Recovery of manganese and zinc from spent zinc-carbon dry cells via sulphuric acid leaching using glucose as reductant

The recovery of manganese and zinc from spent zinc-carbon dry cells using sulphuric acid and glucose as the leaching medium and reducing agent  respectively was studied to determine the optimum processing parameters for increasing the recovery of the manganese content. Leaching tests were  done using the Response Surface Methodology with the process variables being leaching time, temperature, acid concentration and glucose dose. Regression equations were obtained from the experimental data for the extraction of manganese and zinc, and the main effects and interactions from  the leaching studies were investigated by the analysis of variance (ANOVA). Experimental results indicate that the dissolution of the battery materials  depends largely on the leaching temperature and glucose dose, with the optimum yield of manganese and zin-c being 81.93 and 98.43 %, respectively  corresponding to a leaching temperature of 70oC, leaching time of 150 min, sulphuric acid concentration of 4 M and glucose dose of 0.5 g/L.