The invention discloses a method for extracting and purifying 5N-grade high-purity
metal through supercritical CO2 fluid, and relates to the technical field of high-purity
metal preparation. Aiming at the problem that an existing process is difficult to give consideration to
environmental protection, large scale and high purity, the method sequentially performs
raw material pretreatment, supercritical CO2
system construction and complexation reaction, multi-stage gradient pressure separation, complex analysis, electrolytic deposition and
raw material recycling. The core lies in that a fluorinated chelating agent is adopted to enhance the selectivity of target
metal ions, ultrasonic-assisted complex reaction acceleration is combined, impurities are removed through multi-stage gradient pressure separation grading, the chelating agent is recovered through low-temperature decompression analysis, finally, 5N-stage high-purity metal is obtained through electrolytic deposition, and meanwhile, circulating reuse of supercritical CO2 and the chelating agent is achieved. The method does not need strong acid, does not
discharge waste water, can obviously improve the product purity, reduces the
energy consumption and cost, and supports large-scale
continuous production.