Chemical synthesis of hydraulic calcium aluminate compounds using the Pechini technique

3CaO·Al2O3 and 4CaO·Al2O3·Fe2O3 are two of the main compounds in portland cement and are conventionally prepared by sintering the solid oxide mixture above 1350 °C for many hours. The Pechini technique is a polymeric precursor route for the synthesis of ceramics. In this work, an equimolar mixture of C3A and C4AF was prepared by the Pechini technique. The preparation of the precursor mixture and the formation of the ceramic product were monitored using TG/DTA, XRD, FTIR and SEM. The combination of these techniques led to the recording of all the transformations occurring during the processing of the precursors and the formation of the final products. As it was concluded, the Pechini technique can be successfully applied for the preparation of 3CaO·Al2O3 and 4CaO·Al2O3·Fe2O3 mixtures. The final products consists of fine and well-formed grains of 3CaO·Al2O3 and 4CaO·Al2O3·Fe2O3. Their formation requires a 3-h sintering at 1000 °C.