Indium obtained from mining waste could become a source for Australia’s future home-grown solar manufacturing industry, according to a new study by the University of Queensland.
In a new scientific paper published in the international journal Science of the Total Environment, **researchers sought to find economic ways to extract indium from mining waste. They examined the Baal Gammon copper mine in Queensland.
The study found that the Baal Gammon mine waste contains an average of 93 parts per million of indium, more than 1,500 times higher that the usual abundance in the earth’s crust. The researchers also found that polluted waters at the site had levels 24,000 times higher than natural waters.
“We detected indium in the acid mine drainage waters at very high levels; however, there is still a knowledge gap regarding whether it poses a contamination risk,” according to Olivia Mejías, an ARC Centre in Critical Resources for the Future research fellow and first author of the paper.
Indium is important to the development of a solar industry as it is commonly used in solar panels due to its ability to conduct electricity and is see through.
However, no mines produce indium as a primary commodity, and the element is imported from China, where it is a major zinc-refining by-product.
In order to achieve an independent supply chain for Australia, reprocessing old mine waste may be a faster way to supply critical minerals rather than developing new deposits.
Mejías noted that if Australia is going to develop its own supply chains for critical minerals, it is important to find and extract those minerals from mine wastes.
“Indium is a key component of solar panels, so if you can extract and use your own resources and you’re manufacturing your own product using green energy, it’s a win-win!”
Dr Thomas Poulet, a study co-author, research scientist and team leader at the Commonwealth Scientific and Industrial Research Organisation (CSIRO), said studying both the extraction and environmental impacts of critical minerals like indium is essential to prevent ecosystem damage.
“Proactive mitigation ensures community trust and preserves companies’ social license to operate while supporting sustainable resource development,” Dr Poulet said.