if silicate-bonded chrome-magnesia bricks are used for the bulk of the furnace wear lining, then direct-bonded magnesia-chrome bricks are used for the tuyere section wear lining, while if direct-bonded magnesia-chrome bricks are used for the bulk of the wear lining, then rebonded co-sintered or fused-grain magnesiachrome bricks are used for the tuyere section wear lining