Spontaneous precipitation of calcium sulphate dihydrate in the presence of some metal ions

✍ Scribed by S.K. Hamdona; R.B. Nessim; S.M. Hamza

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 622 KB
• Volume: 94
• Category: Article
• ISSN: 0011-9164
• DOI: 10.1016/0011-9164(93)80155-g

✦ Synopsis

The precipitation of calcium sulphate dihydrate from aqueous solutions has been studied at super-saturations sufficient for spontaneous precipitation but low enough to enable highly reproducible experiments to be carried out with respect to induction periods and rates of precipitation. The induction periods and rates of precipitation are both strongly dependent on degree of saturation. Over a range of supersaturation, 1.54.1, the precipitation reaction appears to be controlled by a surface polynucleation process. The influence of some metal ions on the precipitation process have been studied at several additive concentrations. The reduction in precipitation rate can be interpreted in terms of a Langmuir-type adsorption insotherm.