Next Article in Journal
The Effect of Conditioning on the Flotation of Pyrrhotite in the Presence of Chlorite
Next Article in Special Issue
Carbonate Apatite Precipitation from Synthetic Municipal Wastewater
Previous Article in Journal
Electron Microscopy Observation of Biomineralization within Wood Tissues of Kurogaki
Previous Article in Special Issue
Desiccator Volume: A Vital Yet Ignored Parameter in CaCO3 Crystallization by the Ammonium Carbonate Diffusion Method
Article

Hydration Effects on the Stability of Calcium Carbonate Pre-Nucleation Species

1
Mineralogy and Petrology Department, University of Granada, 18071 Granada, Spain
2
Institut für Mineralogie, University of Münster, 48149 Münster, Germany
3
Department of Chemistry, Curtin University, Perth 6845, Australia
*
Author to whom correspondence should be addressed.
Minerals 2017, 7(7), 126; https://doi.org/10.3390/min7070126
Received: 1 June 2017 / Revised: 1 July 2017 / Accepted: 14 July 2017 / Published: 20 July 2017
Recent experimental evidence and computer modeling have shown that the crystallization of a range of minerals does not necessarily follow classical models and theories. In several systems, liquid precursors, stable pre-nucleation clusters and amorphous phases precede the nucleation and growth of stable mineral phases. However, little is known on the effect of background ionic species on the formation and stability of pre-nucleation species formed in aqueous solutions. Here, we present a systematic study on the effect of a range of background ions on the crystallization of solid phases in the CaCO3-H2O system, which has been thoroughly studied due to its technical and mineralogical importance, and is known to undergo non-classical crystallization pathways. The induction time for the onset of calcium carbonate nucleation and effective critical supersaturation are systematically higher in the presence of background ions with decreasing ionic radii. We propose that the stabilization of water molecules in the pre-nucleation clusters by background ions can explain these results. The stabilization of solvation water hinders cluster dehydration, which is an essential step for precipitation. This hypothesis is corroborated by the observed correlation between parameters such as the macroscopic equilibrium constant for the formation of calcium/carbonate ion associates, the induction time, and the ionic radius of the background ions in the solution. Overall, these results provide new evidence supporting the hypothesis that pre-nucleation cluster dehydration is the rate-controlling step for calcium carbonate precipitation. View Full-Text
Keywords: background electrolytes; dehydration kinetics; calcium carbonate; calcite; clusters; nucleation; vaterite; ACC background electrolytes; dehydration kinetics; calcium carbonate; calcite; clusters; nucleation; vaterite; ACC
Show Figures

Figure 1

MDPI and ACS Style

Burgos-Cara, A.; Putnis, C.V.; Rodriguez-Navarro, C.; Ruiz-Agudo, E. Hydration Effects on the Stability of Calcium Carbonate Pre-Nucleation Species. Minerals 2017, 7, 126. https://doi.org/10.3390/min7070126

AMA Style

Burgos-Cara A, Putnis CV, Rodriguez-Navarro C, Ruiz-Agudo E. Hydration Effects on the Stability of Calcium Carbonate Pre-Nucleation Species. Minerals. 2017; 7(7):126. https://doi.org/10.3390/min7070126

Chicago/Turabian Style

Burgos-Cara, Alejandro, Christine V. Putnis, Carlos Rodriguez-Navarro, and Encarnacion Ruiz-Agudo. 2017. "Hydration Effects on the Stability of Calcium Carbonate Pre-Nucleation Species" Minerals 7, no. 7: 126. https://doi.org/10.3390/min7070126

Find Other Styles
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop