1

An Overview of
STEEL AUTHORITY OF INDIA
(BOKARO Steel Plant)

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BOKARO STEEL PLANT

CONTENTS

INTRODUCTION

PRIMARY AREA

➢ Raw Material Handling Plant

➢ Coke Ovens and Coal Chemicals
➢ Sinter Plant
➢ Blast Furnace
➢ Steel Melting Shop
➢ Fabrication

MILLS AREA

➢ Blooming & Billet Mill

➢ Rolling mill
➢ Slabbing mill

SERVICES AREA

➢ R & C Laboratory

➢ Foundry Shop

➢ Oxygen Plant

➢ Power Plant

➢ CEM/WRS

➢ Plant Civil Engineering

➢ Electrical Repair Shop

Introduction
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Bokaro Steel Plant - the fourth

integrated plant in the Public
Sector - started taking shape in
1965 in collaboration with the
Soviet Union. It was originally
incorporated as a limited company
on 29th January 1964, and was
later merged with SAIL, first as a
subsidiary and then as a unit,
through the Public Sector Iron &
Steel Companies (Restructuring &
Miscellaneous Provisions) Act
1978. The construction work
started on 6th April 1968.
The Plant is hailed as the country’s first Swadeshi steel plant, built with
maximum indigenous content in terms of equipment, material and know-how.
Its first Blast Furnace started on 2nd October 1972 and the first phase of 1.7
MT ingots steel was completed on 26th February 1978 with the commissioning
of the third Blast Furnace. All units of 4 MT stage have already been
commissioned and the 90s' modernization has further upgraded this to 4.5 MT
of liquid steel.

The new features added in modernization of SMS-II include two twin-strand slab
casters along with a Steel Refining Unit. The Steel Refining Unit was inaugurated
on 19th September, 1997 and the Continuous Casting Machine on 25th April,
1998. The modernization of the Hot Strip Mill saw addition of new features like
high pressure de-scalars, work roll bending, hydraulic automatic gauge control,
quick work roll change, laminar cooling etc. New walking beam reheating
furnaces are replacing the less efficient pusher type furnaces.

A new hydraulic coiler has been added and two

of the existing ones revamped. With the
completion of Hot Strip Mill modernization,
Bokaro is producing top quality hot rolled
products that are well accepted in the global
market.
Bokaro is designed to produce flat products
like Hot Rolled Coils, Hot Rolled Plates, Hot
Rolled Sheets, Cold Rolled Coils, Cold Rolled
Sheets, Tin Mill Black Plates (TMBP) and
Galvanized Plain and Corrugated (GP/GC)
Sheets. Bokaro has provided a strong raw material base for a variety of modern
engineering industries including automobile, pipe and tube, LPG cylinder, barrel
and drum producing industries.

BASIC INFORMATION
➢ Location : Southern bank of Damodar River; approx. 50 kms from

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Dhanbad and 140 kms each from Ranchi and Jamshedpur.

➢ Latitude : 230 39'
➢ Longitude : 860 09'
➢ Altitude: 210 meters (average) varying from 195 to 224 meters.
➢ Climate : Extreme
➢ Annual Rainfall : Average 157 cms; Maximum 195 cms
➢ Temperature : Maximum 48½0 Celsius, Minimum 2½0 Celsius
➢ Wind direction : South-West to North-East
➢ Type of Soil : Loamy up to 1 to 2 meters, 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

PRIMARY AREA
RMHP (RAW MATERIALS HANDLING PLANT
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Raw Material Handling Plant or Ore Handling Plant or Ore Bedding and
Blending Plantplay a very important role in an Integrated Steel Plant. It is the
starting point of an integrated steel plant, where all kinds of raw materials
required for iron making/steel making are handled in a systematic manner, e.g.,
unloading, stacking, screening, crushing, bedding, blending, reclamation, etc.

Different types of major raw materials used in an integrated steel plant are-

1. Iron Ore
2. Lime stone
3. Dolomite
4. Manganese Ore
5. Ferro and Silico manganese
6. Quartzite and Coal

For Blast Furnace route Iron making the main raw materials required are-

1. Iron ore lump

2. Blast furnace grade lime stone
3. Blast furnace grade dolomite
4. Coke
5. Sinter
6. Scrap
7. LD Slag
8. Mn Ore
9. Quartzite

The main objective of raw material handling plant/ore handling plant/ore

bedding and blending plant is to:-
➢ Homogenize materials from different sources by means of blending
➢ Supply consistent quality raw materials un-interruptedly to different
customers
➢ Maintain buffer stock
➢ Unloading of wagons/rakes within specified time norm
➢ Raw material preparation (like crushing, screening etc.).

The main functions of RMP/OHP/OB&BP are –

➢ Unloading& stacking of raw materials,
➢ Screening of iron ore lump & fluxes,
➢ Crushing of coke/flux and base mix preparation,
➢ Dispatch of processed inputs to customer units

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Different types of raw materials such as iron ore lump, iron ore fines, limestone,
dolomite, manganese ore, etc,.are supplied by SAIL mines (Raw Materials
Division, SAIL) or purchased from outside parties. Right quality raw material is
basic requirement to achieve maximum output at lowest operating cost. Quality
of raw materials plays a very important and vital role in entire steel plant
operation. Quality of raw materials (incoming) and processed material(outgoing)
is monitored by checking the incremental samples collected from the whole
consignment Samples are collected at Auto Sampling Unit or Sampling Unit. The
samples prepared after quarter and coning method are sent for further analysis.

Different Raw Materials and Their Sources

Sl. Raw Materials Sources

No.

1 Iron Ore Lumps Barsua,Kalta,Kiriburu,Meghataburu,

(IOL) Bolani,Manoharpur,Gua,Dalli,Rajhara,Rowghat

2 Iron Ore Fines Manoharpur,Gua,Dalli,Rajhara

(IOF) Barsua,Kalta,Kiriburu,Mghataburu, Bolani,
Rowghat

3 BF grade Lime Kuteshwar, Bhabanathpur,Nandini,Katani

Stone

4 BF grade Dolomite Birmitrapur, Sonakhan, Birsa Stone Lime

Company

5 SMS grade Lime Jaiselmer,Imported lime-stone from Dubai

Stone

6 SMS grade Belha, Baraduar

Dolomite

7 Manganese Ore Barjamunda, MOIL(Purchased)

8 Mixed Breeze Coke Generated inside the plant (Blast Furnace &
Coke Ovens)
9 Mill Scale Generated inside the plant

10 Flue dust Generated inside the plant

11 LD Slag Generated inside the plant

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Main functions of RMHP:-

➢ Tippling of wagons.

➢ Stacking and reclaiming of raw materials.

➢ Crushing of flux and coke.

➢ Sinter-mix preparation and supply to Sinter Plant

➢ Iron ore lump screening.

➢ Screened iron ore supply to Blast Furnace.

➢ High grade limestone, dolomite & iron ore lump supply to BOF.

