Fluidized bed reactor and method for recovering active metal of lithium secondary battery using same

In a method for recovering an active metal of a lithium secondary battery according to an embodiment, a waste cathode active material mixture is prepared from a waste cathode of a lithium secondary battery. A preliminary precursor mixture is formed by reacting the waste cathode active material mixture with a reactive gas in a fluidized bed reactor. The preliminary precursor mixture is cooled by spraying different first and second refrigerants to the preliminary precursor mixture. A lithium precursor is recovered from the cooled preliminary precursor mixture.