The effects of fluorine-containing mineralizers and fluxes on the burnability of a series of raw mixes, ranging from the quaternary system CaO-Al_sO₃- Fe₂O₃-SiO₂ to more complex mixtures and industrial mixes, were determined. New evidence has been found to show that fluorine-containing additives have a major influence on the composition of the liquid phase which, in turn, accelerates silicate mineral formation between 1200° and 1300°C. MgO and K₂SO₄ influence the partitioning of fluorine between silicate and interstitial phases. The C₃S crystallization process results in removal of fluorine from the interstitial phases, and causes a compositional shift from C₁₁A₇.CaF₂ to C₃A. Data are given which show the relationships between fluorine content, clinkering temperature, Al₂O₃/Fe₂O₃ ratio, and rates of reaction. Factors that influence hydration and strength development are shown. These results have direct implications on commercial clinker production and energy conservation.