Major Challenges Associated with the Beneficiation of a Petalite-Type Pegmatite

Recently, the European Commission (EC) adopted several Strategic Projects (SPs) to secure the sustainable supply of critical raw materials and improve the competitiveness and manufacturing capacity of European industry, also including the lithium-ion batteries (LIBs) sector. Hard-rock pegmatites rich in spodumene, petalite and lepidolite are the most important lithium resources due to their widespread occurrence, high lithium grade and economically viable extraction and processing. The beneficiation of petalite-type pegmatites presents significant challenges due to their low Li2O content, complex mineralogy and the presence of gangue minerals that exhibit similar physical and chemical properties to petalite. While most previous studies focus on the beneficiation of pure petalite samples, the processing of ores in which petalite is closely associated with various silicate gangue minerals is marginally investigated. The present study discusses the major challenges associated with heavy-liquids separation, magnetic separation and froth flotation when applied for the beneficiation of a petalite-type pegmatite ore containing 0.92% Li2O. The main results indicate that both the sink 2.65 and the float 2.55 fractions are enriched in Li2O (ranging from 1.57 to 1.99% Li2O) compared to the intermediate gravimetric fraction (0.43% Li2O). Magnetic separation shows that although the magnetic product is enriched in iron (Fe2O3 0.81 vs. 0.26%), both products (magnetics and non-magnetics) exhibit similar Li2O contents, which did not exceed 1%. Flotation tests result in a final float product containing 1.16% Li2O, primarily due to its high albite content (~ 55%).