steel authority of india ltd bokaro
DESCRIPTION
Presentation on bokaro steel plant, a SAIL subsidiary unit situated in bokaro steel city, jharkhand. I complied it at the end of my training there in my 2nd year.TRANSCRIPT
Overview of Bokaro Steel
Plant
SUMAN SOURABH06570104910B.TECH(EEE)FINAL YEAR
•Fourth Integrated Steel Plant in Public Sector,well known as Swadeshi Plant, maximum indigenisation in equipment,materials & know-how
•Originally incorporated as a Limited Company on 29.01.64
•Collaboration agreement with Soviet Union (USSR) on 25th Jan, 1965 ( SAIL Foundation Day)
•After formation of SAIL on 24th January 1973, merged with SAIL on 01.05.78
•Collaboration with the then USSR
•Total area 33,045.35 acres
•Flat Product : HR Coil, HR Sheet, CR Coil, CR Sheet, TMBP, GP&GC
BACKGROUND
• Capacity Capacity – First Phase : 1.7 MT of ingot steel– Second Phase : 4.0 MT of ingot steel– After modernization : 4.5 MT of liquid steel– Enough scope for further expansion (Plan for 7 MT)
• MilestonesMilestones– Start of construction : 06.04.68– Start of hot metal production : 02.10.72– Completion of 1.7 MT stage : 26.02.78– Completion of 4 MT stage in phases– Start of last modernization : 23.07.93 (completed in
1997)– Next modernization for 7 MT : Evaluation Process
started
Basic Information Location : Southern bank of ; approx. 50 kms from Dhanbad and 140 kms
each from and Latitude : 230 39' Longitude : 860 09' Altitude : 210 metres (average) varying from 195 to 224 metres Climate : Extreme Annual Rainfall : Average 157 cms; Maximum 195 cms Temperature : Maximum 48½0 Celsius
: Min. 2½0 Celsius Wind direction : South-West to North-East Type of Soil : Loamy up to 1 to 2 metres, sandy soil below that Total land area : 33,045.35 acres Plant, Slag-dump, Cooling
Ponds, Ancillaries, Marshalling Yard
: 17,208.01 acres
Township(including Airstrip) : 10,114.53 acres Garga Reservoir : 3,886.87 acres Railways : 1,835.94 acres
UTILITIES & SERVICES
WATER SUPPLY - GARGA DAM & TENUGHAT DAM
POWER SUPPLY
DVC CHANDRAPURA - 200MVA (Contract)
Bokaro Power Supply Co. Ltd.
- 1 x 12 MW (back pressure)
2 x 55 MW
3 x 60 MW
Total Road length 392 Kms.
Sintering Plant
BF1 BF2 BF3 BF4 BF5
Blast Furnace
300 TCon-1
300 TCon-2
Steel Melting Shop - 2Steel Melting Shop - 1
130TCon-1
130 TCon-2
130 TCon-3
130 TCon-4
130 TCon-5
Tandem Mill-1
Tandem Mill-2
Soaking Pit
ll
SPM 1 & 2
Hot Dip Galvanizing Line
Galvanized Sheet Shearing Line
Galvanized Sheet Corrugation Line
HR Coil
HR PLATE / SHEET
CR Coil
CR Sheet GP Coil
Galvanized Corrugated
& Plain Sheet
Iron Ore
Fluxes
O H P
Continuous Casting
Department
ReheatingFurnace
SAILBokaro
Pig Casting Machine
H R C F
PROCESS FLOW
BF Coke
Coking Coal
Coke Breeze
PL-II
PL-I
ANNEALING CRCF
COKE OVEN BATTERIES
DCR Mill
Slabbing Mill Hot Strip Mill
Iron Ore, Lime Stone & Dolomite Fines
Commissioning dates and Capacity of Major Units
Unit Date of Commissioning
Number Capacity (MT)
Product
Agreement with UUSR 25 Jan, 1965
Coke Ovens Sep'72 – Dec'85 8 Batteries of 69 Ovens 3.48 BF Coke
Sinter Plant Sep'72 – Dec'82 3 Machines of 252 m2 area 6.20 Skip sinter
Blast Furnaces Oct'72 - Jun'85 5 furnaces of 2000 m3 volume 4.585 Hot Metal
Steel Melting Shop I Jan'74 – Dec'78 5 LD converters of 130 T 2.20 Ingot Steel
