Abstract: Guangxi Pingguo aluminum tailings slurry has the characteristics of small particle size, electric charged, large specific surface area, high water content, difficult to settle, and containing Al3+ impurities. As Pingguo aluminum slime particles charged, the Van der Waals force in the mine slurry particles has a great influence on its sedimentation, and the ionization of the inorganic salt will have an impact on the thickness of the electric layer, and then affect the slurry of the sedimentation rate. In this paper, a common inorganic salt, NaCl, was selected to be added into the slurry and fully stirred. The influence of adding the NaCl on the sedimentation rate of the slurry was analyzed according to the relationship between the height and the settling time of the supernatant of the slurry. The results show that there are three stages of the slime sedimentation: the turbulence influence stage, the main settling stage and the secondary settling stage. With the increase of the NaCl concentration, the rate of the slurry gradually decreased.

Key words: Aluminum Slurry, Sedimentation, Inorganic Salt