Hitachi Metals, Ltd.

Hitachi, Ltd.

Toho Titanium Co., Ltd.

The Foundation for the Promotion of Industrial Science

Yu Miyamoto

Atsushi Kikugawa

Masahide Okamoto

Hiroyuki Hoshi

Masanori Yamaguchi

Toru Okabe

An object of the present invention is to provide a method for recovering a rare earth element, including subjecting a workpiece containing at least a rare earth element and an iron group element to an oxidation treatment, then turning the treatment environment into an environment where carbon is present, and subjecting an oxidation-treated workpiece to a heat treatment, thereby separating a rare earth element in the form of an oxide from an iron group element, according to which an oxide of a rare earth element can be efficiently separated from an iron group element at low treatment cost, and also wear and damage to the treatment container can be suppressed to allow the container to be used repeatedly for a long period of time. The method of the present invention as a means for resolution is characterized in that the oxidation-treated workpiece is mixed with petroleum coke as a carbon supply source, placed in a treatment container, and then subjected to the heat treatment in an inert gas atmosphere or in vacuum at a temperature of 950&#xb0; C. to 1150&#xb0; C. (excluding 1150&#xb0; C.).

Method for recovering rare earth element

An object of the present invention is to provide a method for recovering a heavy rare earth element from a workpiece containing at least a heavy rare earth element and an iron group element, which can be put into practical use as a low-cost, simple recycling system. The method for recovering a heavy rare earth element from a workpiece containing at least a heavy rare earth element and an iron group element of the present invention as a means for resolution is characterized by including at least the following step: a workpiece is subjected to an oxidation treatment or mixed with an oxidation-treated R&#x2014;Fe&#x2014;B based magnet alloy, and then subjected to a heat treatment in the presence of carbon at a temperature of 1000&#xb0; C. or more, thereby separating a heavy rare earth element in the form of an oxide from an iron group element.

Method for recovering heavy rare earth element

An object of the present invention is to provide a method for recovering a rare earth element from a workpiece containing at least a rare earth element and an iron group element, which can be put into practical use as a low-cost, simple recycling system. The method for recovering a rare earth element from a workpiece containing at least a rare earth element and an iron group element of the present invention as a means for resolution is characterized by including at least a step of separating a rare earth element in the form of an oxide from an iron group element by subjecting a workpiece to an oxidation treatment, then turning the treatment environment into an environment where carbon black is present, and subjecting the oxidation-treated workpiece to a heat treatment at a temperature of 1000&#xb0; C. or more in an inert gas atmosphere or in vacuum.

An object of the present invention is to provide a method according to which a rare earth element can be efficiently recovered from a workpiece containing at least a rare earth element and an iron group element, and also wear and damage to the treatment container can be suppressed, allowing the container to be used repeatedly for a long period of time. The method of the present invention as a means for resolution is characterized in that in the heat treatment of an oxidation-treated workpiece in the presence of carbon, when the oxidation-treated workpiece is placed in a treatment container, a carbon substance is interposed between the oxidation-treated workpiece and the bottom surface of the container, and the heat treatment is performed in an inert gas atmosphere or in vacuum at a temperature of 1300&#xb0; C. or more.

Growing community of inventors

Mishima-gun, Japan

Yu Miyamoto