Cement calcination in a fluidised bed - with outlet at the bottom and air cooled cooling zone

摘要

Cement is produced by burning raw material in a fluidised bed. The preheated raw material, fuel, preheated air and a recycled part of the burnt material are fed into the bed and the material leaving the bed is cooled in a stream of cold air. Specifically, the preheated raw material is precalcined in a calcination zone with added fuel to remove >=40 pref. 80-95% of the anions. The burnt material is discharged immediately from beneath and part from the sides of the vessel. A uniform end product is obtained with low energy consumption. The cement clinker produced has a low alkali content.