Abstract
The sustainable development goals of the Kazakhstan-2050 strategy emphasize the rational use of industrial by-products and the creation of low-carbon, resource-efficient construction materials. In Kazakhstan, large volumes of fly ash and mineralized wastewater are generated by thermal power and metallurgical industries, requiring effective recycling solutions. This study presents the development of non-autoclaved aerated concrete based on fly ash (40–60%), microsilica (5–10%), and mineralized wastewater as a full replacement for process water. The combined use of these components was analyzed through physical, mechanical, and microstructural tests, including XRF, XRD, MIP, and SEM. Comparative analysis with conventional cement-based and geopolymer concretes shows increased strength (up to +22%), reduced porosity (−15%), and lower water absorption (−12%). Additionally, a simplified CO2reduction and life-cycle perspective highlights a 25–30% reduction in embodied carbon. The research demonstrates that local industrial wastes can serve as effective raw materials for sustainable wall and insulation products, aligning with circular economy principles.