• Bannerman, Marcus N.
• Pisch, Alexander
• Hanein, T.
• Rößler, C.
• Abdul, Wahab
• Mawalala, Chancel

Abstract

Research into thermodynamic modelling allows for product and process optimisation of Portland cement clinkers. Due to the magnitude and chemistry of clinker production, there is a great challenge in modelling such a complex system. The CALPHAD (CALculation of PHAse Diagrams) approach provides a method in overcoming this challenge, by constructing a model, step-by-step with increasing complexity, i.e., starting with the pure solids and liquid to modelling binary and ternary melts, and moving on to higherorder systems, and with the possibility to eventually embed mobility. This approach has had great success in the metals industry and has allowed for production optimisation for a variety of alloys. In this project, we have developed a thermodynamic database for the CaO-Al2O3-SiO2-Fe-O-MgO system. This provides a much-needed update to the underlying thermodynamic data. In addition, prediction calculations made with our thermodynamic database are compared against technical clinkers analysed by XRD, XRF, and SEM-EDX. Future work will include developing further extensions to the thermodynamic database to include other elements such as sulfur to further model clinker diversity.

Topics

• impedance spectroscopy
• mobility
• scanning electron microscopy
• x-ray diffraction
• melt
• cement
• Energy-dispersive X-ray spectroscopy
• phase diagram
• X-ray fluorescence spectroscopy
• CALPHAD