Utilization of Natural Silicate Rocks to Reduce the Carbon Footprint in the Cement Industry

Portland cement production is associated with high energy consumption and CO₂ emissions, highlighting the need for alternative raw materials to improve environmental sustainability. Research findings indicate that porphyrite, a natural silicate rock, exhibits pozzolanic and hydraulic activity, making it a promising additive in composite cement production. In this study, the physicochemical properties and hydration processes of porphyrite-modified Portland cement were analyzed using X-ray diffraction (XRD), differential thermal analysis (DSC), and Fourier-transform infrared spectroscopy (FTIR). The compressive strength and setting time of cement samples were tested according to GOST 30744-2001 and GOST 310-91 standards. The results showed that porphyrite addition slightly slowed the hydration process, reducing C₃S content while promoting the formation of calcium hydroxide (Ca(OH)₂). Cement containing 20% porphyrite met the 32.5N strength class requirements and demonstrated stable mechanical properties. Water absorption tests confirmed a gradual hydration process, with no sudden crystallohydrate formation observed. This study confirms that porphyrite is an effective mineral additive, contributing to cement durability, reduced clinker consumption, and lower energy demand. Future research should focus on the long-term stability of porphyrite-based cement using advanced thermal analysis techniques.