The group of rare earth elements (REE) is considered to comprise 17 elements, i.e. 15 elements in the lanthanide series (lanthanum to lutetium), as well as scandium and yttrium that are characterized by similar chemical and physical properties. Due to the unique magnetic, luminescent and electrochemical properties of the REE, they are widely used in modern technologies, including e.g. wind turbines, hybrid cars, smart phones, lasers but also in health care, e.g. cancer treatment drugs, rheumatoid arthritis medicines and surgical supplies. The demand for REE has thus drastically increased during the last three decades and forecasts predict a continuous raising trend in future. As REE resources are limited, and REE mining/access has long time been dominated/controlled by China, the global political and economical tension have recently increased. Consequently, numerous countries, including the United States, Brazil, Mongolia, India, and last but not least Europe have launched or revived their own REE processing projects. Associated to the industrial use of REE are however also risks of environmental contamination related to toxic wastewaters polluting the groundwater and potential human health threats. As only little attention has been paid until now to the role of REE as contaminants/pollutants, the PANORAMA ITN project was proposed within the EU framework program HORIZON 2020 with the main research objective “to elucidate the man-induced environmental dissemination of REE and the associated effects on the environmental health”. To reach this objective, the project will identify and characterize the involved sources and processes and model the mobility and fluxes of REE.
The PANORAMA project integrates 15 young researchers (PhDs) within an ambitious research and training program allowing them to contribute to reach each scientific (and technical) objective and to disseminate the results towards the scientific community and the relevant stakeholders, therefore supporting Europe in the development of an environmentally clean REE circular economy.
The PhD project proposed by SCK•CEN within the frame of the PANORAMA project aims at studying the speciation and transport of REE in Passive Treatment Systems (PTS) of the Iberian Pyrite Belt. The main objective is to investigate the efficiency of components used in the PTS and more specifically in the reducing and alkalinity producing systems (RAPS= limestone and organic matter) and to determine the immobilization relevant chemical reactions. Column experiments will be used to mimic PT systems under conditions representative for the field site. It is foreseen to perform different types of well constrained column experiments enabling to control at the same time chemical parameters (pH, REE concentration, trace metals… ) as well as hydrological parameters, such as the flow rate and residence time. Batch-type experiments will also be performed to study which mechanisms are involved in the mitigation of REE concentrations in the AMD PTS (sorption, secondary phase formation, (co-)precipitation. It is expected 1/ to identify and quantify the main reactions/processes governing the fate of REE comprised in acid mine drainage in PTS of the Iberian Pyrite Belt and 2/ to model the identified processes to simulate the immobilization of REE in the PTS and thus their potential in the concentration/remediation of REE from acid mine drainage waters. Detailed characterization of the formed precipitates/secondary phases will be performed at the French national synchrotron facility SOLEIL and compared to those obtained by other project participants. Interpretation will be supported by geochemical and colloidal transport modelling (in collaboration with the Spanish consulting company AMPHOS 21). The field work and sampling will be done in collaboration with the Spanish associated partners of the HUELVA University (UHU).