Özet:

Superalloys based on W/WC are widely used as elements of drilling equipment, high-speed steel-cutting tools, penetrators of armor-piercing munitions. The spent or broken superalloy goods are a valuable waste for recycling with extracting of valuable components. The most economically and technologically attractive methods of superalloy scrap recycling is selective treatment with dissolution of metal binder and obtaining of non-oxidized tungsten/tungsten carbide powder. The aim of the present work was to develop a method of selective anodic reprocessing of superalloys. By using voltamperometry method the anodic behavior of VK20KS (20% Со, 80 WC), VN8 (8 % Ni, 92 % WC), VNG (5 % Ni, 5 % Fe, 90 % W) and VNDS (W, Ni, Cu.) superalloys in a proposed solution has been studied. The possibility of selective anodic dissolution of metal binder without oxidation of solid component (tungsten/tungsten carbide) has been demonstrated. The potential and current density values for this process have been determined. Low reactivity of tungsten-based superalloys in comparison to tungsten carbide-based alloy has been demonstrated. Galvanostatic selective anodic treatment of VK20KS superalloy scrap at 15 A/dm2, which is a dissolution peak current density on the anodic curve, has been conducted. A phenomenon of gradual surface passivation due to dissolution of metal binder and increasing the content of passive tungsten carbide has been found. In order to prevent passivation, the use of rotating titanium basket has been proposed. The composition of tungsten-containing products has been determined to be: 23 % WO3 or H2WO4, 73 % WC. Author Biographies Vadym Кovalenko, Ukrainian State University of Chemical Technology Gagarina ave., 8, Dnipro, Ukraine, 49005 Federal State Educational Institution of Higher Education "Vyatka State University" Moskovskaya str., 36, Kirov, Russian Federation, 610000 PhD, Associate Professor Department of Analytical Chemistry and Food Additives and Cosmetics Department of Technologies of Inorganic Substances and Electrochemical Manufacturing

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