Limestone slagging steelmaking lance position control method for basic oxygen furnaces

Abstract

The invention relates to a limestone slagging steelmaking lance position control method for basic oxygen furnaces, which belongs to the technical field of steelmaking. In the technical scheme, after limestone is directly added to replace conventional lime during slagging in the process of converter steelmaking, under the condition of keeping front pressure, the oxygen lance position is lowered to the decarburization-stage lance position in the lime slagging converting method at the early stage of converting in order to blow oxygen, and the lance position is raised at the middle and late stages of converting; when converting is almost ended, the lance position is lowered to the lowest position; and compared with the lime slagging converting method, the original high lance position is changed into the low lance position. The method has the advantages that not only the slag overflow of the mouth of a converter be inhibited, but also the proportion of carbon-oxygen reaction in molten iron is increased as much as possible from the beginning of oxygen blowing, thereby being equivalent to the advancement of the decarburization stage, and the effects of accelerating internal temperature rise, increasing the oxygen utilization rate, increasing the ratio of generated CO and the like can be achieved.

Description

technical field [0001] The invention relates to a method for controlling the position of a limestone slagging steelmaking gun used in an oxygen top-blown converter, and belongs to the technical field of steelmaking production. Background technique [0002] Steelmaking is the process of oxidizing, removing, refining and purifying impurity elements in molten iron. It is necessary to add basic oxides into the furnace and melt them into slag, and to combine with the acidic components oxidized in molten iron, especially P 2 o 5 reaction to generate stable compounds, and ensure that phosphorus is no longer reduced to molten iron. So far, steelmaking has been using lime as an alkaline oxide for slagging. In 1952, the oxygen top-blown converter steelmaking method came out. In the converter, a vertically inserted lance with a Laval nozzle at the bottom and capable of spraying high-speed oxygen was used to blow oxygen into molten iron for rapid smelting. In order to adapt to lime sl...

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Problems solved by technology

However, there is also a worrying problem in this way: if the model of lime slagging is continued and oxygen blowing at high lance position is used in the early stage of steelmaking, the slag overflow will start from 2 to 3 minutes until the decarburization period. It will last for 3 to 4 minutes, so that a large amount of slag has not participated in the fixed slag P 2 o 5 When it is lost, it not only causes a waste of useful slag, and cannot further improve the dephosphorization efficiency, but also needs to keep cleaning the furnace shell, operating platform and under the furnace, which increases the risk and workload of the furnace front workers.

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