TRANSFORMACE BENTONITU V PODMÍNKÁCH ÚLOŽIŠTĚ RADIOAKTIVNÍHO ODPADU: GEOCHEMICKÝ MODEL
Geochemical modeling is (1) one of the ways how to asses bentonite stability and (2) an effective method to define key processes of a bentonite transformation. A simulation of bentonite transformation was performed for various physical and chemical conditions. The influence of pore water and mineral composition was theoretically studied. The modeling has shown that the most important factor which influences stability of bentonite is initial water composition and the presence of accessory minerals such as pyrite and calcite. The type of montmorillonite that forms the main part of bentonite did not play a key role in the bentonite transformation. Initial mixture of Na-, K-, Ca-, montmorillonites was transformed mainly into Mg- and Ca-montmorillonites. Totally 3 to 9 wt. % of initial bentonite was transformed to the secondary minerals.
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