The energy in the furnace gas has been lost in the conventional wetprocess dust collector as the. Total energy consumption by iron production using conventional methods is. Extraction of iron in a blast furnace the significant reactions occuring within the blast furnace can be described via the following steps showing how the reducing agent varies depending on the height in the furnace i. The slag is in molten state and separates out from iron. Iron ore, haematite often contains sand with iron oxide, fe 2 o 3. Analysis of slag flow in blast furnace during the extraction. The iron found in iron ores are found in the form of iron oxides. Milestones of our blast furnace operation technologies tamura categorized our history of pig iron making into the following three periods, in an article. The first metallurgical step is to reduce iron ore to metallic iron, a process which is mostly carried out in a blast furnace, using coke as both a fuel and reducing agent. The blast air causes the iron oxides, flux, and coke to react and iron, carbon monoxide and blastfurnace slag is produced. Pdf leaching of zinc and iron from blast furnace dust in. Smelting the concentrated ore is mixed with calculated quantity of coke, limestone and the mixture is put in the blast furnace from top. The iron is reduced from the ore by carbon in the coke, the limestone aiding slag separation from the molten iron. Concentration of ore calcination or roasting of ore.
Iron is extracted from its ore, haematite, by reduction with carbon. The principle of blast furnace operational technology and. Iron ores are reduced by coke carbon in a blast furnace. The blast furnace is a cylindrical tower like structure about 25m to 35m high. Extracting iron redox, extraction of iron and transition. Extraction of iron metallurgy blast furnace and reactions. 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. On passing pre heated compressed air inside the furnace, four distinct zones are formed. Blast furnace it is a tall cylindrical furnace made of steel.
Processing them in a blast furnace or in wellknown alternatives corex, midrex, hyll, finemet, itmk3, etc. Extraction of iron using blast furnace definition, examples. Shows how iron ore, limestone, and coke are handled and prepared for the blast furnace in the making of iron. Why does iron have to be extracted in a blast furnace iron can be extracted by the blast furnace because it can be displaced by carbon. The energy in blast furnace gas in the forms of pressure and temperature is recovered by a trt generator after passing through the dust collector. Blast furnaces are used to produce pig iron from iron ore for subsequent. Extracting iron from iron ore using a blast furnace. It is dropped into the top of a blastfurnace along with coke purified coal, almost pure carbon and limestone calcium carbonate. Ironmaking blast furnaces consist of several zones. The iron ore is first roasted in air to produce iron iii oxide which is mixed with coke and limestone and then further heated to a very high temperature in a blast furnace. The slag and molten iron are tapped off from the bottom of the furnace, the slag being. Iron ores such as haematite contain iron iii oxide, fe 2 o 3. It constitutes 5 percent by weight of the earths crust, and it is the. The diagram shows the blast furnace for the extraction of iron from its ore, taken as haematite.
Usage of the blast and cupola furnace remained widespread during the song and tang dynasties. Extraction of iron on a match head resource rsc education. The molten iron and blastfurnace slag is collected at the base of the furnace, while the gases are recirculated for fuel in the sinter process, after. Metal is cast into ingots or in the ladle for further refining like steel making. The top of the furnace is closed by a cupcone feeder.
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. These materials are loaded into the blast furnace from the top while a blast of hot air is introduced into it from beneath via small pipes known as tuyeres. Extracting iron iron and aluminium gcse chemistry single. Extraction of iron very unreactive metals are found directly in the ground as elements, eg.
Aug 03, 2011 extracting iron from iron ore using a blast furnace introduction 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. The oxygen must be removed from the iron iii oxide in. In addition, blast furnace operation requires 23,360 mjmetric ton of hot metal. Smelting method used in the extraction of iron definition. Write the equations for each of the following reactions. In a blast furnace, fuel coke, ores, and flux limestone are continuously supplied through. Processes and procedures in the extraction of iron. Oxides ores of iron after concentration through calcinationroasting are mixed with limestone and coke and fed into a blast furnace from its top. Extraction of iron by the blast furnace process extraction. After iron ore is mined it is send to the blast furnace. Hot combustion air is supplied to the furnace and some form of fuel used to raise the temperature. Blast refers to the combustion air being forced or supplied above atmospheric pressure in a blast furnace, fuel, ores, and flux are continuously supplied through the top of the furnace, while a hot blast of air sometimes with.
The molten iron and blast furnace slag is collected at the base of the furnace, while the gases are recirculated for fuel in the sinter process, after separation of particulate material cooper, 2005. The blast furnace is cylindrical steel vessel limed 6m in diameter. The purpose of a blast furnace is to chemically reduce and physically convert iron oxides into liquid iron called hot metal. Iron ore is usually a mixture of iron and vast quantities of impurities such as sand and clay referred to as gangue. Iron ores such as haematite contain ironiii oxide, fe 2o 3. During the production of pig iron in a blast furnace a large quantity of dust is generated. Creating steel from lowgrade iron ore requires a long process of mining, crushing, separating, concentrating, mixing, pelletizing, and shipping. Blast furnaces are used continuously and are only shut down when their brick lining needs replacing. Cast iron is different from pig iron and is made by melting pig iron with scrap iron and coke using hot air blast. Jul 21, 2014 iron ores are reduced by coke carbon in a blast furnace. Blast furnace slag an overview sciencedirect topics.
