Mitsui Minings & Melting Co., Ltd.

Tatsuya Aoki

Kenji Matsuzaki

Hitohiko Ide

Norihiko Miyashita

Takashi Chikumoto

Rintaro Ishii

Mami Yoshida

Relating to a sulfide-based solid electrolyte compound for lithium ion batteries which has a cubic argyrodite-type crystal structure, to provide a compound which can suppress a generation amount of hydrogen sulfide when being left to stand in the air and which can maintain high conductivity even when being left to stand in dry air. Proposed is a sulfide-based solid electrolyte compound for lithium ion batteries containing a crystal phase of the cubic argyrodite-type crystal structure and represented by a composition formula (1): LiPSCl, wherein x and y in the composition formula (1) satisfy 0.05&#x2266;y&#x2266;0.9 and &#x2212;3.0x+1.8&#x2266;y&#x2266;&#x2212;3.0x+5.7.

Sulfide-based solid electrolyte for lithium ion cell, and solid electrolyte compound

There is provided a technology for decreasing copper and tungsten contained in tantalum-containing wastes, and recovering a high-purity tantalum. The present invention is a tantalum recovery method for recovering tantalum from a tantalum-containing waste, the method comprising subjecting the tantalum-containing waste to an acid treatment in an oxidizing atmosphere, thereafter to a roasting treatment and an alkali treatment, and further comprising carrying out a magnetic separation treatment before the acid treatment to thereby separate a tantalum-containing material in the tantalum-containing waste. This is particularly a suitable recovery method for recovering tantalum from wastes containing a relatively large amount of copper and tungsten such as discarded substrates such as printed wiring boards.

Tantalum recovery method

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.

Growing community of inventors

Ageo, Japan

Tatsuya Aoki