Immobilization of Fluorine Using a Dolomite Geochemical Barrier

Abstract

The possibility of using the dolomite geochemical barrier for fine cleaning of alkaline wastewaters against fluorine was substantiated in experiments for coal-burning power plants. It was found that the residual fluorine concentration at pH 10.4–10.6 conformed to the optimum values for potable waters (0.7–0.9 mg/L), whereas the degree of fluorine removal at pH > 12.0 was at a maximum at 99.2% with less than 0.1 mg/L residual fluorine concentration. The optimum residual concentration of fluorine was obtained under the stoichiometric excess of dolomite over reactive CaO in ashes and slag wastes, which allowed calculation of the required capacity of dolomite barriers.