Microorganisms from the guts of termites could be the key to accelerated iron ore mining site rehabilitation, if Dr Emma Gagen and her team from the University of Queensland succeeds in their research.
Canga is a type of iron cement crust which forms over the top of iron ores to create a protective layer. During mining, canga is broken up so as to access the underlying ore.
Once mining stops at an iron ore site, however, canga makes its return. This is critical as canga allows specialised indigenous plants such as bromeliads to grow. These plants are adapted to high iron concentrations and harsh conditions, accelerating the rehabilitation process for the site, and serving as the foundation for more diverse organisms to take over at the site later.
Along with the Brazilian mining company Vale, Dr Gagen is looking at methods to accelerate the formation of canga. Dr Gagen is looking into using microbes to promote growth of canga, and is currently investigating termites that build nests in and over canga. Of particular interest is the gut of these termites.
“The gut of a termite has little oxygen, making it a great environment for microorganisms that can dissolve iron oxides in canga," Dr Gagen explained.
“I am looking at how canga microorganisms dissolve and reform iron oxides which are chemical compounds composed of iron and oxygen."
Dr Gagen said the team planned to establish a field trial in Brazil to develop a bio-remediation strategy for iron ores by re-establishing canga.
Professor Gordon Southam and Professor Paulo Vasconeclos of UQ’s School of Earth Sciences, and Professor Gene Tyson of UQ’s School of Chemistry and Molecular Biosciences are leading the project.
Expected benefits from this collaboration between the university and the industry include improved training in mining-related research, and increasing the speed of site remediation, which completes the mining life cycle.
Emma Gagen and Gordon Southam inside a canga cave. Photo: UQ