Development of precalcining technology in the cement industry

Precalcining technology offers the advantage of carrying out the calcining of limestone to a great extent outside the rotary kiln so that the kiln can be designed with smaller dimensions or it can be operated calcining technology in with higher outputs if the dimensions are maintained. Additionally, it is possible to limit the emission the cement industry of nitrogen oxides and to burn secondary fuels using modern calciners. It took four generations to develop the modern calciners we know today. They are described in this paper and, for the first time, the market shares of the various processes and bidders are presented. Finally it is shown in which regions and countries most of the calciners have been commissioned until now.