解説
白金族金属／合金の有効利用
2012 年 8 巻 2 号 p. 143-150
詳細
2012 年 8 巻 2 号 p. 143-150
Objective. Platinum group metals (PGMs) have been focused on as typical minor elements. In this paper, the reserves, supply, and demand of PGMs are introduced to clarify the present status of PGMs. Several applications of PGMs are also represented to illustrate their importance in various industries and in daily life and society.
Results and Discussion. PGMs have superior physical and chemical properties such as high melting temperatures, good oxidation and corrosion resistance, good catalytic properties, and stability to chemical environments. Thus, PGMs are used in a wide range of application fields such as emission gas purification catalysts in automobiles, catalysts for producing chemical products and for purifying petroleum, electric devices such as magnetic recording materials in hard disks, medical materials, and high-temperature structural and coating materials in the glass and aeronautical industries. On the other hand, the supply of platinum, a representative element of the platinum group metals, is approximately 200 ton per year and PGM resources are concentrated in the Bushveld complex of South Africa, with 75% of PGMs originating from South Africa. The low production and resource concentration in South Africa causes drastic price fluctuations and the unstable supply of PGMs. To maintain a stable supply of PGMs and ensure their effective use, research to extend material life, reduce PGM use, and find alternative materials its being performed. The recycling of PGMs is also very important not only to maintain a stable supply but also to protect the earth from the severe environmental damage caused by mining. The amount of recycling of PGMs has progressively increased since 2004.
Conclusions. This paper clarifies the present status of PGMs from the point of view of reserves, supply, demand, and various applications to illustrate their importance in daily life and their problems. To maintain a sustainable and stable supply of PGMs, their reduced use, replacement with alternative materials and recycling are very important.
