Abstract: In a Chongqing high sulfur bauxite，the main aluminum-containing mineral is diaspore，sulfur-containing mineral is pyrite and the ratio of Al-Si is only 4.73%. The technical conditioning tests on sulfur removal，silicon decrease and aluminum increase were made. The results show that bauxite concentrate with Al₂O₃ grade of 65.81%，S giade of 0.42%，Al-Si ratio of 9.09，and Al₂O₃ recovery of 77.88% was ultimately obtained by the flow-sheet processes of one roughing floatation for sulfur concentration，two roughings,three cleanings and one scavenging and middles back to the flow-sheet in turn. The byproduct sulfur concentrate with S grade of 22.13%，S recovery of 82.69%，Al₂O₃content of 32.94% and the recovery rate of 5.15% was achieved.

Key words: Diaspore, Bauxite, Al-Si ratio