Influence of cetyltrimethylammonium bromide and sodium lauryl sulfate on production of zinc powders by alkaline electrowinning

The effects of cetyltrimethylammonium bromide (CTABr) and sodium lauryl sulfate (SLS) on the current efficiency, cell voltage, voltammetric behavior, and deposit character during production of zinc powder by alkaline electrowinning were investigated. Surface morphologies, crystallographic orientations, and grain size distributions of zinc powders were examined by Scanning Electron Microscopy, X-ray Diffraction, and Malvern Laser Particle Size Analyzer, respectively. Maximum current efficiencies of 97.5 and 98.3% were obtained at 1 mg/L CTABr and 10 mg/L SLS, respectively. Voltammetric studies indicated that the surfactants polarized the cathode, which was reflected in powder character. The surfactants dramatically changed the surface morphology and decreased the grain size. Zinc powders with an average grain size of 34.7 mu m were obtained in the presence of 10 mg L-1 CTABr. At 0-10 mg L-1 CTABr/SLS, zinc powders exhibited an orientation dominated by (101) (002) (100). 1 mg L-1 SLS hadapositive effect on counteracting the influence of Sb.