Petalite was the first mineral in which lithium was detected, but its economic importance is less than that of the lithium-rich spodumene. Both minerals occur in pegmatitic deposits (LCT pegmatites), which were explored in the past mainly for tin and tantalum. Nowadays, lithium-bearing minerals are the focus of mining. Although both minerals are similar in the processing and extraction of lithium, their mineralogical properties differ. Through roasting, petalite undergoes a phase transformation to β-spodumene, producing quartz as an excess. Subsequently, the roasted material can be fed into the established converter process to produce lithium hydroxide or lithium carbonate.
In order to cover the increasing demand for lithium for use in lithium-ion batteries as a contribution to the energy transition and the associated turn away from fossil fuels, investments in mining projects away from the particularly lucrative spodumene pegmatites are necessary. Petalite is one such alternative.
Using petalite deposits in Namibia as an example, we will show whether it is possible to determine the mine of origin based on mineralogical and geochemical properties to contribute to possible lithium fingerprinting as proof of origin. The approach is based on the combination of different analytical methods, such as EDX, electron microprobe and trace element distribution using ICP-MS. Lithium fingerprinting can then be used as a tool for material-based control of ESG criteria upstream in the lithium value chain.