Carbon-containing Refractories with Antioxidants in Laboratory and Practical Application

Helge Jansen

REFRATECHNIK Steel GmbH, 40549 Düsseldorf/Germany

Revision

Volume 4, Issue 3, Pages 87 - 93

Abstract

Antioxidants are common additives to carbon-containing refractories. They reinforce the carbon-bond by creation of new oxidic or non-oxidic bonds while reacting with refractory components and ambient oxygen. Strength is increased and porosity reduced, but elasticity and slag resistance as well as resistance towards thermal decomposition is lowered, particularly under vacuum conditions. Antioxidants can be recommended for applications with strong abrasion and erosion loads, e.g. in ladle impact pads. Problems with hydration of used Al-containing MgO-C bricks can be avoided by using Al-Mg alloys in distinct ratios. Apparently Al-additives cannot be recommended in slag zones of ladles with deep-vacuum treatment at high temperatures.Although boron containing additives are in industrial use to some extent, their benefit could not be verified in ladle slag line tests, most likely due to formation of low melting phases and subsequent slagging.

Keywords

antioxidants, carbon-containing refractories, reinforcement, carbides, spinel, hydration, ladle, slag zone, impact pad, deep-vacuum treatment

References

Copyright

Göller Verlag GmbH