EVOLUTION OF BLAST FURNACE TECHNOLOGY THE FIRST BLAST FURNACE WAS BUILT IN GERMANY IN 1300 AD. BY 1850, BF OF ABOUT 18.3 M HIGH AND HEARTH DIAMETER OF 2.4 M WERE BUILT TO PRODUCE 27 THM / DAY. BY 1900, A TYPICAL BF TO PRODUCE 180 THM/DAY WAS BUILT. NEXT 80 YEARS, SAW A MAJOR CHANGE IN SIZE AND CAPACITY OF BLAST FURNACES. A BF TO PRODUCE 1900 THM/DAY WAS BUILT IN 1950. THE LARGEST BF OF THE WORLD HAVING A USEFUL VOLUME OF 5,580 CU.METRE AND HEARTH DIS OF 15.1 M WAS COMMISSIONED ON 14TH APR1986 AT THE CHEREPOVETS STEEL PLANT OF FORMER USSR. THIS FURNACE CAN PRODUCE OVER 11000 THM/DAY. THREE SMALLER BLAST FURNACE OF RSP WERE COMMISSIONED IN 1959, 1960 AND 1962 RESPECTIVELY TO

OBJECTIVE OF BLAST FURNACEPRODUCT COMPOSITION HOT METAL FOR STEEL MELTING SHOP 94 % Fe 4.0 % C 0.8 % Si 0.5 % Mn 0.20 % P 0.050 % S

14500 C H.M TEMP AT CAST HOUSE BY-PRODUCTS LIQUID SLAG / GR. SLAG 32 - 34 % SiO2 20 22 % Al2O3 28 30 % CaO BF GAS 22 24 % CO 16 18 % CO2 2%H 56 - 58 % N CV - 850 K/CAL/M3 DUST < 8 Mg/M3 10 11 % MgO 1 % MAX FeO 0.94 % BASICITY

HISTORY OF BLAST FURNACE AT RSPINSTALLED CAPACITY 1.0 MT OF HOT METAL

BF - I, II, III

1000 T / DAY IN 1960s

1.8 MT AFTER EXPANSION IN 1970s BF - I, II, III -1000 T / DAY BF IV -1500 T / DAY

2.0 MT AFTER MODERNISATION IN 1998s BF I, II, III -1200 T / DAY BF IV -1800 T / DAY BF - IV -2200 T / DAY (AFTER MODERNISATION COMMISIONING DATES OF BLAST FURNACEIN 2005) 27.01.1959 LAST RELINING ON BF-1 = 01.11.2001 BF-2 = 10.12.2002 BF-3 = 09.09.1997 12.01.1960 LAST RELINING ON 08.01.1962 LAST RELINING ON

FURNACE PROPERBF I,II,III PROD. CAPACITY USEFUL VOLUME WORKING VOLUME HEARTH DIAMETERS HEARTH VOLUME BOSH VOLUME NO. OF TUYERES SIZE OF TUYERS NO. OF STOVES BLAST TEMPERATURE BLAST VOLUME (MAX) 1200 THM/DAY 1139 M3 995 M3 7.4 M 129.10 M3 168.70 M3 18 140 160 MM 3/FURNACE 950oC 90,000 M3/HR. BF IV 2200 THM/DAY 1658 M3 1448 M3 9.0 M 191.0 M 227.0 M 21 140 160 MM 3/FURNACE 1000oC 160,000 M3/HR.

FIXED THROAT ARMOUR

+ 35225

OVER BURDEN PROBE

STACK COOLERS

NORMAL CARBON + 14000 + 11300 MODIFIED TUYERE STOCK

+ 7500

1100

IMPROVED REFRECTORY GRAPHITE 45% Al2O3

BLAST FURNACE

BLAST FURNACE IS A COUNTER CURRENT HEAT EXCHANGER LIQUID METAL AND SLAG ARE COLLECTED AT HEARTH. TAPPINGS AT REGULAR INTERVALS ARE DONE TO EMPTY THE FURNACE. HOT METAL IS SENT TO SMS SLAG IS SENT TO SGP / INBA / DUMP

