Refractories For Blast Furnace Body

The refractory industry is an important basic industry serving high-temperature technology and is particularly closely related to the iron and steel industry, ceramic industry, and glass industry. The new development of the high-temperature industry, especially iron and steel smelting technology, has promoted the technological progress of the refractory industry. The technological progress of the refractory industry has guaranteed the implementation of new technologies in the high-temperature industry. The stable production, high production, and long life of various kilns in the iron and steel industry are inseparable from refractory materials. Due to different uses and conditions of use, various kilns have different requirements for refractory materials that constitute their main bodies, and different types of refractory materials are also different. Due to the difference in chemical composition, microstructure, and production process, it shows different basic characteristics. Therefore, it is necessary to understand the basic properties of refractory materials to understand and study refractory materials for industrial kilns. On this basis, this article focuses on refractories for blast furnaces and hot blast stoves.

The blast furnace is the main equipment for ironmaking. It has the advantages of large output, high productivity, and low cost, which is unmatched by other ironmaking methods.

With the progress of the iron and steel industry in various countries in the world, blast furnaces are developing towards large-scale, high-efficiency, and long-life development, and new smelting technologies such as oxygen-enriched coal injection, high-air temperature operation, and high-pressure furnace roof are gradually adopted. The working conditions of the blast furnace lining have undergone major changes, and its service life has been greatly reduced, generally only 5 to 6 years. Especially the lower part of the blast furnace shaft and the furnace waist and furnace belly position, its service life is just shorter. In order to adapt to this development, the refractory materials used in blast furnaces have also undergone major changes. New types of long-life and high-efficiency refractory materials have been gradually applied, and the service life of blast furnaces has gradually increased.

According to the operating conditions and corrosion characteristics of the blast furnace lining, refractory materials are required to have:

1. Good high-temperature performance, and good thermal stability under long-term high temperatures.

2. The strength at room temperature and high temperature is high, and the wear resistance is good.

3. High density, good thermal conductivity, low apparent porosity, and small shrinkage at high temperatures.

4. It can resist the severe erosion and erosion of molten iron, slag, blast furnace gas, and furnace dust under high temperatures and high pressure.

5. The shape and size of refractory bricks are accurate, which can ensure that the brick joints meet the specified requirements.

At present, there are many kinds of refractory materials for blast furnaces. The middle and upper parts of the furnace body are generally made of clay bricks or high-alumina bricks with excellent performance, while the lower part of the furnace body, the furnace waist, both are made of carbonaceous products, silicon carbide bricks, mullite bricks, Special refractory materials such as corundum bricks, especially the recently developed silicon carbide bricks, have been successfully applied in blast furnaces. At the same time, other unshaped refractory materials have also been widely used.