Lead bisilicate, PbO·0.03Al2O3 · 1.95SiO2, is a pale yellow powder, insoluble in water. Its composition, by weight, is 65% PbO, 1% Al2O3, and 34% SiO2. Lead bisilicate is available as granular, <1.68 mm (10 mesh), and ground, 88% through 44 μm (325 mesh). It was developed as a low solubility source of lead in glazes, where its high viscosity and low volatility are equally important.
Lead silicate is used as an X-ray absorber for color picture tubes, and also in the glass and enamel industry. It is mainly used in the manufacture of optical glass, optical fibers, daily utensils, and low-melting-point welding.
