Effect of molding pressure and firing temperature on the properties of ceramics from natural zeolite

Abstract

In recent years, there has been growing interest in eco-friendly and sustainable construction materials that reduce environmental impact while maintaining high-performance standards. The brick industry, in particular, is under pressure to develop solutions that incorporate waste and natural-based materials, reducing reliance on traditional energy-intensive manufacturing processes. In response, this study explores the fabrication of ceramic bricks using naturally occurring zeolite, which is widely available and offers promising properties for use in construction. The ceramic matrix is made with natural zeolite and water, pressed at three different pressures, and fired at three different temperatures. The study investigates the impact of varying molding pressures and firing temperatures on the microstructural and mechanical properties of ceramic bricks made with natural zeolite. XRF and XRD techniques were used to analyze the raw material's chemical composition, and TGA tests were conducted to evaluate the bricks' chemical stability. The study finds that the compressive strength of zeolite bricks molded at 15 MPa pressure and fired at 900 ℃ increased from 7.1 MPa to 51.2 MPa when fired at 1100 ℃. Increasing the molding pressure led to a higher compressive strength of the specimens, but the effect was minimal compared to the influence of firing temperature on the compressive strength. The apparent porosity and water absorption of the bricks decreased with increasing molding pressure and firing temperature. Further, clinoptilolite, a zeolite phase, decomposes during firing and transforms into silica polymorphs, feldspathic phases, and glassy phases. As the molding pressure increased, the irregular-shaped pores in the brick specimens decreased. Moreover, the density of the bricks increased with the firing temperature due to sintering between particles in the microstructure. By investigating the impact of molding pressure and firing temperature on the microstructural and mechanical properties of these eco-friendly bricks, this study offers insight into a potential solution for sustainable construction practices. By investigating the impact of pressing pressure and firing temperature on the microstructural and mechanical properties of these eco-friendly bricks, this study demonstrated that optimizing firing temperature and pressing pressure can significantly improve the physical and mechanical properties of zeolite bricks, including bulk density, compressive strength, water absorption, and porosity, while also reducing the environmental impact of the production process. Thus, this study offers insight into a potential solution for sustainable construction practices.