Optimising the allowable rate of deposition on tailings dams

A methodology to optimise the rate of rise of tailings dams, based on adopting the finite strain theory of consolidation is provided. The analysis is carried out using a Visual Basic program, which makes use of a speadsheet for input and presentation of the results. The results are used to predict the change in drainage path length, and the subsequent build-up of pore water pressure in the tailings, to determine the overall stability of a tailings dam. Published and tested properties of a number of different tailings are used to predict pore pressure profiles for both one- and two-way drainage, and these are presented. The analysis is also used to predict the effect on the storage capacity of a dam. This research can now be adopted to revise the present South African guidelines for tailings dams, which presently limit the rate of rise for tailings dams to 1 and 2.5 meters per annum on impermeable and permeable foundations respectively.