Bayer process

A Bayer process for dissolving alumina contained in bauxite comprising controlling the concentration of oxalates in solution in Bayer liquor in a red side of the process to be as high as possible to drive oxalate removal from Bayer liquor in the red side of the process without resulting in oxalate precipitation in a precipitation step in a white side of the process, the process including:

• adding a reagent that has oxalate modifying properties to Bayer liquor to minimize oxalate precipitation in the precipitation step, controlling a bauxite reactive silica concentration in Bayer liquor to facilitate removal of oxalates from solution in Bayer liquor in the red side of the process in accordance with a relationship that the concentration of oxalate in solution in Bayer liquor decreases as the bauxite reactive silica concentration increases, and adding Bayer liquor to bauxite on the red side of the process to increase the oxalate concentration in solution in Bayer liquor resulting from digestion of bauxite in the red side of the process, with the increased oxalate in solution driving removal of oxalate as a desilication product (DSP) on the red side of the process.