Effect of Cr2O3 and NiO additions on the phase transformations at high temperature in Portland cement

Abstract Although there exists much work to characterize the effect of minor elements on the properties of Portland cement, the same is not valid for the knowledge about their impact on the clinkering process. The goal of this work is to study the effects of chromium and nickel oxide additions on the transformations during the production of Portland cement clinker. The experiments were carried out using a differential thermal analysis (DTA) piece of equipment to obtain the heating and cooling transitions. Samples were prepared using high-purity reactants. The achieved results showed that the Cr2O3 additions to cement raw meal act as an inhibitor of C2S formation and increase the amount of liquid phase. On the other hand, NiO has very little effect on the clinkering reactions, but NiO does cause a small increase in the temperature of C2S formation and an opposite effect on the temperatures of liquid and the polymorphic transformation of C2S.