Fineness And Specific Surface Area Of Refractory Bricks

Fineness indicates the degree of thickness of the powdered raw material, and is often expressed as the percentage of sieve residue or specific surface area of a standard sieve. It can also be expressed as the percentage composition of the particle size or the average diameter per unit weight of the material. There is no strict difference between fineness and particle size, but the former is used to express the thickness of fine powdered raw materials.

The specific surface area refers to the surface area per unit mass of the raw material, and the unit is m/g. The specific surface integrates the external surface area and the internal surface area. The ideal non-porous raw material has only the external surface area; but the raw material with pores has an internal surface area in addition to the surface area. There are many methods for measuring the specific surface area, and the commonly used methods include gas adsorption method, organic molecule adsorption method and gas permeability method.