Analysis of temperature profile and % metallization in. 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. Heat transfer in rotary kilns rahbord engineering services co the rotary kiln model being developed encompasses a general mass and energy balance over the process. A wide variety of iron sponge rotary kiln options are available to you, such as condition. Having a comprehensive model of the kiln in order to reduce manufacturing costs, better performance can be created. The reduction is carried out in a rotary kiln of a predetermined temperature and controlled atmospheric pressure. Pdf operation of coalbased sponge iron rotary kiln to reduce.
A lot of graphics, tables and equation to understand kiln beahavior. May 01, 20 ferrous metallurgy wikipedia, the free encyclopedia. Sponge iron is produced using noncoking coal by the process of reduction of iron are in a rotary kiln. 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. The mining company lkab runs four grate kiln production sites. In this study modelling work of the no x formation in the facility is carried out. This professional reference book will be the first comprehensive book in many years that treats all engineering aspects of rotary kilns, including a thorough grounding in the thermal and fluid principles involved in their operation, as well as how to properly design an engineering process that uses rotary kilns. 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.
Rotary kiln is a rotating cylindrical vessel which is used for drying, calcination and sintering in a continuous process with the use of hot gases. An empirical equation correlating different operating variables has been derived on the basis of. Method for the production of low sulfur sponge iron buehl, russell c. Rotarykiln process a process for treatment of the polymetallic byproducts of metallurgical production the slags of lead, copper, and tin production, the solid residues of zinc production cakes, and so on in order to extract valuable metals.
Evaluation of the no formation in a rotary kiln test facility. The original rotary cement kilns were called wet process kilns. The iron ore and coal crushed and screened to respective sizes are fed to rotary kiln through feed tube in predetermined ratio. When ring masonry, ring joint deviation allows 2mm every meter. Cement kiln coprocessing high temperature treatment page 3 of 11 pesticides treatment technology fact sheet john vijgen, international hch and pesticides assoc iation and dr. Our process experts work with our innovation center to develop a process around your materials.
This plant type normally operates with a steam boiler and turbine circuit, which requires special operating personal. The input raw material such as iron ore, noncoking coal with high reactivity and the fluxing materials. 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. However, rotary kiln process suffers from serious limitations like low productivity and pollution.
Prasad and ray simulated flow pattern of air using fluent software in rotary kiln of a typical 100 tpd sponge iron process. 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. Simulation of rotary kiln used in sponge iron process using ann iacsit international journal of engineering and technology, vol. Generation and retention of reducing environment in the free board region. Aug 24, 2015 a rotary kiln is a pyroprocessing device used to raise materials to a high temperature calcination in a continuous process. What is the maximum continuous shell temperature a kiln stands without permanent damage to the shell. Rotary kiln is a pyroprocessing equipment used to raise materials to a high temperature calcinationin a continuous process, chaeng has 3005000. Rotary kilns have been widely used in the cement industry to produce clinker.
Coal based rotary kiln for direct reduced iron sponge iron 100 tpd, 350 tpd, 500 tpd solid state reduction of iron ore using either coalgas as a medium of reduction to produce a substitute raw material for steel making is termed as direct reduced iron dri. Rotary kiln plant types rotary kiln pyrolysis thermolysis. As the focus of the present work is to study the kiln of sponge iron process, literature related to it is discussed here. The construction, position and alignment of kiln is a essential factor for the. The mining company lkab runs four gratekiln production sites in.
Rotary kiln cement rotary kiln and sponge iron rotary kiln. Hot mix asphalt, is a highly energyintensive process involving three. A wall heat transfer correlation for the baffledrotary. Pdf heat recovery analysis of a rotary kiln in cement industry. Pdf heat recovery analysis of a rotary kiln in cement. Coal is used as a reducent for sponge iron making in the furnace. Introduction in todays world, powering along the supply of raw materials, cement production is the most important factor. The rotary kiln process for iron ore pelletizing is one of the main methods to upgrade crude iron ore. A wet process kiln may be up to 200m long and 6m in diameter.
