Perspective on glass properties influencing perlite expansion and strength

Perlite, a naturally occurring volcanic glass, expands upon rapid heating due to internal steam pressure, forming a lightweight, foam-like porous structure with applications in construction, filtration, and catalysis. Given its industrial significance, the next generation of expanded perlite aims to achieve an optimal balance of lightweight, controlled porosity, and surface characteristics, alongside enhanced mechanical strength to meet the demands of advanced applications. However, achieving these target properties is challenging due to natural composition fluctuations, the rapid expansion kinetics of the perlite skeleton, and its high sensitivity to processing conditions. This perspective article examines the state of the art and provides insight into the effect of glass (perlite) composition, viscosity, fragility, and gas release on pore morphology and compressive and isostatic strength. Based on these fundamental insights from glass properties, we propose strategies to enhance the mechanical performance of expanded perlite. Future developments will benefit from high-accuracy modeling practices integrating composition-processing-property relationships to produce expanded perlite with targeted mechanical properties.