Sumitomo Metal Mining Company, Ltd.

Yukie Kawakami

Satoshi Asano

Keiji Kudo

Hitoshi Ishida

Masatoshi Takano

Kazunari Maeba

Masahiro Tanaka

Ishida Hitoshi

The object of the present invention is to provide a method for recovering a rare earth element, which is capable of efficiently recovering a rare earth element with high recovery rate without using any expensive chemicals, solvents or the like. In the present invention, a water-soluble salt other than sulfate ions is allowed to coexist with an aqueous solution that contains a rare earth element, and then an alkali metal sulfate is added to the aqueous solution, thereby producing a precipitate of a double sulfate of the rare earth element.

Method for recovering rare earth element

The present invention provides a valuable metal leaching method and a valuable metal collection method, in each of which valuable metals can be leached efficiently, the amount of a reducing agent used can be reduced, and cost reduction can be achieved. In the present invention, a positive electrode material is immersed in an acidic solution together with a metal having a lower reduction potential than a reduction potential of hydrogen, whereby valuable metals are leached out from a positive-electrode active substance.

Valuable metal leaching method, and valuable metal collection method employing the leaching method

The present invention aims at improving a recovery rate of a positive-pole active substance and preventing a recovery loss of valuable metals when a positive-pole active substance is separated from a lithium ion battery. In the present invention, a material resulting from battery dismantling obtained by dismantling a lithium ion battery is stirred using a surfactant solution, whereby a positive-pole active substance is separated from a positive-electrode substrate. Also, it is preferable that an alkaline solution is added to a positive-electrode material of a material resulting from battery dismantling, thereby dissolving a positive-electrode substrate to which a positive-pole active substance adheres to obtain a slurry containing the positive-pole active substance, and a surfactant solution is added to the slurry to disperse the positive-pole active substance in the slurry, whereby the positive-pole active substance is separated from the alkaline solution.

Method for separating positive-pole active substance and method for recovering valuable metals from lithium ion battery

Growing community of inventors

Ehime, Japan

Yukie Kawakami