Blast furnaces are core equipment in steel production, and their internal environment is extremely harsh. Refractory bricks, as a key lining material, are crucial to ensuring the safe and stable operation of blast furnaces.
1.What is actually “burning” inside a blast furnace?
What happens inside a blast furnace is not a simple combustion, but a complex physical and chemical process.
First, iron ore is reduced to molten iron by carbon monoxide at high temperatures, often exceeding 1500°C.
blast furnace
Secondly, the coke acts as fuel and reacts with the hot air. This not only provides heat but also generates reducing gases.
At the same time, impurities in the raw materials form molten slag. This slag reaches temperatures exceeding 1400°C and is highly chemically corrosive.
In short, the inside of a blast furnace is an extreme environment that combines ultra-high temperature, strong chemical corrosion, and mechanical scouring.
2.The protective effect of refractory bricks on blast furnaces
Different refractory bricks need to be selected for different parts to provide targeted protection for the blast furnace.
(1)Furnace throat and upper and middle parts of furnace body – high alumina bricks or clay bricks
These two types of bricks have high wear resistance and certain high temperature resistance. They can effectively resist the mechanical impact and wear when the charge falls, and protect the furnace throat steel ring structure.
high-alumina bricks
The upper and middle sections of the furnace body must withstand the friction of descending charge materials and the erosion of rising air currents. These two types of bricks provide sufficient mechanical strength and wear resistance. They are also relatively cost-effective.
(2)The lower part of the furnace body, furnace waist and furnace belly – carbon bricks, silicon carbide bricks or corundum bricks
These areas are the most severe areas in the blast furnace, with temperatures reaching 1400-1600°C and in direct contact with molten iron and slag.
Carbon bricks offer excellent corrosion resistance and good thermal conductivity, forming a protective “slag skin.” Silicon carbide bricks are known for their exceptional strength, wear resistance, and thermal shock resistance. Corundum bricks offer exceptional resistance to high temperatures and chemical corrosion.
(3)Furnace hearth and furnace bottom – microporous carbon bricks, corundum bricks
This is a key area for storing molten iron and slag.
chrome corundum brick
Microporous carbon bricks effectively prevent molten iron penetration, extending the life of the furnace hearth. Corundum bricks provide a denser, more corrosion-resistant lining, directly protecting the furnace bottom steel plate.
These specific bricks, through their unique physical and chemical properties, build a solid defense for the blast furnace in their respective locations.
3.What will the price be for blast furnaces without refractory bricks?
Without the protection of refractory bricks, the blast furnace will face serious consequences.
First, the furnace shell steel plate is directly exposed to high-temperature melt and corrosive gases. Under the continuous high temperature, the furnace shell will quickly soften and deform, and even melt through accidents.
Secondly, the production process will be forced to be interrupted and the maintenance cost will increase significantly.
blast furnace
What’s more serious is that damage to the furnace structure may cause safety accidents and threaten the lives of on-site personnel.
It is no exaggeration to say that the lack of refractory bricks may directly lead to the blast furnace being unable to operate normally.
Reliable refractory bricks are the fundamental guarantee for the long-term operation of blast furnaces. Therefore, choosing a high-quality refractory brick supplier that can provide high-quality and high-quality services is crucial to ensuring the safety, stability and efficiency of steel production.
