Handheld LIBS contribution to quantify critical elements during mining operations: The Beauvoir granite case study

Developing innovative methodologies has become essential for mining companies to optimize resource management and achieve economic sustainability. The spectroscopic techniques such as laser-induced breakdown spectroscopy (LIBS), used for on-site analyses, have great potential to provide reliable qualitative and quantitative geochemical data to support rapid decision-making. In this context, handheld LIBS was used to predict the concentrations of the main targeted elements lithium (Li), and rubidium (Rb), on unprepared core samples from the Beauvoir granite, a rare-metal granite currently studied to achieve lithium exploitation by 2028. The models were built using different spectral parameters and statistical approaches. A comprehensive comparative analysis was conducted to determine the optimal protocol for each element. Signal variation over successive measurements, as well as the minimum number of analyses required to maintain a representative LIBS signal of the whole rock composition, were investigated. The predicted concentrations are consistent with the reference geochemical analyses confirming the ability of handheld LIBS to provide relevant analytical results, in a short period, directly at the exploitation site.