Effect of fluidized bed calcination on cement clinker intermediate products formation under the eutectic temperature

Abstract

The cement industry is now confronted with the pressure of strict requirements of energy consumption and pollution emission. To solve the problem, a two-process clinker manufacturing method consisting of a pretreatment process and a final calcination process is raised. The new method uses fluidized bed reactors to substitute the rotary kiln and cyclone preheater. Applicable operation conditions of the brand-new pretreatment process are firstly investigated to make sure the method will succeed. The intermediate product is used to describe the material obtained from the pretreatment process. Influences of the variants including calcination temperature, calcination time, and calcination atmosphere on the formation of intermediate products were discussed in the study. Results showed that the amount of C2S (dicalcium silicate) and strength of the intermediate product particles increased with the rising temperature. The superiority of rapid heating and fluidization in the pretreatment process was illustrated by comparing three heating styles. The recommended sequence of calcination was fluidized bed calcination > rapid calcination > slow calcination. Calcined for 10 min at 1200 °C is the optimal condition for the pretreatment process. The influence of atmospheres on C2S formation was not obvious. Operation conditions of the pretreatment process were determined for further study.