Thermodynamic Modeling of Calcium Sulfate Hydrates in the CaSO4-H2O System from 273.15 to 473.15 K with Extension to 548.15 K

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@article{7e9fdfa33e774e70b82bda0669e6a333,
title = "Thermodynamic Modeling of Calcium Sulfate Hydrates in the CaSO4-H2O System from 273.15 to 473.15 K with Extension to 548.15 K",
abstract = "Calcium sulfate is one of the most common inorganic salts with a high scaling potential. The solubility of calcium sulfate was modeled with the Pitzer equation at a temperature range from 273.15 to 473.15 K from published solubility data, which was critically evaluated. Only two Pitzer parameters, β(1) and β(2), with simple temperature dependency are required to model the solubility with excellent extrapolating capabilities up to 548.15 K. The stable temperature range for gypsum is 273.15-315.95 K, whereas above 315.95 K the stable phase is anhydrite. Hemihydrate is in the metastable phase in the whole temperature range, and the obtained metastable invariant temperature from gypsum to hemihydrate is 374.55 K. The obtained enthalpy and entropy changes at 298.15 K for the solubility reactions are in good agreement with literature values yielding solubility products of 2.40 × 10-05, 3.22 × 10-05, and 8.75 × 10-05 for gypsum, anhydrite, and hemihydrate, respectively. The obtained Pitzer model for the CaSO4-H2O system is capable of predicting the independent activity and osmotic coefficient data with experimental accuracy. The mean absolute average error of activity coefficient data at 298.15 K is less than 2.2{\%}. Our model predicts the osmotic coefficient on the ice curve within 1.5{\%} maximum error.",
author = "Leiting Shen and Hannu Sippola and Xiaobin Li and Daniel Lindberg and Pekka Taskinen",
note = "| openaire: EC/H2020/730480/EU//ITERAMS",
year = "2019",
month = "6",
day = "13",
doi = "10.1021/acs.jced.9b00112",
language = "English",
volume = "64",
pages = "2697--2709",
journal = "Journal of Chemical and Engineering Data",
issn = "0021-9568",
publisher = "AMERICAN CHEMICAL SOCIETY",
number = "6",

}

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TY - JOUR

T1 - Thermodynamic Modeling of Calcium Sulfate Hydrates in the CaSO4-H2O System from 273.15 to 473.15 K with Extension to 548.15 K

AU - Shen, Leiting

AU - Sippola, Hannu

AU - Li, Xiaobin

AU - Lindberg, Daniel

AU - Taskinen, Pekka

N1 - | openaire: EC/H2020/730480/EU//ITERAMS

PY - 2019/6/13

Y1 - 2019/6/13

N2 - Calcium sulfate is one of the most common inorganic salts with a high scaling potential. The solubility of calcium sulfate was modeled with the Pitzer equation at a temperature range from 273.15 to 473.15 K from published solubility data, which was critically evaluated. Only two Pitzer parameters, β(1) and β(2), with simple temperature dependency are required to model the solubility with excellent extrapolating capabilities up to 548.15 K. The stable temperature range for gypsum is 273.15-315.95 K, whereas above 315.95 K the stable phase is anhydrite. Hemihydrate is in the metastable phase in the whole temperature range, and the obtained metastable invariant temperature from gypsum to hemihydrate is 374.55 K. The obtained enthalpy and entropy changes at 298.15 K for the solubility reactions are in good agreement with literature values yielding solubility products of 2.40 × 10-05, 3.22 × 10-05, and 8.75 × 10-05 for gypsum, anhydrite, and hemihydrate, respectively. The obtained Pitzer model for the CaSO4-H2O system is capable of predicting the independent activity and osmotic coefficient data with experimental accuracy. The mean absolute average error of activity coefficient data at 298.15 K is less than 2.2%. Our model predicts the osmotic coefficient on the ice curve within 1.5% maximum error.

AB - Calcium sulfate is one of the most common inorganic salts with a high scaling potential. The solubility of calcium sulfate was modeled with the Pitzer equation at a temperature range from 273.15 to 473.15 K from published solubility data, which was critically evaluated. Only two Pitzer parameters, β(1) and β(2), with simple temperature dependency are required to model the solubility with excellent extrapolating capabilities up to 548.15 K. The stable temperature range for gypsum is 273.15-315.95 K, whereas above 315.95 K the stable phase is anhydrite. Hemihydrate is in the metastable phase in the whole temperature range, and the obtained metastable invariant temperature from gypsum to hemihydrate is 374.55 K. The obtained enthalpy and entropy changes at 298.15 K for the solubility reactions are in good agreement with literature values yielding solubility products of 2.40 × 10-05, 3.22 × 10-05, and 8.75 × 10-05 for gypsum, anhydrite, and hemihydrate, respectively. The obtained Pitzer model for the CaSO4-H2O system is capable of predicting the independent activity and osmotic coefficient data with experimental accuracy. The mean absolute average error of activity coefficient data at 298.15 K is less than 2.2%. Our model predicts the osmotic coefficient on the ice curve within 1.5% maximum error.

UR - http://www.scopus.com/inward/record.url?scp=85067431307&partnerID=8YFLogxK

U2 - 10.1021/acs.jced.9b00112

DO - 10.1021/acs.jced.9b00112

M3 - Article

VL - 64

SP - 2697

EP - 2709

JO - Journal of Chemical and Engineering Data

JF - Journal of Chemical and Engineering Data

SN - 0021-9568

IS - 6

ER -

ID: 34996269