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Evaluating fluorspar for fluoridation
Author(s) -
Peng ChingGang,
Qi Jian,
Rubin Alan J.
Publication year - 1996
Publication title -
journal ‐ american water works association
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.466
H-Index - 74
eISSN - 1551-8833
pISSN - 0003-150X
DOI - 10.1002/j.1551-8833.1996.tb06489.x
Subject(s) - water fluoridation , fluoride , dissolution , calcium , environmental science , fluorite , chemistry , environmental chemistry , inorganic chemistry , organic chemistry
Data from this study indicate that fluoridation with natural fluorspar could be practical if the raw water is of an appropriate quality. There has been concern about the availability of commercial fluoride chemicals for publicly fluoridated water, coupled with potential problems of overdosing. Fluorspar, a mineral form of CaF 2 , may provide a more publicly acceptable approach with many advantages over other widely used fluoridation chemicals. This article describes work aimed at gaining insight into the dissolution equilibrium behavior of fluorspar under various conditions for its use in water fluoridation. By treating fluorspar as a blend of CaF 2 and CaCO 3 , the dissolution equilibria were accurately predicted by a theoretical model that accounted for the effects of temperature, background calcium ion concentration, and initial pH. Experimental results and calculations both showed that the ultimate fluoride concentration was approximately 6.0 mg/L at room temperature. Effects of temperature and background calcium ion concentration were much more significant than initial pH. Fluoridation with natural fluorspar could be a practical process with influents of the appropriate quality.