Influence mechanism of surface electrical behaviors of clay particles on the settlement of tailings slurry
In order to explore the risk of the long time maintaining of flow state of tailings mud,the bauxite tailings of Guangxi Branch of China Aluminum Industry was taken as the research object.pH value was used to change the charged characteristics of the particle surface.The sedimentation charac-teristics of tailing slurry were explored.The settlement characteristics of tailings slurry under different salt solutions were explored.The results show that the Zeta potential of the sodium ion environment changes from posi-tive to negative with the increase of pH.When the calcium ion concentration is greater than 0.1 mol/L,at high pH,due to the selec-tive adsorption of calcium ions on the negatively charged kaolinite HD surface,the protonation and deprotonation area of the HD sur-face decreases.Under the action of pH-cation coupling,the minimum values of flocculation sedimentation rate and sedimentation stable void ratio are observed at pH=PZCedge=5.It can be seen that when the pH of the solution is 5 and the concentration of cal-cium chloride is 2.0 mol/L,the final settlement of the tailings slurry is the largest and the settlement effect is the best.Therefore,with the pH adjustment and appropriate salt solution,it can effectively increase the sedimentation rate of tailings slurry and reduce potential safety risks.
tailings slurrynuclear magnetic resonanceZeta potentialfree settlementpH value
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