Refractory brick for blast furnace masonry provide a basic guarantee for the modernization of blast furnaces. The blast furnace body structure (furnace wall) is composed of three parts: the furnace shell, the cooler and the refractory lining. The main function of the inner lining is to directly resist mechanical, thermal and chemical erosion during the smelting process to protect the furnace shell and other metal structures, reduce heat loss, and form a certain smelting space, that is, the furnace type. The furnace shell plays the role of sealing slag, iron, and gas, and undertakes certain building structure tasks. The cooler is used to protect the inner lining and the furnace shell, and its layout determines the furnace type to a large extent.
There are many factors that affect the life of the blast furnace, and the damage of the inner lining is the fundamental factor. Practice shows that the life of the furnace lining varies with the smelting conditions. The belly, waist and lower part of the furnace body are the most severely corroded parts of the blast furnace lining, especially the furnace waist and the lower part of the furnace body, which are difficult to form a protective layer, which have become the weakest link of the blast furnace lining. The furnace throat is mainly affected by the erosion of the solid charge sassafras and the blast furnace gas flow entrained with furnace dust, as well as the rapid changes in temperature when the charge is loaded.
Refractory bricks for blast furnace lining
Modern large and medium-sized blast furnaces require a generation of furnace life of more than 10 years, and blast furnace is a continuous production of metallurgical equipment under high temperature and high pressure, so the quality of refractory materials has a direct impact on the service life of the blast furnace.
A blast furnace bricks requirements for the use of refractory materials
During the smelting process, extremely complex physical and chemical reactions occur inside the blast furnace, the temperature can be as high as 2000 ℃, and the temperature distribution in the furnace is uneven from top to bottom. In order to keep the reaction in the furnace physically and chemically stable, Refractory materials for blast furnaces should generally meet the following requirements: at high temperatures, they should not melt, soften, and volatility: at the same time, they should have the strength to maintain the integrity of the furnace structure under high temperature and high pressure conditions: they must be able to withstand temperature changes in the furnace. Thermal shock and wear caused by material drop and gas rise: At the same time, it must be chemically stable to molten iron, slag and gas in the furnace. Since most modern blast furnaces use water-cooled wall technology, it is required that the refractory materials in some parts should have appropriate The thermal conductivity without affecting the cooling effect.
2. Refractory bricks for all parts of the blast furnace
A Refractory bricks for furnace throat
The furnace throat plays a role in protecting the furnace lining and reasonable cloth. This area is mainly affected by the direct impact and friction of the incoming materials from the blast furnace. Because the temperature of this part is not high, about 400~500℃, the refractory materials used are mostly dense clay bricks and high alumina bricks, but the service life is still short, so wear-resistant and impact-resistant cast steel bricks are used for protection.
B Refractory bricks for the upper and middle parts of the furnace
The upper and middle parts of the furnace are the places where the blast furnace can't stop and the lump materials fall. The temperature of the upper part of the furnace is relatively low, and the main reason for its damage is the mechanical erosion caused by the falling of cloth and charge, and the chemical attack of the alkali metal that accumulates here with the updraft. In the middle of the furnace body, the temperature is relatively high, the temperature fluctuates greatly, and some boring materials are heated and decomposed here. Therefore, the main cause of refractory damage is the thermal shock damage caused by the temperature change in the furnace, followed by material drop and furnace gas Rising mechanical scour effect. On the whole, the requirements for refractory materials used in the upper and middle parts of the blast furnace should be: the lining material for riding pigs should have low porosity, high mechanical strength, and be able to resist the wear of the charge and updraft, and should also have good It is resistant to alkali metal corrosion, and requires low iron oxide content in the material to avoid oxidation-reduction reactions with rising CO. See the table below for the reasons for the corrosion of the body and the medium corrosion of the blast furnace and the requirements for refractory materials:
Causes of corrosion on the body and middle of blast furnace and performance requirements for refractory materials
C Refractory bricks for the lower part of the furnace body and the furnace waist
The temperature of the lower part of the blast furnace shaft and the furnace waist is as high as 1400~1600℃, which is the main area where blast furnace slag and metallic iron are formed. The brick lining from the lower part of the furnace lining to the furnace waist is not only affected by the thermal shock caused by the falling charge and rising high temperature and high pressure gas and the temperature change, but also by the chemical erosion of the FeO high basicity primary slag, and the more serious alkali metals and zinc Carbon deposition and chemical reaction caused by steam make the structure of the refractory brick brittle and lose its strength.
Wechat Us 
