A converter low-silicon molten iron blowing method using cast steel slag

Abstract

The invention discloses a converter low-silicon hot metal blow smelting method using residual slag of steel casting. The converter low-silicon hot metal blow smelting method has the advantages that the residual slag of steel casting is added in the blow smelting process, so that the slag decomposing condition by blow smelting is improved, the slag can be early melted by a converter in the low-silicon hot metal blow smelting process, the slag is thoroughly and well melted, and the dephosphorization efficiency is obviously improved; the converter slag can completely cover the liquid level of hotmetal, the problem of steel sticking of oxygen guns, furnace mouths, smoke covers and the like due to dry return and spraying is favorably relieved, the loss of steel and iron material is reduced, the tonnage iron and steel consumption is reduced, the labor intensity is decreased, the cost is favorably reduced, the safety in production is improved, and the good popularization and application value is realized.

Description

technical field [0001] The invention belongs to the technical field of converter blowing, and in particular relates to a converter low-silicon molten iron blowing method using cast steel slag. Background technique [0002] The use of low-silicon molten iron in modern large-scale blast furnace production can bring great economic benefits to iron and steel enterprises. For every 0.1% reduction in silicon content in blast furnace molten iron, the output can be increased by 1.0%~1.5%. The silicon content of molten iron in large blast furnaces in the United States, Japan, and European countries has been reduced. However, compared with normal silicon-containing molten iron steelmaking, in the smelting process of low-silicon molten iron, the decarburization reaction is advanced, the oxidation of carbon is prior to the oxidation of silicon, and the SiO in the slag 2 It is difficult to enrich, and the early appearance of dicalcium silicate in the initial slag hinders the melting of...

AI Technical Summary

Problems solved by technology

However, ferrosilicon itself is expensive, and river sand and silica have complex components and long melting time, so they are not ideal as supplementary silicon sources.

[0003] In actual operation, when the oxygen lance position is low to a certain extent, or a certain low lance position is used for blowing for a long time, the decarburization speed in the molten pool is fast, the consumption of FeO is large, and the content of TFe will decrease, resulting in the return of slag. Dry, severe metal spatter

Thereby further causing serious accidents such as oxygen lance sticking to steel, which not only increases the processing cost, but also affects the smooth progress of production

[0004] During converter blowing, due to the abundance of heat, the furnace temperature will be too high, and the furnace lining is susceptible to impact corrosion

Moreover, the dephosphorization reaction is highly sensitive to temperature during the blowing process, and the distribution ratio of phosphorus decreases under high temperature conditions, making it difficult to reduce the phosphorus content in molten steel below the requirement

The gas dissolved in molten steel increases, thus affecting the quality of steel

And because the temperature of the molten steel is too high, it is easy to cause casting accidents