The effect of sintering temperature on cavitation erosion in glass–ceramics based on coal fly ash

The incombustible portion of coal that remains after burning is known as bottom or fly ash, and it has a detrimental influence on the environment. One of the possible alternatives for reducing the amount of ash deposited in landfills might be the production of useful glass–ceramic from vitrified fly ash. Glass–ceramic was synthesized using fly ash from the thermal power plant "Nikola Tesla" and fluxing additives. Sinter crystallization of the parent glass resulted in glass ceramics. The glass was created by melting a combination of coal fly ash (CFA), Na2CO3, and CaCO3 at T = 1500 °C and quenching the melt in the air. Glass powders were sintered at temperatures 850 and 900 °C. The resulting glass–ceramics were characterized microstructurally, physically, and mechanically. The cavitation erosion of samples was evaluated. The cavitation rate was 0.015 mg/min for the sample sintered at 850 °C and 0.0053 mg/min for the sample sintered at 900 °C. The leaching of heavy metals in glass–ceramic samples was determined using Toxicity Characteristic Leaching Procedure. A low concentration of heavy metals in the leaching solution showed that heavy metals were successfully incorporated in the glass matrix and that obtained glass–ceramics are ecologically safe for usage. Both samples exhibit good resistance to cavitation erosion, suggesting their potential as possible replacements for structural ceramics commonly employed components of hydraulic machinery.