Reduced iron derives its name from the chemical change that iron ore undergoes when it is heated in a furnace at high. There has been a disturbing increase in the number of potential life threatening incidents involving the carriage of direct reduced iron dri. The midrex direct reduction process is the industrys most productive technology for making highquality direct reduced iron dri products, accounting for approximately 60% of the worlds total annual production. The volume of steel produced by the, now oldfashioned, blast furnace. Processes that produce iron by reduction of iron ore in solid state below the. The australasian institute of mining and metallurgy. Direct reduced iron dri international iron metallics. The dri is used mainly as the raw material for electric arc furnaces eafs, as a.
The process reduces iron ore using a reforming gas made from natural gas. Production of direct reduced iron in rotary hearth furnace. Nov 05, 2015 midrex is an innovative ironmaking process, developed for the production of direct reduced iron dri from iron ores and primarily natural gas. Direct reduction process an overview sciencedirect topics. In addition to the process route via the blast furnace process, there is another option for extracting crude steel from iron ores using the socalled direct reduced iron dri process secondary route. Download it once and read it on your kindle device, pc, phones or tablets.
Coating of iron oxide pellets for direct reduction. The midrex process the worlds most reliable and productive direct reduction ironmaking technology. Modelling and optimization of a rotary kiln direct. It is a recyclingbased route contrary to the three abovementioned orebased routes see. Alternative iron source produced by heating an iron ore generally having 65 to 70 percent iron at a temperature high enough to burn off its carbon and oxygen content a process called reduction but below irons melting point1535c or 2795f. Optimization of the iron ore direct reduction process through. There is a newer version of this article lothar formanek. The increasing role of direct reduced iron in global. In this paper the direct reduction of iron ore to sponge iron is used as an example. Especially, it is known since decades that iron can be reduced rapidly and efficiently from iron carrier materials using such devices. Therefore, dr plants have nbeen built mainly in oil and natural gas producing countries to supply raw iron for eaf processes. Conditions for minimizing direct reduction in smelting.
This product is known as direct reduced iron dri or sponge iron. The stack gas from a shaft furnace in which iron ore is directly reduced is cooled and filtered and then subjected to steam so as to convert its carbon monoxide into carbon dioxide and water. There has been a disturbing increase in the number of potential. The production of direct reduced iron dri, a basic raw material for making steel, is concentrated in a few countries in the middle east and latin america. 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. Only highgrade ores and pellets made from superconcentrates 66 percent iron are therefore really suitable for dr iron making. Directreduced iron process dri nippon steel engineering. 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.
The hamburg plant already has one of the most efficient production processes of the arcelormittal group due to the use of natural gas in a direct reduction plant dri, direct reduced iron. Coal, dolomite and iron ore or pellets are fed into one end of a rotary kiln, while sponge iron and char are withdrawn from the other end. Regarding the reduction rate of iron ore, the effect of temperature5 and the effect of h 2 6 were. Rob cheeley senior sales engineer, midrex direct reduction corporation introduction the production of direct reduced iron dri, a basic raw material for making steel, is concentrated in a. Economic aspects of direct reduction of iron ore in illinois. Arcelormittal investigates hydrogenbased direct reduction. Other articles where directreduced iron is discussed. Direct use of iron ore fines without prior agglomeration, such as pelletizing or sintering. Your partner for contracting to commissioning direct reduced iron plants. This gave an overview of the environmental aspects and highlighted the main environmentally related issues involved in the process of producing liquid steel from iron ore by. Outotec gmbh formerly lurgi metallurgie, oberursel, germany. Sponge iron production by direct reduction of iron oxide. The world market for steel is expected to continue to increase.
Nov 27, 2014 in the search for a pure, available iron source, steelmakers are focusing their attention on directly reduced iron dri. Gasification and the midrex direct reduction process by. Use features like bookmarks, note taking and highlighting while reading sponge iron production by direct reduction of iron oxide. Direct reduction of iron ore refers to the conversion of solid iron ore to metallic iron without conversion to the liquid phase 37. The dri is used mainly as the raw material for electric arc furnaces eafs, as a clean iron source substitute for scrap iron. Somedirectreductionprocessesusecoke,char,anthracitefines,orcoal as areducingagent. Direct reduced 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. Dri and its derivatives, including hot briquetted iron hbi, are a virgin iron feedstock that is often used in steelmaking. 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. It requires much less capital investment than the bf process and requires no coke.
