A converter smelting method for increasing residual manganese in end-point molten steel with medium-high manganese molten iron

Abstract

The invention discloses a converter smelting method for increasing residual manganese of end point liquid steel by high and medium-manganese hot metal (C, 0.75 to 1.10wt% of Mn, 0.25 to 0.45wt% of Si,0.090 to 0.120wt% of P, and less than or equal to 0.045wt% of S). The converter smelting method has the advantages that the technologies of remaining slag operation, low-alkalinity BaCO3 system slagmanufacturing, fewer-slag smelting, constant-pressure and low-gun level gun change in a smelting process, slag washing in a whole tapping process and the like are adopted, integrated and innovated, soas to optimize the reaction dynamics and thermodynamics conditions of smelting, avoid the splashing of liquid steel and furnace slag in the smelting process, and increase the distribution concentration of slag (MnO) in the smelting process; the good smelting slugging and dephosphorization effect is obtained under the technology conditions of low-alkalinity slag system and fewer slag, and the phosphor return degree of the liquid steel in the later smelting process and the tapping process is effectively reduced; the content of residual Mn in the end point liquid steel is obviously increased to0.38 to 0.50wt%, the adding amount of manganese alloy in the deoxidizing alloy process is greatly reduced, the consumption of steel smelting alloy and the alloying cost are obviously reduced, the improvement of technical and economic indexes in smelting are promoted, and the market competitiveness of a product is improved.

Description

technical field [0001] The invention belongs to the technical field of iron and steel metallurgy and steelmaking technology, and in particular relates to a converter smelting method for increasing residual manganese in end-point molten steel by medium-high manganese molten iron. Background technique [0002] Manganese (Mn) element is a beneficial element in steel. At present, most of the Mn in the molten iron used in converter smelting is oxidized during the converter blowing process, and a small amount of Mn (residual Mn) remains in the molten steel at the end of smelting. The Mn content of molten steel at the end of converter smelting mainly comes from Mn in molten iron. During the blowing process, manganese oxidation and reduction reactions occur between the molten metal pool, slag and oxygen, and the residual Mn content in molten steel at the end of converter is affected by The influence of factors such as the amount of slag, the oxidation of molten steel and slag at the...

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Problems solved by technology

At present, most domestic steel mills basically use low-Mn and low-P molten iron with the following chemical composition (Mn≤0.60wt%, Si0.30-0.50wt%, P≤0.085wt%) for smelting. There are certain research reports on the converter smelting process to increase the residual Mn content of molten steel at the end point, but the use of medium-high manganese molten iron with the following chemical composition (Mn0.75-1.10wt%, Si 0.25-0.45wt%, P 0.090-0.120wt%) There is no relevant research report on the converter smelting method to increase the residual manganese in molten steel at the end point