Understanding fluid–rock interactions and lixiviant/oxidant behaviour for the in-situ recovery of metals from deep ore bodies

The Challenge

Limited understanding of the performance of chemical recovery systems in real ore bodies has held back development of practical in-situ recovery (ISR) technology in mining.

Key Findings

Sulfate and salt solutions reacting with copper ores produce mineral precipitates which prevent the reactive fluids reaching the surface of the copper minerals, slowing reactions.

This behaviour prevents accurate prediction of ISR performance in real ore systems, where porosity of rocks and ability of chemical reactants to interact with the ore are critical.

The greatest recovery efficiency obtained in this study was delivered by a solution of ferric chloride and hydrochloric acid.

Benefit to WA

Western Australia is the world’s sixth-largest copper producer, with recent major discoveries and a wealth of exploration prospects adding to the future potential significance of this metal for the state.

By supporting practical and environmentally sensitive development of ISR technology, the findings of this research could prolong the operation of many existing copper mines in Western Australia or help convert currently sub-economic systems into commercial prospects, all while reducing the impact of mining on the landscape.

Keywords: in-situ recovery; fluid–rock interactions; deep ore bodies; chalcopyrite; bornite; reaction kinetics