熱間に於ける鐵鑛石並に耐火爐材の瓦斯通氣率の變化 (其一)

Abstract

An arrangement for measuring the behavior of the permeability of gas as the temperature of the specimen rises up to 800°C continuously, the specimens measured being eight iron ores and five types of refractory brick. Some of the important results are as follows:(1) The gas permeability decreases with the temperature in the logarithmic power if the expansion of the specimen increases linearly as temperature rises, this comes to the contrary to the common idea that the pores would open as the specimen expands.(2) The course of the gas permeability curve can be classified in three types from the results measured with the eight iron ores, such as limonitic, hematic, and magnetic type, which would be characterized due to the nature of original formation of the specimen, but not the kind of iron ore.(3) The limonite is generally most permeous to gas up to 800°C, hematite comes next to it, and the magnetite is most impermeous, the ratio of the permeability for the three types of iron ore being about the order of 100-10000 for the limonite, 1-10 for hematite, and 0-1 for magnetite.(4) From the measuring of the permeability with the preheated ore up to 800°C before the test, it is found that to be subjected to preheating is very effectual treatment for the iron ore, for it increases in some cases as much ten times as the original raw ore.