A team of international researchers, including Dr Rich Crane from the Camborne School of Mines, University of Exeter, have developed new method to extract metals, like copper, from their parent ore body.
The research team have provided a symbol of concept for the appliance of an electrical field to control the movement of an acid within a low–permeability copper-bearing ore deposit to selectively dissolve and recover the metal in place .
This is in contrast to the traditional approach for the mining of such deposits where the material must be physically excavated, which needs removal of both overburden and any impurities within the ore (known as gangue material).
The researchers believe the new technique has the potential to rework the mining industry, because it’s the potential to dissolve metals from a good range of ore deposits that were previously considered inaccessible.
Furthermore, due to the non-invasive nature of the extraction, the research team are hopeful that the study will help inaugurate a more sustainable future for the industry.
This is urgently required now in order to provide the plethora of metals required to deliver green technology, like renewable energy infrastructure and electrified vehicles, whilst limiting any potential environmental damage related to the mining of such vitally important metals.
The study was recently published in Science Advances.
Dr Rich Crane from the Camborne School of Mines, University of Exeter, and co-author of the study, said: “This new approach, analogous to “key-hole surgery,” has the potential to supply a more sustainable future for the mining industry, by enabling the recovery of metals, like copper, which are urgently needed for our global transition to new Green Economy, whilst avoiding unwanted environmental disturbance and energy consumption.”
The central principle behind latest mining techniques has not fundamentally changed since their original conception, which marked the start of the Bronze Age: metals are recovered from the subsurface via physical excavation, i.e., contruction of tunnels to gain access to the deposits, or by creating “open cast” mines.
This technique demands large volumes of surface soil, overburden and gangue material to even be excavated, which may contain many tonnes of material — and may also cause habitat destruction.
In this new publication, experts from the University of Western Australia , the Commonwealth Scientific and Industrial Research Organisation (CSIRO), the Technical University of Denmark and the University of Exeter, have demonstrated that a targeted electrical field are often to dissolve then recover copper in place from the ore — avoiding any requirement to physically excavate the material .
This new technology comprises the contruction (drilling) of electrodes directly into an ore body. An electrical current is then applied which may end in the transport of electrically charged metal ions, like copper, through the rock via a process called electromigration.
The research team have now provided proof of Concept for this new technology at laboratory scale, which has also been verified using computer modelling. They’re confident that the idea will work beyond the laboratory-scale.
The Findings were reported in University of Exeter