This seedling is literally 'growing' metals and it's called phytomining. Somewhat bizarrely, plants might be set to become the host of essential ingredients in your phone, computer or car battery - or even a wind turbine.
In August this year, the University of Queensland (UQ) in Australia, who have been working in the phytomining area for a number of years, was granted $1 million to research the hyperaccumulation capacity of selenium weed and macadamia trees.
THE RESEARCHERS ARE CONFIDENT THAT THE PHYTOMINING OF NICKEL COULD QUICKLY PROCEED TO FULL-SCALE PRODUCTION AND THAT THE PHYTOMINING OF COBALT, THALLIUM AND SELENIUM ARE ON THE HORIZON.
The researchers already know that a field of hyperaccumulators planted across a nickel-rich tailings dam can deliver 300 kg of nickel per hectare per year. UQ's Associate Professor Peter Erskine said the study is investigating if this process, once implemented at a large scale, could be a sustainable option for mining rare metals and the transition from carbon-fuelled mining.
Metals are extracted in different ways, but mostly burned to extract the mineral from the ash once it grows to the optimum specified level. When nickel is extracted from the shoots of a burned plant, the ash can yield more than 25 percent metal.
“PHYTOMINING IS AN INNOVATIVE SOLUTION BECAUSE IT COMPLEMENTS THE GLOBAL SUPPLY CHAIN FOR CRITICAL MINERALS LIKE COBALT WHILE PROMOTING THE CIRCULAR ECONOMY BY UTILISING MINING WASTE.
SOME SPECIES OF PLANTS CAN CONTAIN UP TO ONE PER CENT OF COBALT OR FOUR PER CENT OF NICKEL IN THEIR SHOOTS, TRANSLATING TO MORE THAN 25 PER CENT METAL IN THEIR ASH WHICH IS DUBBED ‘BIO-ORE'."
Screening efforts in global herbaria had led to the discovery of more than 100 hyperaccumulator plants new to science. One of the more interesting opportunities for phytomining is the voracious ability of certain Australian native plants to absorb metals.
“THANKS TO A PREVIOUS STUDY CONDUCTED BY UQ RESEARCHERS, WE KNOW QUEENSLAND IS HOME TO NATIVE PLANTS THAT HAVE THIS ABILITY TO ABSORB METAL, WHICH ARE KNOWN AS HYPERACCUMULATORS."
Fieldwork at the Queensland’s MMG Dugald River Mine discovered zinc hyperaccumulation in the native legume Crotalaria novae-hollandiae, which opens up the possibility of zinc phytomining.
Metal plant farms are already springing up in China, Europe and Malaysia. And they look set to disrupt the mining industry as on the face of it, these farms are all-round winners: good profits and excellent environmental credentials.
Images: University of Queensland | Image of Green phloem tissue of the tree Hybanthus austrocaledonicus from New Caledonia is rich in nickel giving it a green coloration by Antony van der Ent, UQ