Thermodynamic study on recovery of lead and antimony from a used lead-battery

Phase equilibria and activities of the components in the liquid lead-antimony-oxygen ternary system, which is of fundamental importance for discussing the recovery of lead and antimony from a used lead-battery, have been investigated at 1173 and 1223 K. The two liquid phases of metal and oxide, were observed at the temperatures studied, and the tie lines indicating isoactivities were determined. The activities of PbO, SbO1.5 and Sb2O3 in the PbO-SbO1.5 and PbO-Sb2O3 pseudo-binary systems were then obtained by applying the Gibbs-Duhem equation to the phase relation of metal-oxide equilibrium. Both in the pseudo-binary systems the activities exhibit negative deviations from Raoult's law. The vapor pressures of lead, antimony and lead oxide, antimony oxide were calculated by using the activities of the components in the lead-antimony-oxygen ternary system. As a result, an oxidation of antimony concentrated in an anode slime followed by evaporation as antimony oxide Sb4O6 was found to be considerably effective for the recovery of lead and antimony from a used lead-battery.