A kind of preparation method of converter smelting high manganese, low silicon and high phosphorus iron water to extract carbon and preserve manganese

Abstract

The invention discloses a preparation method of a preparation method of C-extracted and Mn-kept molten steel (Mn 1.20wt%-1.50wt%, Si smaller than or equal to 0.20wt%, 0.130wt%-0.180wt% of P) with high-Mn, low-Si and high-P molten iron for converter smelting. Integrated innovation is performed on processes such as slag remaining operation, little slag smelting, constant-pressure lance change operation in the smelting process, converter-lowest lance position press operation, slag washing in the tapping process and bottom argon blowing in the whole process, the smelting reaction kinetics and thermodynamic conditions are optimized, good slagging dephosphorization and desulfurization effects are obtained, molten steel and slag splashing in the smelting process are avoided, the distribution concentration of MnO in slag is effectively increased, reduction of MnO in slag in the middle period of smelting, reoxidation of Mn in molten steel in the later period of smelting is reduced, the residualMn content (0.40wt%-0.60wt%) in end molten steel is significantly increased, the addition amount of a manganese alloy in the deoxidation alloying process is substantially reduced, the steelmaking alloy consumption and alloying cost is reduced significantly, and the market competitiveness of steel products 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 preparation method for extracting carbon and manganese from molten iron smelted with high manganese, low silicon and high phosphorus by a converter. Background technique [0002] Manganese (Mn) is a beneficial element in steel. During the converter smelting process, as the converting process continues, most of the Mn in the molten iron is oxidized, and the residual Mn content in the molten steel at the end of smelting is low, resulting in deoxidation and alloying of Mn. The cost of the series alloy is higher. The Mn content of the molten steel at the end of the converter smelting mainly comes from Mn in the molten iron. During the blowing process, oxidation and reduction of manganese occur between the metal bath, slag and oxygen, and the residual Mn content in the molten steel at the end of the converter is affected. The infl...

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Problems solved by technology

At present, domestic steel mills basically use low-Mn and low-P molten iron with the following chemical compositions (Mn≤0.60wt%, Si 0.30-0.55wt%, P≤0.100wt%). There are certain research reports on the process, but there is no relevant research and report on the process of using high-manganese, low-silicon, high-phosphorus molten iron to smelt carbon, extract carbon and preserve manganese