This article describes the types of refractory bricks required for different positions in converters, electric furnaces, and open hearth furnaces during steelmaking.
Key words: steelmaking; refractory brick
Refractory bricks for converters
At present, magnesia-carbon bricks are used for the furnace cap, tapping hole, front and rear surfaces, molten pool and furnace bottom of the converter; high-strength magnesia-carbon bricks are used for the trunnion and axis. The MgO content in magnesia carbon bricks is generally 70-75%, the graphite content is 16-20%, the bulk density is 2.8-2.9g/cm3, and the 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.
Refractory bricks for electric furnaces
The furnace bottom, furnace slope and molten pool of the electric furnace are integrally knotted with magnesia, or magnesia bricks combined with tar pitch are used; high-quality magnesia carbon bricks are used for hot spots and slag line areas; both sides of the furnace door and the tapping port It is magnesia brick and magnesia chrome brick; the cover of electric furnace is high alumina brick or high alumina unfired brick.
Refractory bricks for ultra-high power electric furnaces
The permanent lining of the ultra-high power electric furnace is magnesia brick, the side column of the furnace door is magnesia chrome brick, the slag line is magnesia brick, the hot spot is magnesia carbon brick, the furnace wall is magnesia carbon brick, the eccentric bottom and the melting pool are magnesia brick, The steel mouth is made of magnesia-carbon bricks, the electric furnace cover is made of high-alumina bricks, and the filling material of the tapping hole is high-iron dolomite filling material.
Open hearth refractory bricks
The open hearth furnace smelting chamber is composed of furnace bottom, front and rear walls and furnace roof. The refractory materials used include: lightweight clay bricks, clay bricks, magnesia bricks, etc., while the furnace roof is made of high-quality alkaline refractory materials such as magnesia-chrome bricks and magnesia-alumina bricks. .
From the working conditions of various steelmaking furnaces, it can be seen that the working environment of refractory materials is very harsh. Therefore, no matter what refractory materials are used, they must have the following properties:
(1) High temperature resistance, high refractoriness.
(2) Resistance to erosion and erosion of high temperature molten steel and slag.
(3) The steelmaking furnace is intermittently operated, and the refractory material is required to have good thermal shock resistance and spalling resistance.
(4) It has high mechanical strength and can withstand the impact of tilting the furnace body and charging the furnace charge without damage.