Direct iron ore smelting process development

IntroductionThe smelting ebb ( SR ) of Fe ore is an alternate natural stuffs treating mode convertible to the blast furnace. It begins with solid natural stuffs such as coal and Fe ore. The concluding swap of this summons is a liquid Fe based stuff known as fiery metal, or hog Fe when it is solidified. This terminal merchandise is the same as that generated by blast furnaces. Typical hot metal composings are about 4-4.5 % C, .3-1.5 % Si, .25-2.2 % manganese, .03-.08 % S, and.04-.2 % phosphoric. SR is the new age alternate to pig Fe output signal with the capableness of uninterrupted operation. The engineerings utilize in this appendage are similar to those used in both modern blast furnaces and conventional non-ferrous smelting operations. As developments in blast furnaces and non-ferrous smelters were made, such as the innovation of the Cu flash smelting engineering, developments were made in SR of Fe.Smelting Reduction Chemical replysThe natural stuffs used in SR are pul verized Fe ore which consist of Fe2O3 and Fe3O4 with remainders, powdered coal, limestone ( CaCO3 ) , and dolomitic limestone ( CaMg ( CO3 ) 2 ) . The transition of Fe ore into a liquid hot metal begins with the combustion of coal into C monoxide ( CO ) and H gas ( H2 ) which are the cardinal compounds for Fe decrease, equivalence 1. The C monoxide and H gas produced from the burning is used to get coldcock the decrease of Fe ore by equation 2. The chemical reaction for regenerating the CO and H2 with coal from equation 2 merchandises is given by equation 3. Full decrease of the Fe ore is so shown by equations 4 and 5.Coal + ?O2 CO + H2 ( 1 )6Fe2O3 + CO +H2 4Fe3O4 + H2O + CO2 ( 2 )2C + CO2 + H2O 3CO +H2 ( 3 )2 Fe3O4 + CO + H2 6FeO + H2O + CO2 ( 4 )2FeO + CO + H2 Fe + H2O + CO2 ( 5 )These reactions begin in the solid land nevertheless, as decrease series begins the reactions become liquid province. The limestone and dolomitic limestone are added as fluxes/slag agents. The ad aptability of umteen of these procedures to utilize a assortment of coal chemical sciences without the coking round is the most alone belongings of SR fuel over blast furnace fuel. This usage of coal rather of coke eliminates the demand for a coking furnace all bit good as the usage of lower pattern coal.Smelting Decrease FirstsArchaeological finds in Africa show a crude smelting decrease signifier dating back every bit early as 2500BC. These ancient craftsmen would cut down Fe ore utilizing coke by blowing demeanor into a shaft furnace. Martin Wiberg of Sweden every bit good as W. and E. Engell of Denmark began look intoing the smelting decrease procedure in 1938. However, much of the impulse in smelting decrease was lost between the 1950 s and 70 s referable to progresss in the solid province decrease procedure known as DRI ( direct reduced Fe ) and in blast furnace engineering. It is of import to observe that without the air separation engineering conceived during the Seco nd World contend SR would non be executable. By 1981 the first SR buffer store works was constructed in Germany based dour the COREX design construct. In 1988 the first all-out SR installation was constructed based cancelled the same pilot works at the site of a old blast furnace.Smelting Reduction Reactor TypesThree chief SR convertor types exist the shaft convertor procedure, a both phase chemical procedure, and the intercrossed procedure. both(prenominal) the shaft convertor procedure and the two phase procedure usage chemical life force for the decrease. However, the two phase procedure differs from the shaft procedure by implementing two transition Chamberss, a solid province chamber followed by a liquid province chamber. The intercrossed procedure is the most alone because it gets energy parts from chemical reactions and electrical current. Of these three types merely two procedures have been put into operation in all-out installations, the COREX procedure and the HIsm elt procedure.The COREX procedure was the first all-out SR installation as antecedently mentioned. This procedure is a two phase procedure. The first phase in decrease is the solid province reaction and natural stuffs preheating subdivision. Off gas from the 2nd phase is used to cut down and preheat in the first phase. As the ore transforms into a liquid it moves to the 2nd convertor phase where the liquid province decrease is completed.The COREX procedure has three theoretical accounts, the C-1000, 2000, and 3000. Primary differences between the theoretical accounts are the production capablenesss. The C-1000 installed in 1988 has a solar day-to-day production capableness of 1000 dozenss of hot metal. The C-2000 will bring forth 2000 tons/day it presently has 4 operating workss with the first installed in S. Korea, 1995. 