{"id":{"repo_id":"colo-mines","oai_identifier":"oai:repository.mines.edu:11124/172317"},"canonical_url":"https://search.dev.ndltd.org/etd/colo-mines/oai:repository.mines.edu:11124/172317","repository":{"repo_id":"colo-mines","name":"Colorado School of Mines","base_url":"https://repository.mines.edu/server/oai/request"},"display":{"title":"Low temperature aqueous solubility of fluorite at temperatures of 5, 25, and 50°C and ionic strengths up to 0.72M","abstract":"Historical fluorite solubility research found that fluorite solubilities varied over three orders-of-magnitude and appear to be inconsistent with several recently determined fluorite solubilities. This research involved a comprehensive series of solubility experiments run over a period of three years using nine natural fluorites and one synthetic fluorite to determine their solubility in low temperature (5, 25, and 50oC) aqueous solutions and ionic strengths ranging from near zero to 0.72M. Equilibrium was approached from both undersaturated and supersaturated initial conditions. The fluorites were chemically and physically characterized using laboratory analyses, thin section petrography, UV fluorescence, and x-ray diffraction. The fluorite samples were generally found to have similar chemical and physical properties. The chemical composition was approximately stoichiometric, with a mean calcium concentration of 51.6 ± 0.6 wt % and mean fluorine concentration of 50.2 ± 0.7 wt %. Fluorite unit cell edge lengths, volumes, and densities averaged 5.4630 ± 0.0007 Å, 163.04 ± 0.06 Å3, and 3.181 ± 0.009 g/cm3, respectively. The fluorite solubility results showed that fluorite dissolved congruently and increased in solubility with both temperature and ionic strength. The fluorite solubilities determined were relatively consistent, with median log Ksp values that ranged from -10.81 ± 0.02 at 5oC, -10.63 ± 0.02 at 25oC, and -10.49 ± 0.03 at 50oC. An internally consistent set of fluorite thermodynamic data were determined from the log Ksp results which yielded a ∆G_f^0.of -1,177.7 ± 0.2 kJ/mol, ∆H_f^0 of -1,226.9 ± 1.1 kJ/mol, and S_f^0 of 76.0 ± 3.7 J/mol*K. However, the third law entropy value determined for this study was about 9% higher than the reported value Soof 68.9 ± 0.3 J/mol*K. This discrepancy in entropy values likely results from the range in log Ksp values determined for the fluorites during this study. This study’s results resolve the uncertainty in past work and provides an optimal solubility dataset for fluorite going forward.","abstract_html":"Historical fluorite solubility research found that fluorite solubilities varied over three orders-of-magnitude and appear to be inconsistent with several recently determined fluorite solubilities. This research involved a comprehensive series of solubility experiments run over a period of three years using nine natural fluorites and one synthetic fluorite to determine their solubility in low temperature (5, 25, and 50oC) aqueous solutions and ionic strengths ranging from near zero to 0.72M. Equilibrium was approached from both undersaturated and supersaturated initial conditions. The fluorites were chemically and physically characterized using laboratory analyses, thin section petrography, UV fluorescence, and x-ray diffraction. The fluorite samples were generally found to have similar chemical and physical properties. The chemical composition was approximately stoichiometric, with a mean calcium concentration of 51.6 ± 0.6 wt % and mean fluorine concentration of 50.2 ± 0.7 wt %. Fluorite unit cell edge lengths, volumes, and densities averaged 5.4630 ± 0.0007 Å, 163.04 ± 0.06 Å3, and 3.181 ± 0.009 g/cm3, respectively. The fluorite solubility results showed that fluorite dissolved congruently and increased in solubility with both temperature and ionic strength. The fluorite solubilities determined were relatively consistent, with median log Ksp values that ranged from -10.81 ± 0.02 at 5oC, -10.63 ± 0.02 at 25oC, and -10.49 ± 0.03 at 50oC. An internally consistent set of fluorite thermodynamic data were determined from the log Ksp results which yielded a ∆G_f^0.of -1,177.7 ± 0.2 kJ/mol, ∆H_f^0 of -1,226.9 ± 1.1 kJ/mol, and S_f^0 of 76.0 ± 3.7 J/mol*K. However, the third law entropy value determined for this study was about 9% higher than the reported value Soof 68.9 ± 0.3 J/mol*K. This discrepancy in entropy values likely results from the range in log Ksp values determined for the fluorites during this study. This study’s results resolve the uncertainty in past work and provides an optimal solubility dataset for fluorite going forward.","abstract_has_math":false,"creators":["Henry, Richard L."],"institution":"Colorado School of Mines. Arthur Lakes Library","degree_name":"Doctor of Philosophy (Ph.D.)","degree_level":"Doctoral","degree_discipline":"Geology and Geological Engineering","degree_department":null,"school":null,"contributors":[],"advisors":["Harrison, Wendy J."],"committee_chairs":[],"committee_members":["Wendlandt, Richard F.","Simmons, Edwin C.","Wanty, Richard B."],"year":2018,"date_issued":"2018","date_published":"2018","updated_at":"2026-07-24T01:43:42Z","subjects":["solubility","fluorite"],"languages":["eng","English"],"rights":["Copyright of the original work is retained by the author."],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["T 8486"],"render_values":[{"text":"T 8486","href":null,"code":true}]}]},"links":{"outbound_url":"https://hdl.handle.net/11124/172317","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Harrison, Wendy J."]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Wendlandt, Richard F.","Simmons, Edwin C.","Wanty, Richard B."]},{"key":"dc:creator","label":"Author","values":["Henry, Richard L."]