Optimization and kinetics of the cementation of lead with aluminum powder

The cementation of lead with aluminum powder from the brine-leaching filtrate of lead-bearing zinc plant residues (ZPRs) has been investigated. The influence of several parameters on the course of the reaction such as aluminum powder quantity, time, aluminum powder particle size and temperature was examined. The optimum cementation conditions were found to be as aluminum powder quantity = 1.5 times of stoichiometric value, time = 90 min, aluminum powder fraction with a particle size − 125 + 88 µm and temperature = 70 °C. Cementation of lead was shown to be a feasible process to achieve a high degree of lead removal (~ 95%) within a fairly reasonable contact time. Also, the kinetics of the cementation was studied over a range of experimental parameters. The cementation was shown to be a diffusion-controlled reaction in the range of 50–70 °C with activation energy of 23.6 kJ/mol. However, the process was found to be highly temperature sensitive in the range 40–50 °C, suggesting a chemical reaction control model for that range. This finding was in concordance with a severe slope change in Arrhenius curve in the range 40–50 °C.