Major equipments:-

(A) Wagon tipplers:-

➢ These are 3 in number

➢ To unload the raw materials brought in rakes of
wagons from various mines
(B) Wing Trippers:-
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➢ These are 3 in number

➢ Two operated mechanically and one hydraulically
➢ To stack material on the beds

(C) Old Reclaimers:-

➢ These are 4 in number

➢ Plough and Harrow type
➢ For reclaiming the materials

(D) Stacker cum Reclaimers:-

➢ 4 in number
➢ For stacking on beds as well as reclaiming from
beds
➢ Two beds for Iron ore and two beds for flux

(E) Slewable Stacker:-

➢ 1 in number
➢ For Sinter-mix preparation (i.e. stacking for
Sinter-mix)

(F) Blender Reclaimer:-

➢ 1 in number
➢ To reclaim the Sinter-mix

Major sections:
(1) Sinter-mix preparation:
➢ Capacity of 12051 T/day
➢ Raw Materials stored in 18 bunkers of junction
25

Main constituents of sinter mix:

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Iron ore fines 0-10 mm

Limestone fines 0-3mm

Dolomite fines 0-3mm

Coke fines 0-3mm

➢ Also waste generated in the plant like flue dust,

mill scale, Ferro scraps are added
➢ Sinter mix is sent to the Sinter Plant

(2) Flux Crushing Plant:

➢ 6 Impact hammer type crusher to crush
Limestone and Dolomite
➢ 3 Primary Crushers of 200 TPH and 3 Secondary
Crushers of 250 TPH
➢ Required size of –3 mm obtained by closed loop
crushing system
➢ Crushed Limestone and Dolomite conveyed to
sinter-mix proportioning bunkers.
(3) Coke Crushing Plant:
➢ 6 Smooth Roll Crushers to crush the coke
➢ Coke breeze offloaded at track hoppers is
reclaimed by two paddle feeders and conveyed
to storage bunkers
➢ Coke crushed to –3 mm and conveyed to
sinter-mix proportioning bunkers.

There are 8 dust extraction system and 8 dust suppression system for pollution control.

Sources of raw materials

Raw Material Size (in mm) Main Source

Iron ore fines 0-10 Bolani

Iron ore lump 10-50 Bolani

BF/SP gr. L.S 5-50 Birimitrapur

BF/SP gr. dolo 5-50 Birimitrapur

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BOF gr. L.S 25-55 Jaisalmer

Coke breeze 0-20 Internal

COCC (COKE OVENS & COAL CHEMICALS):-

Coke Ovens is an important department in an integrated steel plant. The

main objective of this department is to produce coke by carbonization of coal.
Coke is an essential raw material for production of Hot Metal.

During the process of carbonization of coal, a number of valuable chemicals

are obtained. This department also deals with the recovery and processing of these
chemicals.

Input – Output Model:

Washed Coal Wagon Wing Bed Reclimer

(-25 mm) Tipplers Tripper erners

Blending
Silos

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Primary
Crusher

Service
Pneumatic Selective Crushing
Bunkers 4 of
Classifier
4000T each
Unit

Secondary
Crusher
Coal for
BF coke Crusher
making

To Battery

Major Sections:

(1) Coal Handling:

➢ To supply coal of required quality and quantity to

service bunkers for BF coke making
➢ Washed coal and imported coal received in
wagons are unloaded by means of Box Tipplers (3)
➢ The tippled coal is stacked in silos (14) as per
quality and grade

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➢ Coal of different quantity is drawn from Blending

silos and selectively crushed and blended in
Selective Crushing Unit
➢ Blended coal is sent to service bunkers for BF
coke making
(2) Coke Ovens Battery:
➢ There were 5 batteries of 78 ovens each and a
half battery of 39 ovens
➢ Now we have 3 batteries of 78 ovens each and a
half battery of 39 ovens
➢ Capacity of oven is 16.6 tonnes on dry basis
➢ Coking time 18 to 20 hours
➢ Flue temperature 1230o C
➢ Coke of size 20 to 80 mm is sent to BF,
undersize coke is sent to RMHP.

There are four special cars in this section:

(a) Charging Car: Takes coal from service bunkers to individual ovens

(b) Ram Car: Pushes the coke out of individual ovens

(c) Guide Car: Guides the coke during pushing operation

(d) Quenching Car: Receives the hot coke for quenching

The quality parameters of cleaned coal are:

Blend coal ash 15%

Ash in BF coke 19%

Fineness of crushing -3 mm (85%)

(3) Coal Chemicals Plant:

➢ By–product plant which recovers the chemicals
from the gas and allows clean gas to be used in
coke ovens and other plant as fuel
➢ 4 gas streams with capacity of 3300 cube
meter/Hr each

This plant has four major sections:

➢ Benzol Plant

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➢ Tar distillation
➢ MNCP
➢ BOD plant

Properties / Requirement of Coke for BF use:

➢ As fuel

➢ As reducing agent

➢ Must have high mechanical strength

➢ Must be in required size range

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SINTER PLANT

A large quantity of fines is generated in the mines, which cannot be charged

directly into the Blast furnace. Moreover many metallurgical wastes are
generated in the steel industry itself, disposal of which is very difficult. In order
to consume this otherwise waste fine material they are compacted together and
made into lumps by a process known as SINTERING. Sintering is a technology
for agglomeration of fine mineral particles into useful Blast furnace burden
material. This technology was developed for the treatment of waste fines in the
early 20th century. Since then sinter has become the widely accepted &

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preferred Blast furnace burden material. At present improvement in Iron & Steel
production without sinter is unbelievable. No iron & Steel making plant can be
conceived without sintering process.
Raw materials used in Sinter Plant

1. Iron ore fines

2. Coke breeze fines
3. Millscale+fines
4. Lime stone fines
5. B.O.F.Sludge
6. B.O.F.Slag
7. Dolomitefines
8. BurntLime
9. BFReturnfines+InplantR/fine

The ore fines, lime stone fines, dolomite fines, lime dust, coke breeze & some
other metallurgical wastes are proportioned based on charge calculation. Then
these are mixed in a balling drum with the addition of water and then loaded
into grates of moving pallets. The purpose of Balling drum is to mix the raw
materials (called base mix) with water and make balls. After mixing and ball
formation this base mix is loaded on moving sinter machine pallets. HEARTH
LAYER which consists of finished sinter of size fraction 16to 25mm forms the
bottom layer. Base mix is loaded above the hearth layer. As soon as these raw
materials reach the ignition furnace, Top layer is ignited in the IGNITION
FURNACE by burning of gases. Air is drawn downwards through exhausters.
The heat from top layer is gradually transferred to subsequent bottom layers.
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Due to burning of coke particles bonding take place between the grains and a
strong & porous aggregate is formed known as “SINTER”. This sintering process
is over when bottom layer coke fine burning is completed. The sinter cake is
then crushed, screened, cooled and dispatched to Blast furnace. The
ideal size of sinter required in blast furnace is in between 5mm to 40mm. The
other sizes are screened & returned back to sinter bins.

Sinter making

Sintering of fines by the under grate suction method consists of the mixing of
fines with finely crushed coke as fuel and loading the mixture on the pallet
grates. Ignition of the fuel proceeds on the surface of charge by a special ignition
arrangement, called ignition furnace (where gaseous fuel is burnt to produce
high temperature to ignite the fuel in sinter mix) the gases used in ignition
furnace are mainly coke oven gas and mixed gas. Mixed gas is combination of
coke oven gas and blast furnace gas. Further the combustion
is continued due to suction of air through the layers of the charge by means of
Exhausters. Due to this, the process of combustion of fuel gradually moves
downwards up to the grates.