BELT

HIGH LINE RAW MATERIAL BUNKERSTHROUGH SKIP

WAGONS IRON ORE SINTER (SCREENED AT BF) COKE (SCREENDED AT BF LIME STONE / LD SLAG MANGANESE ORE QUARTZITE

COLD BLAST FROM TURBO BLOWER

STOVE S

PIG CASTING MACHINE HOT METAL TAP HOLE

HOT BLAST

BLAST FURNACEBF RAW GAS

SMS-I

S M S - II SLAG SLAG GRANULATION PLANT INBA CAST HOUSE GRANULATION

GAS CLEANING PLANTTO STOVE FOR HEATING TO OTHER CLEAN GAS

FLOW DIAGRAM OF BLAST FURNACE PROCESS

MATERIAL BALANCE FOR 1 T OF IRON

INPUT

OUTPUT

AIR 2.42 T SINTER 1.25 T + ORE 0.45 T LDS/LS 0.005 T QTZ. 0.001 T COKE 0.600 T

GAS 3.615 T

BLAST FURNACE

DUST 0.045 T PIG IRON 1.0 T SLAG 0.400 T

RAW MATERIALS FOR BLAST FURNACESMATERIALS IRON ORE SOURCE BARSUAN, KALTA, MEGHATABURU, KIRIBURU, PURCHASED FROM OMC etc.THROUGH OBBP SP I & SP II PURNAPANI, BIRMITRAPUR and PURCHASED FROM OUTSIDE ROXY, BARAJAMDA, NAGPUR( PURCHASED ) PURCHASED SMS COKE OVENS (COAL FROM DUGDA, BHOJUDIH, KARGALI, RAJRAPPA and Imported coal) COKE OVENS THROUGH SINTER

SINTER LIME STONE Mn ORE QUARTZITE LD SLAG COKE

NUT COKE

PIG IRON CHIPS PIG CASTING M/C SHOP

RAW-MATERIAL COMPOSITION NORMSCOKE ASH : 16 -18 0.5 CARBON : 82 % VOLATILE MATTER, VM : 0.9 % GROSS MOISTURE .GM : 4.0 % SULPHUR : 1% MICUM -10mm : 8 % MAX. MICUM +40mm : 80 % MIN. HEAT VALUE : 6500 Kcal /Kg SIZE RANGE : 20 40 mm Fe FeO SiO2 Al2O3 CaO MgO -5mm CaO/ SiO2 Al2O3 / SiO2 SIZE RANGE : : : : : : : : : : 55 % 1 % 10 % MAX. 4 TO 5 % 2.5% MAX 10.5 % 0.5 % 3.0 % 0.5 % 10 % MAX. 2.8 TO 3.0 0.5 TO 0.6 +5 +25 mm

SINTER

RAW-MATERIAL COMPOSITION NORMSBARSUA ORE Fe Al2O3 SiO2 -10 mm KALTA ORE Fe Al2O3 SiO2 -10 mm : : : : : : : : 63 % MIN. (Fe2O3 = 86-87%) 2.5 % MAX. SIZE 20 40 mm 1.5 % 0.5 % 10% MAX. 64 % MIN. SIZE 20 40 mm 2.5 % MAX. 1.5 % 0.5 % 10 % MAX. 9% 45 % 10 % 10 % 1% SIZE 20 40 mm 1% MAX. MAX. SIZE 10mm TO 50 MnO2 = Pyrolusite,

LIME STONE TI : CaO : -25mm : +50mm : MN ORE Fe : mm Mn : max. P CaO : MgO P2O5 SiO2

24 % 1 % 26 % 1 % : 0.15 : : :

LD SLAG

% 45 %2O3= Braunits mm Mn 40 SIZE 20 40 67% 2 % MAX. 99 % MIN SIZE 20 40 mm

QUARTZITE

OUTPUT NORMSHOT METAL Si 0.8 - 1.0 % S 0.045 - 0.05 % TEMP 14500 C AT CAST HOUSE CaO SiO2 MgO MnO FeO S 32 30 34 % 35 % 22 % 11 %

SLAG

Al2O3 20

10 2 % MAX. 1 % MAX. 1 % MAX.

