Occurrences of Ag–Zn Alloys in the Desilverizing of Lead Bullion

AbstractSilver-zinc alloys of several morphologies are found in silver crusts originating from industrial and laboratory lead-desilverizing processes. Electron microprobe analyses indicate specific compositional ranges for these morphologies. The silver content of the alloys varied from 11 to 36 wt.%; Ag/Zn ratios generally were in the range 0.15–0.55. Copper generally replaces silver in the recovery process, and its presence therefore reduces the yield of silver. Application of an inverted temperature gradient to a desilverizing kettle was found to be ineffectivefor batch processes. High-temperature centrifugation of highly oxidized crusts resulted in improved metal separation. Resume Les alliages d'argent-zinc de plusieurs morphologies sont trouves dans les croutes d'argent provenant des procedes de desargentation du plomb, en industries et laboratoire. Des microanalyses a sonde electronique indiquent des zones constituantes specifiques pour ces morphologies. Le contenu specific des alliages varient de ...