From the scheme obtained in a few minutes after ignition, it is observed that
the sintering process can be divided into six distinct zones:

1. Zone of Cold Sinter (60 to 100 degree Celsius)

2. Zone of hot Sinter (100 to 1000 degree Celsius)
3. Zone of intensive combustion of fuel (1000 to 1350 degree Celsius)
4. Heating zone (1000 to 700 degree Celsius)
5. Zone of Pre-heating of charge (700 to 60 degree Celsius)
6. Zone of Re-condensation of moisture (60 to 30 degree Celsius)

In all the zones except the zone of combustion, the reactions taking place are
purely thermal where as in the zone of combustion reactions are thermal and
chemical. The maximum temperature attained in the zone of combustion will be
1300-1350 degree Celsius. The vertical speed of movement of the zones depends
on the vertical speed of sintering. Heat from the zone of ready sinter is intensively
transmitted to the sucked air. In the zone of combustion of fuel hot air and
preheated charge comes into contact with each other24which with the burning
fuel will result in the formation of high temperature. Maximum temperature will
be developed in this zone and all the physical-chemical process takes place
resulting in the formation of Sinter. In the zone of pre-heating the charge is
intensively heated up due to transfer of heat from the sucked product of
combustion. In the zone of re-condensation of moisture, the exhaust gases
during cooling transfer excess moisture to the charge. Temperature of this zone
sharply decreases and will not increase till all the moisture is driven off. As the
fuel in the zone of combustion is burnt away, Sinter, the height of which
increases towards the grates, is formed above this zone from the red hot semi-

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fluid mass, forcing out subsequent zones. Disappearance of the zone of

combustion means the end of sintering process.
The sinter cake is then crushed, screened, cooled and dispatched to Blast
furnace. The ideal size of sinter required in blast furnace is in between 5mm to
40mm. The other sizes are screened & returned back to sinter bin.

Chemical reactions in sintering process:

Sinter is produced as a combined result of locally limited melting, grain
boundary diffusion and re-crystallization of iron oxide during sintering. The
basic metallurgical

Reaction takes place in sintering zone.

1. C+O2---CO2 + 4220calories
2. CO2 + C --- 2CO + 53140 calories
3. 3Fe2O3+ CO ---- 2Fe3O4 + CO2 + 8870 calories
4. Fe3O4 + CO ---- 3FeO + CO2 - 4990 calories

Factors affecting sintering process

1. Quality of Input raw materials

a. Quality of Iron ore fines: +10 mm should be nil
: -1mm should be 30% maximum
: Alumina (Al2O3) 2.5% maximum
: Silica (SiO2) 2.5% maximum
Increase in +10mm fraction will result in weak sinter & low productivity Increase
in –1mm fraction will decrease bed permeability resulting in low productivity
Increase in % of Alumina increases RDI(Reduction Degradation Index) resulting
in generation of –5mm fraction & also resulting in chute jamming.(Due to high
Alumina in B/Mix.

b. Quality of Flux: -3mm fraction should be 90% minimum (Crushing index)

: Less crushing index results in free lime, causing weak sinter 25
c. Quality of Coke: -3mm fraction should be 90% minimum (Crushing index of
coke)
: +5mm fraction should be nil
: Increase in 5mm fraction decreases the productivity

2. Moisture:
Moisture in the form of water is added in the base mix in balling/nodulising
drums. Water acts as binder of base mix. Addition of water in base mix plays
important role in sinter bed permeability. Ideally 6 to 7% of total base mix of
water are used. Higher % of water results in low permeability & less sintering
speed. Less % of water results in less balling, hence less permeability, resulting
in low productivity.
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3. Ignition furnace temperature:

Ignition of sinter mix is carried out through ignition hearth where a temperature
of 1150to 1350 degree Celsius is maintained by burning gaseous fuel by the help
optimum air/gas ratio.32.5% of co gas & 67.5% of Bf gas is used to maintain
calorific value1900kcal/m3.Higher hearth temperature results in fusing of
sinter at top layer. This reduces the bed permeability, hence low productivity.
Low heart temperature results in improper ignition. Sintering process will not
be completed, hence –5mm fraction will increase, i.e recalculating load will
increase.
Note- BF&CO gas mixing ratio and calorific value varies in different plant under
SAIL unit.
4. Coke rate:
Coke acts as a solid fuel in base mix in the sintering process. It is normally 6%
of total charge. Higher coke rate will fuse the top layer, thereby decreases the
bed permeability. Sticker formation will increase. Low coke rate will result in
incomplete sintering.

5. Machine speed:
Speed of sinter machine can be varied as per the condition of sintering process.
BTP (Burn through Point) temperature decides the completion of sintering
process. It is observed normally in second last wind box from discharge end side
of sinter machine where the temperature reaches up to 400 degree Celsius
(approximately). Higher machine speed, lower BTP causes more–5mm
generation, hence lower productivity. Lower m/cspeed, higher BTP temperature
causes low productivity
Note: BTP Exhaust gas temperature which indicates the completion of sintering
processes called BTP. It is approximately around 400 degree centigrade.
Crushing, Cooling & Screening of sinter
The finished sinter cake is then crushed to the size of 100mm by using
crushers.Normalising of finished crushed sinter is then done on coolers by
means of air blowers(induced draught fans),so that cooler discharge end
temperature is about 80 degree centigrade. For effective cooling, bigger size of
sinter should be on bottom portion &smaller size should be on top. Finally
various fractions of sinter is screened out.-5mm fraction of sinter returns back
to bunkers. 16 to 25mm fraction is also screened out to be used as hearth layer.
Rest sizes goes to blast furnace, after screening +10mm fraction should be
65%minimum and –5mmfraction should be 8% maximum as per requirement of
blast furnace

Advantages of using Sinter

1. To utilize the ore fines generated at mines to transform to an acceptable feed
in blast furnace
2. To utilize economically all the metallurgical wastes like Mill scale, L.D slag,
B.O.F slurry, Flue dust, Ferro scraps etc.
3. To utilize the coke breeze generated in coke screening at coke ovens as fuel,
otherwise has no metallurgical use

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4. To reduce coke rate in B.F by ensuring free available lime for slag.
5. To increase productivity of B.F

BLAST FURNACE

Blast Furnace is the most important part of an integrated steel plant. It is

considered as the heart of an ISP. The objective of Blast Furnace is to take the
raw material from RMHP, coke from Coke Ovens and Sinter from Sinter Plant
and convert it into pig iron or ”Hot Metal”. Coke serves as the heat source and
reducing agent while Limestone and Dolomite are used as flux, which combines
with gangue to produce slag. A Blast Furnace is so called because it uses air blast
as oxygen source for the process.

There are four Blast Furnaces in DSP, out of which 3 are in running condition.

Input – Output Model:

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Sinter Iron ore lump

Coke

Hot Blast
Blast
Hot Blas BF Gas Clean BF
Furnace GCP
Gas

Hot metal

Slag

PCM

SMS

BF is a counter current heat and mass exchanger, in which solid raw materials
are charged from the top of the furnace and hot blast, is sent through the bottom
via tuyeres.The heat and is transferred from the gas to the burden and oxygen
from the burden to the gas. Gas ascends up the furnace while burden and coke
descend down through the furnace. The counter current nature of the reactions
makes the overall process an extremely efficient one in reducing atmosphere.
The real growth of blast furnace technology came with the production of high
strength coke which enabled the construction of large size blast furnaces.

The raw materials and their quality:

In India steel is being produced largely through the blast furnace/ B.O.F.route.
Iron ore, sinter and coke are the major raw materials for blast furnace
smelting.

The following raw materials used for the production of pig iron: -
(i) Iron ore
(ii) Limestone
(iii) Dolomite
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(iv) Quartzite
(v) Manganese ore
(vi) Sinter.

Iron ore: Iron bearing materials; provides iron to the hot metal. It is the principal
mineral in blast furnace for extraction of pig iron; generally rich in iron content
varying from 60% to 66%. The high alumina content makes the slag highly
viscous and creates problems for stable furnace operation.

Limestone: Acts as flux. Helps in reducing the melting point of gangue present
in the iron bearing material and combines effectively with acidic impurities to
form slag in iron making.

Quartzite: Acts as an additive quartzite is a mineral of sio2 (silica) and under

normal circumstances contains about 96-97% of sio2 rest being impurities.

