Effects of TiO2 waste on the formation of clinker phases and mechanical performance and hydration of Portand cement

The incorporation of different levels of UOW into Portland clinker raw meals and its effects on the clinker and cement properties were evaluated. Clinkers were produced and characterized by X-ray diffractometry (XRD) and optical microscopy; the cements were produced and physically characterized. Finally, pastes were produced and analyzed using isothermal calorimetry, thermogravimetry, XRD, and compressive strength tests. UOW, when added up to 1.29% in Portland clinker raw meal, acts as a mineralizer, increasing the content of alite by 6.44%. The incorporation of UOW reduces the hydration rate in the first days owing to the increase in the size of the alite crystals and delays the point of sulfate depletion due to the increase in the SO₃ content of the clinkers. Owing to the higher content of alite formed, the cement produced from the raw meal with 1.29% of UOW presents the highest early mechanical strength (up to 7 days).