Processes which produce DRI by reduction of iron ore below the melting point of the iron are normally known as the direct reduction processes. The reducing agents are carbon monoxide (CO) and hydrogen (H2), coming from reformed natural gas, syngas, or coal. Iron ore is used mostly in pellet and/or lumpy form.
WhatsApp: +86 18838072829Request PDF | Effect of Limestone and Dolomite Flux on the Quality of Pellets using High LOI Iron Ore | Owing to the depletion of highgrade iron ore quality, many steel plants over the world are ...
WhatsApp: +86 18838072829Most of the plants in India use DRI process—a solid state direct reduction process by which iron ore is reduced to sponge ... Raw material mixiron 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. ... Thus the final stoichiometric ratio becomes: Ore:Coal:Air ...
WhatsApp: +86 18838072829Iron ore Coal Crude oil World exports, 2021 (Mt) 1 650 1 333 2 059 Iron ore Steel is an alloy consisting primarily of iron and less than 2% carbon. Iron ore is, therefore, essential for steel production, which is essential in maintaining a strong industrial base. 98% of mined iron ore is used to make steel. Iron is one of
WhatsApp: +86 18838072829In 2000, DRI produced from the gasbased processes accounted for 93%, while the coalbased processes produced 7%. Gasbased processes have shaft furnaces for reducing. These furnaces can be either a moving bed or a fluidized bed.
WhatsApp: +86 18838072829Natekar. India is the largest producer of sponge iron or direct reduced iron (DRI) in the world. The important step in the manufacture of DRI is direct reduction of iron ore by coal or ...
WhatsApp: +86 18838072829efficiency. Both coal and gasbased DRI plants are operational in India. However, the share of coalbased DRI production is quite substantial and in comparison to gasbased production, this route is energy and carbonintensive. To meet the DRI production target of 80 million tonne by 203031 as envisaged under the
WhatsApp: +86 18838072829The quality of ore is determined by the iron percentage as it has direct bearing on the yield. The best quality feed has the following characteristics Fe (total): 65% or more; LOI 1% SiO2 + Al2O3 (Gangue material): 5% Sulphur: % Phosphorous: % Moisture: 1% Size: 3 18 mm (no crushing required, can be fed to kiln directly)
WhatsApp: +86 18838072829The study put forward by [1] compared sinter to pellets and clearly stated various environmental and technical benefits of using pellets instead of sinters. To increase the gas permeability in the ...
WhatsApp: +86 18838072829Specific energy consumption in Indian plants varies in the range of Gcal/tcs as compared to international benchmark of around 5 Gcal/tcs. Similarly, GHG emission in Indian plants varies in the range of Tonnes/tcs (BFBOF: Coal DRIEAF/IF: )) which is almost times the international benchmark of Tonnes/tcs.
WhatsApp: +86 18838072829of steel requires t of iron ore pellets, t of coking coal, and t of steel scrap, as well as million British thermal units of natural gas, using blast furnaces at normal operating conditions. in 2018, consumption of iron ore, by gross weight, reported by the American iron and Steel institute (2019,
WhatsApp: +86 18838072829Direct Reduced Iron Direct reduced iron is produced by the reduction of iron ore by carbon monoxide and hydrogen, as illustrated in simplified form in the equations below: Fe 2O 3 + 3CO → 2Fe + 3CO 2. Fe 2O 3 + 3H 2 → 2Fe + 3H 2O . There are several processes for direct reduction of iron ore, principally gasbased shaft furnaces
WhatsApp: +86 18838072829Since 1969, MIDREX Plants have produced more than 1 billion tons of DRI made with over 50% hydrogen. Direct reduction with higher levels of hydrogen has been proven in a MIDREX Shaft Furnace. The FMO MIDREX Plant in Venezuela uses a steam reformer, and the H2/CO ratio has varied from to
WhatsApp: +86 18838072829An established alternative to coal and cokebased reduction of iron ores in blast furnaces is the ore reduction by coal or reformed natural gas (CO, H2) to direct reduced iron (DRI) or hot ...
WhatsApp: +86 18838072829Direct Reduced Iron (DRI) is produced when sized Iron Ore from Iron Ore Mines are subjected to a high temperature of about 1070 °C (below the fusion temperature of Ore, which is about 1535 °C) [6] in a rotary Kiln along with Coal Dolomite.
WhatsApp: +86 18838072829The importantstep in the manufacture of DRI is direct reduction of iron ore by coal or reducing gases such ascarbon monoxide and hydrogen. Majority of the Indian plants utilise locally available ...
WhatsApp: +86 18838072829using coalfired rotary kilns or natural gasfired shaft furnaces are logical choices as production in blast furnaces is constrained by the need to import coking coal. Rotary kiln DRI capacity has been installed because it makes use of domestic iron ore and coal, but there is a limit to the growth of this technology because rotary
WhatsApp: +86 18838072829A survey is made on a typical coal based Indian sponge iron plant of capacity 500 t/d in order to identify the largest energy losses and find ways to increase the efficiency.
