Refractories for Furnace Waist and Bosh

Furnace Waist With Refractories

The furnace waist acts as a buffer for the rising gas flow. The furnace charge here has been partially reduced to slag, the air permeability of the material layer has become poor, and the slag corrosion is serious at the same time. In addition, the temperature of the furnace waist is high (1400-1600 ℃, high-temperature radiation erosion is serious; alkali erosion is also relatively serious; dusty hot furnace gas rises, which has a strong scouring effect on the furnace lining; coke and other materials produce friction; hot air When passing through, it will cause a sharp change in temperature. The combined effect of the above factors makes the refractory material in this part seriously damaged. Therefore, the refractory material with strong slag erosion resistance and erosion resistance is generally selected for the furnace waist. For the inner part of the cooling plate structure, Graphite bricks are also used for lining.

Bosh Refractories

The bosh connects the furnace hearth and the furnace waist. The temperature in this area is higher, and the temperature of the lower part of the charge is about 1600-1650 °C, and the temperature of the airflow is also high, and a large amount of intermediate slag is formed and begins to drip. The heat radiation and slag erosion of this part is very serious. In addition, the intrusion of alkali metals, the chemical action caused by the deposition of carbon, the erosion of the melt from top to bottom, and the hot air flow from bottom to top are also intensified. Therefore, the furnace belly position has always been the key link with the shortest service life of the blast furnace. Therefore, the material in this area should have high anti-erosion and anti-scouring capabilities, and at the same time have a certain ability to resist thermal shock. Therefore, it is more common for modern large and medium-sized blast furnaces to use this type of refractory material in this part. Burned aluminum-carbon bricks and fired microporous aluminum-carbon bricks also have good resistance to compression, bending, erosion, and erosion, good thermal conductivity, and easy-to-hang-slag. The most important thing is that they have strong thermal shock resistance. The price is also relatively convenient, generally used in medium-sized and medium-sized blast furnaces in my country. Graphite bricks are also used for the inner lining of the cooling plate structure.