The separation of chemical elements is at the heart of the mining, the recycling of nuclear and electronic waste and water decontamination. However, hydrometallurgical leaching and liquid-liquid extraction processes use considerable volumes of water and solvents, which are often polluting and volatile. Environmental issues therefore represent a key challenge for future hydrometallurgical processes.
Hydrophobic eutectic solvents have recently been considered for metal extraction. They offer many advantages, such as lower volatility, higher flash point and improved extraction performance, combined with different extraction mechanisms compared with conventional diluents.
The aim of this thesis will therefore be to prepare and test hydrophobic eutectic solvents (HES) based on extractant molecules known in the laboratory, and to study their liquid-liquid extraction and leaching properties with respect to different metals, with particular interest in the extraction of uranium from mines. Extraction mechanisms in these unconventional solvents will be addressed, with close observation of complexation and structuration effects, in order to optimize performance. The extraction properties of uranium and various metals will be evaluated by ICP-OES and compared with the physico-chemical and structural properties of the systems (density and viscosity measurements, acid-base and Karl Fisher titration, NMR and IR spectroscopies, tensiometry, small-angle X-ray and neutron scattering (SAXS, SANS)...).
Requested skills: chemistry, analytical chemistry, physical chemistry, and knowledge of hydrometallurgy.
The applicant will gain experience in separative chemistry, management of scientific projects and will be eligible for engineering and/or research positions in the fields of chemistry and hydrometallurgy.