Steel Melting Shop II Jun'83 - Jan'85 2 LD Converters of 300 T 2.25 Liquid Steel
Continuous Casting Sep'97 - Mar'98 2 Double Strand casting m/c 2.16 Cast Slab
Commissioning dates and Capacity of Major Units
Unit Date of Commissioning
Number Capacity (MT)
Product
Slabbing Mill Dec'74 8X4 Soaking pits of 160 T & one 1250 mm universal Slabbing Mill
1.90 Rolled slab
Hot Strip Mill Dec'75 4 reheating Furnaces, 5 roughing & 7 finishing stands
3.36 HR Coil
Hot Rolled Coil Finishing
Jan'76 2 Shearing line 1.1 HR Plate/Sheet
Cold Rolling Mill 1 Jun'77 Pickling Lines, Tandem Mills Saleable CR
Cold Rolling Mill 2 Sep'91 Annealing Lines, Skin Pass Mills-2, Temper/DCR Mill-1, Shearing lines-5, Slitting lines-3 & Hot Dip Galvanising Complex -1
1.66 Product CR coils/Slit coil/ sheet, slit coil, Black Plate,
GP&GC
Raw Materials coming from Mines
Wagon Tippler – Tippling a wagon
ORE HANDLING PLANT(RMHP)
Basic functions: Receive different raw materials from various mines
through wagons and their unloading & stacking with the help of tipplers & stackers
Blend raw material by making layers in beds & cross section-wise cutting beds by re-claimer
Keep buffer stock to take care of irregularities and supply raw materials to different Units as per their requirements
Basic facilities: 4 Rotary Wagon Tipplers - 20 Wagons/Hr each 7 Twin boom Stackers - 1200 T/Hr each 5 Barrel Type Reclaimers - 1000 T/Hr each 1 Bucket Wheel Type Reclaimer - 500 T/Hr 2 Transfer Cars, 10 Shuttle Conveyors, 11
Cranes, 8 Telphers
Sources of Raw Material
Material No. of Beds
(240 M)
Stock
No of Days
Source
Iron Ore Lump 4 24 Kiriburu, Meghataburu, Bolani, Barsua
Iron Ore Fines 6 16 Kiriburu, Meghataburu, Bolani, Gua
Lime Stone
BF Grade
4 13 Bhawanathpur, Khanabanjari, Purnapani
Lime Stone
SMS Grade
2 ½ 21 Kuteshwar, Jaisalmer, Nanwara
Dolomite Lump 16 Bhawanathpur Birmitrapur, Tulsidamar, Sonakhand
Dolomite Chips 50 Bhutan, Salwari
Sources of Raw Material
Material No. of Beds
(240 M)
Stock
No of Days
Source
Manganese Ore ½ Barbil, Banspani
Imported Coal Autralia, NewZealand , Haldia, Paradeep, Vizag
Prime Coking Coal 46 Dugda, Munidih, Jamadoba, Belatand
Medium Coking Coal Silos Kathara, Kedla, Rajrappa, Mahuda, Swang
Coal Middlings for Power Plant 38 M high, 12mm dia
2500T 7 Kathara, Rajrappa, Kedla, Swang, Giddi, West Bokaro, Kargali, Mahuda, Dugda, Katrasgarh etc.
Coke Oven Battery
Quenching of Coke
Coke Ovens• 8 Batteries of 5 meter height, 69 Ovens each• The process of coke making consists of destructive distillation of coal in
absence of air. The phenomenon is called high temperature (above 12000c -13000c carbonisation of coal
• Volatile matters are driven out leaving behind the residue called COKE• By-Product Plant: - Gas Condensate Section - Ammonium Sulphate Plant - Benzol Recovery Plant - Tar Distillation Plant - Sulphuric Acid Plant• Desired Analysis vs Indian Coals:
Desired Analysis
Indian Coals Imported Coals
Ash% < 16 19-24 3-12 (Av 9)
Volatile Matters%
> 25 24-26 19-28 (Av 23)
Moisture% 7-9 7-8 8-11 (Av 9)
Sulphur% < 0.05 0.56 < 0.05
Phosphorus% < 0.05 0.09 < 0.05
Material Flow Diagram : Coal & Coke
Coking CoalFrom
Various SourceWagons Coal Handling Plant
Coke Sorting Plant Coke Battery ( 8 Nos.)
