Xi'an Zhibang
News Center
06
2023
-
07
The chromium-free process of five commonly used refractory materials for off-furnace refining furnaces
Author：
The traditional furnace refining mainly uses magnesium-chromium refractory materials as the inner lining, but due to the pollution of magnesia chromium bricks, domestic and foreign enterprises are gradually replacing materials with other materials. The following is a brief introduction to the chromium-free process of commonly used refractory materials for off-furnace refining furnaces:
1. No chromification of refractory materials for RH refining furnace
Because magnesium-chromium refractories are easy to pollute the environment and are harmful to the human body, various steel companies are experimenting to find alternative products, and have successively used fired magnesium zirconium bricks, magnesium spinel bricks, magnesium spinel titanium bricks, magnesium spinel zirconium bricks and non-burning low-carbon magnesium carbon bricks, all of which have not overcome the problem of low service life and high cost.
2. No chromification of refractory materials for DH vacuum degassing furnace
In the 70s of the 20th century, it developed rapidly and achieved large-scale and high-yield. DH furnace began to use high aluminum bricks, magnesia bricks. Later, the upper groove was changed to directly combined magnesia bricks, and the lower groove used electrofusion and then combined with magnesia chromium bricks, and the effect was good.
3. No chromification of refractory materials for AOD refining furnace
AOD is short for argon-oxygen decarburization method. The molten steel is poured into the AOD furnace, with a certain proportion of oxygen-argon or nitrogen mixed gas, blowing into the furnace from the lower side wall of the furnace body, by reducing the partial pressure of CO, to achieve the purpose of decarburization, is the standard process of stainless steel smelting, more than 85% of the world's stainless steel is produced by this process. Now a top oxygen gun has been added, and the erosion characteristics of the furnace body are changed by the top oxygen gun and the bottom side wall.
4. No chromification of refractory materials for VOD furnaces
VOD furnace is refining ladle, VOD method is vacuum oxygen blowing decarburization method, that is, under a certain vacuum degree, oxygen is blown into the molten steel, reducing the partial pressure of CO to achieve decarburization of refining method.
5. No chromification of refractory materials for CAS refining treatment equipment