On the Mineral Composition and the Formation of the Scaffold at the Shaft of Tobata No 1 BF

Abstract

The mineral compositions and formation mechanisms of the scaffolds, taken from Tobata No 1 BF were investigated. In the scaffold sample from the upper level of the shaft, coke breeze and fine or lamelar cementite are combined to the wall by zincite. It is thought that the fragmentation of a cementite particle occurs with the grain growth of matrix zincite and the lamination of cementite is caused by vigorous carbon deposition under the compressive force developed by the burden material. The scaffold rich in silicate from the middle level is estimated to be the sintered body of the particles of the iron are and the compounds formed in ascending gas. Samples. from the lower level of the shaft and the belly are composed mainly of kalsilite and they are formed by the reaction of firebrick of chamotte with alkali oxide. The measures for preventing the growth of scaffold in the shaft are discussed.