Abstract
Behavior of charged materials descending in cupola have been chased with the use of γ-ray level meter. The measurement of bulk density and the thickness of each charged layer in cupola was able to perform by the γ-ray penetration method. As the charged metals and coke were mixed during descending in cupola in general, the bulk density of coke layer increased by mixing some metals into coke layer. The behavior of the charged materials descending in cupola were clarified by investigating these phenomena. The metals and coke are usually charged into cupola layer by layer separately, but it is inevitable that these materials are mixed at the boundary between both layers as they descend in the cupola. It was confirmed that if this type of mixing proceeded so much when they arrived melting zone, the level of melting zone was lowered. Subsequently tapping temperature was lowered and fractuation of iron quality was increased. When the coke size was smaller compared with charge metal size, both layers was more apt to be mixed. Therefore, it is important to avoid the mixing by selecting optimun sizes of metal and coke. The best cupola operation was obtained when the thickness of coke layer was about three times of the coke size which was one sixth of cupola diameter in normal.
