Magnesium aluminate, MgAl2O4, a stable, high-melting compound with good resistance to slag and thermal shock. Magnesia-spinel brick is the chrome-free choice for most cement kiln burning zones, and alumina-spinel or alumina-magnesia castables line steel ladle walls and bottoms. In spinel-forming castables, magnesia and alumina react in service with a controlled expansion that tightens joints and resists slag penetration.
Burning zone gets magnesia-spinel brick, no more chrome since the hazardous waste fight.
Also heard as
- MA spinel
- mag-spinel
- alumina-spinel
Related terms
Magnesia-chrome brick
Basic brick of magnesia and chrome ore, prized for resistance to aggressive slags in copper smelting and degassers.
High-alumina brick
Alumina-silica brick with more than 45 percent alumina, graded in steps such as 50, 60, 70, 80 and 90 percent.
Basic refractory
Refractory based on magnesia, lime or dolomite that resists basic slags with high lime-to-silica ratios.
Low-cement castable
Dense castable with 1 to 2.5 percent lime from cement, using micro-fines and dispersants for strength and low porosity.