A process-integrated method for calcining clays

The use of calcined clays as a main component of cement or as an additive to concrete is becoming increasingly important and of interest from an economic and ecological point of view. Standards such as the European Cement Standard EN 197 already today provide for the use of calcined clays (as natural tempered pozzolan) as a main component of cement. Depending on their chemical and mineralogical composition, the clays used must in principal be heated to temperatures of over 600 °C in order to achieve their pozzolanic potential. VDZ has developed a new process for this purpose, which we are pleased to present to you in the attached document.