This paper attempts to postulate the kinetics and mechanisms of oxidation of dri. The increasing role of direct reduced iron in global. The steel mill is like a big kitchen, where the steel workers are the cooks, and the steel furnace is basically a viking range on steroids. The presentation describes different processes for the production of direct reduced iron. Reduced iron derives its name from the chemical change that iron ore undergoes when it is heated in a furnace at high. The iron in the filtrate is reduced to ironii, which is titrated with potassium dichromate solution. Direct reduced iron industry in india problems and prospects iii. If you continue browsing the site, you agree to the use of cookies on this website. Direct reduced iron dri, also called sponge iron, is produced from the direct reduction of iron ore in the form of lumps, pellets, or fines to iron by a reducing gas or elemental carbon produced from natural gas or coal. Direct reduced iron and its production processes ispatguru.
September 27, 2017 why do i need a chefs toque in a steel mill. The reducing gas is a mixture majority of hydrogen h2 and carbon monoxide co which acts as reducing agent. Direct reduced iron dri production plant nippon steel engineering co. There are two main technologies for direct reduction of iron, midrex and energiron or hyl which together are responsible for. The dri is used mainly as the raw material for electric arc furnaces eafs, as a. This product is known as direct reduced iron dri or sponge iron. Directreduced iron process dri nippon steel engineering. State of direct reduction and reduction smelting processes j. The term direct reduced iron, or dri, has a generic meaning which covers a number of products with a variety of properties and hazards.
The process characteristics allow for independent control of the dri metallization and carbon levels. Direct reduced iron dri international iron metallics. Direct reduced iron determination of metallic iron brominemethanol titrimetric method by bureau of indian standards. After the dri exits the shaft furnace, it can be cooled and compressed to briquetted iron for safe storage and transportation. Direct reduction processes are an alternative to the traditional blast furnace because of the use of h2 in the reducing gases which generate less co2. Properties and features of direct reduced iron request pdf. The output is sold as pellets or briquettes called hot briquetted iron. This statistic shows the amount of direct reduced iron dri into the united kingdom uk from 2009 to 2018, in thousand metric tons. Basic concept or summary s16 u a direct reduced iron dri production plant is a shaft reduction furnace to produce dri with large metal iron content by directly reducing iron ore or iron ore pellets with reducing gases. The direct reduction process drives off the oxygen in order to convert the ore, utilizing gas, coal, or oil as fuel shaft furnace blowers are used in the process to supply combustion air into the reformers and a process gas compressors, seal gas compressor, and a cooling gas compressor are required to help circulating the process gas in the system. The kinetics and mechanisms of oxidation of direct. Sponge iron instead of liquid hot metal is produced and then this direct reduced iron is melted in the electric furnace.
Metallization can be adjusted at will, typically around 94% and higher. The process reduces iron ore using a reforming gas made from natural gas. Direct reduction processes direct reduction is defined as a process of producing solid iron product. National product waiver of pig iron and direct reduced iron pdf 3 pp, 800 k, february 18, 2015. Low decrepitation during reduction less than 5% fines generation vi. Understanding the different direct reduced iron products. Commercially, dri is generated in four different reactors. Direct reduced iron industry in india problems and prospects. Total worlds dri output in 1998, 1999, 2000 and 2001 in % 2 figure 2. There has been a disturbing increase in the number of potential. Minnitt synopsis direct reduced iron dri, produced by the reaction between iron ore and reducing gasses, is used as a source of lowresidual iron, in addition to ferrous scrap and pig iron, in the production of steel. Therefore the agency isauthorized to issue a waiver for iron and steel products composed of nondomestic pig iron and direct reduced iron.
In the search for a pure, available iron source, steelmakers are focusing their attention on directly reduced iron dri. Midrex is an innovative ironmaking process, developed for the production of directreduced iron dri from iron ores and primarily natural gas. Iron ore pellets containing carbon can be reduced by itself at the high temperature and then produce direct reduced iron fed into the blast furnace or electric arc furnace for iron steel. Carriage of direct reduced iron dri by sea chan ges to the imo code of safe practice for solid bulk cargo members will be aware of the general concerns that exist with regard to the carriage of direct reduced iron dri by sea.
Use of direct reduced iron in electric arc furnace ispatguru. Because making steel is the industrial version of cooking. Iso 10835, direct reduced iron and hot briquetted iron sampling and sample preparation 3 principle metallic iron is dissolved by treatment with brominemethanol solution. It is a recyclingbased route contrary to the three abovementioned orebased routes see area of route 4 within dotted line in fig.
Production of direct reduced iron in rotary hearth furnace. This material is produced by the reaction of a low gangue iron ore with a hydrocarbonaceous substance. You may need a pdf reader to view some of the files on this page. Direct reduced iron dri is the product which is produced by the direct reduction of iron ore or other iron bearing materials in the solid state by using noncoking coal or natural gas. National product waiver for pig iron and direct reduced. Direct reduced iron and production of dri part 2 youtube. This forms the direct reduced iron dri which is typically composed of 90 to 94% iron. It is a recyclingbased route contrary to the three abovementioned orebased routes see. Direct reduction process an overview sciencedirect topics. Total worlds dri output by processes in 2001 in % 2 3. Calibrated to size with less fines preferably 616 mm with less than 3% fines iv. Production of direct reduced iron in rotary hearth furnace slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. Despite the fact that the reoxidation of direct reduced iron dri has created wellknown problems for industry involving storage, shipping, and handling of this material, surprisingly very little information on this subject has been reported in the literature.
The volume of steel produced by the, now oldfashioned, blast furnace process is already very low and will continue to decline relative to the volume of steel produced by the electric arc process, for which dri is the raw material. To focus on the emerging market and technological trends for the production, handling and use of dri and hbi products as well as present and future alternative iron production technology. There has been a disturbing increase in the number of potential life threatening incidents involving the carriage of direct reduced iron dri. Most gasbased direct reduction plants are part of integrated steel minimills, located adjacent to the electric arc furnace eaf. Direct reduced iron dri is the product of the direct reduction of iron ore in the solid state by carbon monoxide and hydrogen derived from natural gas or coal. Characteristics of reduced iron the midrex process produces direct reduced iron hereinafter referred to as dri.
Orebased metallics like pig iron and direct reduced iron dri are frequently added to the eaf scrap charge for their pure iron units in eaf steelmaking, but these products can also provide those additional carbon units. Direct reduced iron dri the world market for steel is expected to continue to increase. Direct reduction refers to solidstate processes which reduce iron oxides to metallic iron at temperatures below the melting. These concerns have increased significantly since the. Introduction the processes that produce iron by reduction of iron ore below the melting point of the iron produced are generally classified as direct reduction processes, and the product is referred to as direct reduced iron. The midrex process is a shafttype direct reduction process where iron ore pellets, lump iron ore or a combination are reduced in a vertical shaft reduction furnace to metallic iron by means of a reduction gas see figure 1. Processes which produce dri by reduction of iron ore below the melting point of the iron are normally known as the direct reduction dr processes. Directreduced iron dri, also called sponge iron, is produced from direct reduction of iron ore in the form of lumps, pellets or fines by a reducing gas produced from natural gas or coal. Use of direct reduced iron in electric arc furnace electric arc furnace eaf operations have improved significantly over the past 30 40 years.
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