Apex slag of ladle in use for refinement of vacuum decarburization in vacuum tank

Abstract

This invention provides ladle top-slag used for vacuum decarbonization and refinery in vacuum tank. The ladle top-slag comprises: CaO 30-45 wt.%, SiO2 12-18 wt.%, Al2O3 25-35 wt.%, FeO 5-15 wt.%, MgO 3-8 wt.%, and H2O 0-0.2 wt.%. This ladle top-slag is granular mixture with granule sizes of 3-10 mm. The ladle top-slag can transfer oxygen from to steel melt, promote vacuum decarbonization without air, effectively inhibit residue overflow during decarbonization, improve the adsorption of lards in the steel melt after decarbonization, and promote desulfurization and deoxidization of the steel melt.

Description

technical field [0001] The invention relates to a ladle top slag used for vacuum decarburization refining in a vacuum tank. Background technique [0002] Vacuum tank vacuum refining device (VD unit) is a widely used vacuum tank refining equipment, which has good functions such as dehydrogenation, deoxidation, decarburization, denitrogenation and desulfurization, and can also remove inclusions in steel, and The morphology of inclusions in steel is controlled. Because VD does not have the function of top-blown oxygen, it cannot perform forced decarburization. Therefore, when producing low-carbon steel and ultra-low-carbon steel at home and abroad, RH (vacuum cycle degassing) devices or VOD (vacuum blowing Oxygen decarburization) device decarburizes molten steel, but the cost of the above-mentioned corresponding decarburization device is quite high. For some manufacturers who do not have these devices, it will cause production restrictions and increase production costs. [00...

AI Technical Summary

Problems solved by technology

Because VD does not have the function of top-blowing oxygen, it cannot perform forced decarburization. Therefore, when producing low-carbon steel and ultra-low-carbon steel at home and abroad, RH (vacuum cycle degassing) devices or VOD (vacuum blowing Oxygen decarburization) device decarburizes molten steel, but the cost of the above-mentioned corresponding decarburization device is quite high. For some manufacturers that do not have these devices, it will cause production restrictions and increase production costs

[0003] At present, in the VD vacuum decarburization process that exists abroad, after the steel is tapped from the primary smelting furnace, that is, the electric furnace or the converter, the ladle top slag is basically not treated in any way, and the molten steel directly enters the VD vacuum tank for vacuum decarburization. The slag is basically the slag at the end of the converter or the end of the electric furnace brought into the ladle during the tapping process. The beneficial effect of the top slag in the vacuum decarburization process cannot be brought into play, and the excellent slag-gold reaction conditions in the VD refining process are not fully utilized, sometimes even causing The overflow of slag in the vacuum treatment process affects the smooth flow of the process and causes damage to the equipment