Extinct volcanoes a ‘rich’ source of rare earth elements

Iron-rich magma entombed inside extinct volcanoes is likely abundant with rare earth elements, offering a new way to source these in-demand metals, according to new research from The Australian National University (ANU) and the University of the Chinese Academy of Sciences.

Rare earth elements are vital to the development of electric vehicles and renewable energy technologies such as wind turbines. They are also found in smartphones, flat screen TVs, magnets and even trains and missiles.

With more countries investing heavily in renewable energy technologies, the demand for rare earth elements continues to skyrocket, with demand for these elements expected to?increase fivefold by 2030, according to ANU.

ANU research fellow Michael Anenburg?says the iron-rich magma that solidified to form some extinct volcanoes is up to a hundred times more efficient at concentrating rare earth metals than the magmas that commonly erupt from active volcanoes.

“We have never seen an iron-rich magma erupt from an active volcano, but we know some extinct volcanoes, which are millions of years old, had this enigmatic type of eruption,” he said.

“Our findings suggest that these iron-rich extinct volcanoes across the globe, such as El Laco in Chile, could be studied for the presence of rare earth elements.”

The researchers simulated volcanic eruptions in the lab by sourcing rocks similar to those from iron-rich extinct volcanoes. They put these rocks into a pressurised furnace and heated them to extremely high temperatures to melt them and learn more about the minerals inside the rocks.

This is how they discovered the abundance of rare earth elements contained in iron-rich volcanic rocks.

“Rare earth elements aren’t that rare,” Dr Anenburg?says.

“They are similar in abundance to lead and copper, but breaking down and extracting these metals from the minerals they reside in is challenging and expensive.”

China has the biggest deposit of rare earth elements on the planet, while Europe’s largest deposit of rare earths?is in Sweden.

Australia has a world-class rare earths deposit at Mount Weld in WA, with others near Dubbo, NSW, and Alice Springs in the Northern Territory.

According to Dr Anenburg, Australia has an opportunity to become a major player in the clean energy space by capitalising on its abundance of rare earth resources.