Damage to the refractory lining of aluminum melting furnaces

Aluminum melting furnaces are essential for the aluminum casting industry, specifically used for smelting aluminum ingots and scrap aluminum. They typically operate at temperatures between 800°C and 1300°C. To improve the furnace’s smelting efficiency and extend its lifespan, careful design and the use of high-quality refractory materials are crucial from the initial construction stage.

However, aluminum melting furnaces often experience varying degrees of damage during operation. If not addressed effectively, this can impact the furnace’s normal production efficiency. Today, we will explore the causes of frequent damage to the refractory lining of aluminum melting furnaces and how to address it.

Causes of aluminum melting furnace lining damage:

① Liquid aluminum penetration.

Liquid aluminum penetrates into the pores or cracks of the refractory, causing the lining to gradually peel and directly damage the lining.

② Nodules and bulges.

Molten aluminum reacts with refractory materials and adheres to the refractory lining, easily forming corundum nodules, bulges, and dross. While this doesn’t directly damage the refractory, the nodules will grow larger, causing waste of molten aluminum and damage during mechanical slag removal.

③ Impurity incorporation.

During the smelting process, the refractory materials react with the molten aluminum to produce aluminum ash impurities, which eventually enter the molten aluminum, causing contamination and waste.

④ Mechanical impact.

During the production process, the aluminum melting furnace undergoes a series of mechanical operations, such as charging and slag removal, which directly impact and scour the furnace bottom and walls, damaging the refractory materials.

Solutions for Damaged Aluminum Melting Furnace Linings

To address the four issues mentioned above, the refractory castable used in the furnace lining must be highly dense to prevent erosion and secondary penetration by the molten aluminum. Furthermore, the refractory castable must not produce aluminum ash upon contact with the molten aluminum, minimizing erosion and corundum formation, thereby reducing aluminum loss during the smelting process. Finally, the refractory castable must also possess high wear resistance to withstand the wear and mechanical impact of the furnace during production.