Identification of the Si-F bonds and phase composition of selected slags from the CaO-SiO2-CaF2 system using infrared spectroscopy

The CaO-SiO2-CaF2 phase system was investigated for selected slags using in frared spectroscopy. Si-O, Si-O(Si) and Si-F bonds were found in the slags and the type of occurring phases and chemical compounds was determined. The Si-F type bonds occurred only a larger content of CaF2. Using the examinat ion results, the stages of the reaction of formation of the SiF4 gaseous ph ase were proposed. An important role has been found to be played by Si-F bo nds that initiate two stages of the reaction of formation of the SiF4 gaseo us phase. In the slags containing 4.02% and 9.88% of CaF2, no Si-F bonds we re identified.