Manganese ore: Acts as additive for the supply of Mn in the hot metal. Mn ore
is available in the form of combined oxides of Mn and Fe and content of Mn is
about 31-32% for steel plant use

Coke: Acts as a reluctant and fuel, supports the burden and helps in
maintaining permeable bed.

Sinter: It is iron bearing material. Sintering is the process of agglomeration of

fines(steel plant waste) by incipient fusion caused by heat available from the fuel
contained in the charge. The lumpy porous mass thus available / obtained is
known as “sinter”.

Coal dust: Acts as an auxiliary fuel, reduces coke consumption in the bf

31
Coal tar: Acts as an auxiliary fuel, reduces coke consumption in the bf

High lines and Stock house:

High lines: The main responsibility of high lines section is to receive the raw
materials required for the production of hot metal from various sources, storing
and transporting them to the top of the furnace in time, for the smooth running
of the furnace.

Ore yard: Raw materials arriving to the blast furnace department from various
sources are unloaded in the ore trench of ore yard. After the ore trench, ore yard
is located towards the blast furnace. The ore yard is meant for stocking and
averaging of materials. The materials from ore trench are transported to ore yard
with the help of ore bridge cranes (OBCs). Raw materials from the ore yard are
charged by means of electrically operated transfer cars (OTCs); carry the
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materials into the respective bunkers. Sinter From bunker located on the
extension tracks of high line was collected in transfercars moving on rail tracks
or sinter comes by means of conveyor belt and is stored in receiving hopper.
Sinter is screened, and the fines are returned through conveyor belts Coke (25
-80mm) from coke sorting plant is supplied to the coke bunkers of the blast
furnace with the help of conveyor belts.

Stock house: Below the bunkers there is a vibro-feeder, which feeds the material
to the conveyor belt, which charges the material on screen. The bf size material
is fed to weighing hopper through ore discharge conveyor. The weighing hopper
discharges the material into the skip. There are conveyors to remove the fines
from the system.

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Raw materials including coke are transported and collected into high line
bunkers placed near the furnaces and then properly screened and weighed.
Weighing is done either by scale car or by load cell or by any suitable
arrangement. These batched proportions of the raw materials are conveyed to
the top of the blast furnace via skip car or conveyors and are charged in the
blast furnace. The distribution is maintained in such a fashion that alternate
layers of coke and iron-containing burden (sinter and iron ore) are formed inside
the bf.

Flow of material to charging skip is

➢ Bunkers
➢ vibro feeder
➢ conveyor belts
➢ weighing hopper
➢ Skip car.

Hoist house:
For taking charged materials to the furnace top, two-way skip hoist with 2
skips are provided. The hoist house operates the skip that is driven by two
motors. Bell hoist, equalizing valves test rods etc. are also operated from hoist
house.

Blast Furnace and Accessories

Blast furnace is basically a counter current apparatus, composed of two

truncated cones placed base to base.

➢ The sections from top down are

➢ Throat, where the burden surface is.
➢ The shaft or stack, where the ores are heated and reduction starts.
➢ The bosh parallel or belly and
➢ The bosh, where the reduction is completed and the ores are melted
down.
➢ The hearth, where the molten material is collected and is cast via the tap
hole

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B F Proper

The entire furnace is lined with suitable refractory and carbon blocks in the
hearth and in the periphery of the hearth bottom. In addition to refractory lining,
there are water coolers, designed to enhance the life of the furnaces. There is a
tap hole of suitable dimension and length for the purpose of tapping the hot
metal. The raw material at the top will be charged either through 'double bell
system' or 'bell less system' for furnace smelting. Since blast furnace is basically
a counter current apparatus the descending stream of raw materials extract heat
from the ascending stream of gas generated from the burning of coke at the
tuber level. The ascending stream of gas contains CO (carbon monoxide)
nitrogen and hydrogen and in the events of its coming in contact with the iron
ore, reduction (this reduction is called indirect reduction) of iron ore takes place
at the upper part of the stack. Coke in the form of 'c' also takes part in the
reduction. In the hearth there are slag notches at about 1.1-1.6 meter away from
the hearth bottom for flushing out slag at regular intervals before tapping, the
notches are also extensively water cooled by 'monkeys'. The number of tap hole,
slag notches, their positioning and dimension will depend upon the capacity of
the furnace. Many modern furnaces are having 2-4 tap holes without slag
notches. The furnaces are equipped with tubers (water cooled copper
construction for admission of hot blast of air) through which preheated air blast
at a temperature of about 8500c -10000c is introduced for burning of coke.
Before preheating, the blast of cold air supplied by power and blowing station is
introduced into hot blast stoves at about 3.2-353.5 kg/cm2 (gauge pressure)
wherein the air is pre-heated regenerative and sent to the furnace through hot
blast main and bustle pipe. The air blast then passes from the bustle pipe
through gooseneck and tuber stocks/blow-pipes into tubers. The pressure of the
blast and its flow rate is dependent upon the capacity of the furnaces.

As the stream of the material descends down through different temperature

zones and get two products:-
▪ Metal in the bottom.
▪ Slag, having less density floats at the top of metal, and
▪ BF gas from top of the furnace. It generally comprises of 21-
22% CO; 19-19.5%CO2, 54% of N2, H2 4.4%, O2 0.1%.
Temp.of top gases are in the range of 100-300oc
Liquid iron collected in the hearth is taken out by opening the tap hole with
power driven drill and oxygen lancing after regular interval into a train of ladles
kept below the runner of the cast house. Slag that comes along with the metal
is skimmed off with the help of skimmer plate towards slag runner and collected
in slag thimbles or to slag granulation plant (SGP) of cast house. Slag thimbles
are then sent to the dump yard or slag granulation plant. Metal ladles are either
sent to SMS or pig casting machine (PCM) and foundry depending upon the
composition of the metal being tapped and as per requirement.

Top charging equipment:

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The burden material which reaches to the top of the furnace by skip car or by
conveyer is to be distributed into the furnace. For this double bell charging
system, rotating charging unit (RCU),MTA is provided or equipped with paul-
wurth bell less top (BLT) charging system, which replaces bells with charging
bins, upper material gate, upper sealing valve, lower material gate and lower
sealing valve. This system also has a gearbox to operate rotating chute. The
latter distributes the material inside the furnace peripherally indifferent rings.
This facilitates better burden distribution inside the furnace.

Double bell BLT system

STEEL MAKING

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The Hot Metal, which is produced by Blast Furnaces, consists of various

impurities. Main impurity present is Carbon and other impurities like
phosphorus, sulphur, silicon, nonmetallic inclusions etc are also present. Steel
making is the process of purification of this Hot Metal. Steel such produced is
the pure form of metal. Hot Metal contains around 4%of Carbon, which is
reduced below 0.1% as per the requirement. Other impurities like sulphur,
phosphorus are removed and alloying elements such as manganese, nickel,
Chromium and vanadium are added to produce the exact steel required. The
schematic view and various processes involved in steel making are as follows.

HMDS—HOT METAL DESULPHURISATION

BOF—BASIC OXYGEN FURNACE
OH/TH—OPEN HEARTH/TWIN HEARTH
ARS—ARGON RINSING STATION
LF—LADLE FURNACE
RH DEGASSER—RUHR –STAHL HERAUS (Process is named on a German
town and
a German scientist)
VAD—VACCUM ARC DEGASSER
VOD—VACCUM OXYGEN DECARBURISATION
CCS/CCP—CONTINUOUS CASTING SHOP/ PLANT

The Hot Metal from Blast furnace comes in Hot metal ladles to Steel
Melting Shop by rail. It is poured into a vessel called Mixer. Mixer has a Charging
hole from where Hot metal is being charged into with the help of heavy cranes
and a sprout to take out hot metal by tilting the mixer. Main functions of mixer
are storage and homogenization. Mixed gas is supplied through side burners in
order to maintain temperature in Mixers. Once it is taken out it can go to Hot
metal desulphurization unit and then to either of the process of steel making i.e.
Open/Twin Hearth furnace or Basic Oxygen Furnace (BOF).
SMS (STEEL MELTING SHOP)
SMS or Steel Melting Shop is the section where hot metal from Blast furnace
is converted into steel. The process is Basic Oxygen Furnace or LD process. This
process was first used successfully in a place called Linz in Austria and then at
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Donawitz in Austria. The name LD process came from the names of these places.
Basic Oxygen Furnace was added under modernization of DSP. It has a capacity
of 1.876 MTPA.

