Advances in clinkering technology of calcium sulfoaluminate cement

A new method for producing calcium sulfoaluminate (CS¯A) clinkers is described. Sulfur is introduced from the gas phase as sulfur dioxide and oxygen and reacts with solids during clinkerisation. In this paper, the laboratory experiments are described and thermodynamic calculations are presented. The sulfur-containing phases ye’elimite and ternesite were stabilised together with belite to produce clinkers with various mineralogies. The influences of temperature and sulfur dioxide partial pressure were analysed and their effect on the formation of undesirable anhydrite and gehlenite was examined. The process by which a potentially hazardous waste material such as sulfur can be used as raw material, and possibly as fuel, to form CS¯A cements, is shown to be successful.