(1) Refractories for ARC furnace roof
Electric Arc Furnace life refers to the life of furnace roof. After the 1980s, with the expansion of steel-making electric arc furnace capacity and the increase of unit power, the working conditions of the furnace roof become more demanding, the refractories used for electric Arc furnace also changed.
The roof of arc furnace commonly use high alumina brick to masonry, Al2O3 content of between 75% to 85%. Compared with silica brick, the characterized of high alumina brick is high refractoriness, thermal shock resistance, good slag resistance, high compressive strength. Because of its high thermal shock resistance and structural integrity, it is not necessary to produce shaped bricks. There ie a rich bauxite resources in China, high alumina brick has become the main refractory material on Arc Furnace roof, its life is 2 to 3 times of silica brick roof . With the development of large-scale ultra-high-power electric furnace, the service life of high-alumina brick is reduced, Leading to the further use of calcined or not burning magnesia brick and magnesia-chrome brick and other alkaline brick.
(2) Refractories for ARC furnace wall
The furnace wall is divided into general furnace wall, slag line area and hot spot that near the arc . The main furnace wall mainly uses the magnesia brick, the tar pitch combination and the asphalt impregnation burns the dolomite brick and the magnesite brick masonry, also has uses does not burn the magnesia alkaline brick and the asphalt union magnesia and the dolomite ramming material, That all have longer service life. ARC furnace wall which Ultra-high power or smelting special steel used the magnesia-chrome brick and high-quality magnesia brick to masonry.
Slag line area and the hot spot of furnace wall is weak link. As the furnace wall life depends mainly on the degree of damage of hot spot, so the parts of lining should be special attention. the 20th century 70 years ago, the masonry of the site commonly used cast magnesium chrome bricks, combined with or re-combination of magnesia- chrome brick, the service life is 100 to 250 furnace times. Into the 80's, in these parts widely used Mg-C brick to masonry, showing that in addition to high temperature and slag resistance performance,service life be significantly improved , the high-power electric arc furnace to more than 300 times in China.