Inherent Properties
1. Chemical Composition: The primary constituents determine the quality and characteristics of the refractory material.
2. Bulk Density: Weight per unit volume; higher density indicates greater compactness and potentially higher strength, though thermal conductivity may also increase.
3. Apparent Porosity: While there may be no specific requirement, manufacturers must strictly control apparent porosity.
4. Refractoriness under Load: Also known as the temperature at which deformation begins under load at high temperatures; this is a crucial parameter indicating the material's resistance to high-temperature stress.
5. Thermal Shock Resistance: The ability to withstand rapid temperature fluctuations without structural failure.
6. Compressive Strength: The maximum pressure the material can withstand (at room temperature).
7. Flexural Strength: The ability to withstand shear and bending forces.
8. Linear Change Rate: Also known as reheat linear change or residual linear change; refers to dimensional changes (expansion or contraction) occurring during repeated thermal cycling. If the expansion and contraction are consistent, the linear change rate is defined as zero.

Physicochemical Properties
1. Abrasion Resistance:
2. Thermal Conductivity: The rate of heat flow per unit area under a unit temperature gradient; this is related to porosity.
3. Impact Resistance: Self-explanatory; good impact resistance leads to a longer service life.
4. Slag Resistance: The ability to withstand erosion by molten slag at high temperatures without structural failure.