Cement kiln dust: characterization of dust collected in the various fields of the electrostatic precipitator
C. Lanzerstorfer, K. Feichtinger - Cement kiln dust: characterization of dust collected in the various fields of the electrostatic precipitator - ENVIRONMENTAL ENGINEERING SCIENCE, Vol. 33, No. 33, 2016, pp. 200-206
The dust collected from the off gas of cement kilns (CKD) is usually recycled to the process. In some cases, especially when its chlorine content is higher, the dust has to be discharged. Generally in this study, the chemical composition of CKDs is in the range of the reported concentration data. For the main components Ca, Mg, Si, Al, Fe and C, the concentrations are very similar for all samples, the relative standard deviation for the concentration was less than 10%. For the concentration of K and Cl- a significant increase was found for the consecutive fields of the electrostatic precipitator (ESP). The enrichment factor for Cl- in the dust from the third field of the ESP was approximately 4.0. Therefore, selective exclusion of the CKD from the last field from recycling can be used for Cl- discharge. For the handling, transport and storage of the dust its mechanical properties are important. The mass median diameter of the samples ranged from 1.7 µm to 2.6 µm which is at the lower end of the reported size range for CKDs. The bulk density and the tapped bulk density of the samples decreased significantly from the first field of the ESP to the last field whereas the angle of repose was nearly identical for all three samples. For the angle of internal friction and the wall friction angle of the CKDs a slight increase was found to the last field of the ESP.