TY JOUR TI GLASS FORMATION AND CRYSTALLIZATION STABILITY MULTILAYER GLASSES BASED ON THERMAL POWER PLANT FLY ASH KW iron in glass KW fly ash KW compositions of experimental glasses KW charge compositions KW polythermal studies KW glass formation KW crystallization JO Bulletin of Belgorod State Technological University named after. V. G. Shukhov AU Lazarova, Y.S. AU Onischuk, V.I. AU Shabalin, S.I. AU Doroganov, V.A. AU Evtushenko, E.I. PY 2026 IS 11 PB Belgorod State Technological University named after V.G. Shukhov