An electrochemical model of the induced‐polarization phenomenon in disseminated sulfide ores

A disseminated sulfide ore is idealized by a system of electronically conducting metallic spheres randomly dispersed in an electrolytically conducting host medium. When an external electric field is applied, the transport of cations and anions in the interphase region near the metal‐electrolyte interface will involve both drift and diffusion flux densities. The flow of ions to or from the metal‐electrolyte interface causes an excess or deficit of inactive ions to accumulate there, since the metal is neither a source nor sink for these ions. These inactive ions are loosely held to the metallic particles by image forces, and concentration gradients build up which oppose the migration of these ions due to electric fields. In addition to the inactive anions and cations, a minor concentration of active cations is assumed to exist in the electrolytic medium, and the electric fields at the electrolyte‐metal interface cause these to engage in electrochemical reactions making possible charge transfer across the in...