CERAMIC BOTTOM LINING OF A BLAST FURNACE HEARTH

摘要

The present invention relates to a hearth (10; 210) for a metallurgical furnace, in particular for a blast furnace. The hearth (10; 210) comprises a wall lining (12; 212) and a bottom lining (14; 214) of refractory material for containing a molten metal bath. The bottom lining (14; 214) comprises a lower region (20; 220) and an upper region (22; 222) that is arranged to cover the top of the lower region (20; 220) and that is built of ceramic elements. The ceramic elements (24; 224) of the upper region (22; 222)are made of microporous ceramic material consisting of a granular phase made of a silico-aluminous high alumina content granular material and a binding phase for binding grains of said granular material, said microporous ceramic material having thus an maintaining permanently a thermal conductivity lower than 7 W/m.°K, preferably lower than 5 W/m.°K. The invention also proposes a process for rendering ceramic elements (300) microporous by baking in nitrogen atmosphere, and particular arrangements of the ceramic elements in the bottom lining.