Electrolytic oxidation of strong cyanide wastes

Publisher Website
Google Scholar
Abstract
Solutions of sodium cyanide and solutions containing the complex cyanides of copper, cadmium and zinc have been electrolysed with anodes of graphite or platinised titanium at temperatures in the range 50–90°, and at anode current densities of 0–88 A/ft.2 Cyanide was destroyed at rates of 14.0–15.9 g. of HCN/Faraday (0.5–0.6 mole/Faraday), 1 kWh electricity destroying 146–201 g. of HCN. The rate of destruction was directly proportional to current passed and increased with increase in temperature. Increase in the electrolyte pH decreased the rate of destruction of cyanide. The chief reaction products were ammonium carbonate, and cyanate ions and urea. Stainless steel (EN 58A) was not an efficient anode material. A method for the continuous destruction of solid cyanide waste, on a laboratory scale, by electrolytic oxidation is described. The only products of the process are gaseous (ammonia, carbon dioxide and hydrogen) and solid (sodium carbonate containing 0.05% cyanide and 0.26% sodium oxalate), 1 kWh of electricity destroying 111–143 g. of HCN.

This publication has 2 references indexed in Scilit: