What Are Refractory Products For AOD Refining Furnace?

AOD Refining Furnace,AOD Furnace,refining furnaces

AOD refining furnace is an off-furnace refining technology that uses argon and oxygen mixed gas to refine stainless steel. The process is to pour the molten steel roughly refined in the electric furnace into the AOD furnace, blow a certain proportion of argon-oxygen mixed gas into the furnace from the lower side wall of the furnace body, and decarburize on the surface of O2-Ar bubbles.

Due to the dilution effect of argon on the generated CO, the CO partial pressure in the O2-Ar bubbles is reduced, which can promote decarburization and prevent chromium oxidation. At the same time, as the proportion of oxygen mixed gas blown into the bottom of the furnace continues to increase, stainless steel can be refined under false vacuum conditions.

Selection of Refractory Materials For AOD Refining Furnace

The refractory materials used in AOD Furnace mainly include magnesia-carbon bricks, magnesia-chrome bricks, magnesia-dolomite bricks, dolomite bricks and amorphous refractory materials. These refractories are slightly different in selection according to their position and function in the furnace lining. Specifically, the refractory materials of AOD refining furnaces are mainly the following:

• Magnesium carbon brick:

It has excellent slag resistance, thermal shock resistance and high temperature strength, and is often used in key parts such as lining and furnace mouth of refining furnaces.

• Magnesium chrome brick:

It has good high temperature resistance and corrosion resistance, and is widely used in lining and furnace mouth, but its use has decreased in recent years due to environmental protection issues.

• Magnesium dolomite brick:

It has good slag resistance and corrosion resistance, and is widely used in AOD furnace, especially for the refining of chromium-containing slag.

• Dolomite brick:

It is mainly used for furnace lining, especially for AOD refining of specific slag system.

• Amorphous refractory:

Including castables, plastics, ramming materials, etc., used for local repair and masonry of special shapes.

Selection of Refractory Materials For Different Parts

• Furnace lining: Magnesium carbon bricks, magnesia chrome bricks, magnesium dolomite bricks, etc. are usually used.
• Furnace mouth: high-aluminum plastics, magnesium castables, etc. can be used.
• Tuyere part: usually directly bonded magnesia-chrome bricks, rebonded magnesia-chrome bricks, semi-rebonded magnesia-chrome bricks, etc. are used.

When selecting refractory materials, the following factors need to be considered comprehensively:

• Refined steel grades: different steel grades have different requirements for refractory materials, especially chromium-containing steel.
• Operating conditions: such as refining temperature, slag system, gas flow, etc.
• Service life: It is necessary to meet the requirements of the production refining furnaces process and extend the service life as much as possible.

In short, the selection of refractory materials for AOD refining furnace is a complex issue, and it is necessary to select appropriate materials according to specific circumstances to ensure the smooth progress of the refining process and product quality.