Efficient dephosphorization method of combined blown converter

Abstract

The invention relates to an efficient dephosphorization method of a combined blown converter. The method comprises the steps of: subjecting molten iron to desulphurization, and adding determined scrap steel cold material to the desulfurized molten iron; adjusting the position of an oxygen lance and open blowing parameters; adding a first batch of material, thoroughly melting, lowering the position of the oxygen lance by lowering the position of the spray nozzle of oxygen lance by 40-50 mm every 20-30 s, and adding 2.14-4.44 kg / t of active lime every time before lowering the position of the spray nozzle of the oxygen lance; lowering the position of the oxygen lance to 1500-1600 mm, fixing, adding all the residual active lime and controlling the open blowing oxygen pressure of the spray nozzle of the oxygen lance at 0.83-0.85 Mpa; converting 6-8 min, adding the remaining sinter and grain steel in molten iron by batches under addition amount of the sinter and grain steel of 3.0-6.22 kg / t respectively each batch and feeding interval of 35-60 s, adding all the sinter and grain steel; continuing converting for 3-5min, using a sublance TSC probe to measure temperature of the hot metal and sampling, after measurement of carbon temperature by the sublance TSC probe, adjusting the oxygen pressure of the oxygen lance to 0.83-0.85 Mpa, continuing lowering the position of the oxygen lance to 1200mm until the end of the blowing, and hoisting the oxygen lance; and tapping.

Description

technical field [0001] The invention relates to a method for high-efficiency dephosphorization of a reblowing converter, which belongs to the technical field of converter steelmaking in the iron and steel metallurgy industry. Background technique [0002] In recent years, with the low-phosphorus iron ore on the verge of depletion, the mining and smelting of high-phosphorus iron ore has gradually been put on the agenda. The use of high-phosphorus ore in blast furnaces results in high phosphorus content in molten iron. The traditional converter smelting method cannot meet production needs. , resulting in a large amount of molten steel with high phosphorus, which has a serious impact on the quality and cost of molten steel. [0003] At present, three methods are generally used for smelting high-phosphorus molten iron in converters: [0004] One is to adopt the slag-retaining operation. The slag-retaining operation of the converter is to leave all or part of the final slag form...

AI Technical Summary

Problems solved by technology

Disadvantages of this operation: after the slag is left, safety problems such as splashing are likely to occur when the molten iron is lowered into the furnace, and accidents such as explosive splashing are prone to occur due to the large amount of slag after the blowing is started

The dephosphorization rate of this process is as high as 95%, but the production is not well organized, and improper operation will seriously corrode the furnace lining

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