『Abstract
We revisit a fundamental question in mineral dissolution kinetics,
namely: is the function of dissolution rate versus the distance
from equilibrium continuous, or does the “switch” between two
different reaction mechanisms cause a discontinuity, i.e., a kinetic
bifurcation? Based on new insight from experimental results, including
direct observations of retreating crystal surfaces with vertical
scanning interferometry (VSI), we present evidence that a discontinuity
does indeed exist. Through a carefully designed near-equilibrium
albite dissolution experiment, we show how a non-steady-state
dissolution rate observed on a crystal surface reflects reactivity
inherited from earlier episodes of undersaturation. This outcome
forces us to re-think the common practice of extrapolating overall
dissolution rates measured far-from-equilibrium to near-equilibrium
conditions.
Keywords: Dissolution kinetics; Free energy; Equilibrium; Albite
Feldspar』
1. Introduction
2. Experimental and analytical methods
2.1. Solutions
2.2. Solids
3. Results
3.1. Solutions
3.2. Solids
4. Discussion
5. Conclusions
Acknowledgments
References