The Application Of Castables in Aluminum Melting Furnaces

The application of castables in aluminum melting furnaces mainly revolves around core requirements such as resistance to aluminum liquid penetration, high temperature resistance, good thermal shock stability, and non aluminum adhesion. According to publicly available information, combined with current (2026) technological developments and industry practices, its application situation is as follows:
1, Main application areas and corresponding material types
Furnace bottom and wall (molten pool area): In direct contact with aluminum liquid, non stick aluminum castable or anti-seepage castable should be used to prevent aluminum liquid from penetrating and corroding
Furnace door and mouth: withstand frequent feeding impacts and rapid cooling and heating. It is recommended to use high-strength wear-resistant and steel fiber reinforced castables to enhance thermal shock stability and mechanical wear resistance
Furnace top and upper furnace wall: located in the flame radiation zone with high temperature, heavy high aluminum castable is usually used as the working layer, and lightweight insulation castable is added to reduce heat loss
Burner and burner: high temperature+airflow erosion, self flowing high temperature high-strength wear-resistant castable should be selected
2, Main types and characteristics of castables
Calcium aluminate (CAA) low cement castable
Combining calcium aluminate as aggregate with calcium aluminate cement (CAC), the apparent porosity is extremely low and almost not penetrated by aluminum liquid.
The operating temperature can reach 1350 ℃, and even if the furnace overheats, it is not easily damaged.
Excellent resistance to CO erosion, suitable for aluminum smelting and petrochemical fields
Non stick aluminum casting material
Main ingredients: mullite, brown corundum, high-purity corundum, composite additives.
Characteristics: High density, not wetted by aluminum liquid, high strength.
Applied to areas in contact with aluminum liquid such as furnace walls, furnace bottoms, degassing boxes, and flow channels
Anti-seepage castable
Aggregate: clay clinker+tertiary alumina clinker; Adhesive: CA-50 cement+anti-seepage agent.
Function: Prevent the penetration of active substances such as NaF and Al, and protect the insulation layer.
Used for furnace bottom, furnace wall, and electrolytic cell side wall
Steel fiber reinforced castable
Adding stainless steel or heat-resistant steel fibers significantly improves crack resistance and toughness.
Specially suitable for furnace doors, furnace openings, and other parts that are susceptible to mechanical impact
3, Construction and usage precautions
Construction environment: The temperature should be controlled between 10-30 ℃; Heating and maintenance are required for temperatures below 5 ℃ in winter
Water addition amount: It must be strictly controlled. It is recommended to use pure tap water and use it within 30 minutes after mixing
Oven requirements: The overall casting should be baked slowly to prevent cracking; Prefabricated block+post pouring strip technology can significantly shorten the drying time and avoid aluminum infiltration
Material selection criteria: The selection of materials should be based on the actual temperature of each part of the furnace, the contact situation of the aluminum liquid, and the comprehensive selection of mechanical loads