Synthesis of zeolite type analcime from industrial wastes

Abstract

A range of industrial wastes (recycled glass, silica fume, siliceous concrete waste aggregates, sterile coal and foundry sand from the steel industry) are employed in the formation of secondary raw materials following their hydrothermal treatment. Composed mainly of zeolites, these secondary materials, in almost all cases, formed analcime. The sterile coal yielded the best defined analcime crystals. In addition, the secondary raw materials are incorporated as an addition in cement paste formulations, to evaluate their effect at early stages of the hydration process. The secondary materials from the siliceous concrete waste aggregates and recycled glass produced a 23% increase in the compressive strength of the paste after 1 day of curing (in comparison with the cement paste reference). • Different waste has been validated for the formation of zeolites. • The formation are following hydrothermal treatment. • The treatment applied to these silica-rich wastes leads to analcime phase neoformation. • Analcime crystals have the best-defined faces and angles. • The wastes are using as accelerators in the hydration of cement pastes.