Kiln process free download as powerpoint presentation. Rotary kiln process a process for treatment of the polymetallic byproducts of metallurgical production the slags of lead, copper, and tin production, the solid residues of zinc production cakes, and so on in order to extract valuable metals. 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. Thermodynamic process evaluation of a rotary kiln unit at lkab kiruna. With the development of market economy, we become a dazzling star in chinas machinery industry. A zone wise heat flux model was presented which accounted for the thermal enthalpy of the clinker formation process and gave more insight to fluid flow, temperature, etc. 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. The formation of accretions or rings in rotary kilns used for the manufacture of directly reduced iron sponge iron affects the residence time of the charge, kiln holdup, and the kiln output to a great extent. Rotary kiln maintenance procedures rotary kiln lubrication. The baffledrotary kiln applied to the road pavements production, so called hma hma. In this paper, the influence processes in a simulated cement rotary kiln and operating parameters on the output of the study were to develop and validate the. During this stage the mixture is passed through a kiln and possibly a preheater. A rotary kiln is a device used to raise materials to a high temperature in a continuous process, and the material needs to be free flowing and tumbling as it moves down the length of the drum. Pdf operability analysis of direct reduction of iron ore.
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. Equation 6 and co, cannot exist above c in the presence of free. 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 formation of accretions or rings in rotary kilns used for the manufacture of directly reduced iron sponge iron affects the residence time of the charge, kiln holdup, and the kiln output to a. 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 separated, screened and size wise in finished product. In a typical embodiment of the preferred rotary kiln process for the production of the sponge iron a mixture of the raw. Dri or hbi are virgin iron sources free from tramp elements and are increasingly being used in. Rotary cooler the product come to the water cooled where its temperature reaches to 80100 c 11. 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. This electric arc furnace can also use a form of iron known as sponge iron or there is no difference between the ecotech and alltech performance. This can be done best, by full contact on ring and supporter roller surfaces and minimum ovality in kiln shell. New kiln and kiln body with complete shape without badly change generally adopts ring masonry. Apr 07, 2015 rotary kiln is the key equipment in rotary kiln process, rotary kiln refers to rotary calcining kiln which belongs to building material equipment. One of the major challenges for sponge iron plant is the accretion formation.
Clearing build up in rotary kiln using cardox system. Study on accretion formation on dri kiln during spong iron production chandrashekhar shrivas, himanshu shrivas abstracttoday is an era of competition, and contrary to this the iron and steel industries are also suffering from the same. Modelling and optimization of a rotary kiln direct reduction process 55 figure 3. Energy efficiency of a cement production process is quite small due to large amounts of heat loss from the systems. Process description rotary kiln pyrolysis thermolysis. The literature discussed above is based on cfd analysis of rotary kiln of cement plant. Sponge iron rotary kiln process anticorruption helpline. Iron ore fines and the low grade beneficiated iron ore cake are directly used for manufacturing of sponge iron in tunnel kilns. It has to be long because a lot of water has to be evaporated. Simulation of rotary kiln used in sponge iron process.
Cement lime refractories metakaolin titanium dioxide alumina vermiculite iron ore pellets. They are also used for roasting a wide variety of sulfide ores prior to metal extraction. Some clean iron units free of residual elements, copper, tin and zinc are. The grate kiln process which is part of the pelletizing and of great importance for this work, is further described in chapter 2. Iron ore pelletizing, gratekiln process, magnetite oxidation, rotary kiln, process modelling. This book comprehensively deals with the production of sponge iron in the rotary kiln. Sponge iron composition manufacturing process lloy. Criteria on the adaptation of the technology to the country a. Pdf modeling of rotary kiln for sponge iron processing using. Ron mcdowall, auckland new zealan d for secretariat of the basel convention part i. A rotary kiln is a cylinder which rotates around its cylindrical axis and acts as a device to exchange the heat. 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. Cement production is a highly energyintensive process, and the rotary kiln is the most important part of the process. Alibaba offers 274 iron sponge rotary kiln products.
Setting up of modalities for normative coal requirement in. Thermodynamic process evaluation of a rotary kiln unit at. The process of reducing the iron ore in solid form by reducing gases is called direct reduction. Pdf industrial applications of rotary kiln in various. Directions in electric arc furnace steelmaking are towards increased clean iron unit usage. Study on accretion formation on dri kiln during spong iron. Direct reduction process an overview sciencedirect topics. Operation and construction details a schematic diagram of the rotary kiln of sponge iron process considered for the present work is shown in fig. Energy audit methodology of sponge iron manufacturing. Typical 3d image of accretions in kiln 3 at tata sponge, developed from the model which uses inputs. Rotarykiln process article about rotarykiln process by. Cement kiln coprocessing high temperature treatment.
