Neue Publikation zur Thermodynamik verschiedener Te-Phasen

Tellurium (Te) is a rare element in the Earth's crust but the number of known minerals of Te, relative to its crustal abundance, is very high. Therefore, tellurium is one of the mineralogically most diverse elements. One way to understand this diversity is through thermodynamic analysis, by identifying the minerals which are stable and quantifying the metastability margin of the other ones. In the newest work, we investigated thermodynamics of several TeO2 phases and anhydrous metal tellurites. More than 200 synthesis protocols were tested in order to obtain phase pure phases and calorimetry returned the needed thermodynamic functions. We determined that the tetragonal TeO2 (the mineral paratellurite) is the stable TeO2 polymorph. Aqueous concentrations of Te(IV), necessary to precipitate the investigated minerals, are 3-5 orders of magnitude higher than the natural geochemical background. Such minerals are restricted to hot spots where primary Te-bearing ores are weathering. More information can be found at https://doi.org/10.1016/j.chemer.2022.125915Externer Link