Separation of lepidolite from hard-rock pegmatite ore via dry processing and flotation

A mineralogical study of Gonçalo lithium-bearing mica-rich pegmatite ore (Portugal) indicated that lepidolite occurs in coarse-grained textures, which allows an appreciable liberation gangue minerals (quartz, k-feldspar, and albite) from lepidolite. However, the intergrowth these results uncomplicated (i.e., inclusions). Taking advantage this coarse liberation, optical sorting through image analysis was attempted order to predict grades different-sized fractions using a random comminution algorithm. The ore-sorting process allowed production marketable Li pre-concentrate product for metallurgy. Moreover, method also highlighted possible valuation reject as low-Li-content quartz–feldspar mixtures ceramic industry (reduction temperature porosity closing). Furthermore, scaled approach grinding sieving formation lepidolite-rich fraction (>210 ?m), processed electrostatic separator by varying key parameters. muscovite were separated obtain assaying 3.5 % Li2O feed grade containing 1.8 Li2O. Nevertheless, according zeta-potential measurements, flotation test performed with finer-sized (–210 + 63 ?m) showed optimised between pH 3 5. In range, concentrates rougher stage assayed 4.2–4.5 Li2O, corresponding 87–95 recovery. At > 5, selectivity decreases, SiO2 suggests quartz other silicates rather than Feldspar/quartz tested rejects promote separation feldspars products applications.