MODIFICATION OF NEUTRALIZED FLUOROGYPSUM USING HEAT TREATMENT AND A GYPSUM CONVERTER ADDITIVE

This article investigates the potential of utilizing technogenic fluorogypsum as a raw material for producing gypsum binders. A comparative analysis of the phase composition, morphology, and thermal behavior of fluorogypsum samples and natural gypsum rock was conducted using a suite of analytical techniques: X-ray diffraction (XRD), scanning electron microscopy (SEM), and simultaneous thermal analysis coupled with evolved gas analysis (TG/DTA-EGA).It was established that heating fluorogypsum within the temperature range of approximately 325°C to 475°C results in the release of hydrogen fluoride (HF). Based on XRD data, the optimal calcination temperature for fluorogypsum was determined to achieve the maximum content of calcium sulfate hemihydrate (bassanite). Physical and mechanical tests of the obtained binder were performed in accordance with GOST standards. These tests included determining standard consistency, setting times, compressive strength, and flexural strength. Testing was conducted both with and without the addition of a commercial gypsum modifier (CBB-500). The CBB-500 modifier was found to effectively enhance the strength characteristics of the binder at all stages of hardening.The study demonstrated that the hemihydrate gypsum produced by calcination, when used within the fluorogypsum binder, exhibits higher specific activity during hardening compared to the hemihydrate gypsum present in commercial construction gypsum.The obtained data indicate the promising potential of fluorogypsum for the production of high-quality construction materials.