Powder blowing lance and method for refining molten iron using the powder blowing lance

Abstract

A powder blowing lance comprising a refining oxygen blowing nozzle and a burner, the refining oxygen blowing nozzle having a plurality of blowing openings, the plurality of blowing openings being spaced apart along a circular track Arranged to blow oxygen into the iron bath accommodated in the reaction vessel through the plurality of ejection openings, the ejection nozzles have ejection openings, and the ejection openings have a center axis coaxial with the circular rail. The shaft core of the shaft forms a flame inside the oxygen injection nozzle for refining, and blows the powder heated by the flame into the iron bath through the ejection opening, indicating the oxygen for refining The index A of the positional relationship between the discharge opening of the injection nozzle and the discharge opening of the injection burner satisfies A=1.7(R-r-d / 2) / L+tan(θ-12°)-0.0524>0. Here, R: the radius (mm) of the above-mentioned circular orbit, r: the radius (mm) of the discharge opening of the injection burner, d: the diameter (mm) of the discharge opening of the oxygen nozzle for refining, θ: for refining The inclination angle (°) of the shaft core of the oxygen blown into the nozzle, L: the height of the spray gun (mm). As a result, the heat imparting efficiency to the molten iron is improved.

Description

technical field [0001] The present invention relates to a powder injection lance with a spray burning function, and a refining method and a smelting reduction method of molten iron using the powder injection lance. Background technique [0002] From the viewpoint of environmental protection, it is imperative to suppress CO in the steel manufacturing process. 2 emissions. In order to reduce CO 2 In terms of emissions, in the steelmaking process, measures such as increasing the use of cold iron sources such as scrap iron as iron sources and reducing the blending ratio of molten iron have been studied and implemented. The reason for increasing the use of cold iron sources is as follows: When producing steel products, a large amount of energy is required to reduce and melt iron ore in the process of producing molten iron (molten iron) in a blast furnace, and at the same time, also emit large amounts of CO 2 , in contrast, the cold iron source only needs the heat of fusion, s...

AI Technical Summary

Problems solved by technology

In Patent Document 1, although the temperature of molten iron is raised by adding a carbon source to the generated slag, the sulfur contained in the carbon source is mixed in, resulting in an increase in the sulfur concentration in the steel.

In addition, there is a problem that the refining time is prolonged in order to secure the burning time of the carbon source, resulting in an increase in manufacturing cost

In addition, there is also a problem that CO is naturally generated by burning carbon sources. 2 increased production of

[0022] Furthermore, in the methods disclosed in Patent Documents 4, 5, and 6, a top blowing lance consisting of a 4-layer tube or 5-layer tube structure is used, and the dephosphorization agent etc. etc. Reactive powder insufflation

In addition, the amount of injection and the flow rate of propane are low, so it cannot be expected to have a sufficient effect on reducing the ratio of molten iron

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