amount of used solar panels to be thrown away for land reclamation. Urban mine is a very important source of metals. The Institute of Metal Sciences reckons that urban mine in Japan is estimated to have more than 10% of world’s reserves of such metals as gold, silver, tin, and iridium.

Tantalum, for example, is a rare metal. Mitsui Kinzoku Recycle is developing a technology to recover tantalum from tantalum capacitors in collaboration with National Institute of Advanced Industrial Science and Technology. The technology is to separate capacitors from electronic substrates and recover tantalum at a high purity utilizing the difference of specific gravity. The company is scheduled to start commercial production of tantalum in 2016.

Ricoh and Japan Future Eco-Systems are jointly developing a technology to change waste plastics not to resin materials but to oil. They heat waste plastics to 600-800 degrees centigrade in an iron container, and recover heating oil and heavy oil from vaporized substance. They are in the middle of putting this technology into practical application. Ricoh is receiving inquiries on this technology from Southeast Asian countries and confident of spreading this technology worldwide.

The Japanese domestic recycling market is estimated at 7 trillion yen and supposed to grow further thanks to technological innovation that increases recoverable amount and expands the products subject to recycling.

 Exploring urban mines

Rare metal selection equipment (1)

Rare metal selection equipment (2)

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