final_report

An Industrial Training Report on
“Detail Study of Working in Blast Furnace
Area (VIZAG STEEL PLANT)”
For the award of degree of
BACHELOR OF TECHNOLOGY
In
METALLURGY AND MATERIALS ENGINEERING
By
Arijit Karmakar (12/MME/29)
Under the guidance of
Mr. K. Soloman Raju
Asst. General Manager (Oprn)
Blast Furnace Department
DEPARTMENT OF METALLURGY AND MATERIALS ENGINEERING
NATIONAL OF INSTITUTE OF TECHNOLOGY, DURGAPUR

CERTIFICATE
This is to certify Industrial Training Work entitled “Detail Study of
Working in Blast Furnace Area (VIZAG STEEL PLANT)” that is
submitted by Arijit Karmakar (12/MME/29), student of 2nd year
,B.Tech, Metallurgy and Materials Engineering of National Institute
of Technology, Durgapur, during the academic year 2013-2014 and
it has found worthy of acceptance.
Date:
Mr. K. Soloman Raju
Department of Blast furnace

ACKNOWLEDGEMENT
First of all I would like to thank Vizag Steel Plant to grant me this unique
opportunity to see and learn the practical applications of Blast furnace.
I highly oblige Mr. Soloman Raju and Mr. Utpal Kumar Parui for their
mastery supervision through all the phases of my industrial training work
with valuable suggestions, resources and support.
I would also like to thank all my friends who helped me by sharing their
knowledge and materials to complete this training.
Finally, a word of gratitude for my parents who are my constant source of
support and encouragement.

DECLARATION
I hereby declare that the project report entitled “Detail Study of
Working in Blast Furnace Area (VIZAG STEEL PLANT)”
submitted is an original work carried out by me.
The matter embodied in this Industrial Training Report is a genuine
work by me done during the visit to VSP and has not been submitted
earlier to college or any other university.
Arijit Karmakar

TABLE OF CONTENT
1. Day 1- Introduction to the steel making industry
Various departments and their roles
Main products of VSP
2. Day 2- Blast Furnace Area
Various Departments under Blast Furnace Area
Introduction to Burden Handling Section
3. Day 3- Stock House
Stocking of burden
Dust Controlling
4. Day 4- Stock House
Sending charge to the furnace
Screening
5. Day 5- Cast House
Introduction
Blast Furnace Structure
Principle components of the charge
Stove House
Gas Enrichment
Bell-less top charging system
Blast Furnace Operation
Blast furnaces in VSP
8. Day 8- Gas Cleaning Plant
Main components of GCP
9. Day 9- Slag Granulation Plant
10. Day 10- Pig Casting Machine
11. Day 11- Masses and Compound Shop
12. Day 12- Ladle Repair Shop

Day 1- Introduction to the steel making industry (Visakhapatnam Steel
Plant)
Major Departments in VSP and their roles
 Raw Material Handling Plant (RMPH)
 Coke Ovens & Coal Chemical Plant (COCCP)
 Sinter Plant
 Blast Furnace (BF)
 Steel Melt Shop (SMS) & Continuous Casting Department (CCD)
 Rolling Mills
o Light & Medium Merchant Mill (LMMM)
o Wire Rod Mill (WRM)
o Medium Merchant & Structural Mill
Raw Material Handling Plant (RMPH)
VSP requires quality raw material like iron ore, fluxes, coal etc. The vital
function of receiving the materials from various sources and feeding them to
various departments is served by the RMPH.
The unit is provided with elaborate unloading, blending, stacking & reclaiming
facilities.
Coke Ovens & Coal Chemical Plant (COCCP)
The primary goal of Coke Oven is to produce coke for the Blast Furnace, which
require large quantities of any strong, hard and porous fuel in form of hard
metallurgical coke for supplying heat to carry out necessary reactions.
Each coke oven comprises of two chambers. In the hating chamber BF gas,
Coke Oven gas etc. are burned to provide heat to the adjacent coal chamber. In
the coal chamber coal blend charge i.e. crushed coking coal below 3 mm is
heated up to 1050° C in the absence of air for 16-18 hours.
The red-hot coke produced by carbonization is sent to Coke Dry Cooling plant
(CDCP) for cooing using nitrogen gas as cooling medium and produces
 BF Coke (+25-70 mm) which is sent to BF

