Plants found in Australian backyards could unlock future Queensland jobs in new minerals.
A study of native plants like selenium weed and a variety of macadamia tree are being researched for their abilities as “hyperaccumulators” that extract rare earth metals from the ground through a process called “phytomining”, the Palaszczuk Government investing $1 million into joint research with the University of Queensland’s Sustainable Minerals Institute.
The innovative world-first joint study has the potential to change how some mines operate in the future, resources minister Scott Stewart says.
“In a commercial environment, this could mean plants could be used to extract minerals and that means less of a need to disrupt the ground,” he explains.
“Or they could be used to extract minerals from tailings during mine rehabilitation which can then be sold.”
Stewart says the study is in keeping with the growing popularity of renewable technology and electric vehicles, adding that new ways are being considered to handle Queensland’s rich deposits of minerals like cobalt, copper and vanadium.
Researchers found a field of one type of hyperaccumulators planted across a nickel-rich site like a mine tailings dam could yield 300kg of nickel per hectare annually, meaning the important metal used in rechargeable batteries and stainless-steel manufacturing could be harvested rather than mined.
The study will involve determining whether certain types of native plants found at rare earth element rich sites in Queensland can draw those metals out of the soil in high volumes.
University of Queensland professor Rick Valenta says the phytomining study could supply sustainably sourced rare earth metals with low environmental impact.
“The study aims to produce hybrid processing techniques to extract rare earth elements and to unlock a variety of resources typically not considered for rare earth element production,” he says
Stewart says this would be looked upon favourably around the world, enhancing Queensland’s market position.
“Consumers in Europe or the United States want to know that the materials used to make the battery that powers their electric cars were sourced ethically, in both a social and environmental sense.”
Director of UQ’s Centre for Mined Land Rehabilitation associate professor Peter Erskine says phytomining could be used to access unconventional resources that are not viable using existing mineral processing techniques.
“This includes mine wastes, such as tailings, that still hold residual metals of interest – in effect, phytomining could turn waste into new resources.”
The specialised study will run for four and a half years and includes tests on rare earth element-rich material from the Phosphate Hill mine and closed Mary Kathleen mine near Cloncurry, and the Peak Range in Central Queensland.
A series of experiments will follow to establish optimum conditions, range of application and limitations for the identified plant species and different rare earth-rich material types.
The study is a major part of the Palaszczuk Government’s $23 million New Economy Minerals Initiative.