SMS can be divided into 3 sections:

➢ Basic Oxygen Furnace

➢ Continuous Casting Plant

➢ New Lime Calcinations Plant

Basic Oxygen Furnace:

Hot Metal coming out of the Blast Furnace is collected in ladles and poured
into mixers. The mixers (2) serve the purpose of storing as well as homogenization
of temperature and composition. Coke oven gas is used here to maintain the
temperature at 1260o C. the quantity of raw materials for producing one ton of
steel are as follows:

Hot Metal 1073 kg

Scrap 65.9 kg

Iron Ore 15.6 kg

Briquetted lime 10.6 kg

Calcined Lime 81.3 kg

Dolomite 31.3 kg

Fe- Mn 1.11 kg

Fe- Si 1.32 kg

Al 0.15 kg

Coke Breeze 3.27 kg

The shop has three converters each having a capacity of 110-130T per heat. The
converters were commissioned by Mannesmann Damage of Germany. Each
converter has its own lance system for blowing oxygen at high pressure so as to

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form an emulsion on the surface of metal which increases the surface area to such
an extent that separation of impurities takes place very fast.

The oxygen blowing rate through the lance is 415 Nm 3/min. and the blowing
pressure is 14.2 to 14.3 bars from top. The tap to tap time of BOF is approximately
57 minutes out of which oxygen blowing time is 18 min. the gas obtained from
BOF converter has a calorific value of 2100 Kcal/Nm3 which acts as a fuel.

BOF has an online process monitoring system. The system uses VAX/VMS system
which works on the principle of virtual memory. The higher level of
computerization caters to the need of quick retrieval of data about operation
parameters.

(ii) Continuous Casting Plant:

CCP, one of the critical features of DSP is the first billet caster in any ISP in SAIL.
The machines are designed and supplied by Comcast Standard AG, Switzerland.
Presently, we have two machines with six strands in each, capable of producing
billets of sizes varying from 80 mm2 to 150 mm2.

Under traditional route, liquid steel is allowed to solidify into separate moulds and
come out as ingots, which are then rolled to get the billets. Continuous casting
route bypasses the steps of soaking and rolling in blooming and billet mill.

Technical Features of CCP:

No. of machines 2

No. of strands/machines 6

Design Limit 80 -150 mm2

Casting Radius 6m

Heat Size 110T (normal), 130T (max)

Casting time 85 min.

Shear Up cut pendulum type

Molten steel is taken to ladle treatment section. The purpose of ladle treatment
is to homogenize the temperature and composition, floatation of non-metallic
inclusions and to facilitate active slag metal reactions. A dummy bar is inserted
in the mould, up to 100 mm with the help of pinch rolls. The mould is surrounded
by 4 mm water jackets through which primary water is circulated internally.

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Primary cooling is thus done by dematerialized water. Other zones are kept cool
by industrial water.

The billets formed are cut to proper lengths and are allowed to cool in air and
then packed and sent to stock yard.

(iii) NLCP (New Lime Calcinations Plant):

NLCP came up during during modernization in 94-95. This plant came up

to cater to the need of BOF. The main function of this plant is to produce lime
from naturally available limestone. Lime is mainly required in steel making
process to reduce sulphur and phosphorous content of steel. Presently, Limestone
from Jaywalker is used as input material for the plant.

There are three kilns (Annular kiln shaped), of capacity 300T/day, one is kept
standby; each kiln is a vertical cylindrical structure. Limestone, which is charged
from the top, gradually descends through the kiln, where it is subjected to control
heating by two firing zones preventing the charge from direct exposure to base
flame. Coke oven gas at 5500 mm water pressure is used as fuel for heating.
Temperature range of heating is 12000 C - 1250o C

The calcinations process is almost complete as the charge reaches the bottom
portion of lower combustion zone and the calcite lime is discharged into a silo by
Lime Discharging device.

NLCP has got bunkers and conveyors for storage, handling and supply of fluxes
to converter shop.

ROLLING MILLS

The process of plastically deforming metal by passing it between rolls is known

as rolling.
TYPES OF MILLS:-

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A. PRIMARY MILLS
• Blooming & Billet Mill
B. FINISHING MILLS
• Section mill
• Skelp mill
• Merchant mill
Semi Finished products of BSP
• Blooms:160 to 250x250 mm
• Billets:125x125 mm,100x100 mm
• Slabs:140 to 225x80 mm
• Ingots: fluted ingots, 8T ingot

BBM (BLOOMING & BILLET MILL)

Main objective of this mill is to produce rectangular sections called blooms.

The 8T ingots produced at the SMS are first sent to the Stripper Bay. After this
the ingots are reheated for hot rolling process to give them different sizes. Sections
above 125x125 are called blooms while sections below 125x125mm are called
billets. Some blooms go to Section Mill and some to Billet Mill. The billets go to
Merchant Mill.

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Major Equipments:
Soaking Pits:

20 n numbers and of 3 types

• Wolman type - Bottom fired with ceramic recuperations

• Ofulyns type - side fired with ceramic recuperations

• Priest type - side fired with ceramic recuperations

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42” Blooming Mill

• 2- high reversing type with twin motor drive

• Driven by two 3000 HP DC motors

• Speeds of 0/40/60 rpm

• Side guard type manipulators to guide the ingot through

various passes

• Generally rolled in 13 passes (19 passes required for special

steel).

Primary Hot Bloom Shearing & Stocking:

• Front and back ends of blooms which develop fish tails are
sheared using1200T shear

• Shear can cut a max. cross section of 256 square inch.

32” Intermediate Mill:

• 2 high reversing mill driven by one 4500 HP DC motor

• Roll diameter varies from 800 mm to 925 mm

• Springs balanced rolls

• Speed range of 0/80/120rpm

700 Shear:

• Blooms are cut to length with nominal blade load of 700 T

Important Parameters:

(a) Pit Time:

This is the amount of time the ingots have to be placed in the soaking
pits. This is equal to 1.5 times the track time, which is around 3 to
4.5 hrs for hot ingots and around 12 hrs for cold ingots.

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(b) No. of passes in blooming mill:

13, in case of normal steel and 19, in case of special steel.

Billet Mill

Blooms produced in Blooming Mill are further rolled into billets of various
sizes. The capacity of Billet Mill is 0.957 tonne per annum. The products of this
mill are 50 mm square to 125 mm square Billets and 140 to 240 mm * 75/80
mm skelp slabs.

Major Equipments:

(a) Mill Train:

• Continuous Morgan design with 8 strands

• Vertical rolls on first and fourth strands & remaining are

horizontal, 1 to 4 are roughing stands each run by 800 HP
DC motor (1 & 2) and 1000 HP DC motor (3 &4)

• 5 to 8 (finishing stands) driven by a single 700 HP

synchronous motor

(b) Up and Down Cut Shear:

• For emergency purpose

(c) Flying Shear:

• Cuts materials in process. (maximum capacity 130

square inch)

CASTING

In modern steel plants everywhere there is a demand for more and more
quality finished products. For rolling to very thinner products, continuous
casting products are the best compared to teeming of the steel to make ingots
and then to roll the ingots to produce slabs or billets or blooms. Continuous
casting not only meets the higher production within same time frame but the
quality of such products is quite lucrative and hence demanding.