 Coke Breeze (+0-15 mm) which is sent to sinter plant
 Nut Coke (+15-25 mm) which is also used in BF
The primary by-products are Ammonium Sulphate ((NH4)2 SO4), Crude Tar,
Crude Benzol. The main by-product is crude coke oven gas which processed in
Coal Chemical Plant gives us Ammonia, Tar and Benzol.
FACILITIES
1. Four coke oven batteries each 7 m tall and with 67 ovens.
2. Each oven of size 41.6 m3 and of capacity 31.6 ton.
3. Four CCDP each with 4 chambers, each of capacity 50-52 TPH. The heat
brought out is used to produce 7.5 MW each.
Sinter Plant
Sintering is the process of agglomeration of fine mineral particles into porous
mass by incipient fusion caused by heat produced by combustion within the
mass itself.
In the sinter plant a mixture of iron ore fines, coke breeze, limestone, dolomite
and some recycled metallurgical waste undergoes sintering to produce
agglomerated mass or sinter of iron of +5 mm size.
This sinter makes up the 70-80 % of iron bearing charge of BF.
FACILITIES
1. Two sintering machines of grate area 312 m2 of Dwight Lloyd type.
Capacity of 450 ton/hour each.
2. Two exhauster each driven by 5.6 MW motor capable of creating 1500
mm water column suction under the grate.
Blast Furnace (BF)
The basic reaction taking place in a BF is smelting and roasting of charge
comprising of iron ore, sinter & various other additives in presence of hot air
& coke to produce hot metal i.e. pig iron.
The solid charge materials are introduced in the vertical shaft of the furnace
from the top. Paul-Wurth, bell less top system is installed for furnace charging.
And hot air blasts are blown through tuyeres located at the bottom.

Oxygen from the hot air combines with carbon from the coke to produce large
amount of heat and Carbon Monoxide (CO).
Gas along with the heat moves in upward direction and solid in downward
direction. They react to give hot metal and slag.
The remaining gas is collected and cooled to be used as fuel in the plant.
FACILITIES
1. Two Blast Furnaces of 3200 cm3 useful volume each.
2. One Blast Furnace of 3800 cm3 useful volume.
Steel Melt Shop (SMS) & Continuous Casting Department (CCD)
While iron making is a reduction process, steel making is oxidation process.
Hot metal received from BF has 3.5-4.25 % Carbon and various other
impurities while steel only has up to 1.8 % Carbon.
In SMS steel is made in refractory lined vessels known as LD Converters or
Oxygen Furnace/Converter. 99.5 % pure oxygen is blown through the metal
bath at 15-16 kg/cm2 pressure. With the help of basic fluxes and lime the heat
released from the oxidation process helps in metal refining and slag
formation.
Gases released from the converter is called LD gas, is collected, cooled, cleaned
and used as secondary fuel in the plant.
The entire molten steel at the plant is continuously cast at the radical type
continuous casting machine resulting significant energy conservation and
better quality steel (100 % Continuous Casting).
FACILITIES
1. Three LD Converters of 133 cm3 volume each. Capacity of 150 ton per
heat/blow.
2. Six 4-Strand continuous casting bloom machines.
Rolling Mills

