Controlling factors, reaction mechanisms and vcr concerns. This reaction occurs optimally at a temperature of around 800 oc, which is lower than the temperature needed in a blast furnace vogl et al. Blast furnace gas has a high carbon monoxide co content and a low heating value. Gasification reactions of metallurgical coke and its application improvement of carbon use efficiency in blast furnace 53 from the viewpoint of the strength caused by promotion of solutionloss reactivity is noted, and the phenomena of highly reactive and normal coke are investigated in order to provide the solution of the issue. Blast furnace gas is produced during the iron oxide reduction in blast furnace iron making in which iron ore, coke and limestone are heated and melted in a blast furnace and is an indigenous process gas of the steelworks industry pugh et al. In the case of steelmaking slag, the slag contains metal elements such as iron in oxide form. And a piece of good news at the end of the article we have two surprises, one is i give you the pdf of this article and the second is a. The iron ore concentrate is now mixed and ready for the pelletizing process.
Blast furnace slag is formed when iron ore or iron pellets, coke and a flux either limestone or dolomite are melted together in a blast furnace. They can be up to 60 metres 200 ft tall and 15 metres 49 ft in diameter. In this reaction, the iron iii oxide is reduced to iron, and the carbon is oxidised to carbon dioxide. The air blown into the bottom of the furnace is heated using the hot waste gases from the top. Basic oxygen steelmaking bos, bop, bof, or osm, also known as linzdonawitzsteelmaking or the oxygen converter process is a method of primary steelmaking in which carbonrich molten pig iron is made into steel. Blast furnace slag an overview sciencedirect topics. Iron blast furnace is a vertical shaft, which is used to melt the iron ore and to produce hot metal by heat exchange and chemical reaction. What is the difference between metastable and stable solidification. Gasification reactions of metallurgical coke and its. Pdf complexity in blast furnace as a part of one day seminar on.
A blast furnace is a gigantic, steel stack lined with refractory brick where the concentrated iron ore, coke, and limestone are dumped from the top, and a blast of hot air is blown into the bottom. Modelling of blast furnace with respective chemical. The blast furnace process has auxiliary equipment associated with it. The co and heat now move upwards and meet the raw material running down from the top.
Carbon monoxide explosion hazards in electric arc furnace. Pdf using blended learning method, blast furnace subject was analysed. This reaction is the main source of heat in the furnace. Blast furnaces are used to produce pig iron from iron ore for subsequent. Get an answer for what is the equation of the exothermic reaction in a blast furnace. The co 2 then reacts with more coke to give carbon monoxide. Controlling nonenergy emissions in a 100 percent wind. How a blast furnace works introduction the purpose of a blast furnace is to chemically reduce and physically convert iron oxides into liquid iron called hot metal. Blast furnace slag cement manufacture, properties and uses. Carbon reacts with oxygen and generates heat as follows.
Click download or read online button to get blast furnace simulation book now. Physical and chemical characteristics of blast furnace. Liquid iron hot metal is produced in a blast furnace from the burden materials through a series of chemical reactions which are taking place at various levels in a blast furnace. However, due to the stable structures and properties of blast. How important is the boudouard reaction for the blast furnace process. Get an answer for what are the balanced chemical eqations for the reactions that take place in a blast furnance. The total blast furnace model which integrates all these submodels is used to calculate the.
The reaction eliminates chemical co 2 produced from the hematite reaction with carbon during ironmaking. The principle of blast furnace operational technology and. The coke carbon burns with oxygen to produce carbon dioxide. So today we discuss the working principle of cupola furnace as well as see the construction, advantages, disadvantages, and applications of cupola furnace. A blast furnace is a special type of furnace for smelting iron from ore. Development of mathematical model of blast furnace1115kb. Air heated in the blast furnace stoves, is applied from the bottom of the. At a later ebf campaign, offgas dust was sampled during operation with different. However, something else actually reacts with iron oxide to produce iron in the blast furnace. Iron oxides, flux agents, and metallurgical coke are. A blast furnace works by blasting hot air up through the furnace while fuels, limestone, and ore move continuously through the top of the furnace. Blast furnace slag bfs is a product of iron production, which has been widely investigated and utilized, particularly as a supplementary cementitious material for cement or alkaliactivated material, owing to its high hydraulic property or alkali activation reactivity. It examines the enthalpy, entropy, and free energy change for each reaction. This site is like a library, use search box in the widget to get ebook that you want.
Write down the reactions taking place in different zones. What chemical processes distinguish indirect reduction from direct reduction of iron ores. When a larger amount of coke exists, relatively, at the center of a blast furnace, the high temperature gas, consisting mainly of co generated at the tuyeres. Blast furnace simulation download ebook pdf, epub, tuebl. Carbon dioxide mineralization for the disposition of blast. Other components of blast furnace slag include alumina alsub2 o 3 and magnesium oxide mgo, as well as a small amount of sulfur s, while steelmaking slag contains iron oxide feo and magnesium oxide mgo. Blast furnace slag as a substitute for the fine fraction of aggregates in an asphalt mixture. Granulated blast furnace slag is a glassy granular material that varies, depending on the chemical composition and method of production, from a coarse, popcornlike friable structure greater than 4. Ground granulated blast furnace slag cement ggbfs is a fine glassy granules which contain cementatious properties. The temperature in the upper parts of the blast furnace is considerably lower than the 2200k at the bottom. The blast furnace is a huge, steel stack lined with refractory brick, where iron ore, coke and limestone are dumped into the top, and preheated air is blown into the bottom. Extracting iron redox, extraction of iron and transition. The blast furnace process can be briefly described as follows. Such respective reacting burden layers have not been considered explicitly in the previous bf models.
