Integrated technology for ferrous metal production using low-temperature plasma

Abstract

A concept of a modern metallurgical plant is proposed, based on the following key principles: the carbon in coal is primarily considered as a reducing agent for the reduction of iron oxides; carbon dioxide is utilized for coal gasification; off-gases are used for electricity generation, which supplies the energy needs of steel production, casting, and forming; low-temperature plasma is applied to maintain the required thermal level of the iron reduction processes. The core operations of the proposed integrated plant include coal gasification, final reduction of iron oxides, carburization of iron, and the formation of pig iron and slag — all carried out in a single unit: a plasma-chemical smelting reactor. The gasification products formed in the reactor possess high temperature and reducing potential and are directed toward heating and metallization of pellets. Steel is produced from hot metallized pellets and pig iron in an electric arc furnace using electricity generated from the high-temperature, low-reducing-potential off-gas produced after the metallized product stage. Casting and forming are carried out using a technology that eliminates intermediate billet storage, resulting in energy savings and shorter production cycles. The final result of such production yields a high quality of metal which cannot be achieved by smelting using the converter method. The proposed integrated ferrous metallurgy plant features an efficient thermal utilization scheme with minimized heat losses from equipment cooling. The system for CO₂ capture and its subsequent use represents the most rational use of carbon, since, unlike conventional systems where CO₂ is emitted into the atmosphere, it is reused to increase the carbon content in the technological process. This concept is in line with modern trends in global steel production