Permeability of carbon refractory materials used in a blast furnace hearth

Abstract Permeability of experimental and standard micropore carbon materials, before and after the heat treatment at 1550 oC, was investigated using gas permeability measurements (GP) and mercury intrusion porosimetry (MIP). Permeability of both materials increased after the annealing. Experimental micropore carbon material was less permeable than standard one, both before and after the heat treatment. Measured gas permeabilities were compared with permeabilities determined based on MIP measurements using two different models: Hagen−Poiseuille and Carman−Kozeny equation. Using the inverse problem approach, for the first time Carman−Kozeny constant was determined for micropore carbon materials. Carman−Kozeny model gave more accurate results (i.e. close to gas permeability measurements) than Hagen−Poiseuille model. Performed investigations showed that mercury intrusion porosimetry might be alternative method to investigate infiltration resistance of low permeable materials.