Improper refractory mixing leads to kiln lining damage and shortened service life. Variances in chemical composition, thermal performance and bonding structure cause high-temperature deterioration, deformation and strength loss. The following guidelines must be followed.
1. Separate Acid and Alkaline Refractories
Direct contact between acidic and alkaline refractories causes high-temperature erosion, slag penetration and cracking. A neutral refractory isolation layer is mandatory for adjacent installation.
2. Use Thermally Matched Refractories in the Same Zone
Mismatched thermal properties cause asynchronous deformation during temperature cycling, resulting in joint cracking, loose masonry and lining spalling. Uniform, performance-matched refractories are required per furnace section.
3. Never Mix Different Castables
Castables and repair materials of different systems, formulas or batches can’t be mixed. Blending undermines structural strength and causes high-temperature pulverization or collapse. Store and construct each material separately.
4. Match Refractory Bricks with Compatible Mortar
Bricks and mortar must be identical in material composition. Mismatching produces low-melting impurities, causing high-temperature erosion, flame leakage and masonry failure.
5. Standardize the Use of Special Refractories
Special refractories shall not be mixed randomly. Lightweight insulation bricks are for thermal insulation only and can’t replace heavy-duty bricks. Functional refractories such as silicon carbide and carburization-resistant materials must be used independently.
In short, refractory mixing requires chemical compatibility, performance consistency, system matching and zoned application. Standardized material selection and construction avoid lining damage, reduce maintenance costs and extend kiln service life.
