Semi-steel dephosphorization agent and semi-steel dephosphorization method

Abstract

The invention discloses a semi-steel dephosphorizing agent and a semi-steel dephosphorizing method. The dephosphorizing agent disclosed by the invention is prepared by the following substances in parts by weight: 35-50 parts of lime, 25-45 parts of oxide scale and 15-25 parts of sodium oxide. The method disclosed by the invention comprises the following steps of: uniformly adding the semi-steel dephosphorizing agent into discharged molten steel during discharging steel and controlling the adding amount of the semi-steel dephosphorizing agent as 10-20kg / t; blowing nitrogen to the bottom of the molten steel after finishing discharging steel; and carrying out slag pulling treatment after ending the blowing of the nitrogen. The semi-steel dephosphorizing agent and the semi-steel dephosphorizing method disclosed by the invention have the advantages of reducing the dephosphorizing task of a steel smelting converter during smelting the molten steel, creating the conditions for smelting low-phosphorus steel and realizing smelting steel with less slag, effectively removing the phosphorus content in the semi-steel, having a dephosphorizing rate which reaches greater than 40%, being simple to operate, having no requirement of additionally establishing facility equipment, not extending the time of working procedure, reducing the auxiliary material consumption of smelting steel via the converter, effectively avoiding the problem that the converter lining is corroded by a common dephosphorizing and vanadium-extracting agent and simultaneously reducing the content of sodium in the vanadium slag.

Description

technical field

[0001] The invention belongs to the technical field of semi-steel dephosphorization, and more specifically relates to a semi-steel dephosphorization agent and a dephosphorization method using the semi-steel dephosphorization agent. Background technique

[0002] In general, phosphorus is a harmful element in most steel grades. In recent years, with the rapid development of science and technology, low-temperature steel, marine steel, hydrogen-induced cracking-resistant steel and steel for some thick plates must not only have extremely low sulfur content, but also require the phosphorus content in steel to be less than 0.01% or 0.005%. Since the 1980s, various treatment methods have been developed for the pre-dephosphorization of molten iron. The dephosphorization pretreatment of molten iron is carried out in-house, and both methods have been applied industrially. Dephosphorization of ladles or torpedo tanks mainly has problems such as large temperature drop,...