Evaluation of Polymer Feed Rate, Polymer Dose, and Mixing Duration for Flocculation Optimization of Clayey Tailings with Various Solid Contents

ABSTRACT: Fluid Fine Tailings (FFTs) are clayey type of tailings produced during bitumen extraction from oil-sands ore. FFTs are often treated with synthetic polymer for transforming their dispersed structure into flocculated structure such that their dewatering and settling tendency is improved. The flocculation quality, however, is influenced by the several input parameters into the process of flocculation including the mineral composition of the FFTs, the flocculant concentration, the feed rate of flocculant, and the shear rate and shear time of mixing. In this study, real time assessment of the effects of several input parameters on the flocculation quality of FFTs was conducted. The study tested FFTs with various solid contents ranged between 30 and 35% (w/w) treated with a synthetic polymer at feed rates ranged between 5 and 36 ml/sec. The flocculation process was conducted in an Advanced Couette Rheometer and controlled via an innovative feedback Torque Force-based Technique (TFT). The preliminary results showed that the faster the polymer feed rate the better the flocculation. This coincided with better immediate dewatering, longer-term dewatering, and longer-term settling behaviors. The TFT showed a strong potential for real time optimization of polymer feed rate, polymer dose, and mixing duration for flocculation improvement of FFTs with various solid contents.