2 The C-3000 is the newest installation with one works turn up in China. The SR furnace was installed in 2007 and has a day-to-day production capableness of 4 000 dozenss of hot metal 7 . Figure 2 is an image of the C-3000 works.The HIsmelt was the 2nd SR procedure to go rise production. Pilot proving of this procedure began in 1982. The procedure is a uninterrupted shaft transition furnace. 2 HIsmelt implements many engineerings presently used in non-ferrous smelting like uninterrupted stuffs feed by spears into the liquefied bath and H2O cooled furnace panels. 5 The full graduated table works which was built in 2003 was a 400 million dollar pioneer between RioTinto, Nucor, Mitsubishi, and Shougang coprorations. The works is located in Western Australia. 9 This procedure can utilize the off gas for multiple applications such as fuel for electrical power coevals or preheating the alimentation stuff. A elaborate position of the reactor vas.Additional SR procedure which are non presently commercialize include direct Fe ore smelting ( DIOS, two phase reactor ) , AISI ( two phase reactor ) , and IDI ( intercrossed SR ) . Although SR procedures do non implement coke furnaces the coal demands remain similar holding subatomic consequence on environmental emanations.DecisionSR is an progressing engineering capable of continuously bring forthing hot metal similar to a blast furnace with a wider scope of coal type. This natural stuffs flexibleness is a great favor to SR. The riddance of the coking furnace lessenings project capital although, it has small impact on environmental emanations. SR has many great properties which makes it a competitory option to blare furnaces.Mentions 1 LIFE. ( n.d. ) . Chinese Premier Wen Jiabao Visits Australia. Retrieved declination 06, 2009, from hypertext get rid of communications protocol //www.life.com/image/57232194 2 Chatterjee, A. ( 1994 ) . Beyond the Blast Furnace. Boca Raton, FL CRC Press. 3 Miller, T. W. , Jimenez, J. , Sharan, A. , & A Goldstein, D. A. ( 1998 ) . Steelmaking and Refining, Oxygen Steelmaking Processes. In R. J. Fruehan, & A 11 ( Ed. ) , The Maki ng, Shaping and Treating of Steel ( pp. 489-490 ) . Pittsburgh The AISI Steel Foundation. 4 Davis, M. P. , Dry, R. J. , & A Schwarz, M. P. ( 2003 ) . Flow Simulation of the HISMELT Process. triad International Conferance on CFD in the Minerals and Process Industries ( pp. 305-311 ) . Melbourn, Australia CSIRO. 5 HIsmelt. ( n.d. ) . HIsmelt- The Technology. Retrieved December 06, 2009, from hypertext transfer protocol //www.hismelt.com/EN/HT_PageView.aspx? pageID=8 6 Shalimov, A. G. ( 200 ) . The COREX Process for Making High-Quality Steels at Mini-Mills. Metallurgist, 44, 35-39. 7 Environment Engineering Solution. ( n.d. ) . Environment-friendly Corex procedure of Fe and steel devising. Retrieved December 06, 2009, from hypertext transfer protocol //environmentengineering.blogspot.com /2008/02/environment-friendly-corex-process-of.html 8 Siemens. ( n.d. ) . Siemens AG Pictures. Retrieved December 06, 2009, from hypertext transfer protocol //w1.siemens.com/press/en/presspict ure/ ? press=/en/presspicture/2008/corporate_communication/media_summit_2008/soaxx200803-08.htm 9 Outotec. ( n.d. ) . HIsmelt undertaking in Western Australia. Retrieved December 06, 2009, from hypertext transfer protocol //www.outotec.com/pages/Page____7775.aspx? epslanguage=EN 10 Changqing, H. , Xiaowei, H. , Zhihong, L. , & A Chunxia, Z. ( 2009 ) . Comparison of CO2 Emission Between COREX and Blast Furnace Iron-Making System. daybook of Environmental Sciences, Supplement, 116-120.