Title:
METHOD FOR RECOVERING VALUABLE SUBSTANCE
Document Type and Number:
WIPO Patent Application WO/2023/140198
Kind Code:
A1
Abstract:
The present invention provides a method for recovering a valuable substance, the method recovering lithium carbonate that has a boron level of less than 1 ppm and a calcium level of 100 ppm or less from lithium ion secondary batteries. This method for recovering a valuable substance comprises: a heat treatment step in which a heat treated material is obtained by subjecting the lithium ion secondary batteries to a heat treatment at a temperature of 660°C or higher; a crushing/classifying step in which a coarse grain product and a fine grain product, each containing the valuable substance, are obtained by crushing the heat treated material and subsequently classifying the crushed material; a slurry formation step in which a fine grain product slurry is formed by immersing the fine grain product into water; a wet magnetic separation step in which the fine grain product slurry is subjected to wet magnetic separation so as to be separated into a magnetically attracted material and a magnetically non-attracted slurry; an acid leaching step in which sulfuric acid is added to the magnetically non-attracted slurry and/or a magnetically non-attracted material, which is obtained by subjecting the magnetically non-attracted slurry to solid-liquid separation, so as to set the pH thereof to 0 to 3.5 and leach the magnetically non-attracted material, and the resulting material is subsequently subjected to solid-liquid separation, thereby obtaining an acid leachate and an acid leaching residue; a neutralization step in which the acid leachate is neutralized with calcium hydroxide; a neutralized cake solid-liquid separation step in which a liquid obtained by the neutralization step is subjected to solid-liquid separation; a calcium carbonate crystallization step in which CO2 is added to a liquid that is obtained by the neutralized cake solid-liquid separation step; a calcium carbonate solid-liquid separation step in which a liquid that is obtained by the calcium carbonate crystallization step is subjected to solid-liquid separation; and a calcium adsorptive removal step in which calcium is adsorbed and removed by means of a chelating resin after the calcium carbonate solid-liquid separation step.
Inventors:
NISHIKAWA CHIHIRO (JP)
TAHATA SHOTA (JP)
WATANABE RYOEI (JP)
LIU NOBUYUKI (JP)
YOSHIDA SHOHEI (JP)
TAHATA SHOTA (JP)
WATANABE RYOEI (JP)
LIU NOBUYUKI (JP)
YOSHIDA SHOHEI (JP)
Application Number:
PCT/JP2023/000880
Publication Date:
July 27, 2023
Filing Date:
January 13, 2023
Export Citation:
Assignee:
DOWA ECO SYSTEM CO LTD (JP)
International Classes:
H01M10/54; B09B3/40; B09B3/70; B09B5/00; C01D15/08; C22B1/02; C22B3/08; C22B3/22; C22B3/24; C22B3/44; C22B7/00
Foreign References:
| JP2021147706A | 2021-09-27 | |||
| JP2021172537A | 2021-11-01 | |||
| JP2009270189A | 2009-11-19 | |||
| JPH0835023A | 1996-02-06 |
Attorney, Agent or Firm:
ITOH, Tadashige et al. (JP)
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