○Hiroshi Asahi¹, Hiromichi Takebe², Atsushi Shibayama³, Etsuro Shibata⁴, Taro Kamiya⁵, Yoshinori Yajima⁶, Shuichi Ogasawara¹, Satoshi Asano¹, Keiko Sasaki⁷ (1. Sumitomo Metal Mining Co., Ltd., 2. Ehime University, 3. Akita University, 4. Tohoku University, 5. Japan Organization for Metals and Energy Security, 6. Japan Mining Industry Association, 7. Kyushu University)