MINFLOT - Improving mineral recovery efficiency of flotation using reactive transport modeling from atomic to reactor scale

Project background and objectives

In France, in Europe, and in the rest of the world, conducting the energy transition toward decarbonized and renewable energies induces a growing need for critical metals, particularly lithium, tungsten, cobalt, nickel, mainly extracted from ores and mining residues. The processes commonly used in ore processing lack efficiency to recover minerals and precious metals from the subsoil while respecting the environment. It is therefore essential to improve the efficiency of these techniques in order to sustainably extract critical metals from primary sources, ores, and secondary sources, such as mining residues, in line with the issues of ecological transition.

Flotation is a highly efficient and widely used process to separate minerals of interest from their gangue (non-valuable minerals). This method is based on the use of reagents aimed at modifying the surface tension of minerals and then on the injection of air bubbles that recover the particles rendered hydrophobic. However, flotation is still not optimal, leading to a longer and more costly process, due to the difficulty in understanding and simulating:

• the physico-chemical phenomena of adsorption, at solid/liquid and liquid/gas interfaces;
• their link with particle transport and the recovery of valuable minerals in turbulent flows.

Indeed, this method involves heterogeneous materials, a complex water chemical composition, particles, bubbles, and reagents interacting in complex flows, particularly for fine materials which are attracting growing interest. Currently, only atomic simulations and fluid dynamics simulations at the considerably larger reactor scale are taken into account, without mechanistic understanding of the phenomena at play. The efficiency of flotation can be significantly improved by improving its simulation and ultimately mineral recovery (and therefore metals). This by taking into account multi-physical and multi-scale phenomena, from the atomic scale to the reactor scale, and by understanding and mechanistically simulating the interaction forces between particles and their environment during their transport.