Compound deoxidant for solid steel

Abstract

The composite deoxidant for killed steel contains (wt%) 40-70% of active lime and 30-60% of aluminium, also contains 5-15% of one or several substances selected from fluorite, silica and salt and one or several deoxidizing substances selected from silicon, manganese, barium, magnesium, calcium or its alloy. The described composite deoxidant is a kind of pellet whose diameter is 20-30 mm. Said composite oxide is easy to aggregate in the molten steel, and can be quickly floated upwards into slag, so that it can prevent Al2O3 produced by using aluminium to make deoxidation from being aggregated at steel ladle gate and can eliminate pouring fault of blocking gate.

Description

technical field

[0001] The invention relates to a composite deoxidizer for killed steel. Background technique

[0002] Deoxidizing molten steel with metallic aluminum will generate Al 2 o 3 , This deoxidized product gathers at the nozzle of the ladle, thereby blocking the nozzle and causing pouring accidents. The top-blown converter steelmaking process commonly used at present usually blows the end point carbon very low, so that the oxygen content in molten steel rises sharply, so a large amount of strong deoxidizer is needed to deoxidize molten steel. The most commonly used strong deoxidizer is aluminum, and the process requirements can only be met when the amount of aluminum added is 2.5-5kg / T steel. Since the amount of aluminum added to the ladle is large, and aluminum is generally added to the bottom of the ladle, the deoxidized product Al 2 o 3 A lot gathers at the bottom of the bag. During pouring, these Al 2 o 3 It condenses at the nozzle of the ladle, and as ...