METHOD FOR RECOVERING VALUABLE MATERIAL FROM LITHIUM ION SECONDARY BATTERY

There is provided a means capable of recovering a valuable material such as cobalt and nickel, with a low grade of a metal derived from a negative electrode current collector, a low grade of fluorine, and a low grade of a material derived from a negative electrode active material. A method for recovering a valuable material from a lithium ion secondary battery, is characterized in that it includes: a heat treatment step of performing heat treatment on a lithium ion secondary battery; a crushing step of crushing a heat-treated object obtained through the heat treatment step; a classification step of classifying a crushed object obtained through the crushing step into a coarse particle product and a fine particle product; and a wet magnetic separation step of performing wet magnetic separation on the fine particle product obtained through the classification step.