Application of Compound Flocculant for Oil Sand Mature Fine Tailings Two-Stage Treatment

Abstract

The flocculation method had a good effect in treating oil sands tailings, and polyacrylamide (PAM) was commonly used as an effective flocculant. In this paper, poly diallyl dimethyl ammonium chloride (PDADMAC) combined with PAM and several supplementary materials into three compound flocculants were used to treat oil-sand tailings for the first time. The compound flocculants were applied for two-stage treatment to compare their performance with that of PAM. The first stage flocculation results showed that mature fine tailings (MFT) treated by compound flocculants had faster initial settling rate, higher clarity of supernatant and higher solid content of sediment than PAM, especially Flocculant A. The second stage dewatering of the mud layer indicated that the water release ability of sediment treated with compound flocculants was better than that of PAM, the yield stress was more appropriate and the capillary suction time (CST) was shorter. The deposits treated with the same flocculant for the two stages had great strength gain so reclaimation became much easier, which provided a new and efficient flocculation solution for the treatment of oil sands mature fine tailings.