Pollution Control and Sustainability Challenges of Ironmaking and Steelmaking Operations

Transcription

1 The Third International Conference on Bioenvironment, Biodiversity and Renewable Energies Pollution Control and Sustainability Challenges of Ironmaking and Steelmaking Operations Vladimir Strezov, Faculty of Science, Macquarie University, Sydney, Australia 1 Iron Known to men since 1200BC Simple to make: C + O 2 CO 2 + heat CO 2 + C 2CO 3Fe 2 O 3 + CO CO Fe 3 O 4 (Begins at ) Fe 3 O 4 + CO CO FeO (Begins at C) FeO + CO CO 2 + Fe or FeO + C CO + Fe (Begins at C) Key commodity to modern economy 2

2 Iron ore production 1000 Iron ore production, Million Tonne Year Australia Brazil China Russia United States India Ukraine 3 Ore Extraction and Handling 4

3 Mine Site Processing Plant 5 Port and Shipping 6

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5 AIR POLLUTION Priority Pollutants SO 2, NO x, CO, Pb, photochemical smog (O 3 ), particulate matter PM (PM 10 and PM 2.5 ) Air toxins Metals and metal compounds (As, Cd, Hg, Cr 6+, Ni, Pb) Pesticides Polycyclic Aromatic Hydrocarbons (PAHs) (Benzo(a)pyrene (BaP)) Volatile Organic Compounds (VOCs) (benzene) Persistent Organic Pollutants (POPs) (aldrin, chlordane, DDT, dieldrin, dioxins, furans, endrin, hexachlorobenzene, heptachlor, mirex, polychlorinated biphenyls, toxaphene) Dioxins and Furans (TCDD) Asbestos Greenhouse gases CO 2, CH 4, N 2 O, CFCs GSE803 and HCFs, CF 4, SF9 6 Environmental 9 Ironmaking Emissions 10

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8 Coke Oven Emissions 15 Sinter Plant Stack before and after Energy Recovery System 16

9 Air Pollution and Health 17 Daily mortality and fine particles Fine (PM 2.5 ) and coarse (PM 10 - PM 2.5 ) measured 6 eastern US cities for 8 years aerosol acidity for 1 year Daily mortality Weather measurements PM 2.5, PM 10 and SO 4 2- associated with mortality TSP (coarse particles), aerosol acidity not associated 10 µg/m 3 in PM 2.5 gave a 1.5% increase in daily mortality PM 2.5 are, in general, combustion-derived Mortality Rate Ratio P T W L H Fine Particles (µg m -3 ) Source: Dockery et al., NEJM, 329, 1753, 1993 S 18

10 Particle Formation Mechanism during Ironmaking 19 Volumetric Expansion and Volatile Evolution of Iron Ores during Heating A goethite FeOOH B hematite Fe 2 O 3 Source: Strezov et al., Int. J. Mineral Processing, 100 (2011) 27 20

11 Particle Formation during Thermal Processing of Iron Ores Source: Strezov et al., Int. J. Mineral Processing, 100 (2011) Emissions from Direct Ironmaking Process 22

12 Emissions from Direct Ironmaking 23 Experiment Operating Parameters Feed material s Mass fed (kg) Coal Iron Ore Fluidising gas Fluidising Gas rates (L/min) Other Gas Flows (N 2 ) (L/min) 1 Iron Ore 0 4 N Iron Ore 0 4 H 2 /N 2 30/ Iron Ore + Coal 2 2 N Iron Ore + Coal 2 2 H 2 /N 2 30/ Coal 4 0 CO 2 /N 2 20/ Coal 4 0 Air/N 2 5/ Coal 4 0 Air/N 2 20/

13 FTIR Spectra of Particles Collected from the Fluidised Bed Reactor Iron ore Iron ore with coal Coal Exp2 CYN Exp4 CYN Exp2 BGH Exp4 BGH Exp7 CYN Transmittance Exp2 BD Exp1 CYN Exp1 BGH Transmittance Exp4 BD Exp3 CYN Transmittance Exp7 BGH Exp7 BD Exp6 CYN Exp6 BGH Exp6 BD Exp1 BD Exp3 BGH Exp5 CYN Exp5 BGH Exp3 BD Exp5 BD Wavenumber (cm -1 ) Graduate Wavenumber School of the (cmenvironment -1 ) Wavenumber (cm -1 ) Experiments Trace Element Analysis Raw Samples Iron Ore under N Iron Ore under Iron Ore + 2 H 2 +N coal under 2 N 2 Experiment 1 Experiment 2 Experim 3 Trace Elements Units Iron ore Coal BD BGH CYN BD BGH CYN BD BGH Antimony (Sb) mg/kg < 0.5 < 0.5 < < 0.5 < 0.5 Arsenic (As) mg/kg 3.2 < Berylium (Be) mg/kg Boron (B) mg/kg Cadmium (Cd) mg/kg < 0.5 < 0.5 < < < 0.5 < 0.5 Chromium (Cr) mg/kg Cobalt (Co) mg/kg Copper (Cu) mg/kg Lead (Pb) mg/kg Manganese (Mn) mg/kg Nickel (Ni) mg/kg Selenium (Se) mg/kg < < 0.5 < < 0.5 < < Thorium (Th) mg/kg Uranium (U) mg/kg Zinc (Zn) mg/kg Total Solids %

