A method to synthesize high-purity ternesite at gram scale is presented and a brief description of the product morphology and reactivity is presented. Thermodynamic data for ternesite are derived from vapour pressure measurements and the limits of ternesite stability are explored. An upper temperature stability limit of ≈1290°C at 1 atm is determined; however, this temperature is dependent on the fugacity of the volatile components SO2 and O2 in the kiln atmosphere. Both thermodynamic predictions and lab experiments confirm that Calcium SulfoAluminate-Ternesite clinkers can be readily produced in a single stage process provided the atmosphere and temperature are controlled. To demonstrate this control at larger scales, a conventional 7.4-meter rotary kiln has been used to produce ≈20 kilograms of ternesite-containing clinkers. This demonstrates the usefulness of thermodynamic modelling as it has enabled ternesite based clinkers to be produced at scale in a single-stage process using existing equipment without major modifications.
- Cement Manufacture (E)
- Sulfoaluminate (D)
- Thermodynamic Calculations (B)