MgO-MgAl2O4 Refractories with Low Thermal Conductivity for Energy-saving in Rotary Kilns
UFUK A. 1, GORKEM Y. 1, NURI S. 1
1 Kumas Refractories R&D Center, Kutahya, Turkey
MgO-MgAl2O4 refractory bricks are widely used in rotary kilns since they offer a desirable combination of mechanical, chemical and thermal properties both at ambient and elevated temperatures. Recent trends in energy efficiency and reduction of carbon footprint have pushed refractory manufacturers to develop energy-saving refractory bricks, especially in energy-intensive industries including cement and lime, due to the usage of extensive thermal processes in production.
One possible way to decrease energy consumption is using an energy-saving lining in which the thermal conductivity is reduced by increased porosity. However, mechanical, chemical and thermal limitations of the rotary kilns should be considered in brick design since porosity will degrade those properties.
In this study, novel MgO-MgAl2O4 refractory bricks with reduced thermal conductivity were developed to reduce kiln shell temperature and hence reduce energy consumption. Different pore-forming agents and their influence on microstructure as well as physical, mechanical and thermal properties were investigated. A novel energy-saving basic refractory brick with reduced thermal conductivity by induced porosity is developed without compromising the refractoriness as well as mechanical properties.