What is the permeability of refractory materials? How to measure?

August 20, 2018

Air permeability is the property of a material to allow gas to pass under pressure differentials. The gas permeability is related to the size, number, structure and state of the through-holes and varies depending on the direction of pressurization of the refractory product.


The air permeability of densely shaped refractory products shall be determined in accordance with the national standard GB/T 3000-1999 (equivalent to the international standard ISO 8841-1991).
The refractory air permeability directly affects the erosion resistance, oxidation resistance and venting function of its anti-erosion medium such as slag, molten steel, molten iron and various gases (steam). For products used to isolate flames or hot gases or direct contact with slag, molten metal, it is required to have a very low air permeability; while some functional materials must have a certain degree of air permeability.