Kinetic Studies on Electrochemical Antimony Removal from Concentrated Sulfuric Acid Systems

• Published in: Chemical engineering & technology 2007-02, Vol.30 (2), p.242-249
• Main Authors: Bergmann, M. E. H., Koparal, A. S.
• Format: Article
• Language: English
• Subjects: Applied sciences; Chemical engineering; Electrochemical methods; Exact sciences and technology; Metals; Sulfuric acid
• ISSN: 0930-7516; 1521-4125
• DOI: 10.1002/ceat.200600322

The aim of this study was to separate antimony from its acidic aqueous solution with an electrochemical method by cathodic deposition. For this purpose it is essential to know the electrochemical behavior of antimony. Electrochemical studies were conducted on systems in aqueous sulfuric acid solutions containing 20–30 % of antimony. Cyclic voltammetry and stripping experiments were carried out to characterize the removal or deposition process on cathodes of different materials, such as platinum, copper, or glassy carbon. Besides, several types of electrolytes prepared artificially from dissolved Sb2O3 and antimony standard were employed. The results showed that different species were included in the deposits, depending on the chosen cathode material, cathode potential, time of electrolysis, and type of electrolyte. The electrochemical deposition of antimony was confirmed by X‐ray diffraction experiments. To gain knowledge about the electrochemical behavior of antimony, systematic studies were conducted with artificially prepared electrolytes. The experiments showed that the removal or deposition process is much more complicated than expected.