Extraction of Lead from Spent Leaded Glass in Alkaline Solution

This study evaluates the efficiency of lead (Pb) extraction from spent leaded glass in strongly alkaline solution after mechanical activation in a planetary ball mill as the chemical breakage and defects formed in the inner structures will contribute to the easy dissolution of the activated leaded glass. The influence of rotate speed and time of mechanical activation, NaOH concentrations, leaching temperature, phase ratios (v/w) had been studied. More than 78% of Pb extraction can be achieved after mechanical activation, compared with 3.5% Pb extraction for chemical leaching of non-activated samples. High purity lead powder can be obtained by electrowinning from the leaching solution. The Pb-depleted solution can be recycled into the leaching step. Thus, a novel hydrometallurgical process for recovering Pb from spent leaded glass in alkaline solution is proposed.