Comparison of deep desulfurization methods in alumina production process

Abstract

Several methods of deep desulfurization in alumina production process were studied, and the costs of these methods werecompared. It is found that most of the S²⁻removed by adding sodium nitrate or hydrogen peroxide in digestion process, and in this way the effect of S²⁻ on alumina product quality is eliminated. However, the removal efficiency of S₂O₃²⁻ in sodium aluminate solution is very low by this method. Both S²⁻ and S₂O₃²⁻ in sodium aluminate solution can be removed completely by wet oxidation method in digestion process. The cost of desulfurization by wet oxidation is lower than by adding sodium nitrate or hydrogen peroxide. The results of this research reveal that wet oxidation is an economical and feasible method for the removal of sulfur in alumina production process to improve alumina quality, and provide valuable guidelines for alumina production by high-sulfur bauxite.

Keywords

high-sulfur bauxite / alumina production / desulfurization / wet oxidation

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