System and method for predicating amount of refining slag required during refining and desulfuration of LF (Ladle Furnace) on line

Abstract

The invention provides a system and a method for predicating the amount of refining slag required during refining and desulfuration of an LF (Ladle Furnace) on line, belonging to the field of production and control of the metallurgical process. The system comprises an information acquiring module, a pool depth calculation module, a real-time temperature calculating module, a sulphur activity coefficient calculation module, a top slag quantity calculation module, a sulphur capacity calculation module, an oxygen activity calculation module, an apparent mass transfer coefficient calculation module, a sulphur distribution ratio calculation module, a real-time sulphur content calculation module and a refining slag amount calculation module. The method comprises the following steps of: respectively calculating the top slag quantity, the real-time sulphur distribution ratio, and the real-time sulphur content, and comprehensively calculating the amount of refining slag required in the desulfuration process according to the amount of molten steel, the initial sulphur content of the molten steel, the final sulphur content of the molten steel, the initial sulphur content in slag, and the final sulphur content in slag given by the initial information. According to the system and the method provided by the invention, the on-site production can be dynamically guided on line, and the defect that the refining amount can not be sufficiently and accurately calculated in real time in the prior art is overcome.

Description

technical field [0001] The invention belongs to the field of production and control of metallurgical processes, and more specifically relates to a system and method for online prediction of the amount of refining slag to be added during LF refining and desulfurization. Background technique [0002] During steel production, sulfur is a detrimental element for most steel grades. Sulfur element will cause hot embrittlement of steel, reduce the ductility, toughness and welding performance of steel, and also easily form HIC (hydrogen induced cracking) and SSCC (sulfide stress corrosion cracking). LF Furnace (LADLE FURNACE) is the ladle refining furnace, as an important refining equipment for steel production, due to the four unique metallurgical functions of a good reducing atmosphere in the furnace, electrode heating, white slag refining and bottom blowing argon stirring, it is the molten steel Desulfurization provides favorable thermodynamic and kinetic conditions. When produ...

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Problems solved by technology

[0004] The amount of existing refining slag added in production is roughly calculated based on the information of molten steel entering the station and the information of exiting slag, ignoring the changes in various parameters caused by changes in production conditions during the production process, which will lead to changes in the amount of refining slag , the amount of refining slag added cannot be accurately calculated, which is not conducive to the smooth progress of molten steel desulfurization, and is also not conducive to the automatic control of production and the reduction of production costs

For example, the literature "LF ladle desulfurization test" (Shanghai Metal, 1997, 19(3):5-9, Zhang Xidong, etc.) believes that the desulfurization dose is related to the initial sulfur content in molten steel, the sulfur content of molten steel at time t, the amount of molten steel and the concentration of sulfur. The effect of the initial slag amount and the sulfur content in the primary slag is ignored, and the change of the sulfur distribution ratio in the production process is not fully considered.

The sulfur distribution ratio Ls in the document "Research on Sulfur Distribution Ratio and Desulfurization Kinetic Equation in the LF Refining Process" (Acta Metal Sinica, 2001, 37(10):1014-1016, Wu Keng, etc.) is an empirical formula based on thermodynamic equilibrium It is considered that the desulfurization rate has a good linear relationship with time, and the influence of changes in the operating conditions, steel slag composition, and molten steel temperature in the actual refining process on the model parameters was not considered when calculating the desulfurization dosage and quoted the sulfur distribution ratio, and the calculated As a result, the actual production status on site cannot be tracked dynamically

In previous studies, the temperature of molten steel was often predicted online using mechanism models, statistical regression models, and neural network models. None of these three models could truly reflect the complex factors that affect the temperature of molten steel in the LF production process, and the temperature prediction was inaccurate. directly affect the accurate calculation of the sulfur distribution ratio, and then also affect the prediction accuracy of the model

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