Study on the Settlement Experiment of Iron Tailings

The settlement experiment of representative iron tailings was studied, the iron tailings were from a processing plant of Wuhan Iron and Steel Group. There were four experiments were conducted which includes nature sedimentation test, coagulation sedimentation test of inorganic salt coagulant, flocculation sedimentation test of polymer flocculant and the mix coagulation sedimentation test. The test results showed that the size of sample is relatively fine and unevenly distributed, what's more, the velocity of natural sediment is very slow, and the effect that concentration has on the settling velocity of particles is obvious. The inorganic salt coagulant could reduce turbidity of supernatant, but it play a limited role in improving settling rate, it was found that FeCl3 is the best coagulation agent, PAM is effective flocculant for the sample, and the coagulation effect of cationic flocculation (molecular weight is six million) is better than that of anionic and nonionic. The settling velocity of particles was improved and the solid content of supernatant was reduced in the mix coagulation sedimentation test, but the improvement of settling velocity was not obvious. The author suggests that the single cationic polyacrylamide flocculant which was used for pretreatment on the tailings could meet the requirement of the tailings settlement.