International Secondary Lead Conference 1/Sept/2009

1. International Secondary Lead Conference 1/Sept/2009 Mike Bishop – Technology Manager, BOC. Metals and Combustion.

2. C C O O O O Combustion of Carbon C + O2 → CO2 + heat

3. O O H H O O H H H H H H Combustion of Hydrogen 2H2 + O2→2H2O + heat

4. C C C O C O O O O O O C C O O O Stages of Combustion of Carbon C 2C + O2→ 2CO + heat, then 2CO + O2→2CO2 + heat

5. Comparison of Flue gas composition Air Vs Oxygen Combustion of Methane Air: 1 CH4 + 2 O2 + 8 N2 1 CO2 + 2 H2O + 8 N2 9,1 Vol% +18,2 Vol% + 72,7 Vol% 1m³ + 2m³ + 8m³ 1m³ 2m³ 8m³ = 11m³ Oxygen: 1 CH4 + 2 O2 1 CO2 + 2 H2O + 0 N2 33 Vol% + 66 Vol% 1m³ + 2m³ 1m³ 2m³ 0m³ = 3m³

6. 300 nm3/MWh 1100 nm3/MWh Oxyfuel — combustion without nitrogen ballast

7. Variation of adiabatic flame temperature with concentration of oxygen in oxidant

8. Exhaust Composition at Stoichiometric Combustion 80 70 60 50 Percent of Total Exhaust 40 Airfuel 30 Oxyfuel 20 10 0 CO2 H2O N2 Exhaust Gas Constituent Oxyfuel – Higher content of highly radiating 3-atomic gases

9. Waste gas volume reduction with increased Oxygen additions

10. Fuel savings achievable with various waste gas temps

11. Oxyfuel - Reduced and concentrated CO2 Flue gas volume: 11,725 Nm3/h wet 10,320 Nm3/h dry CO2: 1,035 Nm3/h CO2: 710 Nm3/h Flue gas volume: 2,100 Nm3/h wet 740 Nm3/h dry Oxyfuel Airfuel 10.0 MW 1,000 Nm3/h Natural Gas 10,700 Nm3/h air @ 350°C 6.7 MW 670 Nm3/h Natural Gas 1,400 Nm3/h O2

12. LES OXY/OIL 1.5 MW LES Burner Burner Firing in BOC Test Rig

14. Key techniques for adding oxygen • General Enrichment • Lancing • Underflame lancing • Full Oxy fuel / Flameless (LTOF)

15. Oxygen General enrichment for shaft furnace Shaft furnace General enrichment 0 – 4 % scrap charge combustion air bottom air-burners zone Oxygen

16. Oxygen diffuser in fitted to combustion air main

17. Oxygen Lancing (22-35% O2) • Lance injects oxygen into the existing burner flame

18. Combustion safety system • Pre purge furnace prior to initiating fuel flow to burner – 5 volume changes. • Ignition burner control module – • Gas and Oxygen supply pressure checks • Fuel valves are double block and bleed with leak testing / position sensors. • Fail safe shut off valves • UV self checking flame detector • Ratio controller for fuel and oxygen – lead / lag • Back pressure sensing and hard wired trip • Twin DP transmitters with comparison trip • Furnace exhaust flow trip

19. Water cooled gas- or oil-burner Type 4W1600 Oil-pressure atomizing Type 1W400 Oil-oxygen atomizing

20. Rotary furnace – single pass Furnace types

21. Movable Charge Door Rotary furnace – Double pass Furnace types Exhaust gases Charge Scrap

22. Lead Rotary furnace, doublepass - 16t

23. Section Through Tilting Rotary Furnace With Oxy-Fuel Burner Exhaust Two Part Refractory Lining Door Salt Flux Oxy-Fuel Burner Molten Metal Base Frame On Floor

24. 15 tonne Aluminium TRF fitted BOC LES burner

25. Fluent modelling of burner positioning

26. Linde‘s Oxyfuel in Non-Ferrous Melting • Linde is the leading company in developing and implementing gas solutions in the aluminium and non-ferrous industry. • Since 1988, over (320) Non-Ferrous furnaces have been converted to oxyfuel by Linde engineers (see Fig. 1). • Today (174) of Linde´s oxyfuel installations are operating successfully in (107) aluminium companies .

27. Created by; Linde Gas, Hertwich Engineering and Corus Aluminium Fast heating and melting with oxyfuel burner Contaminants used as fuel by WASTOX oxygen lancing Fast charging and tapping by furnace tilting Universal Rotary Tilt able Furnace (URTF)

28. End of Presentation Thanks for your attention