Shear cell tests for quantification of tailings segregation



Mine tailings consisting of sands, silts and clays may segregate during deposition and flow, leading to problems with storage capacity and strength development of settling pond deposits. Non-segregating tailings (NST) may effectively limit the effect of segregation by increasing the amount of fines retained in deposited tailings. Segregation can be minimised once the settling velocity of the coarse fraction of the tailings is determined as a function of the rheological properties and shear rate. Shear cell testing provides a bench-scale test method to quantify settling velocities of the coarse fraction of slurries. Within the tested conditions, measured settling velocities are about twice as large as settling velocities calculated based on apparent viscosity and hindered settling.