Objective
The question of calcium carbonate solubility in water is one that interests many OLI users, as the software results appear to differ field observations. This article clarifies this discrepancy using OLI Studio: Stream Analyzer.
Disclaimer: The user interface, calculations, and results displayed in this article are from OLI Studio: Stream Analyzer Version 12.0.0. Other software versions may appear different or present slightly distinct results due to continual developments to the software and thermodynamic databanks.
Analysis in OLI Studio: Stream Analyzer
In OLI Studio: Stream Analyzer, the predictions indicate that calcite (CaCO3) solubility increases with temperature, which seems to contradict typical field observations.
However, in real-world conditions, carbon dioxide (CO2) in the atmosphere (~300 ppm) reacts with calcite, affecting its solubility. To align the calculations with experimental data, users need to include this CO2 component.
Let’s explore how to do this in OLI Studio: Stream Analyzer.
Stream Analyzer Calculation Without Air
First, we will perform the calculation without considering the presence of air.
- Open a new file in OLI Studio: Stream Analyzer. Select the MSE thermodynamic framework.
- Add a new stream and name it “CaCO3 in Water – No Air.”
- Keep the default parameters and add CaCO3 as an inflow.
- Add a Survey calculation, name it “No Air – Temp Survey,” and select Survey by > Temperature.
- In the “Specs” window, choose a temperature range of 0-90°C, with a step size of 5°C. Click “OK” to save these settings.
- Set the “Calculation Type” to “Precipitation Point.” Select “CaCO3 (Calcite)” as the Precipitant, and “CaCO3” as the Adjusted Inflow.
- Click the “Calculate” button.
- Navigate to the “Plot” tab to view the results. The plot will show Temperature on the x-axis and the required CaCO3 inflow to reach the precipitation point on the y-axis.
This graph demonstrates a slight increase in calcite solubility with temperature.
Stream Analyzer Calculation With Air
Next, we will perform the calculation with air included.
- Ensure the Object Library is visible by navigating to View > Toolbars > check Object Library.
- Double-click on the “Dry Air (Sample)” object in the Object Library to add it as a new stream.
- Create a new stream and name it “H2O.” Keep all the default parameters and inflows.
- Add a mixer and name it “H2O – Air Mixer.” Select “H2O – [MSE]” and “Dry Air (Sample) – [MSE]” from the Available Streams list. Keep all default properties and choose “Single Point Mix” as the Mixing Method.
- Press the “Calculate” button, and then “Add as Stream.” Change the Name to “H2O-Air Mix” and click “OK” to save the output as a new stream.
- Select the “H2O-Air Mix” stream in the Navigator Panel. Add CaCO3 to the inflows.
- Add a Survey calculation and name it “With Air – Temp Survey.” Follow the same steps as before: select Survey by > Temperature. In the “Specs” window, choose a temperature range of 0-90°C with a step size of 5°C. Set the “Calculation Type” to “Precipitation Point.” Select “CaCO3 (Calcite)” as the Precipitant, and “CaCO3” as the Adjusted Inflow.
- Click the “Calculate” button.
- Navigate to the “Plot” tab to view the results. The plot will show Temperature on the x-axis and the required CaCO3 inflow to reach the precipitation point on the y-axis.
By accounting for the presence of atmospheric CO2 in the system, the calculation results align with field observations of decreased solubility with increased temperature. This trend is supported by the following study:
Coto B., Martos C., Pena J. L., Rodriguez R., Pastor G., "Effects in the Solubility of CaCO3: Experimental Study and Model Description", Fluid Phase Equilibria, 324, 1-7, 2012.
OLI Data Validation Plot
The validation plot below compares OLI’s predictions with experimental data for CaCO3 solubility in water, both with and without air. This plot shows strong agreement between the software predictions and the empirical data.
Conclusion
Calcite solubility varies depending on whether air is present, due to reactions with atmospheric CO2. OLI Studio: Stream Analyzer enables users to investigate these chemical behaviors effectively.
References
Below are some sources OLI referenced to obtain the experimental data in the validation plot above.
With Air
1846
Fresenius R., "Ueber die Loslichkeitsverhaltnisse von Einigen, bei der Quantitativen Analyse als Bestimmungsformen etc. Dienenden Niederschlagen", Justus Liebigs Annalen der Chemie, 59, (1), 117-128, 1846.
1852
Kremers P., "Ueber den Zusammenhang des Specifischen Gewichtes Chemischer Verbindungen Mit Ihrer Aufloslichkeit in Wasser, Nebst Einer Daraus Abgeleiteten Theorie der Wahlverwandtschaften", Annalen der Physik, 161, (2), 246-262, 1852.
1901
Lehmann K. B., Die Methoden der Praktischen Hygiene Wiesbaden, 218, 1901.
1902
Cameron F. K., Seidell A., "Solubility of Calcium Carbonate in Aqueous Solutions of Certain Electrolytes in Equilibrium with Atmospheric Air", Journal of Physical Chemistry, 6, (1), 50-56, 1902.
1912
Kendall J., "The Solubility of Calcium Carbonate in Water", Philosophical Magazine, 23, (6), 958-976, 1912.
1915
Johnston J., "The Solubility - Product Constant of Calcium and Magnesium Carbonates", Journal of the American Chemical Society, 37, (9), 2001-2020, 1915.
1915
Wells R. C., "The Solubility of Calcite in Water in Contact With the Atmosphere, and Its Variation With Temperature", Journal of the Washington Academy of Sciences, 5, 617-622, 1915.
