Assessment of capillary rise in rocks by Time Lapse Digital Imaging

Solution flow can significantly influence metal recovery and kinetics in leaching, especially in heap/dump/Insitu leaching, however, the vast majority of the work in this area has focused on the inter-particle fluid flow, and only a few studies have investigated the capillary rise behaviour within rock samples. This deserves more attention because it plays a fundamental role in the recovery process and the diffusion pathways for lixiviants and reacted products. This short communication presents a simple methodology for the estimation of capillary action by testing different rock types by Time Lapse Digital Imaging. The method was sensitive to pixel variation which can be intercepted as the response in wettability variation. It can certainly be coupled with other technologies for ore characterization, such as X-ray micro-tomography, to further understand how the pore size distribution influences capillary response, and the fluid rise through pore spaces to interact with ore grains.

Automated summary

Solution flow has a significant impact on metal recovery and kinetics in leaching processes, especially in heap/dump/insitu leaching. However, most of the research has focused on inter-particle fluid flow, neglecting the capillary rise behavior within rock samples. This study presents a simple methodology using Time Lapse Digital Imaging to estimate capillary action in different rock types. The method is sensitive to pixel variation, which indicates changes in wettability. It can be combined with other technologies to better understand how pore size distribution influences capillary response and fluid movement in ore.