Non-isothermal kinetics of the thermal desorption of mercuryfrom a contaminated soil

摘要

The Almadén mining district (Ciudad Real, Spain) was the largest cinnabar (mercury sulphide) mine in the world. Its soils have high levels of mercury a consequence of its natural lithology, but often made much worse by its mining history. The present work examines the thermal desorption of two contaminated soils from the Almadén area under non-isothermal conditions in a N2 atmosphere, using differential scanning calorimetry (DSC). DSC was performed at different heating rates between room temperature and 600 °C. Desorption temperatures for different mercury species were determined. The Friedman, Flynn-Wall-Ozawa and Coasts-Redfern methods were employed to determine the reaction kinetics from the DSC data. The activation energy and pre-exponential factor for mercury desorption were calculated. © 2014 CSIC.