1929
Frear G. L., Johnston J., "The Solubility of Calcium Carbonate (Calcite) in Certain Aqueous Solutions at 25 C", Journal of the American Chemical Society, 51, (7), 2082-2093, 1929.
1929
Heyrovsky J., Berezicky S., Collection of Czechoslovak Chemical Communications, 1, 19-46, 1929.
1929
Kline W. D., "Experimental Redeterminations of the Solubility of Calcite in Water at 25 C", Journal of the American Chemical Society, 51, (7), 2086-2086, 1929.
1932
Leick J., "The Solubilities of Calcium Carbonate and of Magnesium Carbonate in Water That is Free From Carbonic Acid", Zeitschrift fur Analytische Chemie, 87, 415-422, 1932.
1933
Leick J., "The Equilibria in the Conversion of Sodium Carbonate, Sodium Hydroxide, Calcium Hydroxide and Trisodium Phosphate with Calcium- and Magnesium Sulphate", Zeitschrift fur Anorganische und Allgemeine Chemie, 210, (2), 203-209, 1933.
1937
Wattenberg V. H., Timmermann E., "Die Loslichkeit von Magnesiumkarbonat und Strontiumkarbonat in Seewasser", Kieler Meeresforschungen, 11, (1), 81-94, 1937.
1952
Shternina E. B., Frolova E. V., "The Solubility of Calcite in the Presence of CO2 and NaCl", Izvestiya Sektora Fiziko Khimicheskogo Analiza Institut Obshchei Neorganicheskoi Khimii Akademiia Nauk SSSR, 21, 271-287, 1952.
2004
Loos D., Pasel C., Luckas M., Schmidt K. G., Herbell J. D., "Experimental Investigation and Modelling of the Solubility of Calcite and Gypsum in Aqueous Systems at Higher Ionic Strength", Fluid Phase Equilibria, 219, (2), 219-229, 2004.
Without Air
1857
Bineau A., "Remarques sur les Dissolutions de Quelques Carbonates et Notamment du Carbonate de Chaux", Annales de Chimie et de Physique, 51, (3), 290-305, 1857.
1872
Schloesing T., "Sur la Dissolution du Carbonate de Chaux par L'Acide Carbonique", Comptes Rendus Hebdomadaires des Seances de L'Academie des Sciences, 75, 70-73, 1872.
1892
Lubavin N. N., Journal of the Russian Physical Chemical Society, 24, 389, 1892.
1893
Holleman A. F., Kohlrausch F., Rose F., "Bestimmungen der Loslichkeit Sogenannter Unloslicher Salze", Zeitschrift fur Physikalische Chemie Stochiometrie und Verwandtschaftslehre, 12, 125-139, 1893.
1906
LeBlanc M., Novotny K., "The Caustization of Sodium Carbonate and Kalium Carbonate With Calk", Zeitschrift fur Anorganische Chemie, 51, (1), 181-201, 1906.
1907
Cameron F. K., Robinson W. O., "The Solubility of Calcium Carbonate in Aqueous Solutions of Potassium Chloride and Potassium Sulphate at 25 C", Journal of Physical Chemistry, 11, (8), 577-580, 1907.
1911
Prudhomme M., Journal de Chimie Physique et de Physico Chimie Biologique, 9, 532, 1911.
1915
Johnston J., "The Solubility - Product Constant of Calcium and Magnesium Carbonates", Journal of the American Chemical Society, 37, (9), 2001-2020, 1915.
Wells R. C., "The Solubility of Calcite in Water in Contact With the Atmosphere, and Its Variation With Temperature", Journal of the Washington Academy of Sciences, 5, 617-622, 1915.
1923
Askew H. O., "Solubility and Hydrolysis of Calcium Carbonate", Transactions and Proceedings of the Royal Society of New Zealand, 54, 791-796, 1923.
1925
Pratolongo U., Atti Della Accademia Nazionale dei Lincei, 1, (6), 238-243, 1925.
1925
Stumper R., Bulletin des Societes Chimiques Belges, 34, 422-427, 1925.
1929
Pauli W., Stenzinger T., "On Solubility Influence of Not Easily Dissoluble Lime Salts Through Protein Borders and On Carbonic Acid Compounds of Proteins", Biochemische Zeitschrift, 205, 71-103, 1929.
1931
Dubrisay R., Francois R., "Solubilite du Carbonate de Calcium Dans L'Eau en Presence de Chlorures Alcalins", Comptes Rendus Hebdomadaires des Seances de L'Academie des Sciences, 192, 741-743, 1931.
1932
Bar O., "Beitrag zum Thema Dolomitentstehung", Centralblatt fur Mineralogie Geologie und Palaontologie, 46-62, 1932.
1932
Straub F. G., "Solubility of Calcium Sulfate and Calcium Carbonate at Temperatures Between 182 and 316 C", Industrial and Engineering Chemistry, 24, (8), 914-917, 1932.
1938
Franquin J., Marecaux P., 18th Congress Chim. Industrielle, 532c-547c, 1938.
1944
Wesley W., Chemiker Zeitung, 68, 189, 1944.
1963
Malinin S. D., "Experimental Investigation of Calcite and Witherite Solubility Under Hydrothermal Conditions", Geochemistry, (7), 650-667, 1963.
2004
Loos D., Pasel C., Luckas M., Schmidt K. G., Herbell J. D., "Experimental Investigation and Modelling of the Solubility of Calcite and Gypsum in Aqueous Systems at Higher Ionic Strength", Fluid Phase Equilibria, 219, (2), 219-229, 2004.