Novel pretreatment process for converter blowing end point steel slag

Abstract

The invention discloses a novel pretreatment process for converter blowing end point steel slag. The process comprises the step of immediately blowing converter gas instead to the top slag surface for40-120 seconds at the end of the oxygen blowing at the converter blowing end point. With the technical solution, the process is simple and the cost is low. Steel slag is gasified and dephosphorized to obtain lower iron oxide content, the yield of molten steel is increased, and the consumption of a deoxidizer and alloy is reduced. The process is beneficial to the whole slag-retaining operation andslagless steelmaking, is beneficial to smelting low-phosphorus steel and ultra-low-phosphorus steel, is beneficial to slag stopping and slag splashing for protection of a converter, and has great economic benefits.

Description

technical field [0001] The invention relates to the field of steelmaking, in particular to a process for treating steel slag at the end point of converter steelmaking. Background technique [0002] The steel slag at the end of the converter is a kind of steel slag with high basicity, high iron oxide and high temperature containing P2O5. The high iron oxide of the end steel slag, that is, the high oxidizability, leads to high oxidation of molten steel, resulting in a decrease in the yield of molten steel and subsequent deoxidizers and alloys. The consumption increases and there are many inclusions, which greatly increases the cost of steelmaking and affects the quality of steel. "In the later stage of smelting, with the increase of the molten steel temperature, the molten steel will return to phosphorus, and the amount of phosphorus returned varies depending on the temperature increase. See the author Yang Xinquan of "Converter phosphorus behavior and molten steel phosphorus ...

AI Technical Summary

Problems solved by technology

In order to make better use of the end-point steel slag, steel workers are currently trying to remove part of the phosphorus in the steel slag during the process of steel tapping or slag tapping. For example, in the patent "Steel Slag Roasting Dephosphorization Method", the steel slag needs to be ground and pelletized , drying, preheating, and roasting; the patent "method for recycling steel slag" [201410352003.1] is to remove phosphorus in steel slag by flotation, and then use it for sintering. , after dephosphorization, the steel slag is used for sintering, which is a large external circulation path, with high cost and low utilization rate; "A method for on-line upgrading of liquid steel slag (201510116835.8)", the patented method is to reform into synthetic slag outside the furnace, Then return to the converter for use, one is that there is no dephosphorization and practical application is not feasible

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