Results on alunite and basaluminite (felsobanyaite) dissolution kinetics presented at the 2015 Goldschmidt Conference

Our work on alunite and basaluminite (IMA-accepted mineral name: felsobanyaite) dissolution has been recently presented at the 2015 Goldschmidt Conference, held in Prague, Czech Republic, between the 16th and the 21st of August 2015. Our contribution, entitled "Alunite and basaluminite dissolution: Comparison and insights from batch experiments and atomistic computer simulations" described many of the results obtained during the EC-funded RASMIM project and compared the dissolution rates of alunite and basaluminite (felsobanyaite) under similar pH and temperature conditions. 

One of the main findings of the study is the higher stability of alunite, with dissolution rates noticeably slower than the ones for felsobanyaite under similar conditions. Even though the dissolution rates for both minerals seems to increase with both the increase of pH and temperature, such dependence is much weaker in the case of alunite than in the case of felsobanyaite.

Atomistic computer simulations for alunite suggest that most mineral surfaces expose K atoms and/or hydroxyl groups. Thus, these components should be the easiest to detach from dissolving alunite, whereas Al and sulphate tetrahedra seem to be much less accessible to the solution and should be the ones limiting alunite dissolution.

The conference contribution is available in the form of conference abstract at the Goldschmidt 2015 website.

RASMIM Project results presented at the EGU 2015

Some of the results of the RASMIM Project have recently been presented at the European Geosciences Union General Assembly 2015, held 12-17 April, 2015 in Vienna, Austria, as a part of the session entitled "The nature of the mineral-fluid interface: relevance to dissolution and growth processes".

Our contribution, entitled "Influence of pH and temperature on alunite dissolution rates and products", by Patricia Acero and Karen Hudson-Edwards, presents some of our data on the dissolution rates of alunite under similar conditions to the ones in many sulphate natural waters (pH between 3 and 8 and temperature between 6 and 40 degrees celsius). The solution and mineral data are interpreted together with the assistance of X-ray Photoelectron Spectroscopy, Scanning Electron Microscopy and geochemical modelling, among other techniques.

The abstract of the contribution with further information can be accessed via the Copernicus webpage.