Alucoque a by-product from the aluminium manufacture as mineralizer in the clinker production

EDGARDO FABIAN IRASSAR; ALEJANDRA TIRONI; ANABELLA MOCCIARO; ERNESTO MOYAS; CLAUDIA CRISTINA CASTELLANOS; VIVIANA BONAVETTI; MONICA A. TREZZA; VIVIANA RAHHAL; ALBERTO N. SCIAN

Praga

Congreso; 15th International Congress on the Chemistry of Cement; 2019

The use of mineralizers in the clinker production facilitate the clinkerization process, decrease the liquid phase temperature and mineral eutectic melt as consequently save of energy. Calcium fluoride is used as mineralizer in the manufacturing of Portland cement clinker, but also, by-products with fluorides could be valorized as mineralizers. The aim of this work is to study the spent potlining (SPLalucoque) from the aluminum manufacture in Argentine on the Portland cement clinker phases and cement hydration. Alucoque contains carbon, cyanides and fluorides minerals from the electrolytic tanks. The chemical composition of alucoque was measured by X-ray fluorescente. Reference flourfrom the industrial raw mixture and four modified flours prepared adding 0.25, 0.50, 1.0 and 1.50 % w/w of the alucoque, were burned on propilot klin to produce Portland clinker. The effects of alucoque addition on the clinker mineralogy and on the cement hydration (clinker with 5% gypsum w/w) were evaluated. The clinker phases were determined by XRD. The combined water and the Ca(OH)2 content in hydrated pastes were determined using thermal gravimetric analysis (DTA/TG). For all modified samples the phases associated with the production of clinker are recorded, suggesting satisfactory burning and clinkerization of all samples. Different C3S polymorphs are identified: the M3 polymorph is observed in reference clinker and M1 polymorph in the clinker of modified samples. Finally, the hydration shows that small additions of the added alucoque (up to 1%) do not significantly affect the total rate of hydration