Method for producing cast iron by adopting electric furnace blowing smelting and purification

Abstract

A method for producing cast iron by adopting electric furnace blowing smelting and purification comprises the following steps: 1, adding an iron-containing raw material and auxiliary materials into a furnace in a charging proportioning stage; 2, heating and making oxidizing slag in a preliminary melting stage; 3, blowing gas to the above obtained melt and making the oxidizing slag in an oxygen blowing heating oxidation stage; 4, blowing the gas to the melt and making reducing slag in a blowing purification and reduction stage; and 5, carbonizing iron or graphitizing. O2 is blown to provide oxidizing atmosphere and is used for oxidizing impurities, a large amount of impurities are carried by the upward floatation of a CO gas in the oxidation and reduction process, and N2, CO2 and Ar blown in the invention are used to eliminate harmful gases and the impurities carried by the upward floatation. Various iron and steel scraps are effectively decomposed through a redox chemical reaction and various high temperature stirring, blowing purification and evacuation modes in order to eliminate various impurities in the iron-containing raw material and the auxiliary materials and impurities generated in the production, eliminate the harms of low melting point elements, high melting point elements, nonmetal inclusions and gases and enlarge the application range of the cast iron raw materials.

Description

technical field [0001] The invention relates to the iron and steel smelting industry, and specifically belongs to the category of producing cast iron through a smelting purification process. Background technique [0002] The basic status of the steelmaking and iron casting industries: developed countries such as Europe and the United States mainly use scrap iron and steel as raw materials to produce steel through the oxidation and reduction process of the gas blowing electric arc furnace, accounting for about 90% of their total steel production in recent years. In 2002, 2005, and 2011, China's crude steel output was about 180, 350, and 700 million tons respectively, accounting for about 45% of the world's total in 2011, mainly using iron ore as raw material through oxidation and reduction of blast furnaces and gas blowing smelting converters The production of steel products by technology, mainly using electric arc furnaces to produce special steel, accounts for only about 10...

AI Technical Summary

Problems solved by technology

It is also impossible to effectively remove the gas and inclusions produced by the use of cast iron in the remelting process, improve the grade of cast iron and reduce the amount of precious metals added