Fused magnesia-alumina spinel AM65

"Jun" brand AM-65 fused magnesia-alumina spinel is smelted from high-purity magnesium powder and industrial alumina powder in large-scale high-temperature electric arc furnaces. It boasts characteristics such as high density, well-developed crystals, high refractoriness, good high-temperature volume stability, excellent resistance to alkaline slag erosion and penetration, and superior thermal shock stability. It is mainly used in alkaline bricks, especially in the burning zone and upper/lower transition zones of large cement rotary kilns. It also finds applications in regenerators of glass furnaces, lime kilns, lithium battery saggers, and some castables.

AM-65 spinel is widely used to replace chromium oxide in the production of alkaline bricks. Similar to chromium oxide, it can significantly improve the thermal shock stability of materials. Moreover, it avoids potential issues related to the disposal of toxic waste bricks. Magnesium-aluminum spinel bricks containing AM-65 outperform magnesia-chrome bricks in all properties. Their extended service life is attributed to the formation of a stable kiln coating on the magnesia-alumina spinel bricks, which prevents further penetration of cement clinker and the consequent spalling. AM-65 spinel can also replace chromium-containing refractories in other fields, such as lime kilns and regenerators of glass furnaces.

Our AM-65 product contains a small amount of free magnesium oxide (MgO), which can react with aluminum oxide (Al₂O₃) in aluminum-based refractories to form secondary spinel. The reaction of the secondary spinel generates a volume expansion of approximately 5%, which can be properly utilized in aluminum-based refractories. Additionally, the free MgO in AM-65 can serve as a setting accelerator for phosphate bonding, facilitating the production of cold-setting refractory castables or fire clay.

Physicochemical Indicators