Mitsui Minings & Melting Co., Ltd.

Mami Yoshida

Isamu Yashima

Yasunori Tabira

Rintaro Ishii

Yoichi Kamikoriyama

Kazuhiko Kato

Kenji Suzuoka

Kenji Matsuzaki

Shinichi Yamauchi

Shigeki Nakayama

Tatsuya Aoki

Hiroshi Imamura

Yuji Asano

There is provided a copper powder containing an organic compound containing carbon and nitrogen. The powder has a ratio of carbon content PC (mass %) to specific surface area SSA (m/g), PC/SSA, of 0.005 to 0.1 and a ratio of nitrogen content PN (mass %) to specific surface area SSA (m/g), PN/SSA, of 0.001 to 0.05. The organic compound preferably contains two or more of nitrogen atom per molecule and is preferably capable of forming a five-membered ring complex with copper. The organic compound preferably includes one or more of dimethyl glyoxime, ethylenediamine, and polyethyleneimine.

Copper powder and conductive composition containing same

A manganese oxide particle having a hexagonal crystal structure or an analogous hexagonal crystal structure with an a-axis length of 8.73&#xb1;1 &#x212b; and a c-axis length of 14.86&#xb1;1 &#x212b;. The manganese oxide particle is preferably produced by a process including mixing an aqueous solution containing manganese (II) and an organic compound having a hydroxyl group while in a heated state with an alkali.

Manganese oxide particles and process for producing same

The present invention provides a technology for recovering high-content tantalum from tantalum-containing waste with reducing various impurities such as antimony (Sb) and phosphorus (P) which hinder reuse of the tantalum in tantalum capacitors. The method for recovering tantalum from tantalum-containing waste according to the present invention is characterized in that tantalum-containing waste is subjected to an acid treatment and then to an alkali treatment, thereby recovering tantalum. The acid treatment is preferably performed with use of an acid containing hydrochloric acid and the alkali treatment is preferably performed with use of sodium hydroxide or potassium hydroxide. The tantalum-containing waste in the present invention is preferably a tantalum sintered compact collected from a tantalum capacitor.

Method for recovering tantalum

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Saitama, Japan

Mami Yoshida