Thermodynamic process evaluation of a rotary kiln unit at lkab kiruna. Modeling of rotary kiln for sponge iron processing using. Rotary kiln is widely used in cement and steel industries. The rotary kiln is slightly inclined at an angle 2. The carbon content in gas based processes can be controlled to a level of 1. It has to be long because a lot of water has to be evaporated. Analysis of temperature profile and % metallization in rotary. Schematic view of internal heat exchange in rotary kiln.
They are also used for roasting a wide variety of sulfide ores prior to metal extraction. We then illustrate the approach using the cement and the iron and steel industries. In their basic form they were relatively simple compared with modern developments. Operational guidance and control of sponge iron rotary kilns at tata sponge, soft computi ng for problem solving, socpros 2017, advances in intelligent sy stems and computing 816, ed. Industrial rotary kilns used in iron making are complex reactors having several functions.
Details of rotary kiln pdf file process detail henan. For questions or problems with your specific application please contact north american kiln for assistance. Sponge iron making is a process in which iron ore lumps typically 5mm18mm size are tumbled with a selectgrade of ironcoking coal little dolomite inside an inclined rotary kiln and control busted in the presence of air for about 12 hours before the products are air cooled, magnetically. Pdf operability analysis of direct reduction of iron ore. Pdf quality prediction and control in coalfired rotary. Modelling and optimization of a rotary kiln direct reduction. Pdf the present paper deals with 2d cfd model of rotary kilns employed in sponge iron process. Flow of materials in rotary kilns used for sponge iron manufacture. Jun 14, 20 direct reduced iron wikipedia, the free encyclopedia. A rotary kiln is a pyroprocessing device used to raise materials to a high temperature calcination in a continuous process. Expired lifetime application number us700181a inventor john p riott original assignee john. Sponge iron being magnetic gets attracted and gets separated from non magnetic char. Our cement rotary kiln and sponge iron rotary kiln has been developed for performing drying, calcination and sintering work in a continuous process.
The electric arc furnace uses primarily electrical energy to supply heat to melt scrap steel, sponge iron, or mixtures of scrap and other iron units. Operation and construction details a schematic diagram of the rotary kiln of sponge iron process considered for the present work is shown in fig. Regardless of rotary kiln size or configuration the basic principles outlined in this manual govern the reliable operation of every rotary kiln, calciner, dryer, incinerator, digester and cooler application. During this stage the mixture is passed through a kiln and possibly a preheater. Erection of chain systems in a rotary kiln pdf and ppt pdf procedure for erection of kiln mill 2. The coal reacts with air to form carbon monoxide which then reduces iron oxide ore to iron. Plant details mgm group in the first phase one 350 tpd rotary kiln and 8mw power plant have been missioned and are operating smoothly sponge iron plant sponge iron plant or direct reduction plant drp is designed to produce 350tons of sponge iron per day in a rotary kiln using iron ore, non coking coal and dolomite as. Jun 19, 20 rotary kiln process of making sponge iron new age international. Flow of materials in rotary kilns used for sponge iron. As the focus of the present work is to study the kiln of sponge iron process, literature related to it is discussed here. Us2462900a reduction accelerator for the sponge iron. Rotary kiln is a pyroprocessing equipment used to raise materials to a high temperature calcinationin a continuous process, chaeng has 3005000 td cement rotray kiln, 150 td lime rotary kiln. Dry process rotary kiln is composed of cylinder, supporting device, kiln, kiln sealing device, pulverized coal burner device and other components. In all coalbased dr processes using rotary kilns, sized.
Study on air tubes failure in sponge iron rotary kiln. The reduction is carried out in a rotary kiln of a predetermined temperature and controlled atmospheric pressure. The raw meal was supplied at ambient temperature in the form of a slurry. The maximum recommended kiln shell temperature varies by plant, by country and by kiln manufacturer, despite the fact that most kiln shells are made of low alloy carbon steel. Rotary kiln maintenance procedures rotary kiln lubrication. Pdf 2 d model of sponge iron rotary kiln developed using cfd. At first, the crude ore is mined by drilling or blasting at a depth of approximately. Walk by inspection of a sponge iron kilnyes guys kiln in cement and sponge iron isnt the samesee it to believe it. We are here to bring together china factories that supply manufacturing systems and machinery that are used by processing industries including but not limited to. Modelling and optimization of a rotary kiln direct. These treatments can be applied to powders, granulates, suspensions and green bodies. Rotary kilns sometimes called calciners or rotary furnaces are used for thermal treatment processes such as calcination, sintering, pyrolysis and firing, as well as for oxidation and reduction. Us2462900a reduction accelerator for the sponge iron rotary. Simulation of rotary kiln used in sponge iron process using ann iacsit international journal of engineering and technology, vol.
