An overview of simple basic equations used in glass dissolution modelling: consequences for long term leaching and element profiles

Over the last decades, several models describing glass dissolution have been published: many of them were only used by their author during a short time period, and only some survived through newer versions. Starting from the basic equations in their simplest form, the relations between those models will be showed: where lies progress?, what is the resulting long term leach rate? and to which element (water, boron, + alkalis) profiles do they lead?. Many tend to believe that element profiles evolve towards a stationary state, but in several models such a stationary state does not exist. It will be shown that the existence of a stationary state is equivalent to the existence of a long term rate. In addition, recent simulation results will be compared with the basic equations of the models. This presentation relates to the Glamor project, where two models, the r(t) and the GM models, are examined in detail and used for fitting experimental data. In this presentation, other models are examined as well and compared with those two models, but no data is considered. Besides, an analytical solution is proposed for the water diffusion part of the GM model.