High‑efficiency recovery of lithium from an amblygonite ore via low-temperature sulphate roasting and aqueous leaching techniques

Hard-rock minerals have become an important source of lithium extraction due to the increasing demand for this strategic resource in energy-storage applications. This study investigates the recovery of lithium from an underexplored amblygonite ore (LiAlPO4F) using a hydrometallurgical route involving sulphate roasting followed by aqueous leaching. The operating parameters studied include the following: Na2SO4: amblygonite mass ratio, time, temperature, and influence of particle size for determination of extent of extraction prior to subsequent beneficiation. The calcined and resulting leached residues were analysed using X-ray Diffraction (XRD), X-ray Fluorescence (XRF), Atomic Absorption Spectroscopy (AAS), and Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM-EDS), respectively. A lithium extraction efficiency as high as 99.8% was achieved at an ore-to-salt ratio of 1: 4 w/w, with roasting conducted at 800°C for 90 minutes and a particle size fraction of approximately −45 µm. XRD characterisation revealed that sulphate roasting promoted the formation of new residual phases, including albite (NaAlSi3O8), orthoclase (KAlSi3O8), and anorthite (CaAl2Si2O8) respectively from the initial calcine phases.