Slagging and dephosphorizing agent for converter steelmaking and dephosphorizing process

Abstract

The invention discloses a slagging and dephosphorizing agent for converter steelmaking, which belongs to the technical field of metallurgical engineering and comprises an oxidizing agent, a slagging constituent and a fluxing agent. The oxidizing agent is O2, and a spray gun is adopted for blowing; the slag former is CaO and FeO; the dosage mass ratio of CaO to FeO is (7-8): 11. The fluxing agent used in the invention has similar chemical properties to fluorite, has a lower melting point, can better reduce the melting point of a slag system, and has better slagging and fluxing effects; furthermore, the cosolvent contains a large amount of Na, Al and other elements, so that the probability of generating HF, SiF4, MgF2 and other fluorides at high temperature can be effectively reduced, the pollution corrosion defect of the cosolvent is improved, and the energy-saving and environment-friendly requirements are met; according to the method, dephosphorization treatment process parameters are optimized, the content of calcium oxide and ferrous oxide dissolved in the slag can be increased, the early-stage slag can be activated, then the slagging rate can be remarkably increased, the slagging effect can be improved, and therefore the dephosphorization effect is improved.

Description

technical field [0001] The invention belongs to the technical field of metallurgical engineering, and in particular relates to a slag dephosphorization agent for converter steelmaking and a dephosphorization process. Background technique [0002] The dephosphorization agent is added to the molten iron or the surface of the molten iron in various ways to react with phosphorus in the molten iron to form phosphorus compounds, so that the phosphorus is fixed in the slag or enters the gas phase to achieve the purpose of pre-dephosphorization of the molten iron. Hot metal dephosphorization agent is mainly composed of oxidant, slag-forming agent and flux. The function of the oxidant is to supply oxygen and oxidize the phosphorus in the molten iron to P 2 O 5 , so that it combines with the slag-forming agent to form phosphate and remains in the dephosphorization slag. The oxidant is generally a gaseous oxidant (mainly O 2 ) and solid oxidants (rolled steel sheet, iron ore, sinte...

AI Technical Summary

Problems solved by technology

CaF 2 As the main component of fluorite, it has a good slag fluxing effect, but CaF 2 A large amount of HF and SiF will be generated under high temperature reaction in the furnace 4 , MgF 2 When fluoride gas enters the atmosphere, some unreacted solid-phase fluoride will exist in the waste slag and enter the soil, causing serious pollution to the environment; in addition, with the continuous improvement of steel quality requirements, the existing dephosphorization The dephosphorization effect needs to be further improved