Permeability of blast furnace burdens

This paper defines the permeability of blast furnace burdens. Examples given show how diagrams can assist in practice and economies achieved. In common with developments in general, the diagrams would be refined as experience is accummulated and new knowledge gained. Noting that without appropriate measuring equipment there are no quantitative measurements, hence no modern ironmaking and associated economies; and, that these things are inextricably connected with management concepts and attitudes. The question of quantitative measurements is particularly important where modern charging gear is used, e.g. The bell-less top - unless of course, it is exclusively used to imitate bell charging only. But then the corresponding bell charged metallurgical and economic performance must also be accepted and the furnace should be drawn with a bell top - NOT BELL-LESS TOP. If for the specific burden material properties and furnace, the bell gives the desired burden distribution - both structurally and chemically - then burdening with a bell is metallurgically just as valid as burdening with a bell-less top. The only metallurgical difference is in the versatility of the bell-less top to enable the metallurgical ideals of burden distribution to be closely achieved for a wide variety of burden materials and furnaces.more » The permeability of a given mixture remains the same no matter how that mixture was deposited or arrived at. The validity of the permeability diagrams is affected only if one of the size fractions is removed (cf. Figs. 3-5), or the normal plant variations become dramatically different. For such, and other cases, correction factors would be applied - this procedure being more preferable in practice than constructing a diagram that is so complicated as to be useless. 10 figures, 1 table.« less