MgO–C Bricks Containing Nano-boron Carbide
1 MAGNESITA, 32000-000 Contagem/Brazil
2 Federal University of São Carlos (UFSCar), 13565-905 São Carlos/Brazil
Revision 10.02.2014, 17.02.2014
Volume 6, Issue 2, Pages 89 - 92
Abstract
MgO–C refractories are widely used as working lining for BOF vessels. Nowadays, the association of top and bottom gas blowing is a usual procedure exposing bricks to severe oxidation, corrosion, erosion and thermal shock. In order to attain such requirements, the MgO–C bricks are produced using high quality raw materials, novel binding systems and specific additives. Adding a blend of metals prevents oxidation, increases hot mechanical properties and also induces better physical and corrosion properties. Boron carbide (B4C) is a key additive which provides high oxidation resistance, speeds up the phenolic resin crystallization and helps to mineralize the magnesia dense layer in MgO–C bricks at high temperatures. Besides that, B4C and Al metal induces the formation and growth of MgO•Al2O3 spinel crystals in the matrix. In this work, nano- B4C was synthesized to replace commercial coarser grain boron carbide. Comparative tests between these two antioxidant sources were carried out to evaluate the effects of nanotechnology in MgO–C bricks. The powder characterization and the product properties are highlighted in this paper.
Keywords
MgO-C bricks, boron carbide, nanotechonology
References
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