Abstract:Production of alumina in China ranks top in the world, and its dependence on overseas bauxite rises year by year. Test to extract alumina from an imported high grade and organics-bearing bauxite by low-pressure leaching process was conducted. Effects of digestion temperature, caustic concentration, time, L/S on alumina dissolution rate and organic carbon conversion rate were investigated. The results of XRF and XRD show that this ore contains high carbon content and low boehmite content, which is suitable for low pressure digestion production. The experimental results show that alumina digestion rate is 86% and conversion rate of organic carbon is 58% under the conditions including digestion temperature of 145 ℃, concentration of caustic soda of 190 g/L, digestion time of 20 min, and L/S=6.