Uso De Nefelina Na Aciaria: Uma Revisão

Abstract

The technological characteristics of the use of nepheline as a substitute for traditional fluorine-based fluxes are presented, detailing the physical-chemical mechanism and its influence as a former of steel slag. A summary is made of the use in steelmaking processes such as desulphurization of pig iron (De-S), primary refining (BOF-LD, FEA), De-S in steel casting and ladle metallurgy (Ladle Furnace, AHF, RH-OB ). One of the critical points of this review is the comparison of refractory wear between fluorspar (CaF2) and nepheline in BOF-LD slags, in addition to the influence of nepheline on their viscosity, demonstrating the need for a balance between refractory wear parameters with the fluidity of the slag, so that the metallurgical reactions for refining the steel occur within the standards required for the final product. Questions are raised about the use of fluorspar-free continuous casting flux powders, particularly with regard to greenhouse gases and occupational health. The text is finalized with the thermodynamic simulation (FactSage®) of De-S of hot metal with fluorspar and nepheline, resulting in an equivalence of results in relation to the final S content in the liquid metal, being considered similar with the same amount of flows.