The determination of the hydraulic flow and solute transport parameters for several heap leach materials

The hydraulic and solute transport characteristics of several heap leach materials from northern Nevada are determined. Data from the United States Bureau of Mines laboratory column tracer tests and new data collected from a series of tracer experiments with sodium bromide on heap material collected from the Barrick operation, Elko County, Nevada are presented. A six meter scale column incorporating time domain reflectometry was used to investigate the rinsing characteristics of spent heap leach material. The breakthrough curve data from these experiments are analyzed using the traditional advection-dispersion equation and a dual-porosity model. The dual-porosity model provided significantly improved fits to the observed data as compared with the advection-dispersion model. Data from the experimental results are used to show that optimal rinsing strategies can be developed when heap hydraulic properties are properly considered.