Cobalt recovery method

Cobalt is recovered with high purity from a liquid to be treated in which cobalt and impurity metals are dissolved. In the cobalt recovery method, the pH is adjusted to 4-7 (step S3) by adding a base to a liquid to be treated; a step (step S4) for solid-liquid separation of the precipitate of the crystals of the salt containing the impurity metal precipitated in step S3; adjusting the pH to 7 or more by adding a base to the liquid to be treated after step S4 (step S5); a step (step S6) for solid-liquid separation of a precipitate containing the cobalt salt crystal precipitated in step S5; dissolving the precipitate after step S6 with an inorganic acid (step S7-1); adjusting the pH to 4-7 (step S7-2) by adding a base to the redissolved solution; a step (step S7-3) in which the precipitate of the crystals of the salt containing the impurity metal precipitated in the step S7-2 is precipitated by self weight or centrifugal separation and separated into a supernatant and a slurry containing the precipitate; adjust