Blast furnace slips and accompanying emissions as an air. Small local irregularities in the surface such as shrink marks or pimples are not taken into account. When burnt, it can cover 35% to 45% of heat demand in the energy balance of metals companies 32. It is determined by the burden material properties and charging equipment used.
Effect of al 2o3 content on alkali holding capacity of. In normal blast furnace operations, when the coke carbon starts reacting with co2 resulting in the. Smallvolume blastfurnaces the future of blastfurnace. Nov 02, 20 blast furnace, breakout, channeling, hanging, scab, scaffolding, slipping, irregularities in blast furnace during operation. Monitoring and control of the blast furnace hearth is critical to. Blast furnace equipment is in continuous evolution and modern, giant furnaces produce,000 tons per day. Iron ore processing for the blast furnace courtesy of the national steel pellet company the following describes operations at the national steel pellet company, an iron ore mining and processing facility located on the mesabi iron range of minnesota.
Cn102518111a blast furnace slag replacement method for. Contrarily, it did caused some severe irregularities for the bf process during the full scale trials, such as higher pressure drop, higher fuel consumption but unstable process. The ussr was the world leader in largevolume blast furnace manufacture. Furnace hanging and slipping when the materials charged at the top of the blast furnace do not move continuously towards the hearth of the furnace, the phenomenon is called hanging of the burden. Ofurnace dust enters between gasket and furnace shell and into compensators ocompensator fills with dust and locks stave movements oweld of pipe to stave body fails in fatigue owater leaks into furnace. Drain rate and liquid level simulation in blast furnace hearth. Various operational problems like irregular casting intervals, damage to lining, low blast intake, furnace pressurization, and so forth are normally encountered when liquid levels in the hearth exceed a critical limit where hearth coke and deadman. The blast furnace bf is the most widely used ironmaking. The following module describes all the main and auxiliary components into this process.
The furnaces are preserved in a park or museum, or as a site otherwise open to visitors, or intended to become such. Introduction kobe steel started operation as an integrated steel manufacturing company with the blowingin of the no. Drain rate and liquid level simulation in blast furnace hearth hemant upadhyay 1 and dr. The method of operating a blast furnace having u bell chamber which comprises the step 85 of removing from the furnace top gases carrying entrained solids and having the pressures exist ing in u e furnace about the stock line, remov ing solids from substantially all of said gase. The reactivity and strength of coke play a very important role in selection of coke as reductant in blast furnace. The gas cleaning system contains two stages, the coarse cleaning system and the fine cleaning system. Symptoms of alkali the importance of alkali is realized only when problems like scaffolding, scabs, leading to furnace irregularities like hanging and slipping occur.
Delmia operations intelligence for steel production enables companies to improve operational efficiency of their steel plants with a closed loop continuous improvement process. Description of a blast furnace plant main parts of a blast furnace, description and function composition of a charge in the production of pig iron in a blast furnace agglomeration and pelletization of iron ores requirements to individual components of a blast furnace charge time for the study. Blast refers to the combustion air being forced or supplied above atmospheric pressure. Principal component analysis of blast furnace drainage patterns. Drain rate and liquid level simulation in blast furnace. Pdf technological changes in blast furnace iron making in. Steel furnace slag in hot mix asphalt purdue engineering. List of preserved historic blast furnaces wikipedia. This chapter discusses the principles of design and use of furnaces. 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. Arc furnaces used in research laboratories and by dentists may have a capacity of. Significant properties of blast furnace coke ausimm.
While gasbased as well as coalbased dri production routes produced 2. This sometimes mistakenly blames the coke for the poor descending of burden. Granulated blastfurnace slag is formed when molten blast furnace slag is quenched in water. 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. Mini blast furnace mbf is the most proven technology, as revealed by one recent global iron production data. High temperature top combustion hot stoves of kalugin design for blast furnaces b. High temperature top combustion hot stoves of kalugin design. The principle of blast furnace operational technology and. The first blast furnaces appeared in the 14th century and produced one ton per day. Alkali input and output is usually ignored by most blast furnace operators. These aggregates increased the productivity and therefore proved the economic benefit of the blastfurnace. Other methods of iron refining although almost all the iron and steel manufactured in the world is made from pig iron produced by the blastfurnace process, other methods of iron refining are possible and have been practiced to a limited extent. In the blast furnace route of ironmaking, metallurgical coke are used for four. Grinding reduces the particle size of the granulated blastfurnace slag to the same fineness as cement, and the resulting product, ground granulated blast furnace slag.
When the metallurgical smelting process is complete, the lime in the flux has been chemically combined with the aluminates and silicates of the ore and coke ash to form a nonmetallic product called blast furnace slag. Productivity and irregularities aspects of the blast furnace along with the environmental impact and carbon capturing. Creating steel from lowgrade iron ore requires a long process of mining, crushing. Method of firing blast furnaces riddle, lawrence e. 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. A solidstate radar scanner measures the complete burden surface without any assumptions of symmetry. Working toward technology demonstration the ulcosbf developments in europe ir. It is very important to minimise the operational cost, reduce fuel consumption, and optimise the overall efficiency of the blast furnace and. For last three years, hblast furnace tata steel was able to reduce coke rate from 450 kgthm to 350 kgthm with an increase in coal injection to 200 kgthm which are close to world benchmarks and expand profitability.
