Recovery of Manganese from Spent Batteries Using Guar Meal as a Reducing Agent in a Sulfuric Acid Medium

The reductive leaching of manganese from mixed zinc-carbon and alkaline battery powder using guar meal as a new reducing agent in a sulfuric acid medium was investigated. The effects of the sulfuric acid concentration, amount of guar meal, leaching temperature, leaching time, and stirring speed were tested. The optimal leaching conditions for -88 mu m particles were determined to be a sulfuric acid concentration of 2 mol L-1, a guar meal concentration of 100 g L-1, a stirring speed of 400 rpm, a leaching time of 180 min, and a leaching temperature of 70 degrees C. Under these conditions, 99.7% of the manganese was leached. The zinc was almost completely dissolved without a reducing agent because zinc oxide dissolved directly in the sulfuric acid medium. The SEM-EDX, FT-IR, and XRD results showed that no manganese-containing phases were detected in the remaining leach residue.