BF GAS

CV + 850 K.cal / Nm3 DUST CONTENT < 8 MG / Nm3

OPERATING PARAMETERSparameters BLAST PRESSURE BLAST VOLUME BLAST TEMPERATURE BLAST MOISTURE STOCK LEVEL % Sinter in Burden Fe / C TOP GAS TEMPERATURE TOP GAS CO TOP GAS CO2 BFs I, II ,III 1.15 KG/CM2 90,000 Nm3/hr. 950 DEG C 1.5 2 T/HR 1.0 M 70.0 2.0 1500 C 22 - 24 % 16 18 % BF IV 2 KG/CM2 0.8 HTP 160,000 Nm3/hr. 1000 DEG C 2 4 T/HR 0.5 M 72.0 2.0 1500 C 22 - 24 % 16 18 %

OPERATING PARAMETERSBFs I, II ,III HOT METAL Si HOT METAL S HOT METAL TEMPERATURE SLAG RATE SLAG BASICITY NO. OF CAST / DAY COKE RATE DUST RATE 0.80 1.00 0.045 - 0.050 14300 C BF IV 0.80 1.00 0.045 - 0.050 14600 C

400 Kg/THM 0.95 0.05 9 570 Kg/THM 8-10 Kg/THM

400 Kg/THM 0.95 0.05 9 570 Kg/THM 3-5 Kg/THM

ROLE OF COKE ACTS AS A FUEL ACTS AS A REDUCING AGENT SUPPORTS THE BURDEN PROVIDES PERMEABILITY IN THE BURDEN COLUMN

CONE PRE-HEATING ZONE 150 3000 C

CROWN RING

THROAT

MOISTURE REMOVAL UPPER REDUCTION ZONE 300 9000 C REDUCTION OF IRON

BREAK UP OF CaCO3 BELLY LOWER REDUCTION ZONE 900 12000 C

FUSION ZONE1200 16000 C

SLAG BIGINS TO FORM

PIG IRON BIGINS MELTING

BOSH COKE BURNS TUYERE

TUYERE ZONE, 16000 C SLAG, 1420 C0

SLAG FORMATION ENDS TAP HOLE

HOT METAL, 13200 C

VOLATISATION IN TOP ZONE

REACTIONS IN BLAST FURNACES

DE-COMPOSITION OF HYDRATES OF IRON AND ALUMINIUM AT 3000 TO 4000 C. THE RELEASED H2O ABOVE 4000 C REST WITH CO AS H2 + CO CO2 + H2 (WATER GAS) CARBON DEPOSITION REACTION AT 4500 6000 C [ 2CO = CO2 + C + 41.2 K.CAL.) THE REDUCTION REACTIONS AT 700 9000 C 3 Fe2O3 + CO = 2 Fe3O4 + CO2 + 10.33 K.CAL Fe3O4 + CO = 3FeO + CO2 8.75 K.CAL FeO + CO = Fe + CO2 + 3.99 K.CAL DECOMPOSITION OF CARBONATES AT 900 11000 C [ CaCO3 CaO + CO2 X K.CAL] METALLOID REACTIONS COMBUSTION ZONE REACTIONS SLAG METAL REACTION

OREPREHEATING ZONE

TOP GAS 100 = 2500 C 10 20 % CO2 + 20 30% CO + REST N2 GAS SOLIDS 3Fe2O3 + CO = 2Fe3O4 + CO2 Fe3O4 + CO = 3FeO + CO2 INACTIVE ZONEINDIRECT REDUCTION ZONE

COKE

GRANULAR ZONE

THERMAL RESERVE ZONE

INDIRECT REDUCTION ZONE OF WUSTITE

FeO + CO = Fe + CO2 + UNREDUCED FeO

ACTIVE COKE ZONE

RACEWAY

STAGNANT COKE ZONE

SLAG HEARTH METAL

DIRECT REDUCTION AND MELTING ZONE SLAG AND IRON

FeO + CO = CaCO3 = CO2 + C = MnO + C = P2O5 + 5C = SiO2 + 2C = S+ CaO + C =

Fe + CO2 CaO + CO2 2 CO Mn + CO 2P + 5CO Si + 2CO CaS + CO

PRINCIPLES OF IRON MAKING COKE BURNING SHOULD BE FAST BURDEN MATERIAL SHOULD HAVE SUFFICIENT BED PERMEABILITY , OTHERWISE HANGING WILL OCCUR GANGUE MATERIALS SHOULD BE AS LOW AS POSSIBILE FLUCTUATIONS OF BLAST PRESSURE, BLAST VOLUME & FINES PERCENTAGE SHOULD BE LOW SO THAT THE FURNACE BEHAVES SYSTEMATICALLY . SLAG FLUIDITY MUST BE SUCH THAT IT FLOWS EASILY LOCAL OVERHEATING IS TO BE MINIMISED

