sponge iron industry –past-present-future - SIMA

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tubes. The newly reformed gas, containing 90- 92 percent H2 and CO, is then fed hot directly to the shaft furnace as reducing gas. Heat Recovery The thermal efficiency of the MIDREX® Reformer is greatly enhanced by the heat recovery system. Sensible heat is recovered from the reformer flue gas to preheat the feed gas mixture, the burner combustion air and the natural gas feed. In addition, depending on the economics, the fuel gas may also be preheated Process Advantage l World Wide commercial use l Proven performance l Raw material flexibility l CO2 reformer eliminates need for steam system, reformed gas quench, reducing gas heating and CO2 removal system. HYL - Technology – Gas based Sponge iron The HYL plants operate with iron ore, iron oxide pellets or mixture of the Two and natural gas. The main equipment of HYL-III comprises a DR shaft furnace, a gas reformer, and a gas reheater. The principles of operation of the furnace are similar to the midrex shaft furnace described previously. Continuously descending iron- bearing material is reduced in an upper zone by the counter current flow of gas, which is rich in carbon monoxide and hydrogen. Reduction is accomplished by reaction of the reducing gas which is introduced through a distribution system around the circumference of the shaft at an intermediate height. A proper selection of iron oxide feed stock permit operation at 950 °C. After reduction, the hot DRI continues to descend through a constant pressure zone, which separates the upper reducing zone from the lower cooling JANUARY-2011/16
zone. The DRI is cooled to below 50°C by an independent gas stream. The cooling gas is withdrawn at the top of the cooling zone, after cooling, cleaning and compressing. This gas is recirculated at the bottom of the shaft furnace. The composition and temperature of gas flow to the shaft furnace are carefully controlled to permit independent control of the metallization and carbon content of the DRI. It is claimed that a high reduction temperature and the formation of an iron carbide shell protect the DRI from spontaneous re oxidation . Like Midrex , there is provision for hot briquetting facilities in the system. The HYL III shaft furnace operates at about 54 kg/cm 2 (5atm) for this reason, the design incorporates special pressure lock system for charging iron oxide feed materials at the roof and for discharging cold DRI at the bottom. Possible advantages of high pressure operation are enhanced reduction kinetics, higher gas throughput, and condensation at elevated pressure which lowers the moisture SL/RN technology for Coal based sponge iron content of the re circulated top gas. Insofar as reducing gas is concerned, the HYL IlI process employs catalytic steam reforming of natural gas. As in the original HYL process excess steam is used, the reformed gas is cooled to condense water, which increases the carbon monoxide plus hydrogen content to a high percentage .The sensible energy of the reformed gas is recovered during cooling by heat exchangers to the steam system. The usual heat recovery system in the flue gas stack of the reformer and gas re heater is also used. The cold reformed gas is mixed with compressed top gas from the shaft furnace This top gas had previously been processed to remove a substantial part of its moisture and particulates. The mixed reducing gas is then reheated and introduced in to the shaft furnace along with natural gas, excess shaft furnace of gas (over that amount re circulated the process) is used as fuel in the reformer and gas heater. JANUARY-2011/17
Page 2 and 3: CHAIRMAN V S BAPNA VICE CHAIRMAN B
Page 4 and 5: UPGRADING QUALITY OF INPUTS TO AUGM
Page 6 and 7: There is acute shortage of high gra
Page 8 and 9: SUCCESSFUL STARTUP AND OPERATION OF
Page 10 and 11: GSPI Micro-Module Control Room Gulf
Page 12 and 13: SPONGE IRON INDUSTRY -PAST-PRESENT-
Page 14 and 15: JANUARY-2011/12
Page 16 and 17: From a meager production of 1.31 mi
Page 20 and 21: Process Advantage l Proven performa
Page 22 and 23: Annexure I Map of Natural Gas pipel
Page 24 and 25: SIMA DELEGATE TO CHIN JANUARY-2011/
Page 30 and 31: CONTRIBUTION OF SECONDARY STEEL SEC
Page 32 and 33: in total crude steel production wou
Page 34 and 35: New product developments Sabyasachi
Page 36 and 37: advantages over the conventional he
Page 38 and 39: Description “Graspan Tri Flo ® P
Page 42 and 43: Moreover, some analyst suggest that
Page 44 and 45: BRIEF REPORT ON ONE DAY SEMINAR ON
Page 46: JANUARY-2011/44

sponge iron industry –past-present-future - SIMA

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