C/CLAY^® – Experiences with clay calcining and grinding to achieve high SCM rates

The cement industry has committed to take drastic steps to reduce process‐related CO₂ emissions to achieve climate neutrality by 2050. One essential part of the solution is the reduction of the average clinker content in cement. However, the limits of availability of common composite materials are already reached, and focus is laid meanwhile on calcined clays as the next generation SCM. The knowledge about the effects of calcined clay in cement and also the development of production technologies are well‐advanced. Now it is the task to earn acceptance on customer's side project by project.

For that purpose, the presented paper sums up the state of the art of clay activation by answering the most urgent questions of clients. This also includes a review of LOESCHE's experiences with clay calcination and grinding gained in the recent years. LOESCHE combines its competence in this technology in the product C/CLAY^® supplying individual solutions for all process steps from pretreatment over calcination to finish grinding. The most practical C/CLAY^® methods, the flash‐calcination and rotary kiln firing, are explained with their complete process chains, whereby the latter provides a suitable option for retrofitting stopped cement production lines. As example, the layout of the world's biggest clay calcination plant designed by LOESCHE's subsidiary DYNAMIS is presented.