Si & S ARE NOT DESIRABLE IN HM. Si CAUSES SLOPING IN PRINCIPLES OF IRON MAKING L.D. CONVERTER. IF RAFT IS MORE SiO2 GET REDUCED AND OTHERS METAL HAS HIGH Si & COKE RATE HIGHER. IT TEMP. IS LOW S IS HIGH IN HOT METAL FLUIDITY WILL BE LOW. INCREASING SLAG BASACITY LOWER THE SI IN HM AS CaO COMBINES WITH SiO2 TO FORM COMPLEX COMPOUNDS WHICH DO NOT GET REDUCED . THE S IN HM IS LOWERED AS CaO COMBINES WITH MnS OR FeS IS FORM CaS. INCREASE IN MNO IN SLAG LOWERS SI IN HM AS MNO COMBINES WITH SiO2 TO FORM COMPLEX COMPOUNDS WHICH DO NOT GET REDUCED. THE S IN HM IS

ESSENTIALS OF GOOD BF OPERATION SCREENED AND SIZED RAW MATERIAL CONSISTENCY IN ALL RAW MATERIAL SUPPLY & QUALITY MAINTAINING THE FURNACE STOCK LEVEL PROPER CHARGE DISTRIBUTION FOLLOW SPECIFIED OPERATING PARAMETERS VIZ. ADHERENCE TO SOPS & SMPS ADHERENCE TO CASTING SCHEDULE GOOD CAST HOUSE PRACTIVE ASSURED OFF TAKE OF HOT METAL REGULAR DRYING OF DUST CATCHER

DIFFERENT UNITS OF BLAST FURNACE DEPTT. HIGH LINES, STOCK HOUSE & CHARGING SECTION FURNACE PROPER GAS CLEANING PLANT PIG CASTING M/C & LADLE REPAIR SHOP SLAG POT HANDLING UNIT & SLAG DUMPING INBA CAST HOUSE SLAG GRANULATION PLANT ATTACHED TO BF 1 & 4. DE-SULPHERISATION PLANT WORK SHOP PUG MILL

FUNCTIONS OF DIFFERENT UNITSCHARGING SECTION MATERIAL PROCUREMENT STORAGE & STOCK LEVEL CONTROL CHARGING

FURNACE & STOVES REDUCTION OF IRON ORE FORMATION OF LIQUID METAL AND FLUID SLAG REGULAR HEARTH DRAINAGE MAINTAIN METAL & SLAG CHEMISTRY & TEMP. GAS CLEANING PLANT CLEAN BF GAS MAINTAIN LINE PRESSURE OF CLEANED BF GAS SUPPLY COOLING WATER FOR BLAST FURNACES PIG CASTING M/C PROVIDE EMERGENCY OUTLET OF HOT METAL IN CASE OF OFFTAKE PROBLEM CAST OFF GRADE HOT METAL INTO PIGS

FUNCTIONS OF DIFFERENT UNITSLADLE REPAIR SHOPS CLEANING OF LADLES MINOR REPAIRS OF LADLES RELINING OF LADLES SLAG POT HANDLING UNIT TRANSPORT OF SLAG TO SGP & SLAG DUMP MAINTAIN REQUIRED FLEET OF SLAG POTS SLAG DUMP SUPPLY CLEAN SLAG POTS TO FURNACES INBA CAST HOUSE SGP GRANULATE SLAG PRODUCED IN BF 1 & 4 TRANSPORT GRANULATED SLAG TO BUNKER / STORAGE YARD DE-SULPHERISATION PLANT DESULPHERISE HIGH S HOT METAL (MAX 4 LADLES AT A TIME

FUNCTIONS OF DIFFERENT UNITSWORKSHOP MACHANICAL REPAIR JOBS PUG MILL FITTING / ASSEMBLY OF PLANT EQUIPMENT FABRICATION OF SPARE PARTS PREPARE MUDGUN CLAY PREPARE CAST HOUSE TROUGH / RUNNER MASS PREPARE PCM TROUGH & RUNNER CLAY

FUTURE TECHNOLOGY IN BLAST FURNACE WILL AIM AT

PRODUCTIVITY LEVEL OF 2.0 T/M3/DAY FOR LARGE FURNACES

TOTAL FUEL REQUIREMENT LESS THAN 500 KG/THM

COAL DUST > 100 KG/THM

OXYGEN > 3.0 %

SILICON IN HOT METAL 0.3 %

CAMPAIGN LIFE TO 15 YEARS

INCREASED AVAILABILITY TO 100 % BETWEEN SCHEDULE STOP

ON-LINE AUTOMATIC CONTROL OF BLAST FURNACE

IMPROVED ENVIRONMENTAL CONTROL

ACHIEVE 4.1 MT PRODUCTION / YEAR FROM 2010 2011 BF # 1 BF # 2 BF # 3 BF # 4 BF # 5 DAILY PRODUCTION : : : : : : 1500 T 1500 T 1500 T 2500 T 4500 T

