Abstract
In modern construction, the development of environmentally safe, fire-resistant, and energy-efficient thermal insulation materials is one of the key priorities. The flammability and chemical instability of traditional organic insulation materials necessitate the search for new mineral-based alternatives. In this context, the use of natural siliceous rock – opoka, which represents an abundant raw material resource in Western Kazakhstan – for the synthesis of foam-crystalline materials is of significant scientific interest. This approach not only enhances the energy efficiency of buildings but also elevates fire safety to a new level. The opoka from the Taskala deposit was selected as the object of this study. The material synthesis technology is based on alkali activation of opoka using a sodium hydroxide solution, followed by thermal treatment. To comprehensively investigate the physicochemical properties, modern analytical techniques were employed, including derivatographic analysis to determine phase transformations and scanning electron microscopy (SEM) to visualize the microstructure. The results demonstrate that the high reactivity of opoka enables the formation of a uniform porous structure during the transition to a pyroplastic state without the use of additional foaming agents. Thermal analysis confirmed the material’s high fire resistance and mass stability up to 1000°C, indicating its suitability for operation under extreme temperature conditions. Microstructural analysis revealed a closed-pore morphology and a strong glass-crystalline framework. The obtained results indicate that opoka-based materials fully meet modern construction requirements. The closed-cell structure ensures low thermal conductivity and high mechanical strength. The low-temperature synthesis method significantly reduces energy consumption compared to conventional foam glass technologies and enables efficient utilization of local raw materials. This approach reduces production costs and provides an environmentally friendly solution for advanced thermal insulation materials.