Solubility and Physical Properties of Calcium Sulfate Dihydrate in NaCl and Glycerol Aqueous Solution at 303.15, 323.15, and 343.15 K

Abstract

The solubility of calcium sulfate dihydrate (CaSO 4 •2H 2 O) was measured in NaCl and glycerol aqueous solution with the mass fraction of glycerol 0−80% and molality of NaCl 0−6 m in the temperature range of 303.15 to 343.15 K and atmospheric pressure. The results showed that the dissolution of CaSO 4 •2H 2 O obviously decreased in aqueous solution with the increase of glycerol content. Addition of NaCl increased the solubility of CaSO 4 •2H 2 O in glycerol aqueous solution, and then solubility decreased with a further increase of molality in which the solubility maximum increase rate is 246.15%. Temperature has a little effect on solubility in the CaSO 4 • 2H 2 O/NaCl/glycerol/H 2 O system. We also studied the physical properties (density and viscosity) of this system and used the least squares method to correlate the solubility, density, and viscosity with the molality of NaCl in a polynomial equation.

Intensification of Sonocrystallization of CaSO4 in Continuous Operation Using a Tube Sonicator

“…The TGA results (shown in Figure ) also confirmed that the only phase formed is the dihydrate phase confirmed from the ∼21% weight loss of the compound, and also the absence of NaCl being trapped in the crystal lattice of gypsum. The findings are also in accordance with the values reported by Miao et al with an approximate weight difference of 20.8%.…”

Solubility and Physical Properties of α-Calcium Sulfate Hemihydrate in NaCl and Glycerol Aqueous Solutions at 303.15, 323.15, and 343.15 K

“…Compared with formamide aqueous solution, 24 NaCl has the same properties as formamide, which makes the solubility of calcium sulfate increase first and then decrease. Compared with the solubility of DH in the NaCl−glycerol−H 2 O system, 25 the effect of glycerol and NaCl on the solubility of α-HH is the same as that on DH. However, by comparing the solubility curves of α-HH and DH in the NaCl−glycerol−H 2 O system, we cannot find any useful theoretical research results at this stage.…”

“…Our group has studied the solubility of DH and α-HH in a formamide aqueous solution and DH in a glycerol−sodium chloride aqueous solution. 24,25 Therefore, in this paper, we studied the solubility behavior of α-HH in a NaCl−glycerol−H 2 O system with 0−6 molality (m) NaCl and 30−80 wt % glycerol at 303.15, 323.15, and 343.15 K. The relationship among solubility, density, viscosity, and NaCl concentration was established by a polynomial equation.…”

“…Because the solubility and crystal morphology of calcium sulfate change by adding an organic solvent, it is necessary to study the solubility of calcium sulfate in an organic solvent–salt–H 2 O system. Our group has studied the solubility of DH and α-HH in a formamide aqueous solution and DH in a glycerol–sodium chloride aqueous solution. , …”