Blast FurnaceCoke
+ 25 -80 mm
NutCoke
CokeBreeze-15 mm
Blast Furnace
Coke Oven Gas
By Product Plant
Sinter PlantSold
By-Product PlantIt consists of : • Gas Condensate Section • Ammonium Sulphate Plant• Benzol Recovery Plant• Tar Distillation Plant • Sulphuric Acid Plant
Products produced from by product plant. • N G Benzol• N G Toluene• Xylene• L S Naptha• S B Oil• PCM• Road Tar• Coal tar wash oil• Extra hard pitch• Hard medium pitch• Hot Pressed naphthalene
All by products of By Product Plant are sold through e- auction.
Tech-economic factors
CO Gas yield : 325.0 Nm3 / TDC
Coke Rate --- : 505.0 Kg / THM
Sp. Heat Consumption : 0.583 Gcal / TDC
Sp. Power consumption : 29.50 KWh /Ton of BF Coke
Ammonium Sulphate yield : 10.50 Kg/ TDC
Crude Tar yield : 30.80 Kg/ TDC
A view of Sinter belt
Sintering Plant• 3 Sinter Machines: Capacity 6.25 million tonnes per
annum• Sintering is the process where incipient fusion takes
place by combustion of Coke within moving bed of loosely packed fines of mainly Iron ore, Coke & Flux so as to agglomerate into a compact porous mass called Sinter
• 75-80% Sinter is being used in the burden of BF• Area of each Siter belt is 252 sq.m.• Productivity of Sintering Band : 1.2 T/M2/hr• Three Sectionsa) Raw Material Sectionb) Stock Bin & Proportioning Sectionc) Sinter Machine Section
Cleaned Water
Hot Rolling Mill Refractory Mat Plant Ore Handling Plant Coke Ovens
Raw Mat Section
Iron OreFines, LimeStone,Dolomite, Sand
Stock Bins
LimeStone Fine ,Coke Fine, Dolomite Fine
Lime Dust Fine
Waste Bins Section
Lime Dust Coarse
Mill Scale Coke Breeze
Mill Scale, Flue Dust, Lime Dust Coarse Mixed Raw Charge
Palletizing/Balling Drums
Raw Charge(Moist & Balle)
Sinter Machine Building
Blast Furnace Deptt
Slime Thickening
SectionLime Sludge
Hot Sinter Return
Cold Sinter Return
Sinter
Material Flow Diagram
Sintering Plant
Return Sinter to Stock Bin
Flue dust to waste bin
Screened coke return to raw material section
Raw material sinter
Technical Specifications of some critical equipments
Sl.no Name Quantity Capacity Installation Area01 Hammer crushers
05 250 ton/hour Raw material
02 Coke crusher 08 16 ton/hour Raw material03 Flux Screen 10 150 ton/hour Raw material04 Sinter Machine 03 300-450 ton/hour M/c building05 Sinter area 252 square metre M/c building06 Pallets 130 in each m/c M/c building07 Vacuum chambers 26 in each m/c M/c building08 Exhausters 6nos(2nos/m/c) 12000 m3/minute M/c building
Technical Specifications of some critical equipments
Sl.no Parameters Norms Actual in 2007-08
01 Specific fines consumption 1093kg/t of hot metal 1025kg/THM
02 Specific flux consumption 255 kg/THM 244kg/THM
03 Specific Coke consumption 85 kg/THM 86kg/THM
04 Specific Power consumption 45KWH/Tgross sinter 48.33KWH/TGS
05 Specific Heat consumption 0.024Gcal/TGS 0.025Gcal/TGS
A view of Blast Furnace
A Closer view of Blast Furnace
Blast Furnace• The iron oxide of ore and sinter is reduced to iron with
the help of carbon monoxide & Coke• Functions of coke in BF are manifold. It provides strong
porous bed to burden and supplies the heat load. Part of the heat load is supplied by the hot air blast
• 5 Furnaces each of 2000 cubic meter useful volume and 2640T/day HM capacity
• All furnaces have Bell-less Top charging System for continuous charging & better distribution of charge
