▎ 摘　　要

NOVELTY - Method of synthesizing corundum nanoparticles involves mixing a reaction precursor with a conductive additive to form a mixture, where the reaction precursor is an aluminum compound; and applying a voltage across the mixture to form the corundum nanoparticles, where the voltage is applied in voltage pulses, duration of each of the voltage pulses is for a duration period, and the voltage pulses increase the temperature of the mixture to at most 1500 K. USE - The method is useful for synthesizing corundum nanoparticles. ADVANTAGE - The method meets the need for a rapid and energy-efficient pretreatment for the REE recovery from ores, fly ash, and bauxite residue (red mud) and the need to develop a 'dry' method to directly recovery the rare earth elements in ores, fly ash, and bauxite residue (red mud). DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a system for performing the above method comprising (a) a source of the mixture comprising the material and conductive additive; (b) a cell operably connected to the source such that the mixture can be flowed into the cell and held under compression; (c) electrodes operatively connected to the cell; and (d) a flash power supply for applying a voltage across the mixture to recover the metal from the material.