A simplified flow diagram of sponge iron making in rotary kilns is given in fig51. Energy audit methodology of sponge iron manufacturing. Raw material mix iron ore, dolomite and coal are fed to one end of rotary kiln and product sponge iron along with char is taken out from the other end. Rotary kiln body, with drive gear and 2 tyres riding rings a rotary kiln is a pyroprocessing device used to raise materials to a high temperature calcination in a continuous process. It is used to create cement, lime, metakaolin, titanium dioxide, alumina, iron ore pellets, and more. A thesis submitted for partial fulfillment of the degree. Heres a little bit about what a rotary kiln is and the seals we make for them. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed. The production capacities of these industries depend significantly on the. In this pilot plant, a totally indigenous technology for. Requirements for coal for sponge iron industry in case direct reduction in rotary kiln and in other reactors is 11860. Setting up of modalities for normative coal requirement in. The present work identifies the basic features of burden movement in a rotary kiln.
Directreduced iron dri, also called sponge iron, is produced from direct this process of directly reducing the iron ore in solid form by reducing gases is called direct reduction, an alternative route of iron making, has been developed to. Consequently, they were replaced by the high production rate indirect process, and the development of modern dr process did not begin until the middle of 19th century. The product of direct reduction processes known as sponge iron is used mainly as high quality melting stock for steelmaking. China manufacturing industries are full of strong and consistent exporters. An empirical equation correlating different operating variables has been derived on the basis of. Hot products used for rotary impact mill pdf rotary mill utiliing an impact reduction chamber and a vertical air flow classification. Modelling and optimization of a rotary kiln direct reduction process 55 figure 3. Raw materials, like iron ore and noncoking coal, are continuously fed whilst product sponge iron is continuously discharged from the downstream end, while the waste gases in counter current flow, exit through the uphill end. Whatever your requirements, you ll find the perfect serviceoriented solution to. Most of the plants in india use dri process a solid state direct reduction process by which iron ore is reduced to sponge without phase change figure 1. Simulation of rotary kiln used in sponge iron process. Kiln temperature distribution for the base case the feed material bed enters the kiln at ambient temperature and rapidly heats up due to the hot gas in the freeboard.
The input raw material such as iron ore, noncoking coal with high reactivity and the fluxing materials. An empirical equation correlating different operating variables has been derived on. Details of rotary kiln pdf file process detail henan fumine. The carbon content in sponge iron produced by coal based rotary kiln processes are generally low and is in the range of 0. Rotary kiln process of making sponge iron new age international.
The cold model study was conducted with iron ore as the feed material to determine the influence of length to diameter ratio ld of a rotary kiln on the filling degree, holdup, and residence time of the charge. However, rotary kiln process suffers from serious limitations like low productivity and pollution. The feed is introduced together with reducing and desulphurizing agents limestone or raw dolomite into an inclined rotary kiln, heated counter current to the flow of hot gas and reduced to form sponge. Prasad and ray simulated flow pattern of air using fluent software in rotary kiln of a typical 100 tpd sponge iron process. The rotary kiln process is a commonly practiced method in india for producing coal based sponge iron. Nov 05, 2016 rotary kiln is a pyroprocessing equipment used to raise materials to a high temperature calcinationin a continuous process, chaeng has 3005000 td cement rotray kiln, 150 td lime rotary kiln. The original rotary cement kilns were called wet process kilns. This is to certify that the thesis entitled design of waste heat recovery system in a sponge 2. This electric arc furnace can also use a form of iron known as sponge iron or there is no difference between the ecotech and. Analysis of temperature profile and % metallization in.
In this communication, oi methodology is used to study the operability characteristics of direct reduction of iron ore by coal in a rotary kiln using a rigorous process model. A rotary kiln is a pyroprocessing device that raises materials to very high temperatures in a continuous process. Typical 3d image of accretions in kiln 3 at tata sponge, developed. Pdf operation of coalbased sponge iron rotary kiln to reduce. Iron ore fines and the low grade beneficiated iron ore cake are directly used for manufacturing of sponge iron in tunnel kilns.
