Sumitomo Metal Mining Company, Ltd.

Kazuhiro Mori

Jun-ichi Takahashi

Toshirou Tan

Jun-Ichi Takahashi

Provided is a method for increasing the rate of recovery of valuable metals when waste batteries batteries are treated by a dry process. The valuable metal recovery method in the dry step Sincludes a melting step STincluding melting waste batteries to form a melt, a slag separation step STincluding separating slag from the melt, and an alloy separation step STincluding separating an alloy of valuable metals from the melt, wherein the slag has an aluminium oxide content of 20% by weight to less than 75% by weight and an iron content of 5% by weight to 40% by weight, calculated as metallic iron, and silicon oxide and calcium oxide are added as fluxes in the melting step STso that the slag can have a melting point of at least 1,500&#xb0; C., preferably at most 1,650&#xb0; C.

Method for recovering valuable metal

Provided is a method for improving the recovery rate of valuable metals such as cobalt when drying the battery waste of lithium ion batteries and the like. A second alloy excellent in terms of iron-cobalt separation performance and containing a small amount of iron is obtained by performing: a pre-oxidation step (ST) for roasting and pre-oxidizing battery waste containing aluminum and iron; a melting step (ST) for obtaining a molten product by melting the battery waste after the pre-oxidation step; a first slag separation step (ST) for separating and recovering first slag containing aluminum oxide from the molten product; a second oxidation step (ST) for oxidizing a molten first alloy after the first slag separation step; and a second slag separation step (ST) for separating and recovering a second slag containing iron from a second alloy after the second oxidation step (ST).

Valuable metal recovery method

Provided is a method in which, when discarded batteries such as lithium-ion batteries are treated by a dry process, slag having a reduced viscosity is obtained to heighten the recovery of valuable metals. The method for recovering valuable metals includes a dry process (S) which includes a melting step (ST), a slag separation step (ST), and an alloy separation step (ST), the slag having an aluminum oxide content of 5 mass % or higher but less than 20 mass % and an iron content in terms of metallic iron amount of 20-40 mass %. Furthermore, silicon oxide and calcium oxide are added as a flux in the melting step (ST) so that the slag has a melting point of 1,400&#xb0; C. or lower, and the melting step (ST) is conducted at 1,400&#xb0; C. or lower. Thus the recovery of the alloys can be heightened.

Method for recovering valuable metals

A method for recovering valuable metals is provided in which the degree of oxidation of molten waste batteries is stabilized and separation between slag and an alloy is ensured. The method includes a roasting step (ST) in which waste batteries are roasted beforehand at a low temperature of 300&#xb0; C. or higher but lower than 600&#xb0; C., an oxidation step (ST) in which the waste batteries are oxidized by roasting at 1,100-1,200&#xb0; C., and dry step (S) in which the waste batteries that were oxidized in the oxidation step are melted, and slag and an alloy of valuable metals are separated from each other and recovered. By conducting the roasting step (ST), organic carbon, which impairs the stability of the oxidation step (ST) and which is contained, in plastic components, etc., is removed in advance prior to the oxidation step (ST), and the efficiency of slag/alloy separation can be improved.

Provided is a method for stabilizing the degree of oxidation of molten battery waste, and definitively separating slag and alloy. The method is provided with a pre-oxidation step (ST) for roasting and oxidizing battery waste; and a drying step (S) for melting the battery waste oxidized in the pre-oxidation step, and separating and recovering the slag and the valuable metal alloy. By providing the pre-oxidation step (ST) for oxidizing the battery waste by roasting in advance of the drying step (S), it is possible to stably obtain the optimal degree of oxidization in a melting step (ST), and to improve the slag-alloy separation efficiency.

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Ehime, Japan

Kazuhiro Mori