ABSTRACT

Effect of addition of aliphatic alcohols (methanol, ethanol, and isopropyl alcohol) on dissolution characteristics of calcium sulfate dihydrate (gypsum, CaSO4*2H2O) in brines has been studied at 35C. Addition of alcohols decreased the dissolution of CaSO4*2H2O in aqueous NaCl solutions significantly and also shifted its solubility maximum towards lower concentration of NaCl. We have also recorded density () and speed of sound (u) for the quaternary systems (CaSO4*2H2O+NaCl+alcohols+H2O) at 35C. Using primary data we derived isentropic compressibility (S) of the solutions. The experimentally determined physical and derived properties have been correlated using polynomial or linear fits using method of least squares. Crystal growth behaviour and morphology of gypsum co-crystallized with NaCl crystals from different solutions has also been examined. Alcohol additives seem to be an environmentally friendly, low-cost additive to decrease the solubility of gypsum in aqueous systems with or without NaCl.

Compounds

#	Formula	Name
1	CH4O	methanol
2	C2H6O	ethanol
3	C3H8O	propan-2-ol
4	CaO4S	calcium sulfate
5	H2O	water

Datasets

The table above is generated from the ThermoML associated json file (link above). POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied; the numbers refer to the table of compounds on the left.
Type	Compound-#	Property	Variable	Constraint	Phase	Method	#Points
POMD	4 5 1	Molality, mol/kg - 4 ; Liquid	Mass ratio of solute to solvent - 1; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid	Liquid Crystal of intercomponent compound 1	chemical analysis	3
POMD	4 5 1	Mass density, kg/m3 ; Liquid	Mass ratio of solute to solvent - 1; Liquid Molality, mol/kg - 4; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid	Liquid	Vibrating tube method	3
POMD	4 5 1	Speed of sound, m/s ; Liquid	Mass ratio of solute to solvent - 1; Liquid Molality, mol/kg - 4; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid	Liquid	Single path-length method	3
POMD	4 5 2	Molality, mol/kg - 4 ; Liquid	Mass ratio of solute to solvent - 2; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid	Liquid Crystal of intercomponent compound 1	chemical analysis	3
POMD	4 5 2	Mass density, kg/m3 ; Liquid	Mass ratio of solute to solvent - 2; Liquid Molality, mol/kg - 4; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid	Liquid	Vibrating tube method	3
POMD	4 5 2	Speed of sound, m/s ; Liquid	Mass ratio of solute to solvent - 2; Liquid Molality, mol/kg - 4; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid	Liquid	Single path-length method	3
POMD	4 5 3	Molality, mol/kg - 4 ; Liquid	Mass ratio of solute to solvent - 3; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid	Liquid Crystal of intercomponent compound 1	chemical analysis	3
POMD	4 5 3	Mass density, kg/m3 ; Liquid	Mass ratio of solute to solvent - 3; Liquid Molality, mol/kg - 4; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid	Liquid	Vibrating tube method	3
POMD	4 5 3	Speed of sound, m/s ; Liquid	Mass ratio of solute to solvent - 3; Liquid Molality, mol/kg - 4; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid	Liquid	Single path-length method	3
POMD	1 5	Mass density, kg/m3 ; Liquid	Mass ratio of solute to solvent - 1; Liquid	Pressure, kPa; Liquid Temperature, K; Liquid	Liquid	Vibrating tube method	3
POMD	1 5	Speed of sound, m/s ; Liquid	Mass ratio of solute to solvent - 1; Liquid	Pressure, kPa; Liquid Temperature, K; Liquid	Liquid	Single path-length method	3
POMD	2 5	Mass density, kg/m3 ; Liquid	Mass ratio of solute to solvent - 2; Liquid	Pressure, kPa; Liquid Temperature, K; Liquid	Liquid	Vibrating tube method	3
POMD	2 5	Speed of sound, m/s ; Liquid	Mass ratio of solute to solvent - 2; Liquid	Pressure, kPa; Liquid Temperature, K; Liquid	Liquid	Single path-length method	3
POMD	3 5	Mass density, kg/m3 ; Liquid	Mass ratio of solute to solvent - 3; Liquid	Pressure, kPa; Liquid Temperature, K; Liquid	Liquid	Vibrating tube method	3
POMD	3 5	Speed of sound, m/s ; Liquid	Mass ratio of solute to solvent - 3; Liquid	Pressure, kPa; Liquid Temperature, K; Liquid	Liquid	Single path-length method	3

Thermodynamics Research Center / ThermoML | Journal of Chemical and Engineering Data

Effects of Aliphatic Alcohols on Solubility, Physicochemical Properties, and Morphology of Calcium Sulfate Dihydrate (Gypsum) in Aqueous Sodium Chloride Solution at 35 deg.C

Shukla, Jignesh, Mehta, Mohit J., Kumar, Arvind

ABSTRACT