Determination of Trace Elements in Zinc Plant Electrolyte by Differential Pulse Polarography and Anodic Stripping Voltammetry

Rapid determination of a number of trace elements in zinc sulfate electrolyte is essential for adequate plant process control. As a basis for an on-stream monitoring system, differential pulse polarography and differential pulse anodic stripping voltammetry at a hanging drop mercury electrode have been investigated, using conventional and computercontrolled instrumentation, for the determination of Cd, Cu, Pb, Sb, Co, Ni, Tl, and As. Cd and Cu were determined directly In the zinc sulfate solution down to 10 μg/l., and Sb to a similar low level after addition of concentrated hydrochloric acid. Pb, Co, Ni, Tl, and As were determined after addition of appropriate reagents in some cases; however, these determinations are generally better suited to higher concentration levels than for Cd, Cu, and Sb.