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2018-05-22T17:11:57Z","2022-02-03T13:11:29Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2018-05-22T17:11:57Z","2022-02-03T13:11:29Z"]},{"key":"dc:date.issued","label":"Date","values":["2018"]},{"key":"dc:publisher","label":"Institution","values":["Colorado School of Mines. 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This research involved a comprehensive series of solubility experiments run over a period of three years using nine natural fluorites and one synthetic fluorite to determine their solubility in low temperature (5, 25, and 50oC) aqueous solutions and ionic strengths ranging from near zero to 0.72M. Equilibrium was approached from both undersaturated and supersaturated initial conditions. The fluorites were chemically and physically characterized using laboratory analyses, thin section petrography, UV fluorescence, and x-ray diffraction. The fluorite samples were generally found to have similar chemical and physical properties. The chemical composition was approximately stoichiometric, with a mean calcium concentration of 51.6 ± 0.6 wt % and mean fluorine concentration of 50.2 ± 0.7 wt %. Fluorite unit cell edge lengths, volumes, and densities averaged 5.4630 ± 0.0007 Å, 163.04 ± 0.06 Å3, and 3.181 ± 0.009 g/cm3, respectively. The fluorite solubility results showed that fluorite dissolved congruently and increased in solubility with both temperature and ionic strength. The fluorite solubilities determined were relatively consistent, with median log Ksp values that ranged from -10.81 ± 0.02 at 5oC, -10.63 ± 0.02 at 25oC, and -10.49 ± 0.03 at 50oC. An internally consistent set of fluorite thermodynamic data were determined from the log Ksp results which yielded a ∆G_f^0.of -1,177.7 ± 0.2 kJ/mol, ∆H_f^0 of -1,226.9 ± 1.1 kJ/mol, and S_f^0 of 76.0 ± 3.7 J/mol*K. However, the third law entropy value determined for this study was about 9% higher than the reported value Soof 68.9 ± 0.3 J/mol*K. This discrepancy in entropy values likely results from the range in log Ksp values determined for the fluorites during this study. This study’s results resolve the uncertainty in past work and provides an optimal solubility dataset for fluorite going forward."]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["born digital","doctoral dissertations"]},{"key":"dc:title","label":"Title","values":["Low temperature aqueous solubility of fluorite at temperatures of 5, 25, and 50°C and ionic strengths up to 0.72M"]}]}],"canonical_facts":{"dc:contributor.advisor":["Harrison, Wendy J."],"dc:contributor.committeemember":["Wendlandt, Richard F.","Simmons, Edwin C.","Wanty, Richard B."],"dc:creator":["Henry, Richard L."],"dc:date.accessioned":["2018-05-22T17:11:57Z","2022-02-03T13:11:29Z"],"dc:date.available":["2018-05-22T17:11:57Z","2022-02-03T13:11:29Z"],"dc:date.issued":["2018"],"dc:description":["Includes bibliographical references.","2018 Spring."],"dc:description.abstract":["Historical fluorite solubility research found that fluorite solubilities varied over three orders-of-magnitude and appear to be inconsistent with several recently determined fluorite solubilities. This research involved a comprehensive series of solubility experiments run over a period of three years using nine natural fluorites and one synthetic fluorite to determine their solubility in low temperature (5, 25, and 50oC) aqueous solutions and ionic strengths ranging from near zero to 0.72M. Equilibrium was approached from both undersaturated and supersaturated initial conditions. The fluorites were chemically and physically characterized using laboratory analyses, thin section petrography, UV fluorescence, and x-ray diffraction. The fluorite samples were generally found to have similar chemical and physical properties. The chemical composition was approximately stoichiometric, with a mean calcium concentration of 51.6 ± 0.6 wt % and mean fluorine concentration of 50.2 ± 0.7 wt %. Fluorite unit cell edge lengths, volumes, and densities averaged 5.4630 ± 0.0007 Å, 163.04 ± 0.06 Å3, and 3.181 ± 0.009 g/cm3, respectively. The fluorite solubility results showed that fluorite dissolved congruently and increased in solubility with both temperature and ionic strength. The fluorite solubilities determined were relatively consistent, with median log Ksp values that ranged from -10.81 ± 0.02 at 5oC, -10.63 ± 0.02 at 25oC, and -10.49 ± 0.03 at 50oC. An internally consistent set of fluorite thermodynamic data were determined from the log Ksp results which yielded a ∆G_f^0.of -1,177.7 ± 0.2 kJ/mol, ∆H_f^0 of -1,226.9 ± 1.1 kJ/mol, and S_f^0 of 76.0 ± 3.7 J/mol*K. However, the third law entropy value determined for this study was about 9% higher than the reported value Soof 68.9 ± 0.3 J/mol*K. This discrepancy in entropy values likely results from the range in log Ksp values determined for the fluorites during this study. This study’s results resolve the uncertainty in past work and provides an optimal solubility dataset for fluorite going forward."],"dc:format.medium":["born digital","doctoral dissertations"],"dc:identifier":["Henry_mines_0052E_11488.pdf","T 8486"],"dc:identifier.uri":["https://hdl.handle.net/11124/172317"],"dc:language":["English"],"dc:language.iso":["eng"],"dc:publisher":["Colorado School of Mines. Arthur Lakes Library"],"dc:rights":["Copyright of the original work is retained by the author."],"dc:subject":["solubility","fluorite"],"dc:title":["Low temperature aqueous solubility of fluorite at temperatures of 5, 25, and 50°C and ionic strengths up to 0.72M"],"dc:type":["Text"],"thesis:degree_discipline":["Geology and Geological Engineering"],"thesis:degree_level":["Doctoral"],"thesis:degree_name":["Doctor of Philosophy (Ph.D.)"],"thesis:institution_name":["Colorado School of Mines"]},"updated_at":"2026-07-24T01:43:42Z"}