PLAN FOR FUTURE

11,500 T

UP COMING NEW PROJECTS IN BF COAL TAR INJECTION PLANT IN BF # 1 COAL DUST INJECTION IN BF # 1 & 4 CONSTRUCTION OF BF # 5

SALIENT FEATURES1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. NEW FURNACE SHELL WITH A NEW PROFILE, FREE STANDING REPLACEMENT OF UPTAKES, DOWN COMERS, BUSTLE PIPE & DUST CUTOFF VALVE STAVE COOLERS IN HEARTH TO STACK + 28 MTR LEVEL INTRODUCTION OF BREAST COOLERS NEW HOT WATER PUMP HOUSE FOR OVERHEAD RETURN WATER LINES INCREASE IN BOG DEPTH OF FURNACE COMMISSIONING OF NEW GAS CLEANING PLANT WITH VENTURY SCRUBBER. NEW SKIP BRIDGE & MAIN SKIPS HIGHER CAPACITY WINCH FOR MAIN SKIPS & NEW WINCH HOUSE HIGHER CAPACITY COKE & SINTER SCREENS REVIVAL OF DEDUSTING SYSTEM

ENVIRONMENTAL PROTECTION MEASURES FUME EXTRACTION AND COLLECTION FROM FURNACE TAP HOLE COVERED RUNNERS WITH EXTRACTION AND COLLECTION OF FUME EXTRACTION AND COLLECTION AT THE TORPEDO LADLE DURING FILLING PROGRESSIVE MOVES AWAY FROM OPEN AIR COOLING OF SLAG IN PITS, TO ITS GRANULATION AND PELLETISATION MONITORING OF THE FURNACE TOP BY CAMERAS FOR GAS AND DUST EMISSION FOR CHARGING SYSTEM AND BLEEDERS.

UNIT COST OF HOT METAL (2005 06)APP APR MAY JUN JUL AUG SEP OCT NOV 2205 7198 94 DEC TOT FIXED COST 2267 2358 2859 2979 3024 2626 2719 2067 VARIABLE COST IWC WORKS COST 7834 6536 6568 6837 6892 7297 6926 7315 96 111 112 120 124 117 115 92 2181 2546 7412 6622 87 90

1019 9005 9539 9936 1004 10040 9760 9474 9497 9680 9258 7 0 575 166 619 179 654 189 662 191 685 198 646 187 512 148 527 152 515 150 572 174

DEPR. COST 537 INTEREST COST TOTAL COST 156

1089 9746 1033 1077 1089 10923 1059 1013 10176 1034 1000 0 7 9 3 3 4 5 4

CONCLUSION BLAST FURNACE TECHNOLOGY WILL CONTINUE TO SUPPLY BULK OF HOT METAL FOR STEEL PRODUCTION IN YEARS TO COME DECREASE IN COST OF HOT METAL PRODUCTION IS THE NEED OF THE HOUR AND MORE EFFORTS TO BE PUT IN FUTURE. THE ECONOMY IN BLAST FURNACE TECHNOLOGY CAN BE ACHIEVED THROUGH DEPENDING LESS AND LESS ON METALLURGICAL COKE WITH SUITABLE INJECTION TECHNOLOGY INCREASE IN CAMPAIGN LIFE OF BLAST FURNACE IS ANOTHER VERY IMPORTANT AREA OF FOCUS FOR DECREASIONG THE FIXED COST OF HOT METAL THE AUTOMIC OPERATION OF BLAST FURNACE WITH ONLINE CONTROL USING TECHNIQUES OF EXPERT SYSTEMS WILL LEAD TO STANDARDISATION OF BLAST FURNACE OPERATION AND THUS MORE STABLE OPERATION AND LESS DOWN TIME THE COST OF HOT METAL PRODUCTION CAN BE SUBSTANTIALLY DECREASED THROUGH USE OF UNDER SIZE MATERIALS IN BLAST FURNACE SPECIFIC EFFORT ARE REQUIRED TO CREATE