Before going into the details of CCM a brief description of the caster is given below:
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<BOF> => Raw/Crude Steel from converter => <SRU> => Refining crude steel
i.e. killing, Homogeneous Temperature and Composition => <Caster> Turret,
Ladle S/Gate, Shroud => Tundish => Mould

Liquid steel comes from the ladle into the punish. Tunis is a device
where it collects, accumulates liquid steel from the ladle and feeds to two or
more moulds through SEN depending on the m/c and process.

Casting Preparation

1. Steel that is to be cast is treated well at SRU for smooth casting.

2. Tundish through which casting will be done is to be prepared.
Tundish is a device through which continuity of the casting is maintained.
There are two types of casting practices are in use namely cold tundish and hot
tundish practices. Liquid steel comes from the ladle into the tundish and in turn
the tundish feeds the liquid steel into the mould through different outlet at the
bottom of the tundish. Tundish is made of steel and inside of which is lined with
refractory bricks or castable. After that tundish boards are fixed over the
refractory lined. Submerged entry nozzle (SEN) are fixed by clamping device in
each of the tundish outlet
3. Preparing of the mould:

Mould is the most important equipment in the caster m/c. primarily

mould is prepared according to the shape and size of the product. For
solidification of the initial liquid steel that enters into the mould one DUMMY
BAR head is used, which is fed into the mould with a fixed rod or flexible chain.
This DUMMY BAR head is packed. Mould is made purely of copper as copper
has the most heat discharge capacity than any other metal economically
available. All sides of this mould is made up of Cu plate and heat from liquid
steel immediately discharges trough the copper plates by mould cooling system
Copper plates are cooled by circulating soft water through designed tubes
in the form of coils.

Here the difference of MOULD COOLING WATER Outlet Temperature &

Inlet Temperature is monitored continuously. It is very much hazardous part in
caster m/c during casting. An alarm is provided as soon as the difference of
temperature raises more. Immediate actions are to be taken and if necessary
casting should be stopped without waiting for any other decision to be asked
from anyone.

Casting Process
Liquid steel taken into ladle is refined at SRU is placed over the turret arm
and ladle SG is fixed. Then one shroud is fixed at the bottom of the ladle collector

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nozzle so that no stream of liquid steel comes in contact with the atmosphere
and no spillage occurs. This liquid steel gradually fills the tundish and from
there liquid steel leaves tundish nozzle/TSG through SEN into the mould.
Initially steel rests on the DUMMY BAR head on which some chillers are placed
to get the liquid steel freeze/solidifies quickly then the m/c starts with MOM &
casting powder is to be sprayed continuously at a certain mould level. The
process continues after the DUMMY BAR head is disconnected as it reaches at
its particular position. Length of the slab/billet is maintained by using cutting
torch/ shearing blades.

ROLLING MILLS

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HOT AND COLD ROLLING

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Hot Rolling: The rolling process in which rolling is done above recrystallisation
temperature it is called hot rolling.
Cold Rolling: The rolling process in which rolling is done below recrystallisation
temperature is called cold rolling.

Recrystalisation temperature: is the temperature on rolling above which we

get strain free grains and minimum residual stresses in rolled metal. It is
normally 0.5 to 0.7 times of melting point of the metal. All SAIL integrated plants
have hot rolling mills whereas only Bokaro, Rourkela and Salem have cold rolling
mills.

LONG AND FLAT PRODUCTS

During rolling when the input is pressed from both perpendicular directions
(from top-bottom and from both sides) the volume of the metal goes into length.
This is called long product rolling. If the metal is pressed from top to bottom
and spreads on the sides it is called flat product rolling.

PRODUCTS OF ROLLING MILLS OF SAIL Bokaro Steel Plant

• HR coils, sheets, plates

• CR coils, sheets
• Galvanised plain and corrugated sheets
• Tin mill black plates
APPLICATIONS OF ROLLED PRODUCTS OF SAIL

Hot Rolled Coils, Sheets and Skelps

Used for construction of tanks, railway cars, bicycle frames, ships, engineering,
military equipment and automobile and truck wheels, frames, and body parts.
HR coils are also used as feedstock for pipe plants and cold rolling mills where
they undergo further processing.

Plates
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Steel plates are used mainly for the manufacture of bridges, steel structures,
ships, large diameter pipes, storage tanks, boilers, railway wagons, and reassure
vessels. SAIL also produces weather-proof steel plates for the construction of
railcars. SAIL is the only producer of wide and heavy plate products in India.

Cold Rolled Products

The products of the cold rolling mills include cold rolled sheets and coils,
which are used primarily for precision tubes, containers, bicycles, furniture and
for use by the automobile industry to produce car body panels. Cold rolled
products are also used for further processing, including for colour coating,
galvanizing and tinning. Galvanized Sheets are used in roofing, paneling,
industrial sheeting, air condition ducting and structural applications.
Electrolytic Tin Plates are used in containers for packaging of various products
including edible oils, Cola, Fruit Juices, Pickles and confectionary items.

Railway Products
Rails are the main rolled products by SAIL. It is used primarily to upgrade
and expand the existing railway network in India.

Structural’s
I-beams, channels and angle steel are used in mining, construction of
tunnels, factory structures, transmission towers, bridges, ships, railways, and
other infrastructure projects.

Bars and Rods

Reinforcement steel and wire rods are primarily used by the construction
industry.

Semi-Finished Products
Semi-finished products (blooms, billets and slabs) are converted into
finished products in SAIL’s processing plant and, to a lesser extent, sold to
rerollers for conversion to finished products
HOT ROLLING

The rolling process in which rolling is done above re crystallization temperature

is calledhot rolling. More reductions are possible in hot rolling as compared to
cold rolling.

REHEATING FURNACES
In the reheating furnaces the Input materials are heated to a specified
temperature and soaked for given time depending upon size of input and their
metallurgical requirements. Ideally, it is aimed to equalize the surface and the
core temperatures of the slab. Well soaked slabs are discharged from the furnace
at dropout temperature of 1100-1300oC.The furnace discharge temperature also
depends on the extent of heat losses downstream.

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Types of Reheating Furnaces:

In Primary mills Soaking pits are used which are primarily batch type
furnaces. In secondary (finishing) Mills, continuous furnaces are used.
Continuous furnaces are mainly of two types pusher type and walking Beam
type. These furnaces mainly use a mixture of coke oven gas and blast furnace
gas which are readily available in integrated steel plant.

COLD ROLLING
COLD ROLLING MILL (CRM)

Purpose of cold reduction is to achieve, a reduction in the thickness, a

designed surfacefinish, desirable mechanical properties, close dimensional
tolerance and producing as per customer requirements. These thickness
reductions are achieved through multi-pass rolling in a reversing mill or tandem
mill. Apart from such mills, a cold rolling mill complex may include other
facilities for pre-and post-rolling operations. The sequence of operation and
material flow in a typical cold rolling mill complex is shown in Figure 3.1.

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SlabbingMill
Slabbing Mill transforms ingots into slabs by rolling them in its 1250 mm
Universal Four-High Mill. The rolling capacity of the Mill is 4 MT per annum.
The shop has Hot and Cold Scarfing Machines and 2800 T Shearing Machine.

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Controlled heating in Soaking Pits, close dimensional accuracy during rolling

and hot and cold scarfing help produce defect free slabs.

