1. Restart of BF#2 Using Durfee Method

2. Salient Features o Inner volume: 3,814 m3 o Working volume: 3,230 m3
o Number of tuyeres: 34
o Charging system: with belt conveyor and Paul Wurth Parallel hopper Bell Less Top®,
o Cooling system
o Under-hearth: water pipes
o Hearth: cast-iron staves
o Tuyere belt: cast iron staves
o Bosh to lower Stack: copper staves
o Middle Stack to Throat: cast iron staves
o PCI design for 200 kg/thm
o Top Gas Recovery Turbine 14 MW

3. Chilled Hearth Condition
Start Up Situation
Hot Metal and Slag Solidified
Chilled Hearth Condition
Unprepared Shut down for 162 days

4. Major tasks of Recovery Process
Re-instate connection between Tap hole and Tuyeres
Recover the Thermal Status
Melting of Solidified Metal and Slag
Stabilize the Process

5. Process discussed for Revival Durfee Process
Blowing Hot Blast through Tap hole enriched with Oxygen
Normally Used for Prepared shut downs
Less aggressive on Refractory
Oxy-Fuel Process
Installing Oxy-fuel burners through Tap holes equipped with external fuel + Oxygen
Can be used for severe chilled recoveries

6. Process Selected for Revival
Durfee Process
Reasons
Furnace had coke O/C ratio 2.1
Extra Coke of around 90 T available in Lower Stack

7. Durfee Process

8. Time Line of Start Up Day-2 Day-3 Day-4 Day-5
Blast Introduced through Durfee
No Blast flow observed
Durfee removed and Tap Hole Lanced for 20 Hrs
Day-2
Durfee Re-Introduced
Blast Flow Average 7200m3/hr
Blast Enriched with Oxygen
Day-3
Cumulative Flow through Durfee ~ Nm3
4 Tuyere Opened above Tap Hole No 2
Durfee removed and First slag cast through Tap Hole No 2
Day-4
Hot Metal and Slag in Dry Pit
Day-5
Hot Metal taken in Torpedo Ladle
GCP Connected

9. Tuyere Opening & Blast Volume Increase

10. Sequence of Tuyere Opening

11. Hot Metal Production Tons Per Day