The gas flow in the furnace can be controlled by burden distribution. Principal component analysis of blast furnace drainage. Construction traffic shall not be allowed on the aggregate. The production of the blast furnace is base on the temperature and pig iron chemical analysis. The basic materials used for the manufacture of pig iron are iron ore, coke, and limestone. Hanging of the burden material in the blast furnace stack occurs when the material below the hang continues to move downward, forming a space. Modeling of burden distribution in the blast furnace doria. So, abnormality or irregularity in the blast furnace production can develop due to either faulty mechanical devices, yes such as ball cooler or faulty operation such. In the latter half of the past century blast furnaces with the working volume of 86, 15, 1719, 2002, 2300, 2700, 3200, 5014, 5580 m3 were manu factured.
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. Profiling the rock face using simple measuring tapes, conventional surveying techniques, or more advanced laser profiling may be warranted. Changing from blast furnacebasic oxygen furnaces bofs. To reduce the oxides of iron and other elements to metal and to provide the carbon absorbed by the iron. In another case, when the liquid level comes down to a too. So by reducing the constituents in blast furnace gas we can increase the calorific value and can be used to generate heat and rise the temperature in any furnace. For example, at a large ironworks with an output of 7 million tons of raw steel a year. Blast furnaces are used continuously and are only shut down when their brick lining needs replacing. Now there are nearly 700 blast furnace available in world.
An experimental perspective on praxairs hot oxygen. In the blast furnace a very complex process takes place for the production of pig iron, which develops gradually as of the conventional furnace. Studies on influence of liquid level on blast furnace performance and monitoring of hearth drainage dr. It is very important to find a coke with good combination of strength as well as reactivity. In the last instalment we discussed the balance sheet of materials entering and leaving the furnace, showing the dis tribution of the ingredients of the charge and the blast into the various products and byproducts of the furnace.
Because of the diversity of manufacturing processes and raw materials used, the types of furnace required are numerous. Optimizing blast furnace operation to increase efficiency and. The reason for the problems occurred in the blast furnace process could not be. A brief overview of the emerging alternative processes for the production of iron. Blast furnace definition of blast furnace by merriamwebster.
This invention relates to mproved methods of firing and more particularly relates to a method in which a substantial economy in time and materials is effected in lighting up the blowin burden in the case of starting a new, or refiring an extinguished, blast furnace. A blast furnace melt downwards ore by the burning of the coke. The major irregularities in the blast furnace operation are described below. An electric arc furnace eaf is a furnace that heats charged material by means of an electric arc industrial arc furnaces range in size from small units of approximately one ton capacity used in foundries for producing cast iron products up to about 400 ton units used for secondary steelmaking. One such method is the socalled direct method of making iron and steel from ore, without making pig.
An attempt will also be made to indicate the effect on blast furnace operation of significant irregularities in these properties. Blast furnace operators can identify irregularities and unsymmetries in the surface pattern in real time. Profiling the rock face using simple measuring tapes, conventional surveying techniques, or. Air heated in the blast furnace stoves, is applied from the bottom of the. To avoid any irregularity, the hearth liquid level.
The following overview provides basic information necessary for a proper understanding of the problem of heat transfer. Baidya nath roy1 and uddeshya kumar2 hearth affect the smooth operations occurring in the blast furnace by exerting an upward force on th. As the mixture of iron ore, coke and limestone heats, the hot waste gases are collected and cleansed. The probe is continuously in operation 247, and the measured surface is updated every 20 seconds. Blast furnace the blast furnace is a complex machine that is exposed to extreme high temperature and forces. This site is like a library, you could find million book here by using search box in the header. 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. To sustain this regime, elimination of irregularities of blast furnace like hanging, channeling, and scaffolding is very essential. The reactivity and strength of coke are inversely related to each other.
In actual blast furnace process, higher alkali input increases the coke consumption rate, causing economic loss and also lower the stability of the burden resulting in various operational irregularities. The burden distribution in the blast furnace is of great influence on its operation and performance. The accuracy and reproducibility of the feed as well as the reliability and ease of maintenance of the charging device play an essential role. 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. Process 7 in order to analyze more in details blast furnace they will be. 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. The iron ore concentrate is now mixed and ready for the pelletizing process. Almost all manufactured articles go through a process of heating at some stage. The book focuses on the control of the blast furnace process with respect to thermal control, gas flow control and casthouse operation. The blaster should inspect any free rock faces for irregularities and geologic conditions that may affect the blast and adjust the drill hole locations accordingly. If the coke slits are blocked or not pervious enough, furnace irregularities such as hanging or erratic burden descent may occur.
