Researching and practice of demanganization in the process of producing high silica pure iron

Much lower mass fraction of manganese for high silica pure iron for amorphous master alloy is necessary. The technology for the production of high silica pure iron using the long process of "KR desulfurization of molten iron → LF deep desulfurization of molten iron → BOF smelting → LF refining → RH vacuum refining → slab continuous casting", was developed by assessing the capacity of demanganization of 180 t BOF and LF/RH ladle refining furnace and analyzing the scientific principle demanganization. By choosing the molten iron of low manganese, operating double slag at the moment of 30%-35% of blowing oxygen and 1 350-1 400 ℃ of molten bath, pouring out slag amount of 70%-80%, controlling oxygen content of final slag is more than 0.070 0% and tapping temperature vary from 1 610 to 1 625 ℃, improving the basicity of LF slag at 6.5 and so on, which can achieve the production of the steel containing manganese with the mass fraction of less than 0.025% and w(Fe) and w(Si) are equal to 99.90% or larger, meet the requirement of the low manganese and high silica pure during the mass production.