Refractory materials for steelmaking mainly have the following aspects:
(1) Refractories for converters
At present, magnesia carbon bricks are used for the furnace cap, tapping mouth, front and rear faces, molten pool and furnace bottom of the converter; high-strength magnesia carbon bricks are used for the trunnion and slag line.
Magnesium oxide content in magnesia-carbon bricks is generally 70-75%, graphite content is 16-20%, bulk density is 2.8-2.9g/cm3, and compressive strength is 25-30MPa.
High-strength magnesia-carbon bricks have the same composition as magnesia-carbon bricks, but the compressive strength is 30-42MPa.
(2) Refractories for electric furnaces
The furnace bottom, furnace slope and molten pool of the electric furnace are integrally knotted with magnesia, or use magnesia-carbon bricks and tar pitch combined magnesia bricks; hot spots and slag line areas, use high-quality magnesia-carbon bricks; both sides of the furnace door and tapping El It is magnesia brick and chrome magnesia brick; electric furnace cover is high alumina brick or high alumina unburned brick.
(3) Refractories for ultra-high power electric furnaces
The permanent lining of the ultra-high power electric furnace is magnesia, the side pillars of the furnace door are magnesia chrome bricks, the slag line is magnesia bricks, the hot spots are magnesia carbon bricks, the furnace wall is magnesia carbon bricks, the eccentric bottom and the molten pool are magnesia bricks, The steel mouth is made of magnesia carbon bricks, the electric furnace cover is made of high alumina bricks, and the tapping hole filler is made of high-speed iron dolomite filler.
(4) Refractory materials for open hearth furnace
It can be seen from the working conditions of various steelmaking furnaces that the working environment of refractory materials is very harsh. Therefore, no matter what refractory material is used, it must have the following properties:
(1) High temperature resistance and high refractoriness.
(2) Erosion and erosion of high temperature molten steel and slag.
(3) Steelmaking furnaces are intermittent operations, and refractories are required to have good thermal shock resistance and spalling resistance.
(4) It has high mechanical strength and can withstand the impact of furnace body tilting and charging charge without damage.
