Argon oxygen refining low-carbon ferrochromium process endpoint carbon content and temperature control method

Abstract

The invention discloses an argon oxygen refining low-carbon ferrochromium process endpoint carbon content and temperature control method. In the method, molten iron crudely refined in an electric furnace is poured into an AOD (Argon Oxygen Decarburization) furnace, oxygen is blown from a top gun for quick decarburization, when carbon content is reduced to a critical value, oxygen and argon mixed gas is blown from a bottom gun to carry out decarburization reaction, and finally pure Ar gas is blown for several minutes to make residual oxygen in the molten iron continue to react with carbon so as to further reduce the carbon content; when the carbon content reaches a preset target, ferrosilicon is added under the stirring of the Ar gas to carry out reduction; and on the basis of the thoroughanalysis of a smelting process mechanism, partial mathematical models in the low-carbon ferrochromium production process are established, and based on the models, an inference control method is adopted to accurately control the carbon content and the temperature of a molten bath, the hit rate of an endpoint is greatly improved, the output is increased, the quality of iron alloy is improved, the consumption of raw materials and energy is reduced, the production cost is reduced, and the economic benefits are increased.

Description

technical field [0001] The invention relates to a ferroalloy smelting method, in particular to a method for controlling the carbon content and temperature at the end point of an argon-oxygen refining low-carbon ferrochrome process. Background technique [0002] At present, the traditional production process of medium and low carbon ferrochrome adopts a three-step method, such as figure 1 As shown, first use the electric furnace to produce high-carbon ferrochromium (or silicon-manganese alloy); then use high-carbon ferrochromium (or silicon-manganese alloy) as raw material to produce silicon-chromium alloy by electric furnace; finally, silicon-chromium alloy (or silicon-manganese alloy) ) as a reducing agent to reduce chromium ore (or manganese ore) in an electric furnace to produce medium and low carbon ferrochrome and medium and low carbon ferromanganese. This method has a long process flow, and each step is independently remelted from a solid or partially liquid raw mater...

AI Technical Summary

Problems solved by technology

Since the carbon content in high-temperature molten iron cannot be continuously detected online, and the boundary conditions of the smelting process change frequently, it brings great difficulties to the control of the smelting end point. Influenced by the reaction rate of chromium oxidation, the oxygen supply flow should be adjusted for the purpose of controlling the temperature of the ferrochrome alloy

The traditional smelting method is to estimate the carbon content at the end point based on empirically observing the flame and sparks at the furnace mouth, the amount of molten iron charged, and the cumulative consumption of oxygen, without controlling the process temperature. This method not only prolongs the smelting time, but also reduces the Furnace age, and the carbon content in the reaction process is affected by many uncertain factors, which makes the smelting process unstable and directly affects the quality of the final smelted ferroalloy

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