Synthetic rocks shed light on REE formation

“As the world’s population and the fight against carbon emissions increase as a result of global climate change, the demand for REEs is simultaneously increasing, which is why this research is so important. By furthering our understanding of REE formation , we hope to pave the way for a more sustainable future,” said lead researcher Juan Diego Rodriguez-Blanco in a press release.

According to Rodriguez-Blanco, the genesis of rare earth deposits is one of the most complex problems in earth science. However, he believes his team’s approach sheds new light on the formation mechanisms of rocks containing rare earths. This knowledge is essential for the energy transition, as rare earths are key manufacturing ingredients in the renewable energy economy.

The researcher noted that the new study found that REE-containing fluids replace common limestone, and this occurs via complex reactions even at room temperature. Some of these reactions are extremely fast, occurring in the same time it takes to brew a cup of coffee.

This knowledge has allowed the team to better understand the basic mineral reactions that also take place in industrial separation processes, which will allow improving extraction methods and separating REE from fluids.

Since the main objective of the team is to understand the complex processes of formation of REE-carbonate deposits, they decided to synthesize their own minerals and rare-earth carbonate rocks (similar to bastnasite, the critical mineral at from which REEs can be extracted from carbonatite rocks). This, instead of studying natural samples.

Once they have completed the synthesis process, they then mimic natural reactions to learn how REE mineralizations form.

It also allows them to assess how changes in key environmental factors promote their formation. Such knowledge, in turn, can help understand the origin of mineralization on untapped carbonatite resources, which are not only found in China – the supplier of 60% of the world’s REE needs – but also in other regions of the world, such as Brazil, Australia, the United States, India, Vietnam, South Africa and Greenland.

“As REEs play an essential role in a technological and sustainable future, there is a need to understand the behavior of REEs in the geochemical cycle and in basic chemical reactions,” said Adrienn Maria Szucs, lead author of this study.