Electrogenerative Removal of Cobalt from Sulfate Solutions Using a Batch Reactor

Abstract

The electrogenerative removal of cobalt is conducted in a batch reactor equipped with three-dimensional electrodes: Reticulated vitreous carbon (RVC) and porous graphite (PG-25) as cathode materials. In this process, a chemical reaction takes place spontaneously in a divided cell where cobalt is reduced at the cathode and zinc is oxidized to produce electrical energy without an external supply of energy. The results obtained show that RVC serves as a more suitable cathode material than PG-25 in this system. At optimum conditions, more than 99% of cobalt were removed and recovered in its metallic state after 10 h of operation with an initial 200 mg L À1 Co(II) solution at pH 4 in 0.2 M Na 2 SO 4 and 0.4 M boric acid. Scanning electron microscopy and X-ray diffraction analyses are performed to study the morphology and crystallographic patterns of cobalt deposits on the cathodes, respectively.