ABSTRACT
There is a wealth of information on the dissolution behavior of silica and aluminosilicates, mainly in the geochemical literature. This chapter discusses their similarity in susceptibility to attack by alkalis; large affinity for fluoride; the lack of relevant redox pathways; and their simultaneous participation in the description of the dissolution of aluminosilicates. Silicates and aluminosilicates may dissolve congruently or incongruently, depending on the particular mineral and conditions of dissolution. Incongruent dissolution has been amply documented in silicates through the measurement of the leaching rates of the constituent ions and through the spectroscopic characterization of the leached layers. The most important fact to stress is that leached layers do not seem to limit the rate by diffusion, except in the case of glasses. Preferential leaching creates a porous and open structure that allows for continued unhindered attack.