Improvement of blast furnace reaction efficiency by temperature control of thermal reserve zone. The furnace temperature is maintained at around 1200 to 1250 oc. Blast furnace an introduction blast furnace is the focus of any integrated steel plant. The blast furnace is a cylindrical tower like structure about 25m to 35m high. A blast furnace is a type of metallurgical furnace used for smelting to produce industrial metals. Blast furnace is used to reduce the iron ore to iron. The common ores of iron are both iron oxides, and these can be reduced to iron by heating them with carbon in the form of coke. Coke degradation was therefore mostly restricted to the coke surface in the blast furnace.
Grinding reduces the particle size to cement fineness. The production of iron from its ore involves a redox reaction carried out in a blast furnace. However, an injection of carbon into the molten iron during the steelmaking process is. Heat energy is valuable, and it is important not to waste any. Blast furnace slag cement is the mixture of ordinary portland cement and fine granulated blast furnace slag obtained as a by product in the manufacture of steel with percent under 70% to that of cement. What are the balanced chemical eqations for the reactions. Forging furnaces use an open fireplace system and most of the heat is transmitted by radiation. Give simple chemical tests to distinguish between the following pairs of compounds. Temperature of a blast furnace the physics factbook. The primary components of iron and steel slag are limestone cao and silica sio 2. The burden charge consisting of iron oxide, flux and coke and it provides through the throat from the top of the furnace. Blasts furnaces are used for smelting during the production of metals such as iron, lead, zinc, and copper.
This auxiliary equipment and the gaseous pathways inside a blast furnace process are shown in figure 2. This paper discusses the furnace from the perspec tive of chemical thermodynamics. Blast furnaces are used continuously and are only shut down when their brick lining needs replacing. What is the equation of the exothermic reaction in a blast. Blast furnace, a vertical shaft furnace that produces liquid metals by the reaction of a flow of air introduced under pressure into the bottom of the furnace with a mixture of metallic ore, coke, and flux fed into the top. Carbon monoxide explosion hazards in electric arc furnace steelmaking operations. Physical and chemical characteristics of blast furnace, basic oxygen furnace, and electric arc furnace steel industry slags.
Chemistry of the ironmaking by blast furnace process. Blowing oxygen through molten pig iron lowers the carbon content of the alloy and changes it into lowcarbon steel. Pdf blast furnace in engineering education researchgate. The coke layer has a gasflow resistance smaller by a factor of 10 compared to that of the ore layer and has a high gaspermeability. Formation of co 2 is an exothermic reaction in which a huge amount of heat is liberated which rises the temperature to 1900 o c in this region. A blast furnace is usually built with a steel case and bricks made of. Write down the reactions taking place in different zones in the blast furnace during the extraction of iron. All the three ingredients are crushed into small round pieces and mixed and put on a hopper which controls the input.
It is the redox reaction of a chemical equilibrium mixture of carbon monoxide and carbon dioxide at a given temperature. The forging furnace is used for preheating billets and ingots to attain a forge temperature. At such high temperatures, coke reacts with the oxygen in the hot air to form carbon monoxide co. Chemical reactions of coke in the iron blast furnace.
The most important chemical properties are moisture, fixed carbon, ash, sulfur, phosphorus, and alkalies. Blast furnaces are used to produce pig iron from iron ore for subsequent processing into steel. As the mixture of iron ore, coke and limestone heats, the hot waste gases are collected and cleansed. Pelletizing a pellet plant contains a series of balling drums where the iron ore concentrate is formed into soft pellets, in much the same manner that one rolls a snowball, to make a pellet about the size of a marble between 14 and 12. The purpose of a blast furnace is to chemically reduce and physically convert iron oxides into liquid. In the blast furnace, it is so hot that carbon monoxide can be used, in place of carbon, to. The typical load is 5 to 6 ton with the furnace operating for 16 to 18 hours daily. The coke essentially impure carbon burns in the blast of hot air to form carbon dioxide a strongly exothermic reaction. Waste heat recovery from blast furnace slag by chemical reactions article pdf available in jom.
Extraction of iron metallurgy blast furnace and reactions. This page looks at the use of the blast furnace in the extraction of iron from iron ore, and the conversion of the raw iron from the furnace into various kinds of steel. The nature and degree of the coke degradation by the solution loss depends on the rate limiting step, either chemical reaction kinetics or diffusion into pores. The charge, which consists of iron ore, coke and limestone etc. Silicate and aluminate impurities from the ore and coke are combined in the blast furnace with a flux which lowers the viscosity of the slag. In the blast furnace stack, reduction is complicated by the presence of coke that causes the co concentration to be influenced by the boudouard reaction which is named after octave leopold boudouard. In the blast furnace, there are several chemical reactions taking place. They are then used to help heat the air blast, required if blast furnace is to reach the high temperatures needed to produce molten iron. The purpose of a blast furnace is to chemically reduce and physically convert iron oxides into liquid iron called hot metal. To fully understand how the furnace accomplishes its goals we must study its processes form the perspective of chemical thermodynamics. Eafs are often used in steelmaking operations to produce carbon steels, as. Chemical composition of ggbs the chemical composition of a slag varies considerably depending on the composition of the raw materials in the iron production process. The ironmaking blast furnace bf is an efficient chemical reactor for producing liquid iron from solid iron ore, where the solids of coke and iron ore are charged in alternative layers and different chemical reactions occur in the two solid layers as they descend.
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