| 摘要 |
<p>PROBLEM TO BE SOLVED: To recover high-quality cobalt oxide by adding sulfur to a substance containing lithium cobaltate separated from an anode material of a lithium ion secondary battery, carrying out primary baking in a reducing atmosphere, washing the baked material with water and secondarily baking the resultant material in an oxidizing atmosphere. SOLUTION: A substance containing lithium cobaltate separated from a anode material of a lithium ion battery is formulated with 0.5-1.25 equivalent based on lithium cobaltate of sulfur and primarily baked at 270-350 deg.C in a reducing atmospbere. Then the baked material is washed with water to remove a lithium salt prepared as a by-product by the decomposition through the baking. Successively the resultant material is secondarily baked at 750-900 deg.C in an oxidizing atmosphere to produce high-quality cobalt oxide. A method in which a anode material is dissolved in a mineral acid, neutralized to recover cobalt as a cobalt salt requires an expensive cost for the treatment of emitted acidic gas and a method for extracting cobalt ion with an extracting agent requires a large amount of an alkali for treating a waste acid solution after the extraction. But this method solves these problems.</p> |
