Method for slagging steelmaking by side blowing of powder particle limestone in top-bottom combined blown converter

Abstract

The invention belongs to the technical field of metallurgy, and particularly relates to a method for slagging steelmaking by side blowing of powder particle limestone in a top-bottom combined blown converter. The method of the invention comprises the following steps: arranging at least one side blowing spray gun at one side of a converter trunnion center line, wherein the installation site of the side blowing spray gun is located between a molten pool liquid level and a level 500 mm below the liquid level, an angle between the installation range of the side blowing spray gun and the installation site tangent plane is 10 degrees-75 degrees, the side blowing direction of the spray gun is that the included angle between the side blowing spray gun center line and a horizontal line is 10 degrees-60 degrees, the spray gun faces the bottom of the molten pool, the insertion depth of the side blowing spray gun is 0.1-0.6 times larger than the radius of the molten pool; blowing powder particle limestone with carrier gas through a center pipe of the spray gun by using the side blowing spray gun, blowing protective gas around the circular seam. The method of the invention directly sprays powder particle limestone into the molten pool through the side blowing spray gun; the limestone rapidly decomposes and rapidly participates in slagging reactions; limestone taken away by converter furnace gas is reduced; dust is minimized; and the utilization rate of limestone is improved.

Description

technical field [0001] The invention belongs to the technical field of metallurgy, and in particular relates to a method for making slag from powdered limestone and making steel in a top-bottom combined blowing converter. Background technique [0002] At present, converter steelmaking is mostly carried out by top-bottom double-blowing converter. The common method of top-bottom double-blowing converter steelmaking is to blow oxygen into the molten iron from the upper part of the converter molten pool through the oxygen lance, and from the bottom of the converter to the molten iron through the bottom lance. Nitrogen or argon is blown into the molten pool to stir the molten pool, and at the same time, lime blocks are added from the high-level silo at the top to make slag; some enterprises also blow lime powder through the breathable bricks at the bottom of the converter to ensure rapid slagging and save lime consumption. However, lime blocks are directly added through the h...

AI Technical Summary

Problems solved by technology

However, due to the relatively large particle size of the massive limestone added through the high-level silo, the decomposition speed of the limestone block is relatively slow, the penetration depth of the limestone is relatively small, the utilization rate of lime is not high, and the isotopic rate of [O] and CaO is not high. It is not conducive to the early dephosphorization of the converter

[0004] Chinese invention patent 201210240821.3 discloses a steelmaking method for slag-making by using an oxygen lance to inject powdery limestone into a double-blown converter. The inventor has modified the structure of the oxygen lance and used the oxygen lance to inject limestone powder and oxygen at the same time, but in this way The problem is that the limestone is easily carried away by the air flow, resulting in low utilization rate of the limestone and dust pollution. At the same time, it takes time and energy to modify the structure of the oxygen lance

Images