premium aluminas for advanced applications

Calcined Aluminas for the Refractory Market

Almatis offers high-quality calcined aluminas, primarily consisting of robust sintered agglomerates of individual alumina crystals. These aluminas, supplied primarily in ground (<63μm) or fine-ground (<45μm) forms, are distinguished by their partially retained agglomerates, unlike the fully ground reactive aluminas.

Our calcined aluminas are classified by soda content, particle size, and calcination level to meet diverse application needs. They excel as matrix fillers, enhancing natural raw material-based formulations by increasing alumina content and improving particle packing. This results in elevated refractoriness and stronger mechanical properties, such as abrasion resistance and rupture strength.

The efficiency of calcined aluminas is also determined by their surface area and residual agglomerate balance. While low surface area aluminas are preferred for bricks and castables, our special high surface area variants are ideal for gunning and ramming mixes, effectively replacing clay as plasticizers. These adaptations ensure minimal shrinkage post-drying and firing, maintaining optimal installation characteristics.