The rotary kiln consists of a rotating cylindrical shell lined inside with refractory material. A rotary kiln consists of a cylindrical, rotating body mounted between stationary. China rotary kiln, rotary kiln manufacturers, suppliers. Looking forward to the need of developing coalbased sponge iron technology in india, a country having no significant resources of either coking coal or natural gas, the research and development division of the tata iron and steel company limited tisco set up a rotary kiln based direct reduction pilot plant in 1975.
In the industry, there have been many recent reports of premature failures of certain air tubes in rotary kilns. Whatever your requirements, you ll find the perfect serviceoriented solution to match your specific needs with our help. Sponge iron composition manufacturing process lloy. What is the maximum continuous shell temperature a kiln stands without permanent damage to the shell. Raw dri process materials, partly coal, iron ore, after burn flue gas chamber fluxes enter the rotary kiln the remainder rotary kiln coal in 2. Pdf operability analysis of direct reduction of iron ore by. In general the gangue content in sponge iron varies from 4% to 8%. This book deals with the basics of sponge iron production in rotary kiln, describing the operational problems and control needed to produce a quality product. Nov 23, 2017 walk by inspection of a sponge iron kiln yes guys kiln in cement and sponge iron isnt the samesee it to believe it. Sponge iron process uses a rotary kiln for the reduction of high grade lump ores or pellets fig. Rotary kiln the hot gases may be generated in an external furnace or by a flame inside the kiln. Dri is also known as sponge iron because of its spongy micro structure.
The mean particle size of iron ore shall be restricted to 11mm in order to achieve uniform fe metallic of all grain size fraction of the product. Rotary kiln cement rotary kiln and sponge iron rotary kiln. In this pilot plant, a totally indigenous technology for production of sponge iron has been developed in which noncoking coal is essentially used as the reductant. A thesis submitted for partial fulfillment of the degree award of. Simulation of rotary kiln used in sponge iron process using ann. Rotary kiln presentation in microsoft grinding mill china.
In this pilot plant, a totally indigenous technology for production of. Iron ore pelletizing, gratekiln process, magnetite oxidation, rotary kiln, process modelling. The process of reducing the iron ore in solid form by reducing gases is called direct reduction. Sponge iron dri rotary kiln view dry process rotary kiln. This work aims at developing a temperature profile by modelling the heat transfer phenomena happening inside the kiln. The literature discussed above is based on cfd analysis of rotary kiln of cement plant. This book comprehensively deals with the production of sponge iron in the rotary kiln. Sponge iron is produced using noncoking coal by the process of reduction of iron are in a rotary kiln. Schematic of optimised rotary kiln sponge iron making process. Thermodynamic process evaluation of a rotary kiln unit at.
A processstep benchmarking approach to energy use at industrial. The bos process uses pure oxygen, injected by a lance, for refining the relatively impure hot metal and scrap is used for temperature control. Computational fluid dynamics analysis of sponge iron rotary kiln. Ibutec the rotary kiln experts for trials and production. Nov 17, 2012 raw dri process materials, partly coal, iron ore, after burn flue gas chamber fluxes enter the rotary kiln the remainder rotary kiln coal in 2. Index termssponge iron process, rotary kiln, temperature profile, artificial neural network. Characteristics requirement i inherent moisture content, percent by mass, max 4 ii ash, percent by mass, max. The iron ore and coal crushed and screened to respective sizes are fed to rotary kiln through feed tube in predetermined ratio.
Genetic algorithms based multiobjective optimization of. More than 100 dr processes have been invented and operated since 1920. In rotary kiln, carbon is charged from either end, in one end in the form of coal particles and in another in form of coal lumps. In this respect fixed bed tunnel kiln furnace are evolving as an alternative to rotary kiln process. The grate kiln process which is part of the pelletizing and of great importance for this work, is further described in chapter 2. A wet process kiln may be up to 200m long and 6m in diameter. Study on accretion formation on dri kiln during spong iron. The initial chapters give a brief on the fundamental theories and basic principles of sponge iron production, commercially used dr direct reduction processes and physicochemical principles of sponge iron production. Genetic algorithms based multiobjective optimization of an.
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