Battery Recycling

Spent lead-acid battery grids contain notable amounts of tin and antimony. Traditional pyro-refining oxidizes tin, transferring it to dross and complicating recovery. This study introduces a new pyro-refining method using aluminum and calcium to purify lead while retaining more tin. Laboratory tests showed how Al and Ca affect the composition of impure lead alloys. Microanalysis revealed that impurities like Sb, As, Cu, Se, and Te accumulate in Al- or Ca-rich dross. Since industrial dross removal is difficult, a reduction process was tested. Results showed varying impurity return to lead, depending on the method used."