Abstract:High-sulfur and high-carbon bauxite is used in an alumina refinery in Zunyi by Bayer process. Due to its long-term use of this type bauxite, composition of sodium aluminate solution in system is complex, and material is black and viscous, which has a big impact on production, resulting in increase of iron content of alumina products, periodic explosion and refinement of particle size, equipment corrosion and low cycle efficiency. Under the condition that sulfur content of bauxite does not exceed 0.3%, adding a certain amount of sodium nitrate to oxidize low sulfur in process of high temperature dissolution can ensure that iron content of alumina products can meet the requirements of first-grade products, production can run stably, and corrosion of equipment can be reduced to a certain extent. The industrial test results show that oxygen wet deep oxidation desulphurization and decarbonization technology can not only oxidize low sulfur in system, but also realize partial oxidation of organic matter, with better effect and lower cost than adding sodium nitrate.