The electrokinetic response of fluorite, as a function of pH, is shown to be due to a surface carbonation reaction of the type:. CaF2(surf)+CO3→CaCO3(surf)+2F. The carbonation reaction can be predicted from thermodynamics of solution chemistry and has been verified by infrared measurements in the laboratory. In systems open to the atmosphere, 300 ppm CO2, the carbonation reaction begins above pH 8 at which point the electrokinetic response of fluorite becomes strongly dependent on pH. In addition, settling rate experiments revealed that the electrokinetic response of fluorite was sensitive to, and could be predicted by, the partial pressure of carbon dioxide.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Surfaces, Coatings and Films
- Colloid and Surface Chemistry