Geostatistical Analysis Of 3D Electrical Resistivity With Moisture Data To Characterize A Gold Heap

Flow models are used to predict the extraction efficiency of metals in rock piles. These models typically use hydraulic parameters obtained through column studies, which assume that the material in the column wholly represents the entire pile and the parameters can be upscaled several orders of magnitude for model evaluation. This assumption fails for parameters that are spatially variable or scale dependent. To overcome these issues, measurements made directly on the heap at the appropriate model scale can be made with the electrical resistivity method. The method aims to map the variations in the electrical resistivity, which can be associated with moisture content, degree of fines, metal content, and leachate concentration. We present an example of calibrating the resistivity with borehole measurements of moisture using geostatistics to show how the resistivity method can be used to obtain a spatial moisture distribution. It was shown that cokriging the resistivity and moisture together gives a more reliable distribution.