Ekaterinburg Non-Ferrous Metals Processing Plant, Verkhnyaya Pyshma, Russia:

K. P. Konik, Head of Refining Shop
S. V. Lobko, Leading Research Engineer

LLC “ENFMPP — Engineering”, Verkhnyaya Pyshma, Russia:

E. A. Kuzas, Engineer, e-mail: e.kuzas@ezocm.ru

Ural Federal University named after the first President of Russia B. N. Yetlsin, Ekaterinburg, Russia:
S. S. Naboychenko, Professor, Head of a Chair of Metallurgy of Heavy Nonferrous Metals

In Russian and foreign refineries alike, raw materials, containing platinumgroup metals, are processed by applying technologies such as hydrochlorination, sintering with oxidizers or dissolution in a panitrohydrochloric acid. These technologies are highly intensive, but do not ensure the required completeness of raw material opening per phase. Electrochlorination is efficient and promising platinum-group metal opening method, where precious metals are oxidized with atomic chlorine, which is formed during electrochemical oxidization of chloride-ions on the dissolved material surface. The type of current is the most important of the parameters, influencing the electrochlorinator construction. A laboratory research was performed to study the low-frequency symmetrical AC current and DC current influence on electrochlorination dynamics and placer platinum opening completeness. The experiments disclosed that the usage of DC current and Nafion cation exchange membranes enables the highest speed of placer platinum electrochlorination in hydrochloric acid solution. The specialists at Ekaterinburg Non-Ferrous Metals Processing Plant develop a special industrial DC electrochlorinator with a 200 dm³ operating volume. It can dissolute up to 20 kg of placer platinum per day; achieve at least a 99% completeness of placer platinum opening; obtain sulphate-chloride solutions without nitrate ions, whilst the concentration of platinum is at least 100 dm³; automatically support the electrolyte level in anode and cathode chambers, and change the current load depending on the anolyte’s temperature. The industrial electrochlorinator may also be used for dissolution of other types of precious metals containing raw materials.

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