CHARACTERIZATION OF SILICA BRICKS USED IN COKE-OVENBATTERIES 3, 4 AND 5 OF TERNIUM SIDERAR

摘要

Silica bricks are used in the bottom and sidewalls of coke ovens due to its volume stability, appropriate thermomechanical properties and chemical resistance in the coking temperature range. The Standard DIN 1089 specifies the main technical characteristics of these bricks. Batteries No .3 and 4 of Ternium Siderar were built with German refractory materials in 1974 and last repaired during the years 2007-2008 with Chinese bricks under German license. Battery No. 5 was built with Chinese bricks in 2006. In this work, a comparative study of the physical, chemical, mineralogical and thermal properties of the bricks was performed. Also, it was carried out a post-mortem study of original bricks belonging to one of the first ovens of the battery No. 4 to determine the evolution of properties during service. Brick characterization included: bulk density and apparent porosity, thermal conductivity using the calorimeter method, chemical composition by XRF and mineralogical composition by XRD. The bricks presented, during its service, changes in its mineralogical composition (increased of the tridymite content), physical (decrease in apparent porosity) and .thermal properties (increase in its thermal conductivity).