Extinct volcanoes may be hiding an unexpected bounty. A recent study could challenge the current exploitation of rare earths.
Rare earth elements are ubiquitous in our technology: from smartphones to wind turbines. These essential metals are found in modest quantities but are difficult to extract.
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A study, published in
Geochemical Perspectives Letters, proposes a new avenue: exploiting volcanic rocks. These deposits, potentially underexplored, could meet the growing demand. The team reconstructed the conditions of past volcanic eruptions. Through laboratory simulations, they obtained concentrations of rare earth elements a hundred times higher than otherwise observed.
Extinct volcanoes hold ancient magma rich in metals. This type of volcanism no longer exists, but these deposits remain widespread, notably in Sweden and Chile.
This breakthrough comes at a time when global demand for rare earth elements is expected to increase fivefold by 2030. This presents an opportunity to reduce geopolitical dependence.
What are rare earth elements and why are they so valuable?
Rare earth elements refer to a group of 17 chemical elements with unique properties. They include metals such as neodymium, dysprosium, lutetium, and, of course, lithium. Although present in the Earth's crust in similar quantities to other metals, their extraction and separation are complex and costly.
These elements are essential in many industries. They are used to manufacture key components in modern technologies: electric car motors, wind turbine blades, smartphones, and lasers.
Global interest in rare earth elements has skyrocketed in recent years due to their role in the energy transition. They enable the development of green technologies, which are crucial for reducing our dependency on fossil fuels. Their demand could increase fivefold by 2030, sparking a race to discover new exploitable deposits.
How do rare earth deposits form in extinct volcanoes?
Rare earth deposits form under particular geological conditions. Over millions of years, volcanic activity has enriched certain magmas with iron, promoting the incorporation of rare earths during their solidification process.
These extinct volcanoes, rich in iron oxides, contain high concentrations of rare earth elements. The intense heat and pressure promote the crystallization of these elements, which accumulate in magmatic rocks. Previously overlooked, these deposits are now a promising resource.
Researchers simulate these processes in the lab to better understand how rare earths bind to minerals. These studies pave the way for the potential exploitation of extinct volcanoes, an alternative to traditional mining, to meet the growing global demand.
Article author: Cédric DEPOND