After the extraction process, some coke oven gas is returned to the battery where it is mixed with blast furnace gas for use in heating the coking chambers and the. Extraction of iron in a blast furnace reduction haematite o. The most common ore of iron is called haematite ironiii oxide. Oct 04, 2016 blast furnace extraction of iron from blast furnace class 12 ncert chemistry blast furnace working animation extraction of iron metallurgy of iron.
In the basic oxygen process bop, molten iron from a blast furnace and iron scrap are refined in a furnace by lancing or injecting highpurity oxygen. It is dropped into the top of a blast furnace along with coke purified coal, almost pure carbon and limestone calcium carbonate. A dryprocess dust collector for blast furnace is equipment for cleansing blast furnace gas. The iron obtained from blast furnace contains about 4% carbon and some other impurities. Mar 20, 2017 shows how iron ore, limestone, and coke are handled and prepared for the blast furnace in the making of iron. The most common ore of iron is called haematite iron iii oxide. Extraction of iron study material for iit jee askiitians. Iron does not exist on the earth as an element, but rather in the form of its oxides and sulphides in iron ore. The iron ore is first roasted in air to produce ironiii oxide which is mixed with coke and limestone and then further heated to a very high temperature in a blast furnace. Extracting iron from iron ore using a blast furnace introduction 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. The extraction of iron from its ore is a long and subdued process, that helps in separating the useful components from the waste materials such as slag. The common ores of iron are both iron oxides, and these can be reduced to iron by heating. This is more efficient method than electrolysis because it is more cost effective 4. 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.
Extraction of iron in a blast furnace iron is also below carbon in the reactivity series, so therefore carbon can be used to reduce it note. The purpose of a blast furnace is to reduce the concentrated ore chemically to its liquid metal state. Coke is produced by heating coal in the absence of air. Iron fe is a relatively dense metal with a silvery white appearance and distinctive magnetic properties. A blast furnace is a gigantic, steel stack lined with. The main compounds of dust are iron oxides with a share of heavy nonferrous metal oxides, mainly zinc. 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. Iron from the blast furnace is an alloy of about 96 per cent iron with carbon and some other impurities. The production of iron from its ore involves an oxidationreduction reaction carried out in a blast furnace. Direct biohydrometallurgical extraction of iron from ore osti. A mixture of crushed iron ore, coke an almost pure form of carbon and limestone is fed into the top of the blast furnace. Iron smelting may have been introduced into china through central asia.
They are the starting materials for the technical extraction of pig iron in the blast furnace. In a blast furnace oxide ores of iron, after concentration through calcinationroasting are mixed with limestone. Hottest part of the furnace at the bottom of the furnace, adjacent to the hot air blast entry points, the temperature reaches around 1800. Iron processing, use of a smelting process to turn the ore into a form from which products can be fashioned. Included in this article also is a discussion of the mining of iron and of its preparation for smelting. The blast furnace after iron ore is mined it is send to the blast furnace iron is extracted from its ore in a blast furnace.
Milestones of our blast furnace operation technologies tamura categorized our history of pigiron making into the following three periods, in an article. So, most iron from the blast furnace is converted into steel by removing some of the carbon. He washed ore is then strongly heated in the absence of air to expel water shacking to it. Blast refers to the combustion air being forced or supplied above atmospheric pressure. The ore is loaded into a blast furnace along with measured quantities of coke and limestone. 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. Mar 31, 2014 why does iron have to be extracted in a blast furnace iron can be extracted by the blast furnace because it can be displaced by carbon. A blast furnace is a type of metallurgical furnace used for smelting to produce industrial metals, generally pig iron, but also others such as lead or copper.
Coke is cheap and provides both the reducing agent for the reaction and also the heat source. The charge is placed a giant chimney called a blast. The calcined ore is mixed with lime stone caco 3 flux and ore in the ratio of 8. Hot air is blasted in from the side to provide oxygen that allows some of the carbon to burn, releasing enough heat to raise the temperature above 1500 o c. The earliest evidence of the use of a blast furnace in china dates to the 1st century ad, and cupola furnaces were used as early as the warring states period 403221 bc. Iron ores such as haematite contain ironiii oxide, fe 2 o 3. The process of the extraction of iron is carried out by the following steps. Three substances are needed to enable to extraction of iron from its ore.
The iron ore concentrate is now mixed and ready for the pelletizing process. The flowcharacteristic of blast furnace slags is strongly influenced by the extent of reduction of iron oxide at low temperature in the granular zone besides being influenced by the composition, and the quality and the quantity of the gangue in the iron bearing materials. Iron ore, as mined, is a combination of iron with oxygen and various other unwanted substances, generally known as gangue. 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. Extraction of iron examples, answers, activities, experiment. Extraction of iron from haematite grade 12 science notes. Processes and procedures in the extraction of iron gulpmatrix. The blast furnace operates at 1900 c in order to smelt iron from iron ore.
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