Method for producing ultrahigh-purity pig iron with iron bath smelting reduction process

Abstract

The invention relates to a method for producing ultrahigh-purity pig iron with an iron bath smelting reduction process. The method for producing the ultrahigh-purity pig iron comprises following steps: raw materials entering a furnace are screened, and the raw materials entering the furnace comprise mineral powder, pulverized coal, a magnesium-containing flux and limestone flour; the mineral powder is preheated and preoxidized to remove sulfur and arsenic in the mineral powder; the preheated and preoxidized mineral powder and the magnesium-containing flux are blown into a smelting reduction furnace by a mineral powder injection system; the pulverized coal and the limestone flour are blown into the smelting reduction furnace through a pulverized coal injection system; initial molten iron ismade by controlling production conditions in the smelting reduction furnace; and the initial molten iron is subjected to external desulfurization, and the ultrahigh-purity pig iron is made. Accordingto the method, the lower-grade mineral powder is preoxidized firstly before fed into the smelting reduction furnace, desulfurization rate of 50%-80% and dearsenification rate of 30%-40% are realized,then, by controlling for the production conditions in the smelting reduction furnace and the external desulfurization, the ultrahigh-purity pig iron is produced, and therefore, the problem of over dependence on high-quality raw materials in domestic production of the ultrahigh-purity pig iron is solved.

Description

technical field [0001] The application relates to a method for producing ultra-high-purity pig iron by an iron bath smelting reduction method, which belongs to the technical field of smelting reduction metallurgy. Background technique [0002] With the transformation of my country from a big foundry country to a powerful foundry country, and the development of domestic automobile, wind power, shipbuilding, chemical industry, high-speed train and other industries, the demand for high-purity pig iron, especially ultra-high-purity pig iron, is increasing day by day, but the foundry pig iron in my country is generally There are problems of high titanium and phosphorus content and excessive impurities and trace elements. A large number of high-purity pig iron and ultra-high-purity pig iron for high-quality foundry still rely on imports. [0003] In China, most high-purity pig iron and high-quality foundry pig iron are produced by selecting furnace materials and optimizing the blas...

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Problems solved by technology

Since the production of high-purity pig iron and ultra-high-purity pig iron through blast furnaces is highly dependent on high-quality raw materials, and domestic high-quality raw materials are limited, my country imports a large amount of iron ore from Australia, Brazil and other countries every year, which seriously restricts domestic high-purity pig iron and The relationship between the production and supply of ultra-high-purity pig iron, and the low-grade and high-phosphate ore and vanadium-titanium ore with abundant domestic reserves have not been effectively developed and utilized

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