WhatsApp: +86 18838072829In cases of exigency, there are several other iron ore mines in the vicinity which supplies quality iron ore at competitive prices. Dolomite: Dolomite acts in the process as a desulphurise, removing sulphur from the feed mix during the reduction process. As mentioned, since most iron ores contain very low sulphur (%), the sulfur ...
WhatsApp: +86 18838072829The preceding results indicate that the coupling ratio plays a very important role in the size of the fractured zone. This can be proved by earlier tests in Äspö, showing that the depth of blastgenerated disturbed zone is m in the tunnel floor with careful blasting, m with very careful blasting, and m with normal (fullcharge) blasting [39].
WhatsApp: +86 18838072829The averages of three consecutive. day's value are given below [1]: • Coal = tph. • Iron ore = tph. • Dolomite = tph. • Air = tph. • Sponge Iron = tph ...
WhatsApp: +86 18838072829These plants are independent of iron ore mines. These plants receive iron ore mostly by rails. some plant may receive by long distance slurry pipeline. In pelletizing plants located at port which are dependent on imported iron ore, the receiving method involves the transportation of the ore in a dedicated ship, unloading the ore at a quay and ...
WhatsApp: +86 18838072829Direct Reduction. Direct reduced iron is iron ore in the form of lumps, fines or pellets that have had the oxygen removed by using hydrogen and carbon monoxide. Typical sources of carbon monoxide are natural gas, coal gas, and coal. Other energy inputs into the production process often include oil and electricity.
WhatsApp: +86 18838072829Dolomite formed more quickly, approached stoichiometry more rapidly, and became betterordered in less time in samples prepared with Fe+2 and a 1:1 Mg+2/Ca+2 ratio relative to experiments with Fe+3 and a 1:2 Mg+2/Ca+2 ratio. Results suggest that dolomite formed initially by precipitation from solution onto a calcite substrate. Introduction
WhatsApp: +86 18838072829The depositforming problem is one of the main bottlenecks restricting the yield and production benefit of iron ore pellets produced by coalfired rotary kilns. In order to implement measures to ensure the efficient production of pellets by coalfired rotary kilns, the mechanism and influencing factors on the deposit formation were reviewed. The pellet powder and coal ash come together to form ...
WhatsApp: +86 18838072829In India however, as noted above, because less scrap vis a vis iron ore and coal are used, steel produced using the DRI method is more carbonintensive (discussed below). It is also important to note that the steels produced through the IF route have less load bearing properties and so cannot be used in certain instances [ 1, 6 ] (see Fig. 3 ).
WhatsApp: +86 18838072829The main raw materials for the production of DRI by the rotary kiln process are (i) sized graded iron ore or iron ore pellets, (ii) noncoking coal, and (iii) dolomite in small quantities to scavenge the sulphur. Iron ore of the right quality is the basic input for the coal based direct reduction process.
WhatsApp: +86 18838072829In conventional coal based sponge iron plant, Fig. 1, kiln feed (Stream no. 1), which consists of iron ore, feed coal and dolomite, is fed to the rotary kiln (RK).A separate conveyor collects different size fractions of coal (Stream no. 5) for injection into the kiln with the help of pressurized air (Stream no. 4) from discharge end side.
WhatsApp: +86 18838072829The geometry of rotary kiln of sponge iron process is developed using GAMBIT Dimensions of kiln are 80 m length and 4 m internal diameter. The kiln is inclined to degree to the horizontal and rotated with rpm. Bed material consists of iron ore, coal and dolomite, enters the kiln through feed end.
WhatsApp: +86 18838072829OF IRON ORE 0 400 800 1200 1600 2000 2010 2019 Iron Production (Mt) Pig iron Direct reduced iron Figure 1: Iron production, 2000, 2010, 2019 Source: (WSA, 2020) India is the country with the largest DRI production, reaching 34 Mt in 2019, accounting for around a third of global DRI (WSA, 2020). The majority of Indian DRI is produced via the coal
WhatsApp: +86 18838072829The reduction of iron oxides takes place according to the following chemical equations: Fe2O3 Fe2O3 + 3CO + 3H2 → 2Fe → 2Fe + 3CO2 + 3H2O (1) (2) (1) F e 2 O 3 + 3 C O → 2 F e + 3 C O 2 (2) F e 2 O 3 + 3 H 2 → 2 F e + 3 H 2 O. In contrast to the blast furnace process, the directreduced iron process operates at temperatures of up to ...
WhatsApp: +86 18838072829resources natural gas or coal. This process is known as Direct Reduced Ironmaking (DRI). Carbon combines with the oxygen in the iron ore, producing metallic iron and a carbonrich process gas, according to the following simplified chemical reaction: 2Fe 2 O 3 + 3C > 4Fe + 3CO 2 It is also possible to reduce iron ore using hydrogen instead
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