Deeper understanding of metal oxide reduction through mechanochemical ball milling

The reduction of metal oxides is crucial for the extraction of metals from their ores, a fundamental process in metallurgy. Growing demands within a rapidly transforming environment requires the development of innovative and sustainable solutions.[1] Mechanochemistry offers a solvent-free, energy-efficient route to materials processing, aligning with green chemistry principles.[2] By employing mechanical forces to induce chemical transformations, mechanochemical ball milling enables alternative reaction pathways, kinetics and alternative products.[3]

In this study, the mechanochemical reduction of metal oxides (e.g., Co₃O₄) is investigated through ex situ and perspectively in situ X-ray powder diffraction.[4, 5] A systematic study will explore the influence of metallic reductants (e.g., Mg, Al), gas atmospheres (e.g., H₂, NH₃), milling parameters (ball-to-powder-ratio, ball size, frequency), and jar/ball materials (e.g., steel, ZrO₂) on reaction mechanisms, phase evolution, and product properties. Metallic cobalt in both its cubic and hexagonal phases was successfully synthesized via ball milling, without the need for elevated temperatures or hazardous reducing agents such as hydrazine

This research advances the fundamental understanding of reaction mechanisms in mechanochemistry and supports the sustainable material processing. The results will contribute to critical topics such as green synthesis, recycling processes, and environmental aspects of material production. It addresses challenges at the interface of applied mineralogy, crystallography, materials science, and engineering.

1.         Satritama, B., J. Sustain. Metall., 2024. 10

2.         Mateti, S., Chem. Commun., 2021. 57

3.         Takacs, L., Chem. Soc. Rev., 2013. 42

4.         Rathmann, T., Rev. Sci. Instrum., 2021. 92

5.         Weidenthaler, C., Crystals, 2022. 12