Blast furnace is the heart of the steel industry as it produces molten pig iron which is the raw material for steel making. The second most important after blast furnace gas source of carbon monoxide at iron and steel companies is converter gas 32. Coke is the main reductant for iron making in blast furnace. Blast furnace slag is a byproduct of the iron and steel industry. Owater channel isolated stave gets hotter oeventually furnace shell gets hot and cracks occur nonfixed connection stave moves. Proper understanding and control of drainage of hot metal and slag from hearth are essential for a stable and efficient blast furnace operation. Alkalis also attack on and destroy the lining materials and are one of the most impressive scaffoldbuilding components. It is thus clear that a datadriven analysis of the liquids out. Pdf effects of change in blast furnace inner profile on furnace. Pig iron is produced as the output from the blast furnace by the series of several equations. Diagnosing blastfurnace irregularities with an expert system. And from the early 1990s to 2010, as the percent of steel made in the u. The blast furnace is charged with iron ore, coke and.
Permeability and density of the coke grid are not uniform within the hearth. Blast furnace is used to reduce the iron ore to iron. Therefore, this section is included as an introduction chapter, we can say as a refresher. Calculation of blast furnace size is empirical in nature. Increasing the tuyere injection of pulverized solid fuel at a specific hot blast temperature and other tuyere. The scaffolds decrease the effective production volume of the furnace and also. Optimization of blast furnace parameters using artificial. The equipment used for heating can be broadly termed a furnace. It is a proven and scalable execution and production intelligence solution that enables steel manufacturers to further optimize their blast furnace parameters and improve. Gravels can be 60% carbonates prone to polishing aircooled blast furnace slag use predates 1946. In addition to the targeted charging of raw materials into the blast furnace, the placement of raw materials is one of the most important control variables for an optimized blast furnace operation. Even after tapping, there is always some amount of residual slag in the hearth figure 1. Jan van derstel ieaghgiets iron and steel industry ccus and process integration workshop tokyo, japan 4 7 november 20. For a stable and efficient operation of a blast furnace, smooth and uniform movement of burden materials downward and movement of furnace gases in the upward direction is very important.
The blast furnace gas can be used to generate heat. To understand how blast furnace, as well as electric arc furnace, technology is used to make a structural shape, it is important to note the three basic steps. Blast furnace an introduction blast furnace is the focus of any integrated steel plant. This list of preserved historic blast furnaces contains decommissioned blast furnaces, of which substantial remains survive.
Campaign life of furnca ehave increased from 5 yrs 1020ye and more these days. Technological changes in blast furnace iron making in india since last few decades article pdf available in international journal of science and research ijsr 212. A major advance in bf ironmaking has been the use of pulverized coal which partially replaces. Read online irregularities in blast furnace during operation book pdf free download link book now. Blast furnace products and there use size of blast furnace design of blast furnace is evolved through experience. Ore docks, blast furnaces and steel mills, south chicago, ill. Blast furnaces are used to produce pig iron from iron ore for subsequent. A blast furnace is a type of metallurgical furnace used for smelting to produce industrial metals.
Diagnosing blastfurnace irregularities with an expert. They generally apply for all designs and construction parts of any furnace, pipe, chute, chimney, foundation, tank or any other vessel etc. Refractory bricks must always be laid horizontally unless the design of the plant. In the ironmaking blast furnaces, nut coke 1040 mm.
To prevent the above mentioned irregularities, it is necessary to. Pdf drain rate and liquid level simulation in blast furnace. Blast furnaces in the united states wikimedia commons. 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. Pdf technological changes in blast furnace iron making. The effect of sodium on lowering the csr is somewhat stronger than that of potassium. During the 280 years since then, the original iron works at laucherthal near. Stateoftheart computational fluid dynamics model optimizes fuel rate in. Irregularities in blast furnace during operation ispatguru. The blast furnace is the first step in producing steel from iron oxides. Blast furnace refractory lining campaining life starting of blast furnace to shutting down of blast furnace depend on the life of refractory lining which liesa between the inside working volume to that of outer steel sheel, which protects the steel sheel. The invention discloses a blast furnace slag replacement method for highfill steel slag foundation, which comprises the following steps of. The effect of alkali on the reaction kinetics and strength. Unit 5 6 hrs alternatives routes of iron production, low shaft furnace, electro thermal processes, directly.
The charge, which consists of iron ore, coke and limestone etc. We did not there go into the question as to how the proportions. All books are in clear copy here, and all files are secure so dont worry about it. Media in category blast furnaces in the united states the following 10 files are in this category, out of 10 total. These variables effect the output parameters in the operation of the blast furnace. Oct 20, 2018 as a starting point, the blast furnace is seen as a simple iron ore smelter, while gradually the physical, chemical and metallurgical background of the blast furnace process is clarified. Blast furnace definition is a furnace in which combustion is forced by a current of air under pressure. Coke has four important functions in a blast furnace.
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