Corrosion of Lead Glasses in Acid Media: I, Leaching Kinetics

Abstract

The leaching kinetics of lead glasses (25 to 35 mol% PbO‐75 to 65 mol% SiO 2 ; some with K 2 O and A1 2 O 3 , additions) were determined in 10% acetic acid. Except for a ternary glass (SiO 2 ‐PbO‐K 2 O) which had a linear dependence on time, all compositions exhibited a linear dependence on the square root of time for the amount of Pb and K removed. Increasing the SiO 2 : PbO ratio or the Al 2 O 3 content improved the durability whereas adding K 2 O to a binary PbO‐Si0 2 glass greatly increased the corrosion rate. Activation energies for the rates of Pb and K removal were determined for three compositions and it was deduced that the diffusion of H + controlled the leaching for binary and 4‐component glasses whereas dissolution of the silica network was rate‐controlling for the ternary.