Phase Relations for Saline Slurry- Deposited Tailings

Large-strain void ratio-effective stress relationships of tailings measured in a laboratory are used to predict volumetric capacity of tailings facilities required to support mine operations. However, the impact of dissolved salts on phase relationship calculations is often neglected. Methods and phase relationships for measuring and correcting large-strain consolidation calculations for pore-fluid salinity are provided. Example data from three hard rock-mine tailings are evaluated to illustrate the effect of not considering dissolved salts in large-strain consolidation calculations. A greater than 5 % error in void ratio is introduced when the total dissolved solids in the pore water exceeds 20 g/L ( approximately equal to an electrical conductivity of 31 mS/cm) for a tailings with a specific gravity of 2.7. An example forward (predictive) simulation of a 30-m column of slurry-deposited tailings is used to illustrate that neglecting salts in phase relationship calculations does not cancel out when used for design, producing an overprediction in the final settled height.