Electrowinning of lead from its chloride bath containing organic additives

Abstract

The electrowinning of lead from a chloride bath containing additives such as Rosin, Magnefloc, gelatin, glue, β -naphthol individually and glue in combination with β-naphthol was studied. From the preliminary study, it was observed that a chloride bath containing both glue and β-naphthol produced a comparatively compact lead deposit with high current efficieny. The effect of the parameters viz. lead, glue and β-naphthol concentrations, bath pH, temperature, current density, etc., on current efficiency, deposit characteristics and cathode potential were studied. The results indicate that a compact lead deposit with about 90% current efficiency can be achieved when a bath containing lead 30 g l^-1; glue 2 g l^-1; and β-naphthol 0.1 g l^-1 is used and electrolysis is carried out at pH 0.75-0.95, temperature 70° C and at a current density of 50 A m^-2. Agitation of the electrolyte increased the current efficiency by about 5%, with improvement in the nature of the deposit.