Silicon Compounds: Anthropogenic Silicas and Silicates

Abstract

Synthetic alkali silicates, M 2 O· m SiO 2 · n H 2 O, where M = Li, Na, and K, are manufactured as liquids or glasses that readily dissolve in water to form alkaline solutions. These silicates contain a complex mixture of polymeric species with different properties and applications including detergency, soil stabilization, water and waste treatment, and as a raw material for the syntheses of silica sols, gels and precipitates, zeolites, and clays. The article discusses the properties of the synthetic alkali silicates that determine their function in a variety of commercial applications. Economic, manufacturing, regulatory, and environmental aspects of silicate production and usage are reviewed.