Converter low-alkalinity residue high-efficiency dephosphorization method

Abstract

The invention discloses a converter low-alkalinity residue high-efficiency dephosphorization method. A residue remaining method is adopted, so that the FeO content in the residue is improved; a low-lance position operation is adopted in an early blowing stage, so that the temperature of a molten bath is improved, melting of lime is accelerated, primary residues are rapidly formed, and phosphorus is rapidly removed by utilizing high FeO content and low furnace temperature in the early stage. When the Si and Mn oxidizing period is basically ended and a C-O2 reaction begins, the oxygen supply strength is reduced, and soft blow is properly caused, so that the number of reflection streams is increased, the impact area is enlarged, the C-O2 reaction speed is reduced, the FeO content in the residue is increased, the generation of C2s on the lime surface is reduced, and a terminal dephosphorization rate is guaranteed under the conditions that the slag alkalinity and lime addition amount are low by adopting low alkalinity R of less than 2.0. According to a method for adjusting the lance position and controlling the oxygen supply strength, the smelting temperature is controlled, a phosphorus distribution ratio is increased, and the dephosphorization efficiency is improved; the method has the advantages of simple process, simplicity in operation and good dephosphorization effect and can be widely applied to serving as a dephosphorization method in a steel plant.

Description

technical background:

[0001] The invention relates to a converter steelmaking dephosphorization technology. Background technique:

[0002] The content of Si element in the molten iron of the converter raw material is high, the fluctuation is large and the amount of slag is large; the magnesium ball SiO 2 High content (about 5.2%), unsatisfactory lime quality and other factors cause the SiO content in the converter blowing process and the slag at the end of blowing 2 High (25% on average), resulting in low slag basicity, average (R < 2.0), resulting in low dephosphorization and sulfur rates in the converter smelting process, and even "rephosphorization" phenomenon, which makes the supplementary blowing time longer and lime consumption high Causes blowing damage and oxygen consumption too large, but also restricts the production rhythm and worsens production costs. In order to solve these problems, people have made various efforts. For example, Chinese Patent No. CN9...