『Abstract
　Measurements of the dissolution rate of diopside (r) were carried out as a function of the Gibbs free energy of the dissolution reaction (ΔGr) in a continuously stirred flow-through reactor at 90℃ and PH90℃=5.05. The overall relation between r and ΔGr was determined over a free energy range of -130.9＜ΔGr＜-47.0 kJ mol^-1. The data define a highly non-linear, sigmoidal relation between r and ΔGr. A far-from-equilibrium conditions (ΔGr≦-76.2 kJ mol^-1), a rate plateau is observed. In this free energy range, the rates of dissolution are constant, independent of [Ca], [Mg] and [Si] concentrations, and independent of ΔGr. A sharp decrease of the dissolution rate (〜1 order of magnitude) occurs in the transition ΔGr region defined by -76.2＜ΔGr≦-61.5 kJ mol^-1. Dissolution closer to equilibrium (ΔGr＞-61.5 kJ mol^-1) is characterised by a much weaker inverse dependence of the rates on ΔGr. Modeling the experimental r-ΔGr data with a simple classical transition state theory (TST) law as implemented in most available geochemical codes is found inappropriate. An evaluation of the consequences of the use of geochemical codes were the r-ΔGr relation is based on basic TST was carried out and applied to carbonation reactions of diopside, which, among other reactions with Ca- and Mg-bearing minerals, are considered as a promising process for the solid state sequestration of CO2 over long time spans. In order to take into account the actual experimental r-ΔGr relation in the geochemical code that we used, a new module has been developed. It reveals a dramatic overestimation of the carbonation rate when using a TST-based geochemical code. This points out that simulations of water-rock CO2 interactions performed with classical geochemical codes should be evaluated with great caution.』

１. Introduction
2. Materials and methods
　2.1. Starting materials
　2.2. Experimental apparatus
　2.3. Reactor input solutions
　2.4. Experimental protocol and analytical procedures
　2.5. Experimental calculation of dissolution rates
　2.6. Theoretical calculations
3. Results and discussion
　3.1. Behaviour of elemental release from non-steady to steady-state as a function of ΔGr
　3.2. Steady-state dissolution stoichiometry
　　3.2.1. General considerations
　　3.2.2. Was dissolution affected by secondary precipitation processes?
　3.3. Steady-state dissolution rates as a function of ΔGr　
　　3.3.1. Overall r-ΔGr relation
　　3.3.2. Reconsidering what ‘far-from equilibrium conditions’ means
　　3.3.3. Numerical fit of the experimental data
　3.4. Implications for geochemical modeling - application to carbonation reactions
4. Conclusions
Acknowledgments
References