Optimization of packed bed electrolysis of zinc anode casing of spent dry cell batteries

• Packed bed electrolysis of Zn anode casing of spent secondary batteries was statistical modeled.
• The experimental design was based on Box-Behnken design using quadratic polynomial equations.
• The proposed models predict the responses adequately within the limits of the process parameters.
• RSM can be considered as a powerful tool in experimental packed bed electrolysis optimization.

In this research work, statistical analysis and optimization of the production of electrolytic zinc powder from zinc anode casing of spent dry cell batteries by packed bed electrolysis technique were carried out using response surface methodology (RSM). The analysis considered the effect of electrolyte temperature (30–50 °C), stirring rate (250–350 rpm), and current density (500–1000 A/m2) on the cathodic current efficiency, anodic current efficiency, specific energy demand, and powder productivity. The experimental design was based on Box-Behnken design using quadratic polynomial equations for predicting the mathematical models. The results indicate that the proposed models predict the responses adequately within the limits of the packed bed electrolysis process parameters being used. The current density, the second order effect of both current density and stirring rate, and the two level interactions of temperature and current density are the most significant model terms associated with cathodic current efficiency. It was also found that, RSM can be considered as a powerful tool in the optimization of packed bed electrolysis.