The Study of Polyacrylamid Concentration as Flocculant on Sedimentation Velocity

Dewatering of concentrates, tailings, etc. is an important process in most mineral processing operations. Flocculation is usually a necessary pretreatment step in many dewatering streams containing significant quantity of very fine particles. A large volume of research has gone in to optimising the use of various high molecular weight polymers as flocculants for fine particle suspensions.In this research, the effect of anionic polyacrylamide concentration as flocculant on velocity of settling is investigated. Flocculation experiments were conducted using the The kaolin suspension containing 5% solid (w/w) was first stirred thoroughly in a beaker. Then the requisite amount of flocculant was then added drop wise under continued stirring condition. The flocculation experiments were followed by sedimentation tests. The entire suspension after flocculation was transferred to a graduated cylinder and allowed to settle. A clear liquid– slurry interface could be seen descending. The height of this interface was noted at a regular interval of time. Settling rates at concentration of 2,4,6 and 8 ppm from flocculant were measured from the slope of the straight-line portion of the plot of interface height vs. settling time. By use of results, the optimum concentration of flocculant determined.