DEVELOPMENT OF ELECTROCHEMICAL METHODS FOR PRODUCTION OF PURE THALLIUM

In this work, the electrochemical studies were carried out to improve the purity of rough thallium. The results were obtained by the rough thallium refining through the anodic deposition of thallium oxide ([Tl.sub.2][O.sub.3]), followed by its reduction to Tl+ by hydroxylamine and repeated electrolysis. At the same time, platinum anode material was replaced with glassy carbon material to reduce economic costs in production. It was found that the addition of ammonium thiocyanate after the dissolution of thallium oxide(III) in nitric acid promotes the inhibition of re-formation of thallium oxide at the anode, as well as more complete oxidation of trivalent thallium to a monovalent state. The thallium obtained in this way is characterized by a purity of 99.96%. Based on the obtained experimental data the principal schemes for obtaining pure thallium are proposed. Keywords: thallium, glassy carbon, discharge ionization, refining, thallium oxide, reduction, polarity reversal, electrolysis.