Extraction of lead from spent leaded glass in alkaline solution by mechanochemical reduction

This study evaluates the efficiency of lead (Pb) extraction from lead bearing waste glass in strongly alkaline solution after mechanochemical reduction with iron. Less than 5% of the Pb can be leached directly by alkaline solution from the leaded glass. Compared with the non-activated leaded glass, the Pb extraction of leaded glass mechanically activated increased significantly. Around 67% of Pb was released after mechanical activation without iron, while more than 90% of Pb in the glass can be extracted after mechanochemical reduction with iron. The Pb-depleted solution can be recycled into the leaching step after Pb powder was obtained by electrowinning from the leaching solution. Thus, a novel hydrometallurgical process for recovering Pb from lead bearing waste glass in alkaline solution is proposed.