EAF working layer lining erosion factors

Source: | Author:ChangXing Refractory | Published time: 1626 days ago | 954 Views | Share:

EAF steelmaking is a complex high-temperature process. The furnace temperature is high (up to 1700 ~ 1800C), the atmosphere changes greatly, and the smelting cycle is short. The damage factors of the EAF lining are as follows:

The refractory materials of the EAF lining are often in the state of high temperature, slag erosion and rapid cooling and heat, and the working conditions are extremely harsh. During the melting and oxidation period of steelmaking, the furnace lining will not be damaged by high temperature, but in the reduction period, The temperature of the liquid is quite high, and it is directly radiated by the electric arc, and the furnace lining is very easy to damage. In addition, when the steel is discharged and charged; the temperature of the furnace lining suddenly drops, the charging starts to transmit electricity, and the temperature gradually rises. This kind of rapid cold and hot temperature changes are often the direct cause of lining peeling.

The corrosive effect of slag on the furnace lining determines its composition and fluidity. The higher the silica content in the slag, the more serious the alkali furnace lining will be corroded. In addition to silica, the slag contains aluminum oxide, iron oxide, and iron oxide. Dicalcium, etc. also corrode the furnace lining: the fluidity of the slag also affects the furnace lining. The thinning of the slag has a serious effect on the erosion of the furnace lining, and the ability to reflect the arc is strong, which will increase the heat load of the refractory lining; the thick slag makes the molten pool difficult to heat, and the physical and chemical reaction conditions It becomes worse and prolongs the high temperature action time of the furnace lining (that is, the smelting time). These will accelerate the damage of the furnace lining.

In many cases, the damage of the furnace lining is caused by the impact of mechanical force, such as unreasonable cloth, no small scrap steel protection at the bottom of the furnace, and too high charging tank. In these cases, the bottom of the furnace may be large. Scrap steel smashed into pits. Mechanical vibration caused by furnace cover lifting, furnace body opening, and tilting of the furnace is also the cause of damage to the furnace lining. In addition, the proportion of furnace materials is improper, and the smelting operation is incorrect, such as high temperature oxygen flow during oxygen blowing. Straight contact and furnace lining will damage the furnace lining.

Therefore, the refractory materials for masonry EAF should have high refractoriness and load softening point, good thermal stability and slag resistance, sufficient high temperature mechanical strength and low thermal conductivity.