Optimization of removal of lead from bearing-lead anode slime

An optimization process is conducted by the Taguchi experimental design method for removal of lead from decopperized anode slime in aqueous Na₂CO₃/HNO₃ media. The effects of parameters such as reaction temperature, Na₂CO₃ concentration, solid–liquid ratio and reaction period on the conversion are studied. It is seen that the most important parameters affecting the conversion of lead sulphate to lead carbonate are solid–liquid ratio and reaction period. The optimum conversion conditions for process are found to be solid–liquid ratio of 0.05 g/mL, reaction period of 600 s, reaction temperature of 50 °C and Na₂CO₃ concentration of 2 M. Under optimal conditions, the experimental results put out that the conversion of lead sulphate at the 95% confidence level can be 97%, approximately.