高炉シャフト部における装入物の性状変化について

抄録

The burden material samples taken from the three levels of the Tobata No1 BF shaft were classified in sinter, hematite are (Swaziland), magnetice ores (Chilli and Dungun) and so on. The size distribution, degree of reduction and microstructure of them were also examined. Large increases of smallparticles (-5mm) of the iron ores were observed in the sample from the level of 3m bellow the stock line and the mixing ratio of the ores from the level of 8m bellow was close to the proportion of the used ores in operation. The bursting of iron are is considered to be related with the both reduction and turbulent mixing in the shaft. It was found that the silicate glass matrix of sinter became rich in CaO and poor in Al₂O₃ during reduction and the calcium ferrite transformed into the spinet of FeO-Fe₂O₃-Al₂O₃ system. The effect of the composition change of sinter on the softening is discussed.