Last issue we introduced thermal insulating refractory material used for blast furnace body. This issue we will introduce thermal insulating material for blast furnace waist.

     Temperature of blast furnace waist is high(1400~1600℃). Melted slag is formed in a large amount in this part, so the slag corrosion is serious; the erosion of the alkali is also serious; when the dusty hot furnace gas rises, it brings strong scouring effect to furnace lining; the coke and other materials generate friction to furnace lining; when the hot air passes, the temperature changes sharply. The combination of many of the above factors contributes to serious damage to insulation refractory material in this part. In the past, we use clay bricks and high-aluminum bricks to build this part. Now the clay bricks and high-aluminum bricks are not suitable.

     Blast furnace which is above 1000m3should be built with SiC bricks. For blast furnaces below 1000 m3, SiC bricks may also be considered in accordance with the needs of blast furnace reinforcement. When using SiC bricks, it is necessary to simultaneously improve the structure and material of the cooler. And the cooler should be a closed circuit, and the cooling water should be soft water or pure water. During operation, the edge air flow should be controlled. Only suitable technique can make full performance of SiC brick.

     Above is introduction of thermal insulating refractory material for blast furnace waist. Next issue we will introduce thermal insulating material for blast furnace belly. Please stay tuned.