Refractory Materials are used in Lining of Blast Furnace

A blast furnace, in simple terms, is an iron-making equipment. Iron ore, coke, etc. are fed from the top of the furnace in proportion, and high-temperature blast (1000~1200℃) is entered at the lower tuyere. The oxidation-reduction reaction is carried out in the blast furnace. Iron slag is generated, and the iron slag flows out from the iron hole in the lower part of the blast furnace, and separates the 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 swing nozzle, or continues to make steel or is sent to the iron casting machine. Finally, the blast furnace gas is discharged through the dust removal equipment. The whole smelting process is probably like this.
 

Here refractory masonry is used as a protective lining for reasonable cloth. The temperature is 400~500℃, and it is directly impacted and frictional by the charge, and the effect of air flow is slightly lighter. Here, excellent clay bricks, high alumina bricks, clay castables/spray paints, etc. can be used for masonry.
 

The furnace body is an important part of the blast furnace, which is used for heating charge, reducing and slagging. The scour from the material flow and high-temperature air flow is serious here. The temperature in the middle of the furnace body is 400~800℃, and there is no slag erosion. It is mainly affected by the erosion of rising dust, thermal shock, alkali zinc and carbon deposits. Therefore, dense clay bricks and high alumina bricks are used in the upper part of the part, and anti-stripping wear-resistant phosphate clay bricks, high alumina bricks, and sillimanite bricks are used for masonry; the lower part of the furnace body uses dense and wear resistant clay bricks, high alumina bricks, and corundum bricks. , Carborundum bricks for masonry.
 

 
The abdomen of the furnace acts as a buffer for the updraft, where part of the charge is reduced and slagging, and the furnace lining is severely corroded by iron slag. The temperature here is as high as 1400~1600℃ in the upper part and 1600~1650℃ in the lower part. Due to the comprehensive effects of high temperature radiation, alkali erosion, hot dusty rising furnace gas, etc., the refractory materials of the furnace lining here are seriously damaged. Therefore, refractory materials with strong resistance to slag erosion and erosion and abrasion should be selected here. High-quality clay bricks, high-alumina bricks, graphite bricks, silicon carbide bricks, corundum bricks, etc., with low porosity can be used for masonry in the furnace belly.
 

 
The hearth is the place where the molten iron and the molten slag are loaded. The highest temperature in the tuyere area is 1700~2000℃, and the temperature of the furnace bottom is 1450~1500℃. In addition to being affected by high temperature, the hearth lining is also eroded by slag and iron. The hearth tuyere can use corundum mullite bricks, brown corundum bricks, and sillimanite bricks for masonry. Corundum mullite bricks and brown corundum bricks are used for the hot surface of slag-iron contact, and dense carbon bricks and graphite semi-graphite are used for cold surfaces. Carbon bricks, microporous carbon bricks, molded carbon bricks, brown corundum low-cement prefabricated blocks on the side walls, small carbon bricks for hot pressing in the hearth, graphite semi-graphite carbon bricks, microporous carbon bricks, etc. are used for masonry at the bottom of the furnace.
 

 
Clay bricks, silicon carbide bricks, graphite bricks, fused corundum castables, silicon carbide castables, iron ditch thermal spray repairing materials can be used for the tap ditch of the blast furnace. Low cement and high aluminum castables are used for the ditch cover, and the skimmer can be used. The low cement corundum castable and the refractory material of the swing nozzle are similar to the iron ditch material, and the slag ditch can be made of slightly lower material.