New construction or modernization for kiln plants

Most of the 76 rotary kilns currently in operation in Germany were built before the oil price crisis in 1974. These rotary kiln plants are now over 20 years old, which is particularly true of the 26 kilns with grate preheaters. Many operators are therefore faced with the choice of modernizing their plants or building new ones. For the cement works in the new federal states this decision had to be taken, and implemented, within a very short period after reunification. This development now offers the opportunity to reconstruct the important decision criteria - both for modernization and for replacement by new construction - with the aid of examples. The initial situations, the target criteria and respective results of the decision processes are described for the Ruedersdorf, Karsdorf, Bernburg and Laegerdorf projects. Other plants are also included in the examination. Particular emphasis is given to recent innovative technical developments and their implementation when building new plants. Finally, the attempt is made to represent the findings obtained in these examples in a form that is universally applicable.