HotStripMill
Slabs from CCS and Slabbing Mill are processed in the state-of-the-art Hot Strip
Mill. The fully automatic Hot Strip Mill with an annual capacity of 3.363 million
tonnes has a wide range of products - thickness varying from 1.2 mm to 20 mm
and width from 750 mm to 1850 mm. The mill is equipped with state-of-the-art
automation and controls, using advanced systems for process optimization with
on-line real time computer control, PLCs The finishing group consists of a Flying
Shear, Finishing Scale Breaker and seven 4-high Finishing Stands. Hydraulic
Automatic Gauge Control system in the finishing stands ensures close thickness
tolerance. The Work Roll Bending System ensures improved strip crown and
flatness. The rolling speed at the last finishing stand is between 7.5-17.5 meters
per second. The Laminar Cooling System is a unique feature to control coiling
temperature over a wide range within close tolerance. The Hydraulic Coilers
maintain perfect coil shape with On-line Strapping system. On-line Robotic
Marking on the coil helps in tracking its identity.

Hot Rolled Coil Finishing

All the Hot Rolled coils from the Hot Strip Mill are received in HRCF for further
distribution or dispatch. HR Coils rolled against direct shipment orders are
sheared and finished to customer-required sizes and dispatched to customers.
The material is supplied as per Indian specifications and many international/
foreign specifications. The shop has two shearing lines with capacities of 6,
45,000 Tonnes/ year and Rs. 4, 75,000 tones per year respectively.

Cold Rolling Mill

The Cold Rolling Mill at Bokaro uses state-of-the-art technology to produce high
quality sheet gauge material, Tin Mill Black Plate and Galvanized Products. Cold
rolling is done to produce thinner gauge strips of very smooth and dense finish,
with better mechanical properties than hot rolling strips. Rolling is done well
below re-crystallization temperature without any prior heating of the material.
The products of CRM are used for deep drawing purposes, automobile bodies,
steel furniture’s, drums and barrels, railway coaches, other bending and
shaping jobs and coated steels. The CRM complex comprises of two Pickling
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Lines (including a high speed Hydrochloric Acid Pickling Line with re-generation
facilities), two Tandem Mills, an Electrolytic Cleaning Line, a Continuous
Annealing Line, Bell Annealing Furnaces, two Skin-Pass Mills, a Double Cold
Reduction Mill (DCR), Shearing Lines, Slitting Lines and a packaging and
dispatch section. The 5-stand Tandem Mill is capable of rolling sheet gauges up
to 0.15 mm thickness. It has sophisticated Hydraulic Automatic Gauge Control,
computerized mill regulation and optimization control.

Hot Dip Galvanizing Complex

The Hot Dip Galvanizing Complex integrated with the CRM produces zinc-
coated Cold Rolled strips resistant to atmospheric, liquid and soil corrosion. The
Continuous Coil Corrugation Line in the HDGC produces corrugated sheets and
the Galvanized Sheet Shearing Line produces galvanized plain sheets for a
variety of applications. The first shop of Bokaro Steel to get the ISO-9001
certification way back in 1994, this complex has maintained a high-standard of
coating quality and its SAILJYOTI branded products enjoy a loyal market. This
complex made certain innovations for higher productivity to help re-build
earthquake ravaged in Gujarat.

Services - a valuable support network

The service departments like Traffic, Oxygen Plant, Water Management

and Energy Management provide invaluable support to this gigantic plant.
Bokaro Steel has a vast networked of railway tracks and over 40 diesel locos to
smoothly run its operations. The Oxygen Plant provides Oxygen, Nitrogen and
Argon for processes like steelmaking and annealing. Water Management looks
after the huge water requirements of the plant and the township, providing
different grades of water and taking care of recycling needs. Energy Management
juggles the supply and demand of by-product gases and their demand as process
fuel.

Maintenance Departments
Bokaro has centralised maintenance departments for large-scale
electrical and mechanical maintenance, in addition to shop-based maintenance
wings for running repairs and maintenance. These facilities are capable of
executing massive capital repairs, supported by the fabrication facilities of the
auxiliary shops.

Auxiliary Shops

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To meet its needs for maintenance and repairs, Bokaro has a cluster of
engineering shops such as Machine Shop, Forge Shop, Structural Shop, Steel
Foundry, Ingot Mould Foundry, Cast Iron and Non-Ferrous Foundry, Electrical
Repair Shop and Power Facilities Repair Shop in addition to shop-specific Area
Repair Shops. Most of the repairs and maintenance requirements of the plant
are met in-house. The auxiliary shops and maintenance wings of Bokaro Steel,
aided by in-house design teams, have executed a number of highly sophisticated
procurement-substitution, productivity enhancement and quality improvement
jobs, saving revenues and enhancing equipment availability. The expertise and
operational scale of these departments, along with the service departments,
makes Bokaro a truly integrated plant, housing many virtual enterprises within
Bokaro Steel.

The sectioning the product a value based place in customer mind. Finalize
annual sales plan and quantity, monthly, weekly, and daily rolling programme
of Rolling mills in consultation with CMO and mills. This plan is based on the
sales forecast receive from JPU SPL/ Iron and steel controller. Optimizing the
product-mix by proper utilization of available stocks. Receiving Enquiries and
complaints, cancellation of orders etc. Coordinating the works of mills and traffic
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department so as to maximize dispatches. Co-ordinations with CMO from

stages of enquiry, for exports, development of new Profiles, sections,
modification of product scheduling till the orders are completed.

Development of new qualities of steel. Periodical market surveys of products to

analyze the market position. Implementation of suggestions received from the
customers feed bock. Ensure customer satisfaction by meeting customers
regularly, provide redressal to their problems and fulfillment of demand.

STUDY OF FABRICATION

FABRICATOR / WELDER:-

Fabrication

Metal Fabrication is the forming of metal, usually steel plate, into various forms
either by welding or other forms of metal joining processes. Metal fabrication
falls into two categories, either "light" (metals under 3mm thick) or "heavy"
fabrication.

Metal fabricate

A metal fabricator has to be able to interpret engineering drawings and

then accurately cut steel plates into the required shapes. They must then weld
them into the structure according to the drawings. Metal Fabricators must learn
to read engineering drawings, use geometric development methods and metal
forming techniques. They must also be able to use computers in making metal
products, and have a comprehensive knowledge of a range of industrial welding
and joining processes to manufacture the required items.

Fabrication has a great deal to do with manufacturing. Fabrication is an

industrial term that refers to the manipulation of raw materials (such as steel)
for the making of machines and structures. Steel and other metals are cut and
shaped during the fabrication process. Fabrication is a very hands-on part of
the manufacturing process. Although a fabrication shop and a manufacturing
plant can work independently, it is unlikely that you will find a manufacturing
establishment that does not at least have close ties to a fabrication shop. Most
manufacturers have fabricators in-house simply because of the frequency that
most manufacturing processes need the services of a fabrication shop.

The fabrication of a working machine or of an entire structure of a building

from nothing more than metal requires a lot of skill and planning. A fabrication
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shop will begin a business transaction by proposing a plan to the purchasing

party and trying to win their bid for work. If the fabrication shop is awarded the
bid and will be responsible for a specific fabrication job, the specific materials
and sub-contractor work will need to be determined. Also, special equipment
may need to be used to complete the contracted work.

Fabrication involves the skills of engineers. In fabrication it is not enough

to just build something from raw materials; it has to be a working part of a whole
system. When fabrication is being done for a manufacturing plant, the engineers
are most likely going to be a part of that manufacturing organization. The
manufacturers are a part of the fabrication process from the beginning because
it is important for the individuals who will be responsible for the new machine
or structure to have an intimate understanding of the fabricated project's inner
workings. After all, it will be the manufacturing employee's responsibility for the
day-to-day function of that fabricated work.

