『Abstract
　In order to evaluate the complex interplay between dissolution and precipitation reaction kinetics, we examined the hypothesis of partial equilibria between secondary mineral products and aqueous solutions in feldspar-water systems. Speciation and solubility geochemical modeling was used to compute the saturation indices (SI) for product minerals in batch feldspar dissolution experiments at elevated temperatures and pressures and to trace the reaction paths on activity-activity diagrams. The modeling results demonstrated: (1) the experimental aqueous solutions were supersaturated with respect to product minerals for almost the entire duration of the experiments; (2) the aqueous solution chemistry did not evolve along the phase boundaries but crossed the phase boundaries at oblique angles; and (3) the earlier precipitated product minerals did not dissolve but continued to precipitate even after the solution chemistry had evolved into the stability fields of minerals lower in the paragenesis sequence. These three lines of evidence signify that product mineral precipitation is a slow kinetic process and partial equilibria between aqueous solution and product minerals were not held. In contrast, the experimental evidences are consistent with the hypothesis of strong coupling of mineral dissolution/precipitation kinetics [e.g., Zhu C., Blum A.E. and Veblen D.R. (2004a) Feldspar dissolution rates and clay precipitation in the Navajo aquifer at Black Mesa, Arizona, USA. In Water-Rock Interaction (eds. R.B. Wanty and R.R.I. Seal). A.A. Balkema, Saratoga Springs, New York. pp.895-899]. In all batch experiments examined, the time of congruent feldspar dissolution was short and supersaturation with respect to the product minerals was reached within a short period of time. The experimental system progressed from a dissolution driven regime to a precipitation limited regime in a short order. The results of this study suggest a complex feedback between dissolution and precipitation reaction kinetics, which needs to be considered in the interpretation of field based dissolution rates.』

1. Introduction
2. Background
3. Modeling results
　3.1. Alkali feldspar dissolution and clay precipitation
　　3.1.1. Experimental design and results
　　3.1.2. Reaction paths and mineral saturation indices
　3.2. Alkali feldspar dissolution and clay precipitation in CO2 Charged systems
　　3.2.1. Experimental design and results
　　3.2.2. Reaction paths and mineral saturation indices
　3.3. Anorthite dissolution batch experiments
　　3.3.1. Experimental design and results
　　3.3.2. Reaction path and mineral saturation indices
　3.4. Sanidine and albite dissolution experiments
　　3.4.1. Sanidine dissolution in NaHCO3 solution
　　3.4.2. Albite dissolution in KHCO3 solution
4. Discussion
　4.1. Uncertainties of thermodynamic properties on calculated saturation indices
　4.2. The coupling of dissolution and precipitation reaction kinetics
　4.3. Extrapolation to natural systems
5. Concluding remarks
Acknowledgments
Appendix A. Discussion of thermodynamic properties
　A.1. Thermodynamic properties for boehmite
　A.2. Thermodynamic properties for aqueous Al species
　A.3. Chemical impurities and crystallinity
Appendix B. Experimental data
Appendix C. Possible amorphous phases and phase transition
Appendix D. Supplementary data
References