Albite feldspar dissolution kinetics as a function of the Gibbs free energy at high pCO2
We are currently measuring the dissolution kinetics of albite feldspar at 100℃ in the presence of high levels of dissolved CO2 (pCO2=9 MPa) as a function of the saturation state of the feldspar (Gibbs free energy of reaction, △G). The experiments are conducted using a flow through reactor, thereby allowing the dissolution reactions to occur at a fixed pH and at constant, but variable saturation states. Preliminary results indicate that at far-from-equilibrium conditions, the dissolution kinetics of albite are defined by a rate plateau,with R ≈ 5.0 × 10-10 mol m-2 s-1 at -70 ＜△G ＜-40 kJ mol-1. At △G ＞-40 kJ mol-1, the rates decrease sharply, revealing a strong inverse relation between the dissolution rate and free energy. Based on the experiments carried out to date, the dissolution rate-free energy data correspond to a highly non-linear and sigmoidal relation,in accord with recent studies.
R.Hellmann D.Daval D.Tisserand F.Renard
Environmental Geochemistry Group,LGIT, Univ.Grenoble, CNRS UMR C5559, OSUG-Grenoble, France Laboratoire de Géologie, Ecole Normale Supérieure de Paris, CNRS UMR 8538, Paris, France LGIT, Univ.Grenoble, CNRS UMR C5559, OSUG-Grenoble, France
国际会议
第十二届水-岩相互作用国际研讨会(P0roceedings of the 12th International Symposium on Water-Rock Interaction)
昆明
英文
591-595
2007-07-31（万方平台首次上网日期，不代表论文的发表时间）