| In this study, the effect of three polymer flocculants, polyacrylamide (PAM), Magnafloc 1011 (MF) and Al(OH)3-polyacrylamide (Al-PAM), on the settling of mineral freshwater and saline tailings was investigated. The settling of tailings significantly depends on solution salinity, polymer flocculant type and dosage. MF was identified as the most efficient flocculant among the three polymers to enhance the settling of freshwater and saline tailings. The flocculation mechanism of MF was further studied through model clay (i.e. kaolinite) under controlled solution conditions. The maximum initial settling rate (ISR) of kaolinite was found to increase with the addition of NaCl and CaCl2 at the cost of higher MF consumption. Using multiple advanced techniques, the interaction between MF molecules and clay particles were probed. The results indicate that the different settling behaviors of MF treated tailings of various salinities were mainly due to the change of polymer conformations and polymer-particle interactions in the suspensions. |
