Electrochemical removal of antimony from spent battery acid - Part 3: Results of laboratory scale trials [Elektrochemische antimonentfernung aus akkumulatorsäure teil 3: Ergebnisse aus abscheideversuchen in laborzellen]

Abstract

Synthetic and actual spent battery acid with 20 to 36% sulphuric acid was used in laboratory scale trials to remove dissolved antimony. Electrochemical cells, using anion exchange membranes, were operated on a batch basis. Whereas no antimony deposition was observed in undivided cells, in the divided units, Sb concentrations fell from a few ppm to 0.15 ppm. Current efficiencies at these very low concentrations were significantly less than 0.001%, though at 3500 ppm, current efficiencies were in double figures. These values translate to an energy consumption of 100 to 2000 Whr/l in the ppm concentration range. As well as planar electrodes, 3D electrodes were also tried. Preferred cathode materials are copper and carbonaceous materials.