ABSTRACT
Precipitation and inhibition of alkaline earth metal uorides are interesting physicochemical processes and have been the subject of intensive research [1-3]. The crystallization and dissolution reactions involving calcium uoride are of concern in waste water treatment since uoride is introduced into the environment as a natural impurity in ores used to produce phosphoric acid [4] and in the waste water from the semiconductor industry during etching and rinsing operations [5]. Additionally, these residual uoride wastes may result in supersaturated solutions, leading to the formation of calcium uoride precipitates. In oral care, calcium uoride plays an important role in the topical application of uoride solutions to tooth enamel. Such treatment results in the partial transformation of hydroxyapatite, the main inorganic component of the tooth enamel, to uorapatite on the enamel surface, resulting in a much caries-resistant phase [6,7].
