Enhancing Lepidolite Recovery from Beauvoir (Li, Be, F) Rare Metals Granite through Advanced LIBS Mapping Techniques

The ongoing global energy transformation heavily relies on a steady supply of metals and minerals. Amonh all, lithium occupies a crucial role in facilitating this transition, particularly in energy storage through Li-ion batteries. Consequently, lepidolite, a lithium-bearing phyllosilicate, has emerged as a promising source of lithium for European countries. Notably, lepidolite is enriched in the Beauvoir granite of Allier, France, which also contains other critical elements, including fluorine, tin, niobium, tantalum, and beryllium. This valuable mineral is concentrated from other silicates using froth flotation with amine under acidic conditions.In this study, we explore the liberation of lepidolite, focusing on its significant shape factor, and the impact of size fraction on lithium recovery. Four different size fractions (<180, <250, <355, and <500 µm) undergo a standardized beneficiation route, encompassing crushing, grinding, desliming, flotation, and centrifugal separation. By employing mineralogical studies and automated mineralogy methods, the limitations of the flowsheet are identified. Particularly, the integration of Laser-Induced Breakdown Spectroscopy (LIBS) mapping enables precise elemental distribution analysis of Li, F, and Be, which conventional methods like SEM or µXRF cannot provide. This powerful tool allows to effectively differentiate lepidolite from muscovite or other gangue minerals through the computation of lithium and fluorine distributions. Utilizing the LIBS mapping technique, we assess the successful liberation of lepidolite, while also uncovering scientific and technical constraints. Furthermore, by applying LIBS mapping to non-floated products, we can precise the contribution of amblygonite, a lithium-bearing phosphate present in the Beauvoir granite, during the flotation stage.The findings from this study shed light on the strengths and limitations of the developed flowsheet, leading to a comprehensive understanding and potential enhancement of the process recovery of lepidolite and by-products from the Beauvoir granite in different streams. Ultimately, this research contributes to the sustainable supply of lithium, vital for advancing Europe's clean energy ambitions.