This research was designed to investigate the effects of different mixing variables on flocculation kinetics of kaolinite clay suspension at both warm and cold water temperatures (23°C and 5°C) using alum and ferric nitrate under a number of physico-chemical conditions. The following work was performed during this experimental study: (1) G versus rpm curves for different impellers were developed using calculated power based on measured torque. The torque was measured by a rotating torque meter using a photographic technique. (2) The effects of impeller geometry, rapid mixing intensity and pattern, concentration of coagulant dosing solution, coagulant injection pattern, and slow mixing intensity and pattern on flocculation efficiency were investigated in a bench scale batch reactor at both warm and cold water temperatures with metal coagulants;All the experiments were performed in a batch reactor with 18-L liquid working volume inside a walk-in constant temperature room using five impeller geometries. The primary particles were kaolinite and they were flocculated using alum and ferric nitrate (Fe(NO[subscript]3)[subscript]3.9 H[subscript]2 O].;The paddle type mesh impeller performed significantly better than the turbine type impellers (2-blade and A 310) under all conditions tested. All the paddle type impellers (mesh, modified stake, and 2-blade stack) performed almost identically under the conditions tested. Both rapid mixing intensity and pattern had a remarkable impact on flocculation kinetics. An optimum G-value was obtained for each set of conditions. The low intensity, longer duration, rapid mix pattern outperformed the high intensity, short duration, rapid mix pattern in almost all the conditions studied;Slow injection, dilute dosing solution and multi port injection proved more beneficial than the pulse injection, concentrated dosing solution, and the single port injection respectively. There was an optimum slow mix G for each set of experimental conditions when constant G-slow mixing was adopted. Reducing the slow mix G as flocculation progressed resulted in higher flocculation index as flocculation progressed and better settled water turbidity due to less danger of floc breakup. All the mixing variables tested in this study demonstrated a more pronounced effect on flocculation kinetics at cold temperature than at warm temperature.