Process Optimisation in the Retreatment of Gold-Bearing Sand Dumps: A Case Study of Zimbabwe

In this paper, we apply process optimisation to identify opportunities of maximizing gold recovery in a small scale heap leaching plant. Less work on improving leaching gold ore, specifically targeting optimizing most process variables in heap leaching, is available as yet. Bottle rolls gave the total leach result ~ 95 % to use as a base line whilst column tests 81% gave a good indication of the "relative" response of ore to different operating parameters. The choice and blend of test methods is about maximising information return within available time and money. Preliminary pilot results currently underway prove that utilizing heap leaching would potentially reduce capital costs and increase in recoverable gold.

The investigation reported in this paper is not intended to set out ideal operating parameters for industrial processes, but aims to show how process optimisation can be used to develop ways of improving recovery. The anticipated benefits of our research are that it would reduce reagent consumption, create background knowledge and greatly improve overall mineral recoveries.