At KU Leuven, young researchers are already contributing to the future of more sustainable metal production. One of them is Femke Derison, a PhD student at the Solvomet Research Group, who has recently published her first scientific article. This publication marks an important milestone in her doctoral research and contributes to the scientific foundations of the CIRMET project.
Femke’s research focuses on methanesulfonic acid (MSA), a promising reagent for hydrometallurgy whose fundamental chemistry has not yet been fully explored. A deeper understanding of such systems is essential for designing more efficient and environmentally responsible metal extraction processes. In her study, Femke investigated the solubility of nickel(II) methanesulfonate and examined how different concentrations of MSA influence its behavior in aqueous solutions.
One of the most remarkable properties of methanesulfonic acid (MSA) is that metal methanesulfonate salts are highly soluble in water. Combined with the high chemical and electrochemical stability of the methanesulfonate ion, this makes MSA‑based electrolytes very suitable for applications in hydrometallurgy, for instance, for the electrowinning or electrorefining of metals and for use as electrolytes in redox flow batteries (RFBs). However, it is much less known that the solubility of these salts decreases drastically in the presence of MSA. – Prof. Koen Binnemans, head of Solvomet group and Femke's PhD supervisor
Nickel is a key component of cathode materials used in lithium-ion batteries, which play a central role in the global energy transition. To support this transition with more sustainable technologies, hydrometallurgical processes must be based on a strong understanding of the underlying chemistry. Through a detailed study of solid liquid equilibria in Ni(CH3SO3)2–H2O–MSA systems, Femke identified three crystalline hydrates of nickel methanesulfonate: Ni(CH3SO3)2·2H2O, Ni(CH3SO3)2·6H2O and Ni(CH3SO3)2·12H2O. These phases were characterized using thermogravimetric analysis and single crystal X ray diffraction.
Her results show that the solubility of nickel(II) methanesulfonate decreases as the concentration of methanesulfonic acid increases, reaching a minimum at about 95 wt% MSA. The experimental data, obtained across a wide range of concentrations and temperatures, were then used to build a thermodynamic model within the mixed solvent electrolyte framework developed by OLI Systems. This model helps describe the thermodynamic properties of the hydrates and the interactions present in the aqueous phase.
This work is closely connected to the goals of the CIRMET project, which aims to develop a new approach known as circular hydrometallurgy. The project seeks to move away from traditional linear extraction processes and toward flowsheets that minimize reagent consumption, regenerate key chemicals and produce virtually no waste. By improving the understanding of nickel chemistry in methanesulfonic acid systems, Femke’s research provides valuable knowledge for designing more energy-efficient and circular hydrometallurgical processes.
For Femke, this publication represents an important step in her PhD journey. For CIRMET, it is another contribution toward building the scientific knowledge needed to develop the next generation of sustainable metal extraction technologies.
To read the full open-access article, go to RSC website.
