Dual mode dephosphorization method carrying out in hot-metal ladle

Abstract

The invention relates to a dual mode dephosphorization method carrying out in hot-metal ladle and belongs to the technical field of hot metal pretreatment. According to the technical scheme, the method comprises the following steps of: setting two dephosphorization modes in the process of dephosphorization and switching between the two modes, particularly alternately using the dust-spraying mode and the gas-spraying mode for carrying out dephosphorization in the hot-metal ladle. According to the dust-spraying mode, a spray gun is used to spray passivating lime, surface oxygen and scale 1.5-2 meters deep into the hot-metal liquid level with the nitrogen as a carrier; according to the gas-spraying mode, the same spray gun is used to spray nitrogen, lime having a granularity of 5-30mm and transported by a belt, surface oxygen and surface oxygen and scale 1.5-2 meters deep into the hot-metal liquid level, the nitrogen is sprayed separately and just used for stirring. The method realizes flexible switching of the spray gun between the two spraying modes under the hot metal surface level according to pipeline diameter and dynamic conditions, thereby avoiding the hot metal from flowing backward and blocking the spray gun, stabilizing the injection, and shortening the process period and reducing the production cost.

Description

technical field [0001] The invention relates to a dual-mode dephosphorization method implemented in a molten iron tank, belonging to the technical field of molten iron pretreatment. Background technique [0002] At present, spraying passivated lime powder into the molten iron in the molten iron tank with a special dephosphorization spray gun, supplemented by blowing oxygen on the surface of the oxygen lance, is a typical and general method for dephosphorizing the molten iron tank. The whole dephosphorization process sprays a large amount of powder through the spray gun, and the flow is controlled by the powder spray regulating valve. In order to prevent the valve from being stuck by ash powder, the minimum opening value (20-30%) is usually preset in the program, which is As a result, continuous and uninterrupted ash spraying, the actual injection rate is 20-70kg / min, before the dephosphorization target is reached, even if the basicity meets the theoretical requirements, it c...

AI Technical Summary

Problems solved by technology

The whole dephosphorization process sprays a large amount of powder through the spray gun, and the flow is controlled by the powder spray regulating valve. In order to prevent the valve from being stuck by ash powder, the minimum opening value (20-30%) is usually preset in the program, which is As a result, continuous and uninterrupted ash spraying, the actual injection rate is 20-70kg / min, before the dephosphorization target is reached, even if the basicity meets the theoretical requirements, it cannot be stopped, and eventually the slag basicity is out of control and the consumption increases

In addition, the above method can only spray powdered passivation lime (expensive), which virtually increases the production cost

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