In this work the possibility of neutralizing or removing compounds containing fluoride ions from waste silica gel was investigated. The elution of F– ions from waste silica gel to the liquid medium was performed under static and hydrothermal conditions. It was determined that waste silica gel consists of silicon dioxide (77.77%) and other compounds containing 8.64% F– and 4.03% Al3+ ions, which are stable during the drying process (50°C; 48 h). It was determined that under static elution conditions it is possible to remove only 6–7 wt. % F– ions into a liquid medium from waste silica gel. It was found that CaO additive has a positive influence on the decomposition of AlF3·3H2O and the formation of CaF2. It was found that silica gel is a prospective raw material for synthesis of Z-phase because the kinetics of compound formation is faster than in pure mixtures. A principal technological scheme has been designed for waste silica gel neutralization and utilization by using Ca(OH)2 under static or hydrothermal conditions.