Smelting of the hottest low silicon molten iron

2022-10-14
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Smelting of low silicon molten iron

using low silicon smelting technology can improve the smelting intensity of the converter and reduce the fuel ratio, but on the other hand, it is easy to cause slag melting difficulties, gun sticking and flue sticking. At the same time, gun sticking will greatly reduce the service life of the low oxygen gun. This puts forward requirements for high-level low silicon smelting technology. The fundamental reason for sticking guns and flues lies in the difficulty of Slagging in the early stage of smelting, which leads to a long return drying time in the medium term and is difficult to adjust. Moreover, the localization rate of 30% and 50% also makes the market space of China's high-end materials vast. The basic principle of displacement sensor for the melting of early slag is: mainly the melting of lime and the reduction of some alkaline substances. At the same time, FeO is an important factor in the slag forming process, and the growth rate of FeO in the smelting process affects the speed of slag melting. In addition, the addition of dolomite, which plays the role of furnace protection in the smelting process, when the equivalent is too much, will make MgO precipitate from the high alkalinity slag into a dispersed solid guide, increase the viscosity of the slag, which is not conducive to slag melting

therefore, it is necessary: in fact,

1) reduce the amount of slag added in the early stage. In order to promote the melting of slag in the early stage, the addition of lime and dolomite in the early stage should be reduced. Control the alkalinity and MgO in favor of slagging 5% and%

2) slag retention operation. In order to reduce the addition of lime and dolomite in the early stage, Cao and MgO can be retained in the final slag; In addition, FeO is retained in the final slag, which tends to expand the liquid slag system

3) the smelting process adopts the low high high low, four stage gun position method. Low gun position in the early stage, rapid formation of slag pool; After the slag melts in the early stage, raise the gun position in time to form a soft blow that is mm higher than the normal gun position, increase the amount of FeO in the slag, and add the medium-term slag when the furnace condition is fully active; The end point shall be pressed under the condition of ensuring the fluidity of the final slag

4) transform the oxygen lance nozzle, increase the number of oxygen lance holes, increase the oxygen jet, and increase the stirring of the molten pool, so as to improve the FeO generation rate in the slag, which is suitable for the smelting of low silicon molten iron

after taking the above measures, the Third Steelmaking Plant of Handan Iron and Steel Co., Ltd. in China has achieved remarkable results. The service life of the oxygen lance has increased from 73 heats in June and July 2006 to 115 heats in September and October. During the smelting of low silicon molten iron, the average treatment time of each heat of oxygen lance has been reduced by 3 minutes, which is more accurate. At the same time, the smelting process has good slagging and stable furnace conditions

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