Brief introduction of Electric Arc Furnace lining repair
Furnace repair is mainly the vulnerable parts in the EAF gunning furnace, which mainly includes:
(1) Furnace wall slag line position
The part of the lining in the steelmaking furnace that is close to the slag layer is called the slag line part of the lining because it is often in contact with the steelmaking slag. The slag contains calcium oxide (CaO), silicon dioxide (SiO2), ferrous oxide (FeO), calcium fluoride (CaF2), manganese oxide (MnO), aluminum oxide (Al2O3), etc. At high temperature, the acidic oxides in the slag react chemically with the basic furnace lining to form low-melting point compounds, which reduce the refractoriness of the furnace lining. Coupled with the physical scouring effect of the slag flow, the slag line of the furnace lining is severely damaged. The nearby slag line is more seriously damaged due to the high temperature radiation of the arc light.
(2) Furnace wall hot spots
The arc temperature reaches about 4000°C, and the area where the furnace wall is closest to the electrode is a relatively high temperature area, which is often called a hot spot area. The arc light radiates on the furnace wall, and the temperature is as high as 1700°C. The basic furnace lining is made of magnesia bricks or knotted with magnesia. Its refractoriness is about 2000 ℃, but the softening deformation temperature is only about 1500 ℃, so the furnace wall in the high temperature area near the electrodes is easy to be damaged.
(3) Furnace door and tap hole
The furnace door is frequently opened and closed, and the temperature changes drastically, causing damage to the refractory material at the furnace door. The tap hole is damaged by the erosion and erosion of high temperature molten steel and slag.
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