Determination of metallic aluminum in recycled glass

A gas volumetric method was developed for determining metallic aluminum at the 0. 01- to 0. 3% level in 100- g samples of recycled glass. The method is based on the measurement of the change in gas volume produced by the reaction 2 Al plus 2 NaOH plus 2 H2O to 2 NaAlO2 plus 3 H2 using a simple apparatus assembled from readily available glasswave. Metallic iron and metallic zinc do not interfere at the concentrations found in recycled glass recovered from incinerator residues.