Bimodal distribution Crystalline structure 1 Fly ash 1 Higher temperatures 1 Hydrochloric acid 1 Hydrothermal conversion 1 Industrial applications 1 Particle size analysis 1 Peak intensity 1 Pretreatment temperature 1 Raw fly ashes 1 Reaction temperature 1 Silicate minerals 1 Size uniformity 1 Sodium 1 Sodium hydroxide solutions 1 Synthesis (chemical) 1 Synthesis temperatures 1 Waste management 1 XRD analysis 1 Zeolite materials 1 Zeolites 1 fly ash 1 zeolites 1