A new method for estimating the hydraulic behavior of spent ore heaps, waste dumps, and tailing impoundments

WMCI has developed an integrated approach to unsaturated flow through leach pads, waste dumps and tailing impoundments which includes field characterization, data interpretation, calibration and prediction. Material characterization is performed at a scale relevant to the problem at hand. Our approach allows for model calibration based on either existing data or by designing monitoring programs to collect relevant data. Such calibration is straightforward because the strong connection between the numerical model and the physical system. Realistic atmospheric boundary conditions are combined with a rigorous unsaturated flow model. Once calibration is obtained, independent data are used to validate the conceptual model, choice of parameters and the overall simulation approach. The calibrated results provide a means for analyzing alternative operation and closure alternatives, and a technical rationale for environmental and economic decisions. The proposed methodology accurately reproduces the observed short-term discharges from heap leach pads and tailings ponds.