| 摘要 |
A method and unitary apparatus purifies solid metallic gold. For that purpose, the gold to be purified is immersed and electrolytically dissolved into a pregnant electrolyte comprising an aqueous solution of a halide ion source impregnated with a catalyst, preferably a peroxide or a nascent oxygen source, for leveling the overvoltage of gold. The dissolved gold ions are segregated from the cathode by a semi-perme-able barrier, the insoluble impurities are separated from the gold-containing liquidus, and then the gold is selectively reduced to metallic form from the liquidus by a selective chemical reducing agent. With this method and apparatus, gold in metallic form of at least 99.95% purity can be obtained.
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