• Coal Dust Injection in Fce.# 4 & 5• CHSGP in Fce. # 4 & 5• Capacity of B F 4.585 MT of Hot Metal per annum• Hot Metal Temperature 1460-14800C• BF Productivity: 1.4 T/m3/Day• Coke Rate 520 Kg/THM
MATERIAL FLOW DIAGRAM FOR BLAST FURNACESintering
Plant
Dust catcherIn BF
Gas Cleaning Plant
RM & MHP
SP
ProcessSteam
Net work
Stove of BF
ChargingSection
ofBlast
FurnaceCoke Ovens
ForSale
Pig Casting M/C
ForDistribution
Mixer of SMS
IMF
Slag DumpYard
TBS
BFCHSG/SGP
Blast Furnace
Hot Metal
Iron Ore Lime Stone
Mn Ore
Sinter
Coke
Slag Granules for Sale
Raw BF gas Flue Dust
Cleaned BF Gas
Partially Cleaned BF Gas
Iron Ore(Lump)
Lime Stone, Mn Ore, Quartzite
Sinter
Coke
Cold Pig
Process Steam
Hot airCold air
Slag
Quartzite
Hot Metal being charged into the converter
BF
SSD
RMP
FAS
HOT METAL
O2 Plant
BMS
SCRAP
LIME
IRON Ore, BAUXITE, Mn Ore, Lime Stone
Fe-Mn, Fe-Si
99.5 % pure O2
Steel Melting Shop• SMS-I: 5 Converters each of 100/130T capacity, 2 Mixers each
of 1300 T capacity (Rated Capacity 2.5 MT/Yr)
• SMS-II: 2 Converters each of 300 T capacity, 2 Mixers each of 2500 T capacity (Rated Capacity 2.25 MT/Yr)
• Total capacity 4.5 MT of liquid steel
• Oxygen of high purity(99.9 %) is blown into the converter from the top through water cooled lance so as to remove the impurity of hot metal through oxidation
• Impurities of Si, C & P are oxidised and Forms slag with lime
• Killed, Semi-killed and Rimming steels are made
• SMS-II has got suppresed consumption system
• Lining life : SMS-I = 800 – 1000 heats
SMS-II = 2000 – 2500 heats
Concast Slab coming out of Caster
Continuous Casting Shop
• Two Twin strand curvilinear casters with capacity to produce 2.16 MT of Slabs
• Steel Refining Unit (SRU) with LF/LRS for treatment of steel before casting
• On-line slab cutting • Steel Killed with Al/Si to O2<5ppm + Argon purging
sulphur reduced <0.015%• Slab size : Thickness 200, 225 & 250 mm
Width 950-1850 mm Length 9-10.5 mtr.
• MgO lined Tundish of 50 T capacity• Tundish Capacity = 50 T• Slide Gate System• Slab Produced
- Mild Steel : DD, EDD, Bioler Plate etc.- Low Alloy Steel : LPG, WTCR, SAILCOR & API grades
Slabbing Mill• 12 groups of Soaking pits with each group having 4 pits
; total 48 pits wherein ingot are heated to a temperature above 13000C
• On line hot & cold scarfing M/c for surface scale/defect removal
• One 1250 mm Roll dia 2-high Reversible Universal Mill to produce slabs of thickness 150-300 mm, width 950-1850 mm and length 2.5 – 10.5 mtr.
• 2800 Ton Hydraulic Shear (6 cuts/min)• 4MT Capacity (Rolling Rate 600-800T/Hr)• Main Sectionsa) Ingot Storage Yard b) Soaking PitC) Mill Proper d) Slab Storage Yard
Reheating Furnace of HSM
Strip Coming out of Finishing stands
Hot Strip Mill• Hot Rolling involves plastic deformation of a metal under
squeezing force (a pair of Rolls) above its re-crystallization temperature.
• This mill is designed to roll thin & wide strips for use in various industries such as wagon building, tube & pipe industry, drum & furniture manufacturing and further rolling in Cold Rolling Mill
• 3 Walking Beam Reheating Furnaces & 1 Pusher type furnace
• Vertical Scale Breaker
• 5 Roughing Stands, 7 Finishing Stands
• Hydraulic AGC in last four Strands
• 4 Hydraulic Coilers with automatic strapping & Robot marking
• Capacity: 3.955 MT of HR Coils• Coil Dimensions
– Strip thickness 1.6 to 16.0 mm– Strip Width 910 to 1,850 mm– Coil inside dia 650 mm– Max Coil outside dia 2,300 mm– Max coil weight 32 T
• Rolling Speed: 20 m/sec Max.