14 Mercury Analysis 27 28

15 Atmospheric Particle Sampling 29 Sampling details EAF site, Rooty Hill, NSW Background site North Ryde, NSW Sampling locations Eight staged MOUDI sampler Air particulates on Teflon filter 30

16 Air particulates distribution EAF site Background site Min Max Mean Min Max Mean TSP, ug/m PM 10, ug/m PM 2.5, ug/m PM 1, ug/m d m /d lo g (Dp ), u g /m RT01 RT02 RT03 RT04 RT05 RT06 dm /dlog(dp), u g/m MQ01 MQ02 MQ03 MQ04 MQ05 MQ Dp, um Dp, um 31 Elemental concentration, ng/m3 TSP EAF site Background site Min Max Mean Min Max Mean Na nd nd -- nd Al Si P nd nd -- nd nd -- S Cl K Ca Ti V nd nd -- nd nd -- Cr nd nd -- Mn Fe Co nd nd -- nd nd -- Ni Cu Zn Br nd nd -- nd nd -- Sr nd nd -- nd nd -- 32

17 SEM-EDS analysis EAF site: RT Stage VFS = 1350 count 10 µm 004 VFS = 1350 count O C Mn Ca O Fe Mn Fe Zn C Si Mn Al Zn S S Ca Ca FeKesc Fe Mn Fe Mn Zn Zn Fe Si Fe Zn Al Mn S S Ca FeKesc Fe Mn Mn Fe Zn kev kev Sustainability of Iron and Steelmaking Operations 34

18 Sustainability of Industrial Operations Preserving Resources Coal, oil and natural gas Iron ore Industrial Sustainability Preserving Environment GHG Emissions Air Pollution Waste Management Improving Liveability Economic Parameters Social Considerations Quality of Life 35 Sustainability of Ironmaking Case studies selected as examples: BF/BOF Wollongong, Australia EAF Rooty Hill, Australia DRI MIDREX plant in Contrecoeur, Canada Consumption parameters used: Energy consumption, water consumption and land use Emission parameters: Greenhouse gas emissions Priority pollutants (NO x, SO 2, CO, Pb, PM 10 and PM 2.5 ) Priority metals (Pb, As, Cr 6+, Hg, Ni, Cd) Pollutant inventory databases used for emission estimates: Australian National Pollutant Inventory Canadian National Release Pollutant Inventory 36

19 Sustainability parameters, expressed in metric tonne of steel (BF/BOF and EAF) or iron (DRI) BF/BOF EAF DRI Energy consumption (GJ/t) CO 2e emissions (tco 2e /t) Water consumption (m 3 /t) Land use (m 2 /t) Emissions to air (kg/t) NO x SO CO PM PM Pb Hg As Cr Ni Cd Sustainability parameters expressed in product $ value Ironmaking and Steelmaking Coal fired Electricity Production Wheat Production BF/BOF EAF DRI 5 year increase in global production rate 20.6% 3.9% 24.1% 12.9% 15.3% Product value ($/t or $/MWh) Energy consumption (MJ/$) CO2e emissions (kgco 2e/$) Water consumption (l/$) Land use (m 2 /$) Emissions to air (g/$) NO x SO CO PM PM Pb Hg As Cr Ni Cd

20 Normalised sustainability index and technology ranking Ironmaking and Steelmaking BF/BOF EAF DRI Midrex Coal fired Electricity Production Wheat Production Normalised overall sustainability index Technology ranking Recycling Steel Source: Szekely, ISIJ Int, 1996 High demand for scrap steel Developed market 50-67% recycling rate GHG reduction 40

21 Iron ore reserves and availability of scrap steel for recycling Iron ore reserves (Gt) Iron ore reserves Availability of scrap Year Availability of scrap (Gt) 41 Iron Ore Reduction with Biomass Apparent Volumetric Specific Heat (J/m K) 6E+6 5E+6 4E+6 3E+6 2E+6 1E+6 decomposition reduction 0E ,000 1,200 Temperature (degc) 70% Iron Ore - 30% Sawdust Iron Ore Sawdust a) Intensity Fe 2 O 3 FeOOH θ ( o ) Fe SiO2 Fe 2 O 3 Fe Fe 2 O 3 b) 70% iron ore + 30%saw dust heated at 1200 o C iron ore Strezov, Renewable Energy, 31, ,

22 Towards Sustainable Metallurgy Energy Sources Renewable energy sources - wood - bagasse - agricultural waste - weeds - municipal waste Fossil fuels: - thermal coal - coking coal - lignite - anthracite Charcoal conversion Cokemaking Feeds: - metal ores - fluxes - wastes S u s t a i n a b l e M e t a l l u r g i c a l O p e r a t i o n s Energy efficiency Productivity Quality Strezov, Renewable Energy, 31, , Acknowledgement Dr Tim Evans, Rio Tinto Prof Peter Nelson, Macquarie University Dr Artur Ziolkowski Dr Pushan Shah Mr Kazi Mohiuddin, Macquarie University 44