Effects of OH activity and temperature on the dissolution rate of compacted montmorillonite under highly alkaline conditions

Sawaguchi, Takuma; Tsukada, Manabu; Yamaguchi, Tetsuji; Mukai, Masayuki

Clay Minerals, 51(2), p.267 - 278, 2016/05

https://doi.org/10.1180/claymin.2016.051.2.12

The dependences of the dissolution rate of compacted montmorillonite on activity of OH (a-) and temperature (T) were investigated. The dissolution rate of montmorillonite () in compacted pure montmorillonite, which was formulized as = 10 (a-) e, was higher than that in the compacted sand-bentonite mixtures: = 3500 (a-) e. The difference can be explained by considering the decrease in a- in the mixtures accompanied by dissolution of accessory minerals such as quartz and chalcedony. The dissolution rate model developed for pure montmorillonite is expected to be applied to bentonite mixtures if quantification of the decrease in a- is achieved somehow.