Material Flow Diagram of HSM
Slab yard
Furnaces
Furnaces
VSB R1 R2 R3 R4 R5F. Shear
F6
F7
F8
F9
F10
F11
F12CC CC
CoilersFinishing Stands
Roughing Stands
Hot Roll Coil Finishing (HRCF)
•Functions : To shear the coils into plates and sheets
•Facilities : •Shearing Line I : 5-10x1800 mm, 2.5-12 mtr. plates capacity 6,45,000 T/year
•Shearing Line II : 1.6-4x1500 mm, 1.5-4.5 mtr length sheets capacity 4,75,000 T/year
•Slitting Line : 1.5x8x1800 mm, 150mm Min. width capacity 4,00,000 T/year
•Maximum Pkt. Wt.: 15 T
5-Stand Tandem Mill
Zinc coating on Cold Rolled Coil - HDGL
Cold Rolling Mills• Cold rolling is done to produce thinner gauge strip of smooth
finish with better mechanical properties than those obtained by Hot Rolling
• Uses : Automobile Bodies, Steel Furniture, Drum & Barrels, bending and shaping applications.
• Capacity: 1.66 MT of CR saleable
• CRM I: H2So4 Pickling Line, 4-Stand Tandem Mill (2-4.5mm
thick into 0.63-2mm thick) Annealing Furnaces, SPM-I & SPM-II, Shearing Line I & II, Slitting Line and Shipping-I
• CRM II: HCl Pickling Line, 5-stand Tandem Mill (1.4-2mm thick into 0.63-1.6mm thick) , ECL, CAL, DCR Mill, HDGL and Shipping-II
• Besides Continuous Annealing furnace103 Annealing Furnaces and 230 Bases are available in three areas. Annealing is done at 680-7200C in inert atmosphere (95% N2+5%H2) with the help of mixed Gas of 1550-1600 CV
GC Sheets
Ancillary Development• Bokaro Industrial Area Development
Authority (BIADA)– 253 SSI Units registered with BSL– 81 accepted as Ancillary Units
• Various Concessions/Exemptions in– Tender cost, earnest money, security deposit
etc. – Price matching and purchase preference – BSL Laboratories offers testing facilities, help in
developing new designs and products and awareness on ISO 9000 System
• Last Modernization– Con-cast facilities integrated with SMS-II
• Ladle Furnace & Ladle Rinsing Station for Secondary Refining• Two Double Strand Slab Caster
– Up-gradation of Hot Strip Mill including• Change of Pusher Type Reheating Furnaces to Walking Beam
Type• Quick Work Roll Change System• Addition of fourth Coiler
• Next Phase Modernization (by 2010-11)– New SMS-III with 3.8 MT Capacity
• 3 x 160T Converters with 3 x 160T Ladle Furnaces & Degassing facilities
• 2 Single Strand Thin Slab Casters (1.2 MT each) & 1 conventional Slab Caster (1.4 MT)
• 7- Stand Compact Strip Mill & new Coil Yard – New CRM-III with 1.2 MT Capacity
• Coupled Pickling and Tandem Mill • ECL, Bell Annealing Furnace (100% Hydrogen Annealing)
Galvanizing Line with Galvanneal facilities
• Up gradation of 3 BF to 4900T/day capacity by enhancing volume from 2000 to 2365 M3 and installing CDI & CHSGin all BFs (presently 4&5 only)
• Sintering Area 252 m2 to 312m2 and productivity 1.2T/m2/hr
• Rebuilding of 3 CO batteries, computerised combination control system etc.
• Conversion of H2S04 PL-I to HCL Pickling Line• Enhancing capacity of SMS – II from 2.16 to 3.12 MT by
schemes• Addition of O2 generating capacities
Result of Expansion
Sl. No. Description Capacity
1. Hot Metal (MT) 7.44
2. Crude Steel (MT) 7.00
3. Saleable Steel (MT) 6.53
4. Yield of Saleable Steel from Liquid Steel (%)
91.4
5. Specific Energy consumption (Gkcal) 5.5
6. Coke rate Kg/THM 395
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