Fabrication involves the use of many different materials. As most

fabricators are metal fabricators, common metals used in the fabrication process
are plate metal, formed metal, expanded metal, welding wire, hardware, castings
and fittings. The tools used to manipulate these metal projects are also diverse
but some of the more common tolls used include any materials used in the
welding process, band saws, cutting torches, etc. Fabrication is truly a specialty
where visualization is important because fabricators must have the ability to
create an end product with nothing more than a pile of metal pieces.

Fabrication shops are generally limited in their ability to create overly

complex machining capabilities. In terms of manufacturing, the fabrication
process is essential in creating the shell of the machinery or product and it takes
the skills of other parties to complete the mechanical process. Once a fabrication
shop has finished a particular order, the product is inspected and shipped to
the client.

Fabrication is a process that many of the object, tools, and machines that
we use on a regular basis once took part in. Without fabricators we could not be
able to enjoy many of our buildings or anything that is built with the help of
metal. Fabricators are important to manufacturers because they have the ability
to manipulate otherwise functionless materials into something that will help
consumers.
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Welding

Welding is the process of joining metals by melting the parts and then
using a filler to form a joint. Welding can be done using different energy sources,
from a gas flame or electric arc to a laser or ultrasound. Until the beginnings of
the 20th century, welding was done via a process known as forge welding, which
consists of heating up the pieces to be fixed together and then hammering them
until they amalgamate. With the advent of electricity, welding became easier and
faster, and it played an important part of the industry scene during World War
I and II. There are different welding processes in use in modern times:

➢ Arc welding is done through the use of an electrical current, and can
be performed by using inexpensive equipment.

➢ Gas Welding is widely used for repair work, especially in anything

involving pipes and tubes. Gas welding is common in the jewelry
industry, as well as for the welding of plastics and other materials that
cannot stand higher temperatures.

➢ Resistance welding involves the use of additional sheets of metal to

encase the pieces to be welded together. It is the most
environmentally-friendly of all methods, but it requires costly
equipment that cannot be used in all situations.

In an industrial context, welding refers to a fabrication process that joins

materials such as metals and thermoplastics, by causing coalescence. This is
typically done by melting the work pieces and adding a filler material such as a
welding rod, to form a pool of molten material that cools to become a strong
joint. Various processes and energy sources are used for welding such as a gas
flame, electric arc, laser, electric beam, friction, and ultra sound. All these
methods involve the use of various unique equipments, specific to each process.

➢ Plastic welding is the process of joining work pieces made from plastic
with the help of advanced welding techniques. Plastic welding can be used
for joining two or more work pieces made from the same type of plastic or
two or more pieces made from different types of plastic.

➢ Orbital welding is Automatic Tungsten inert gas welding. It eliminates

chances of manual errors in welding. It produces identical welds for
hundreds of times hence accuracy in welding.

Lathes and Lathe machining operations

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The engine lathe, its use, and its principal parts and their uses are
knowledge and skills expected of an EN2. Although machine shop work is
generally done by personnel in the Machinery Repairman (MR) rating, there may
be times that you will find the lathe essential to complete a repair job. This
chapter will help you to identify the engine lathe’s attachments, accessories, and
their uses. Also, it will identify and explain different machining operations and
the factors related to machining operations. Of course, you will be expected to
know and to follow the safety precautions associated with machining operations.

There are a number of different types of lathes installed in the machine

shops in various Navy ships. These include the engine lathe, the horizontal
turret lathe, and several variations of the basic engine lathe, such as bench, tool
room, and gap lathes. All lathes, except the vertical turret type, have one thing
in common. For all usual machining operations, the work piece is held and
rotated about a horizontal axis, while being formed to size and shape by a cutting
tool. In the vertical turret lathe, the work piece is rotated about a vertical axis.
Of the various types of lathes, the type you are most likely to use is the engine
lathe. Therefore, this chapter deals only with engine lathes and the machining
operations you may have to perform.

RCL (The Research & Control Laboratory)

This department is responsible for maintaining the quality of product and
develops new products to cater to the needs of customers with the ever changing
demands of the society. For this purpose periodic monitoring and controlling of
the quality of input raw material, process and final products is required.
Major activities of this department are:
➢ Process control.
➢ Inspection.
➢ Analysis and testing.
➢ Research and development.

To achieve these, it has a main laboratory outside the plant and the other
laboratories are inside the plant. The laboratories inside the plant are at RMHP,
BF, BOF, Coke Ovens, Rolling Mills. The main laboratory is well equipped with
chemical, metallurgical and other test facilities.

FOUNDRY SHOP

BSP is having its own foundry, referred as captive foundry. The main products
are:
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➢ Ingot mould (8.5T)

➢ Bottom Plate (3T)
➢ False Plate

Casting of different small structures is also done here to cater to the needs of
different shops.
Important equipments are:
➢ Pneumatic Rammer
➢ K.S. Drag barrels
➢ Stripping plates
➢ Mix-Muller’s
➢ Jolting Machine
➢ Stoves
➢ Guide Pit
➢ Cupola Furnace

OXYGEN PLANT

This is an important section since oxygen demands of various shops are

met from this department. It has five gaseous O2 storage vessels and two liquid
storage tanks. The capacity of this plant is (2X350=700TPD).

Products of this plant are:

a. Oxygen Gas - for BOF, CCP, BF, Rolling mills, ASP.
b. Liquid Oxygen - Oxygen cylinder filling
c. N2 - BOF, CCP, BF, EMD.
d. Argon - BOF, CCP, VAD

The distribution network is spread over 18 Km in the plant. The gas is also
supplied to ASP. The pressure is 350 mm of water gauge pressure.

POWER PLANT

Main Objectives
• To provide COLD AIR BLAST to blast furnace.
• To provide HP/LP process steam to BF, COCC, SMS, Oxygen Plant
• Power generation

HP steam at 32 Kg/cm2
LP steam at 12.5 Kg/cm2

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The capacity of this plant (4x5 MW = 20 MW). It is also called as blower plant as
its main aim is to generate steam. There are seven boilers each having capacity
60 TPH. Steam is generated at high pressure. Boiler No. 1, 2, 5, and 6 uses coal
and (BF+CO) gas as fuel. Boiler no. 3, 4 and 7 are gas fired using (BF+CO) gas.

CEM (Central Engineering Maintenance)

Its main function is to provide repair and maintenance of all important

equipment of DSP. Some of the main equipments of CEM are:
➢ Horizontal boring machine
➢ Bevel gear making machine
➢ Vertical boring machine
➢ Small pinion making machine
➢ Helical gear making machine
There are six sections in CEM:
1. Planning and Processing
2. Structural
3. Forging
4. Machine shop
5. Fitting shop
6. Tool room
PCE (PLANT CIVIL ENGINEERING)
PCE looks after the maintenance and repair of plant roads, constructions
etc. Design department supply all the design to the PCE department and PCE
implement all those works. All the painting, repairs etc in the plant structures
are done by this department. There is annual maintenance contract with the
outside agencies also. PCE looks after up to flyover and RCL.

ERS (ELECTRICAL REPAIR SHOP)

In this department electrical motor from different units / departments like

BF, Sinter Plant, RMHP etc come for repair. In electrical repair shop winding
insulation leakages, voltage – current balancing etc is rectified. And in
mechanical repair, bearing alignment faults are rectified. A drier is used for
drying the motors during rainy seasons. Depending upon the need of motor in
various departments, priority of work is fixed. In electrical field it plays an
important role in maintenance.

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THERE IS LITTLE BIT OF “SAIL” IN EVERYONES LIFE