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Ferrous & non-ferrous metal _ 2.pdf
- 1. Structural Steelwork atWaterloo Station
- 2. Structural Steelwork atWaterloo Station
- 3. Structural Steel worksat Millennium Stadium
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- 7. MANUFACTURE (Stages) • Makingof Pig Iron • Conversion to steel • Casting of molten steel • Formation into section or strips • Coils of steel strip are cold-rolled into thin sections and profiled sheet
- 8. Manufacture of PigIron • Raw Materials: Iron ore (from America, Australia and Scandinavia - high iron content of the ore) Coke from coking coal (Europe) – sintered with iron ore prior to iron-making process Lime stone
- 9. Blast furnace 1: Ironore + Calcareous sinter 2: coke 3: conveyor belt 4: feeding opening, with a valve that prevents direct contact with the internal parts of the furnace and outdoor air 5: Layer of coke 6: Layers of sinter, iron oxide pellets, ore, 7: Hot air (around 1200°C) 8: Slag 9: Liquid pig iron 10: Mixers 11: Tap for pig iron 12: Dust cyclon for removing dust from exhaust gasses before burning them in 13. 13: air heater 14: Smoke outlet (can be redirected to carbon capture & storage (CCS) tank) 15: feed air for Cowper air heaters 16: Powdered coal 17: cokes oven 18: cokes bin 19: pipes for blast furnace gas
- 10. Chemical Process • 2C(carbon – coke) + O2 → 2CO (carbon monoxide) • Fe2O3 (iron ore – hematite) + 3CO (corbon monoxide) → 2Fe (iron) + 3CO2 (carbon monoxide)
- 11. Process • Limestone formsa liquid slag, floating on surface of molten iron – tapped of for disposal as by product of steel making industry • At this stage, iron is 90-95% pure with impurities (sulphur, phosphorus, manganese and silicon) and carbon content 4-5% . • Blastfurnance operate nonstop for 10 years, producing 40,000 tonnes/week
- 12. Steel Making • Basicoxygen process for manufacture of bulk quantities of standard-grade steel Manchester City Stadium – approximately 2000 tonnes of structural steel • Electric arc furnace – production of high quality special steel and particularly stailess steel.
- 13. Structural Steelwork - ManchesterCity Stadium Steel cables hold the roof in place
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- 15. Basic Oxygen Process •In a refractory lined steel furnace • Can be tilted for charging and tapping • Typically will take a charge of 350 tonnes (scrap metal – ¼ of charge) and convert it into steel in 30 min.
- 16. Basic Oxygen Process •Charge loaded direct from blastfurnace + scrap metal • Water-cooled lance is lowered to blow in high-pressure oxygen to burn off impurities and reduce excess carbon • Argon + small quantities of nitrogen are introduced at bottom • Lime added to form floating slag to remove impurities • Alloying components added to adjust steel composition before tapping • Furnace is inverted to remove any remaining slag • Next cycle
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- 18. Electric Arc Furnace •Refractory-lined hearth covered with removeable roof where graphite electrodes can be raised and lowered • Scrap metal charged in while roof open • Powerful electric arc is struck between electrodes and metal – heating to melting point
- 19. Electric Arc Furnace •Lime and fluorspar are added to form slag • Oxygen is blown to complete purification process • At correct temperature and chemical analysis, furnace is tilted to tap off metal • Added appropriate alloying components • Typically will produce 150 tonnes of high- grade (stainless steel) in 90 min.
- 20. Casting • Molten steelwas cast into ingots (blocks) before hot rolling into slabs and then sheet • Currently, directly being poured or teemed and cast into continuous billets or slabs • Cast into appropriate lengths for subsequent process. • Continuous casting – more energy efficient and produce better surface finish
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- 26. Hot-rolled Steel • Steelsheet is produced by passing 25 tonnes hot slabs at approximately 1250°C through a series of computer-controlled rollers • The thickness between 1.5 to 20 mm • Water cooling and coiling • 25 tonnes slab → 1 km coil of 2 mm sheet • Steel section such as universal beams (UB) and columns, channels and angles are rolled from hot billets through a series of stands to the appropriate section.
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