Utilisation of titanium-containing wastes in the cement industry: A literature review

The metallurgical industry is among the leaders in waste production which has a high potential for recycling. The review paper considers the problems of metallurgical industry waste management and some possible ways of their solution. Waste acidic pickling solutions of titanium (titanium sludge) can be used as an additive to cement clinkers both to improve the characteristics of building materials and the efficiency of their production process. The influence of calcium fluoride (CaF2) and titanium dioxide (TiO2) on cement clinkers at different concentrations of substances and sintering temperatures has been reviewed. The data on changes in the content of free lime (f-CaO), patterns of formation and distribution of clinker phases: alite, belite, celite and calcium aluminiferite have been presented. Mechanisms of CaF2 and TiO2 inclusion in the composition of various cement phases have been explained. The conclusion has been made that the application of titanium-containing wastes allows not only to recycle them, but also to obtain construction materials with improved characteristics.