A team of RSES geologists, led by Professor Frances Wall from the Camborne School of Mines, have discovered a new hypothesis to predict where rare earth elements neodymium and dysprosium could be found.
The elements are among the most sought after, because they are an essential part of digital and clean energy manufacturing, including magnets in large wind turbines and electric cars motors.
For the new research, scientists conducted a series of experiments that showed sodium and potassium — rather than chlorine or fluorine as previously thought — were the key ingredients for making these rare earth elements soluble.
This is crucial as it determines whether they crystalize — making them fit for extraction — or stayed dissolved in fluids.
The experiments could therefore allow geologists to make better predictions about where the best concentrations of neodymium and dysprosium are likely to be found.
CO-AUTHORS CORINNE FRIGO AND MICHAEL ANENBURG IN FRONT OF A PISTON CYLINDER APPARATUS AT THE RESEARCH SCHOOL OF EARTH SCIENCES, AUSTRALIAN NATIONAL UNIVERSITY. CREDIT: MICHAEL ANENBURG, ANU
The results are published in the journal, Science Advances today (Friday, October 9th, 2020).
University of Exeter researchers, through the ‘SoS RARE’ project, have previously studied many natural examples of the roots of very unusual extinct carbonatite volcanoes, where the world’s best rare earth deposits occur, in order to try and identify potential deposits of the rare earth minerals.
However, in order to gain a greater insight into their results, they invited Michael Anenburg to join the team to carry out experiments at the Australian National University (ANU).
He simulated the crystallization of molten carbonate magma to find out which elements would be concentrated in the hot waters left over from the crystallization process.
It showed that sodium and potassium make the rare earths soluble in solution. Without sodium and potassium, rare earth minerals precipitate in the carbonatite itself. With sodium, intermediate minerals like burbankite form and are then replaced. With potassium, dysprosium is more soluble than neodymium and carried out to the surrounding rocks.
Read full article by UNIVERSITY OF EXETER HERE
Reference: “Rare earth element mobility in and around carbonatites controlled by sodium, potassium, and silica” 9 October 2020, Science Advances. DOI: 10.1126/sciadv.abb6570