
A process for producing oxalic acid, sodium oxalate or mixtures thereof comprises treating crude sodium oxalate solids or slurry, such as produced by the Bayer process in treating bauxite. The crude sodium oxalate solids or slurry include at least aluminum metal ions as well as other metal ions common to the Bayer process. The removal process comprises: dissolving the crude sodium oxalate in an aqueous solution to form a solution of sodium oxalate; separating insolubles from the solution; passin...