Commercially, dri is generated in four different reactors. The direct reduction dr process is one such ironmaking process that can substitute for blastfurnace bf ironmaking. Lurgi metallurgies drivers for the development of the circored process were on the one hand the growing demand for a direct reduction process utilizing iron ore fines directly to decrease hbi. The reducing gas is a mixture majority of hydrogen h2 and carbon monoxide co which acts as reducing agent. Direct reduced iron and production of dri part 2 youtube. What is the difference between direct reduction and indirect. What is the difference between direct reduction and. This book provides a fascinating study of the very important emerging field of direct reduction in which iron ore is directly reduced in the solidstate, using either natural gas or noncoking coal, to produce a highly metallised material, referred to as sponge iron or direct reduced iron.
The results show that not only does the hyleaf combination yields the most cost savings over the business as usual scenario, but it also results in the most reduction of co 2. This material is produced by the reaction of a low gangue iron ore with a hydrocarbonaceous substance. Sponge iron instead of liquid hot metal is produced and then this direct reduced iron is melted in the electric furnace. Most gasbased direct reduction plants are part of integrated steel minimills, located adjacent to the electric arc furnace eaf. The term direct reduced iron, or dri, has a generic meaning which covers a number of products with a variety of properties and hazards. Pdf flexibility in using iron ores for direct reduction. In the modern era, direct reduced iron is considered an alternative method of making iron. Iron by direct reduction lepinski major reference works. 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. Resources trend and use of direct reduced iron in steelmaking.
Dri is also known as sponge iron, it is a solidstate direct reduction process fig. Operation with hydrogen as reductant enables reduction with very low co 2 emission values, and allows the application of low reduction temperatures minimizing sticking tendencies. This procedure results in a spongy structure of the product, thus sponge iron, with a high. Processes that produce iron by reduction of iron ore in solid state below the melting point are generally classified as dr. Midrex the worlds leading directreduced iron production. Thus the direct reduction ratio will be changed by the reduction rate of pre reduced iron ore pri, the temperature at which coal can react with co 2 or h 2o and the reaction rate above the temperature. Characteristics of reduced iron the midrex process produces direct reduced iron hereinafter referred to as dri. Direct reduction is a process for reducing iron ore in the solid state. The primary energy sources and reducing agents are co and h 2, which are finally released as co 2 and h 2. The model incorporates a large number of variables, covering, among others.
Directreduced 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. The product of such solid state processes are called direct reduced iron dri, whereas the product of the blast furnace is referred to as hot metal in the molten state, or pig iron in the solidified form. Majority of the direct reduced iron dri 38 is produced by reacting iron oxide with hydrocarbonbased reducing gases produced from reforming natural gas or coal gasi. Understanding the different direct reduced iron products. The process of crafting iron via the direct reduction route has a distinct advantage over the more traditional, blast. Direct reduced iron dri is used as a high quality feed material in electric arc furnace steelmaking, oxygen steelmaking, ladle metallurgy, blast furnace ironmaking, and foundries. Direct reduction is the process of converting iron ore into metallic iron without melting. Pdf coating of iron oxide pellets for direct reduction.
Directreduced iron an overview sciencedirect topics. Arcelormittal investigates hydrogenbased direct reduction of. The starting point for the efforts to find an alternative to the blast furnace process was the relatively high process expenditure. The increasing role of direct reduced iron in global steelmaking. 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.
The results show that not only does the hyleaf combination yields the most cost savings over the business as usual scenario, but it. Direct reduced iron dri, also called sponge iron, is produced from the direct reduction of iron. It is a recyclingbased route contrary to the three abovementioned orebased routes see area of route 4 within dotted line in fig. During direct reduction, oxygen is removed from iron ore in solid state. Sponge iron production by direct reduction of iron oxide kindle edition by chatterjee, amit. Unliketheblastfurnaceprocess,directreduction processes do notrequire a pure and highstrength coke so that coalsconsideredunsuitable. Mar 31, 2019 dri is iron ore that has been reduced to iron with without melting. Direct reduction refers to processes which reduce iron oxides to metallic iron below the melting point of iron. Direct reduced iron dri the world market for steel is expected to continue to increase.
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. Apr 28, 2020 the type of iron made by blast furnaces, however, is not direct reduced iron but pig iron, which isnt as rich as direct reduced iron. Primary and secondary airs are supplied to the kiln to initiate combustion and reaction processes choudhury, 2014. Cost effectiveness analysis of hyl and drex dri te chnologies for the iron and steelking industry pa ge 4 also included in each individual section. Understanding the different direct reduced iron products gard. 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. Femetallicfetotal is an important variable for characterizing the direct reduced iron dri. Direct reduction refers to solidstate processes which reduce iron oxides. Outotec direct reduction technologies are based on almost 50 years experience of delivering solutions for customers in the ferrous direct reduction sector, encompassing the full range of plant types. Aftermarket group dedicated to continual support of your midrex plant.
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