Process for pretreating converter blowing end point steel slag by using calcium carbide CaC2

Abstract

The invention discloses a process for pretreating converter blowing end point steel slag by using calcium carbide CaC2. The process can gasify and dephosphorize the steel slag at the blowing end point, reduce the iron oxide content of the steel slag, improve the molten steel yield, reduce the oxygen content of the molten steel and the consumption of a deoxidizer and alloy, thereby reducing the impurities of the molten steel and improving the quality of the molten steel. CaO generated by CaC2 reduction reaction and CaO brought in by calcium carbide enable the alkalinity of the slag to be improved. Full slag remaining operation is facilitated, consumption of slag such as lime and steel materials is reduced, and less slag steelmaking is achieved. The remaining end slag becomes a good dephosphorizing agent, so that great and rapid dephosphorization in the earlier stage of converter smelting is facilitated, and low-phosphorus steel and ultra-low-phosphorus steel smelting is realized. Slag at the end point is sticky, so that slag stopping and slag splashing furnace protection operation are facilitated. In the steelmaking process, only part of low-alkalinity initial slag needs to be poured out, the poured-out slag amount is reduced, the content of CaO and the content of iron in the poured-out initial slag are greatly reduced, and the poured-out low-alkalinity slag is more beneficial to high-added-value utilization.

Description

technical field [0001] The invention relates to the field of converter steelmaking, in particular to a pretreatment process for steel slag at the end of converter blowing. [0002] technical background [0003] The steel slag at the end of the converter is a kind of steel slag with high alkalinity, high iron oxide and high temperature containing P2O5, especially for low carbon steel and ultra-low carbon steel. , The slag is too thin, which is not conducive to slag blocking or slag splashing to protect the furnace. The large amount of slag will easily lead to the increase of phosphorus return and deoxidizer and alloy consumption in the tapping process, which will lead to the increase of steel inclusions and affect the quality of steel. , In severe cases, a furnace of steel is scrapped, resulting in a decrease in the yield of molten steel and a large number of inclusions, which greatly increases the cost of steelmaking and affects the quality of steel. In order to prevent phos...

AI Technical Summary

Problems solved by technology

But with CaC 2 Reductive deoxidation of converter slag can easily lead to rephosphorization of molten steel

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