Method for controlling lime powder consumption in magnesium-based compound blowing molten iron desulfurization process

Abstract

The invention discloses a method for controlling the lime powder consumption in a magnesium-based compound blowing molten iron desulfurization process, and mainly solves the technical problem that ina conventional compound blowing molten iron desulfurization process, the lime powder consumption control precision in the post-blowing stage is low. The method comprises the following steps: determining the molten iron condition and the steel type of heat with the desulfurization demand; carrying out pre-blowing; carrying out compound blowing, uniformly dividing the compound blowing stage into n sub-stages according to the principle that the passivation magnesium powder blowing time and the lime powder blowing time are the same, and acquiring the difference between the actual lime powder blowing amount with the target lime powder blowing amount through comparison when each sub-stage is finished; and carrying out post-blowing. The method disclosed by the invention has the advantages that the lime powder post-blowing amount can be consistent with the target value without manual monitoring and intervention; accordingly, not only can the operation be simplified, but also the circumstance that a blowing gun is blocked and the lime powder consumption is increased because the blowing process is finished in advance can be effectively prevented, and the production interruption is avoided; and through the application of the method, the lime powder post-blowing amount control precision can reach + / - 2 kg.

Description

technical field [0001] The invention relates to a molten iron pretreatment desulfurization technology, in particular to a method for controlling the amount of lime powder used in a magnesium-based composite injection molten iron desulfurization process, and belongs to the technical field of molten iron pretreatment. Background technique [0002] The existing powder injection desulfurization process for molten iron pretreatment uses nitrogen as the auxiliary blowing gas, using a desulfurization spray gun, single injection or combined injection desulfurization powder to carry out injection desulfurization of molten iron tanks. The magnesium-based composite injection method includes three stages: pre-injection, composite injection, and post-injection. In the composite injection stage, passivated magnesium powder and lime powder are injected simultaneously, and the two are sprayed from their respective injection tanks in a certain proportion. It is sprayed in the spray gun, then...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide a method for controlling the dosage of lime powder in the magnesium-based composite injection molten iron desulfurization process, which mainly solves the technical problem of low control accuracy of the lime powder dosage in the post-injection stage in the existing composite injection molten iron desulfurization process, and realizes Automatic adjustment of the lime powder target injection volume during the injection process to adapt to the continuous change of the injection rate, thereby simplifying the operation, avoiding production interruption, and reducing labor intensity

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