Experimental thermodynamics of rare earth tengerites

CMI Highlight: Experimental thermodynamics of rare earth tengerites

Rare earth-tengerite (REE2(CO3)3⋅3 H2O) enthalpies of formation (from oxides) are plotted against ionic radius as synthesized.
Rare earth-tengerite (REE2(CO3)3⋅3 H2O) enthalpies of formation (from oxides) are plotted against ionic radius as synthesized.

CMI researchers at Arizona State University conducted the research for this highlight

Innovation 
Synthesized rare earth tengerites (carbonates) REE2(CO3)3⋅3H2O and comprehensively evaluated the structural and thermodynamic properties through direct experimental measurements and extrapolated the properties of endmembers that could not be readily synthesized. This study represents the first complete investigation of this structure type across the lanthanide series.

Achievement
Enthalpies of formation (from oxides) of rare earth carbonates have been determined with room temperature acid calorimetry (ThermotU, ASU).

Significance and Impact
Growing demand for rare earth elements (REEs) is driven by their importance in modern technology and challenging global distribution. This highlights a need for improved extraction models and new ore sources. Rare earth carbonates are important REE-bearing minerals, and understanding their thermodynamic stability is essential for geochemical modeling and optimizing extraction.

Hub Target Addressed 
Developing and applying scientific tools to accelerate technology maturation.
 

Rare earth-tengerite (REE2(CO3)3⋅3 H2O) enthalpies of formation (from oxides) shown as the overall trend including extrapolations to end members.
Rare earth-tengerite (REE2(CO3)3⋅3 H2O) enthalpies of formation (from oxides) are shown as the overall trend including extrapolations to end members.