Utilization method for steel scoria

Abstract

The invention relates to an utilization method of steel slag, which includes the following steps: slagging materials are added into an LF ladle refining furnace for slagging and refining and 20kg to 50kg / t of the slagging materials are added into each ton of molten steel; then in the moulding process, the slags of the ladle furnace and remanent molten steel after moulding are returned to an electric furnace for smelting; the slagging materials are added into the electric furnace and 50kg to 70kg / t of the slagging materials are added into one ton of the molten steel; in the smelting process of the electric furnace, the adding amount of the slagging material lime and the power supply volume of the electric furnace are decreased; as for steel grades which need to be deaerated, after the LF ladle refining furnace is refined and slags are made after the slagging materials are added, the molten steel is sent to a VD vacuum degassing furnace for deaeration; then moulding is carried out; and the slags of the ladle furnace and remanent molten steel after moulding are returned to the electric furnace for smelting. The utilization method of the steel slag is lower in cost and can avoid sulfur enrichment in the ladle refining process.

Description

technical field [0001] The invention relates to a steel slag utilization method. Background technique [0002] At present, domestic electric furnace factories basically adopt electric furnace-LF ladle refining furnace-VD vacuum degassing-continuous casting (or mold casting) process for steelmaking production. The amount of slag is controlled when the electric furnace is tapping, alloying is carried out in the ladle during the tapping process, and slag-forming materials such as lime and synthetic slag are added at the same time to form slag, and then the molten steel is deoxidized, desulfurized, fine-tuned the composition, and temperature at the LF ladle furnace station. control and so on. After refining, some steel grades are directly continuous casting or die casting, and some steel grades are subjected to VD vacuum degassing treatment before continuous casting or die casting. After the molten steel is cast, there will be remaining refined steel slag and part of the molte...

AI Technical Summary

Problems solved by technology

If it is not recycled, the steel slag will be sent to the slag yard for treatment, which requires treatment costs and will cause environmental pollution. At the same time, it will cause CaO, Al in the steel slag 2 o 3 waste of

[0003] At present, domestic ladle refining steel slag generally adopts three utilization methods. One is to pour the ladle refining steel slag into the slag pan and transport it to the slag yard for treatment. The treated steel slag is used as roadbed for paving roads or as cement raw materials, which requires a lot of space. storage, and is likely to cause environmental pollution

The second is to mix the ladle refining slag with a certain amount of binder to make pellets after cooling, and then add it to the converter as a slagging agent after drying. This method requires special equipment for processing, and the cost is relatively high.

The third is to return the ladle refining slag to the ladle refining furnace for use. This method is likely to cause sulfur enrichment during the ladle refining process, which affects the refining effect of molten steel and reduces the desulfurization rate of the refining furnace. At the same time, the slag needs to be discarded once in 2-3 furnaces. Realize continuous return utilization

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