Abstract: The present invention is directed to a method for removing organic substances from aluminate liquors of the Bayer process. The method comprises the steps of contacting the liquor with an oxygen containing gas under elevated pressure in the presence of metallic ions acting as a catalyst to oxidize the organic substances, precipitating the metallic ions jointly with aluminum hydroxide, separating the precipitate from the oxidized liquor and recycling the precipitated aluminum hydroxide containing the metallic ions into the oxidation step as a catalyst carrier.