Expanding applications and impending supply risk of minor metals are introduced. The supply risk of metals is analyzed from three different viewpoints : sustainability of national economics, sustainability of the activity of humans, and sustainability of the global environment. A concept of resource-end view is introduced with regard to the supply risk of metals. Urban mining is also mentioned as a measure for easing the risks.

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Personal computers (PCs) were examined as part of a case study to estimate the amount of potentially recoverable metals, including hazardous metals, contained in waste electric and electronic equipment. We first explain comprehensive analytical methods, step-by-step process dismantling and instrumental analysis including X-ray fluorescent spectrometry and ICP mass spectrometry. After using chemical analysis to determine the elements, the total amounts for 47 elements were obtained by adding the mass of each metal in each part or material. In total, the PC contained 794mg of Ag, 143mg of Au, 186mg of Pd, 20g of Pb, and so on. A printed circuit of a note type PC contained the same level of Au in a printed circuit of a desktop type PC, but contained half the amount of Ag, one-tenth of Pd, one-seventh of Pb. There are still some analytical problems that remain to be solved in order to obtain accurate and representative metal concentrations in waste products.

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The present status of mineral resources and recycling of small domestic appliances (SDA) is discussed in this review. Prices for mineral resources had seen a dramatic increase until the global economy was hit with the recent financial crash. The reasons for such price increase were : 1) the strong demands of BRIC countries ; and 2) the birth of giant mineral companies like BHP Billiton. Since Japan has almost no mineral resources, except CaCO₃, the recycling of metals is seen as a countermeasure that can be taken against the issue of resource availability. Artificial ore deposit design has become a significant concept in moving toward progress in rare-metal recycling from e-scrap
We have proposed a new concept for SDA recycling, called RtoS, which is based on the paper, Urban Mine, New Resources for the Year 2000 and Beyond, by Professor Nanjyo, who had been working at the Institute of Mineral Dressing and Metallurgical Processes, Tohoku University.
A comprehensive examination of the metal content of Japanese WEEE (Waste Electrical and Electronic Equipment) was carried out, and based on presumptions made from the quantity of products, etc., the concept of RtoS was realized in Odate City in 2006. Currently, most of the metals found within WEEE are disposed of, and become an unrecoverable resource in landfill sites. The new concept was developed based on calculations showing the annual amount of Japanese WEEE to be 19.4kg/person ; a quantity closely equivalent to the discharge total for all EU countries (approximately 20kg/person). Moreover, it was surprising to find that the four home electronics items which must already be recycled by law in Japan made up for 30% of WEEE weight.
If a recovery system is not put into practice, it will lead to the dissipation of rare metals throughout the country in the future. In the case of WEEE, however, when Cu, Au, and Ag are collected for recycling, rare metals can also be gathered along with them. If rare metals are separated from WEEE using the proper techniques and accumulated for storage, they can then be considered resources. A possible scenario for rare metal recycling is also shown. This could have its own self-supporting economic system if a collection system is devised and the recycling system is changed according to commercial transactions.

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Many kinds of high-tech products require rare metals in order to function. This is also true in the case of LCDs (liquid crystal displays), which are currently in increasing demand. The LCD is a product requiring indium resources for its transparent electrode material. As the production of LCD TVs increases, the demand for indium will simultaneously increase in the future. This makes it important for LCD manufacturers to plan for the securing of indium resources, of which production is in limited quantity. We are developing technologies that work to recover indium resources from LCDs. In particular, the simple and energy-saving ion-exchange resin method is proving to be significant. We have constructed demonstration equipment that can process 240kg of waste LCD panels per day, achieving a recovery rate of 94%.

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