Calcium sulphate hemihydrate hydration leading to gypsum crystallization

Abstract The hydration of calcium sulphate hemihydrate (CaSO 4 ·0.5H 2 O) leading to the crystallization of gypsum (calcium sulphate dihydrate – CaSO 4 ·2H 2 O) has been the subject of several investigations over a long period and a vast amount of data is widely distributed throughout in the literature. In this review article an overall picture of the subject is presented. The properties of the two hemihydrates (α- and β-), their hydration characteristics, the mechanism of their hydration and the crystal growth of gypsum are discussed. Additives modify the microstructures of the hardened gypsum and reduce its strength. A probable mechanism is discussed.

[1]  Jörg-Rüdiger Hill,et al.  Retardation of setting of plaster of Paris by organic acids: Understanding the mechanism through molecular modeling , 2004, J. Comput. Chem..

[2]  B. Molony,et al.  The forms of calcium sulphate hemihydrate , 1966 .

[3]  D. Harker,et al.  A new law of crystal morphology extending the law of Bravais , 1937 .

[4]  R. Hand,et al.  The kinetics of hydration of calcium sulphate hemihydrate: A critical comparison of the models in the literature , 1994 .

[5]  R. Mikhail,et al.  Microstructure of hardened gypsum pastes , 2007 .

[6]  H. Henisch.  Crystal growth in gels , 1970 .

[7]  E. Lesniewska,et al.  Correlation between surface forces and surface reactivity in the setting of plaster by atomic force microscopy , 2000 .

[8]  Jan Skalny,et al.  Materials science of concrete , 1989 .

[9]  G. H. Nancollas,et al.  CHAPTER 9. MECHANISMS OF GROWTH AND DISSOLUTION OF SPARINGLY SOLUBLE SALTS , 1990 .

[10]  B. Middendorf,et al.  Hydration of α-hemihydrate in the presence of carboxylic acids , 2006 .

[11]  M. Hochella,et al.  Gypsum growth in the presence of growth inhibitors: a scanning force microscopy study , 1996 .

[12]  Dino Musmarra,et al.  Calcium Sulfate Dihydrate Nucleation in the Presence of Calcium and Sodium Chloride Salts , 2001 .

[13]  F. Brandt,et al.  Bassanite (CaSO4·0.5H2O) dissolution and gypsum (CaSO4·2H2O) precipitation in the presence of cellulose ethers , 2001 .

[14]  Mualla Öner,et al.  The influence of polyelectrolytes architecture on calcium sulfate dihydrate growth retardation , 1998 .

[15]  J. Prywer.  Kinetic and geometric determination of the growth morphology of bulk crystals: Recent developments , 2005 .

[16]  J. Williamson,et al.  The setting of gypsum plaster , 1994 .

[17]  S. Indris,et al.  The Setting Behaviour of α‐ and β‐CaSO4 · 0,5 H2O as a Function of Crystal Structure and Morphology , 2002 .

[18]  H. Carr,et al.  The Principles of Nuclear Magnetism , 1961 .

[19]  N. N. Bushuev,et al.  X-RAY DIFFRACTION INVESTIGATION OF CASO4∙0,67 H2O , 1982 .

[20]  M. Hochella,et al.  Gypsum growth in the presence of background electrolytes studied by Scanning Force Microscopy , 1996 .

[21]  R. Boistelle,et al.  Improvement of the mechanical properties of set plasters by means of four organic additives inducing {01}faces , 1986 .

[22]  G. Wulff,et al.  XXV. Zur Frage der Geschwindigkeit des Wachsthums und der Auflösung der Krystallflächen , 1901 .

[23]  Jörg Kropp,et al.  Cement and Concrete , 2001 .

[24]  S. Hansen,et al.  Dissolution of CaSO4·1/2H2O and precipitation of CaSO4·2H2O: A kinetic study by synchrotron X-ray powder diffraction , 2001 .

[25]  E. Combe,et al.  Kinetics of hydration of autoclaved calcium sulphate hemihydrate , 2007 .

[26]  S. Veesler,et al.  Crystallization of gypsum from hemihydrate in presence of additives , 1999 .

[27]  P. Niggli.  Geometrische Kristallographie des Diskontinuums , 1973 .

[28]  K. Schiller.  Hydration of Calcium Sulphate Hemihydrate , 1965, Nature.

[29]  R. J. Hand.  A discussion of the paper “The kinetics of hydration of calcium sulphate hemihydrate: A critical comparison of the models in the literature” , 1995 .

[30]  Marc Domenech,et al.  Hydration of calcium sulfate hemihydrate (CaSO4·H2O) into gypsum (CaSO4·2H2O). The influence of the sodium poly(acrylate)/surface interaction and molecular weight , 2000 .

[31]  P. Kotoky,et al.  Sulphate behaviour from dissolution of gypsum in organic acids , 2000 .