The invention discloses a process method for preparing high-purity
rare earth metal through low-temperature
electrolysis, and belongs to the technical field of
rare earth metal metallurgy. The method comprises the following three steps: firstly, adopting a hydrophobic
ionic liquid-supercritical CO2 composite medium, adding a responsive ligand, and triggering phase separation by adjusting temperature or pressure to realize high-selectivity separation and enrichment of target
rare earth ions; secondly, the enriched rare earth
salt solution is subjected to low-temperature
plasma assisted fluorination conversion, and high-purity nano rare earth
fluoride powder is obtained; and finally, dissolving the
powder in a multi-element eutectic
fluoride molten salt with the temperature of 580-650 DEG C, taking a
composite cathode containing a
hexagonal boron nitride interface release layer as a
working electrode, applying programmed potential,
coupling ultrasonic
waves to perform electrolytic deposition, and rapidly cooling and stripping to obtain the high-purity rare earth
metal. According to the method, low-temperature, efficient and green preparation of the rare earth metal is realized, the product purity is high, the
energy consumption is obviously reduced, and the
cathode can be recycled.