Simulation of rotary kiln used in sponge iron process using ann. Characteristics requirement i inherent moisture content, percent by mass, max 4 ii ash, percent by mass, max 24 iii volatile matter percent by mass 2535 iv. A thesis submitted for partial fulfillment of the degree award of. The earliest surviving iron artifacts, from the 5th millennium bc in iran and 2nd. A simple system for cement rotary kiln is shown in figure 1. The byproducts to be treated are mixed with pulverized carbonaceous fuel coke, anthracite, and others to. Modelling and optimization of a rotary kiln direct. In a dr process, iron ore pellets andor lump iron ores are reduced by a. Aggregates rotary kiln at largescale the characterization of convective heat transfer path in an industrial aggregates rotary kiln was performed. Of late however, a number of alternative iron making processes. Analysis of temperature profile and % metallization in rotary.
In their basic form they were relatively simple compared with modern developments. Midrex dri is in the form of a solid sponge, vulnerable to reoxidation and. Heat transfer analysis of recuperative air preheater. The rotary kiln consists of a rotating cylindrical shell lined inside with refractory material. The rotary kiln is slightly inclined at an angle 2. Directreduced iron an overview sciencedirect topics. Based on statistics anon 3, 2014, india is the world leader in dri production. Their design and operation is critical to their efficient usage, which if done incorrectly can result in improperly treated materials and. Rotary kiln is the key equipment in rotary kiln process,rotary kiln refers to rotary calcining kiln which belongs to building material equipment. Very useful book on the cement kiln process and analyse.
At first, the crude ore is mined by drilling or blasting at a depth of approximately. Rotary cooler the product is conveyed to the product separation and storage building the product is. Schematic illustration of a typical grate kiln process in iron ore pellet production. Temperature profile and heat transfer from free board to bed region of kiln. What sets feeco systems apart from our competitors is the customized solutions we offer. They are particularly critical in the manufacture of portland cement. Notes for bricklaying in rotary kiln construction rs. Rotary kiln minerals process applications covers fluid flow, granular flow, mixing and segregation, and aerodynamics during turbulent mixing and recirculation offers hardtofind guidance on fuels used for rotary kilns, including fuel options such as natural gas versus coalfired rotary kilns. Sponge iron process uses a rotary kiln for the reduction of high grade lump ores or pellets fig.
The first rule of operating a rotary kiln without any problem is distributing the forces equally to each piers. The present work identifies the basic features of burden movement in a rotary kiln. For questions or problems with your specific application please contact north american kiln for assistance. Materials produced using rotary k slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. Sponge iron being magnetic gets attracted and gets separated from non magnetic char. Conventional huge size plant type megaultra this plant includes all equipment from product bunker to off gas cleaning system. More than 100 dr processes have been invented and operated since 1920. The raw meal was supplied at ambient temperature in the form of a slurry. 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. Energy balance in a rotary kiln sponge based iron making.
Requirements for coal for sponge iron industry in case direct reduction in rotary kiln and in other reactors is 11860. Flow of materials in rotary kilns used for sponge iron. Rotary kilnsrotating industrial drying ovensare used for a wide variety of applications including processing raw minerals and feedstocks as well as heattreating hazardous wastes. Our company is specialized in rotary kilns, rotary driers and mining machinery manufacturing, integrating scientific research, production and marketing. During kiln mainly on how long it takes until the temperature of the raw material clinker temperature of about 70. The baffled rotary kiln applied to the road pavements production, so called hma hma. Modeling of rotary kiln for sponge iron processing using. 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. In this respect fixed bed tunnel kiln furnace are evolving as an alternative to rotary kiln process. The hot gases may be generated in an external furnace or by a flame inside the kiln. A wall heat transfer correlation for the baffledrotary kilns. A processstep benchmarking approach to energy use at industrial.
Cement production process is extremely timeconsuming 1 and the rotary kiln is the most important part of the. Modelling and optimization of a rotary kiln direct reduction. For questions or problems with your specific application please contact north american kiln. 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. Introduction an air preheater aph is a general term used to describe any device designed to heat air before another process for example, combustion in a boiler with the primary objective of increasing the thermal efficiency of the process. Kiln body for traditional kiln with badly shape changed and the sued bricks with bad quality shape can adopt circle masonry on the position of high alumina brick and fireclay brick. We then illustrate the approach using the cement and the iron and steel industries. In the present work, several challenges faced in sponge iron production have.
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