Refractory materials are used in the throat, body, bosh and hearth of blast furnace. Kerui refractory brick manufacturer will continue to share with you.
Blast furnace, in short, is an ironmaking equipment. Iron ore and coke enter from the top of the furnace in proportion, and high-temperature blast (1000 ~ 1200 ℃) enters at the lower tuyere. Redox reaction is carried out in the blast furnace to generate iron slag. The slag iron flows out from the lower tuyere of the blast furnace to separate iron and slag. The slag enters the slag ditch, flushes the slag or enters the dry slag pit. The molten iron enters the torpedo tank through the swinging nozzle or continues to make steel or is sent to the cast iron machine. Finally, the blast furnace gas is discharged through the dust removal equipment, which is the whole process of blast furnace ironmaking.
With the development and progress of the iron and steel industry in various countries, the blast furnace is gradually developing towards large-scale, high efficiency and long life. Accordingly, the refractory of blast furnace lining also has higher requirements. For example, good fire resistance, high temperature stability, density, thermal conductivity, wear resistance, erosion resistance and slag resistance.
At present, there are many kinds of refractories in blast furnace, and the use of refractories in various parts is different due to the influence of furnace conditions.
At the furnace throat, the refractory masonry here is used as the protective lining for reasonable distribution. When the temperature is 400 ~ 500 ℃, it is directly impacted and rubbed by the furnace charge, and the air flow scouring effect is slightly lighter. Dense clay brick, high alumina brick, clay castable / spray coating can be used for masonry here.
The furnace body is an important part of the blast furnace, which is used for the heating, reduction and slag trough of the furnace charge. It is seriously scoured by materials and high-temperature air flow. The temperature in the middle of the furnace body is 400 ~ 800 ℃, which is not affected by slag erosion. It is mainly affected by the scouring of rising dust gas, thermal shock, alkali zinc and carbon deposition. Therefore, the middle and upper parts of this part are built with dense clay brick, high alumina brick, anti peeling and wear-resistant phosphate clay brick, high alumina brick and sillimanite brick; The lower part of the furnace body is built with dense wear-resistant clay brick, high alumina brick, corundum brick and silicon carbide brick.
The belly of the furnace acts as a buffer for the updraft, where part of the furnace charge is reduced to slag, and the furnace lining is seriously eroded by iron slag. The temperature in the upper part is as high as 1400 ~ 1600 ℃ and that in the lower part is 1600 ~ 1650 ℃. Due to the comprehensive impact of high-temperature radiation, alkali erosion and hot dusty rising furnace gas, the refractory of furnace lining here is seriously damaged. Therefore, refractory with strong slag erosion resistance and erosion wear resistance should be selected here. Low porosity clay bricks, high alumina bricks, graphite bricks, silicon carbide bricks, corundum bricks, etc. can be used for masonry at the belly of the furnace.
The hearth is the bearing part of molten iron and slag. The maximum temperature in the tuyere area is 1700 ~ 2000 ℃ and the furnace bottom temperature is 1450 ~ 1500 ℃. In addition to the influence of high temperature, the hearth lining is also subject to the scouring and erosion of slag iron. Carbon brick and corundum brick can be used for the furnace bottom, carbon brick and corundum brick can be used for the furnace bottom, carbon brick and corundum brick can be used for the furnace bottom, and carbon brick and corundum brick can be used for the furnace bottom.
In addition,magnesia brick, silicon carbide brick, graphite brick, fused corundum castable, silicon carbide castable and hot spray repair material can be used in the iron ditch of blast furnace, low cement and high aluminum castable can be used in the ditch cover, low cement corundum castable can be used in the slag skimmer, and the refractory material at the swing nozzle is similar to that in the iron ditch, and slightly lower material can be used in the slag ditch.