The cast blooms from CCD are sent to high speed rolling mills i.e. LMMM,
WRM and MMSM.
Light & Medium Merchant Mill (LMMM)
FACILITIES
LMMM comprises of two units.
1. Breakdown Mill
a. 7 Stand Break-down Mill
2. Bar Mill
a. Stand Roughing Mill (2 Stand rolling)
b. 2*4 Stand Intermediate Mill (Single strand rolling)
c. 2*4 Stand Finishing Mill (Single Strand rolling)
Wire Rod Mill (WRM)
FACILITIES
1. 7 Stand Rough Mill (4 Strand rolling)
2. 6 Stand Intermediate Mill (4 Strand rolling)
3. 4*2 Stand Pre-finishing Mill (Single Strand rolling)
4. 4*10 Stand Finishing Mill (MORGAN BLOCK-Single Strand rolling)
Medium Merchant & Structural Mill
MMSM is a high capacity continuous mill consisting of 20 stands arranged in 3
trains.
FACILITIES
1. 8 Stand Roughing Mill (4 high horizontal, 2 vertical and 2
combinations).
2. 6 Stand Intermediate Mill (2 high, 2 vertical and 3 universal)
3. 6 Stand Finishing Mill.

Main products of VSP:
 Steel Products
 Angles
 Billets
 Channels
 Beams
 Squares
 Flats
 Rounds
 Re-bars
 Wire-Rods
 By-Products
 Nut Coke
 Coke Dust
 Coal Tar
 Anthracene
 HP Naphthalene
 Benzene
 Toluene
 Xylene
 Wash Oil
 Others
 Granulated Slag
 Lime Fines
 Ammonium Sulphate

Day 2- Blast Furnace (BF) Area
Various Departments under Blast Furnace Area
 Burden Handling Section (BHS) or Stock House
 Cast House or Blast Furnace (BF)
 Gas Cleaning Plant (GCP)
 Slag Granulation Plant (SGP)
 Pig Casting Machine (PCM)
 Masses and Compound Shop (MCS)
 Ladle Repair Shop (LRS)
Burden Handling Section (BHS)
Introduction
As we know process in blast furnace is a continuous reaction not a batch
process. Hence, continuous feeding of the furnace with charge material is
necessary. If failed to do so i.e. if burden sent is not sufficient in amount would
result in increase of pressure in the upper region of the shaft increases. Such
irregularities may lead to severe malfunction or accidents.
Also if raw materials are received in the furnace directly from various sources
and plants, there is a huge risk of failure of transportation facilities, leading to
shortage and problems mentioned above.
So to avoid such situations Burden Handling Section (BHS) came into being. It
receives all the required raw materials for the furnace reaction from all the

available sources and plants. It maintains a stock of all those materials and
later sends them to the furnace as per requirements. Capacity of these stock
houses is sufficient enough for continuous operation of a blast furnace for next
20 to 30 hours. It allows maintaining a continuous process at the furnace even
in case of breaks in supply of materials.
Only those materials whose quality is ascertained and is as per the
requirement is stored in the stock house. In short, Burden handling System is
designed to perform a number of technological operations essential for
proper running of BF process.
BHS:
Following raw materials are stored in the stock house-
 Iron Ore (iron bearing)- Received from Raw Material Handling Plant
(RMPH)

 Sinter (iron bearing)- Received from Sinter Plant
 Coke (fuel)- Received from Coke Oven
 LD Slag (additive)- Received from Steel Melt Shop (SMS)
 Limestone (additive)
 Quartzite (additive)
 Manganese Oxide- MnO (additive)
 DRI- Directly Reduced Iron (additive)
Function Departments:
1. Operational- control storage, technological operations and sending of
raw materials to furnace
2. Mechanical- Day to day maintenance and repairing of mechanical
equipment.
3. Electrical- Day to day maintenance of power supplies to various
machines and process.

Day 3- Stock House
Stocking of burden (Method of storage of raw materials)
In the stock house raw materials are stored in bunkers. Basically there are 20
bunkers (In some stock houses there are 17 bunkers), classified as follows:
 6 sinter bunkers (SB1,SB2,SB3,SB4,SB5,SB6)
 6 coke bunkers (4 surface coke CB1,CB2,CB3,CB4,
2 center coke CcB1, CcB2)
 1 nut coke bunker (NCB1)
 2 ore bunkers (OB1, OB2)
 5 additive bunkers (AB1, AB2, AB3, AB4, AB5)
Raw materials are received via conveyers (series of interlinked conveyers)
from respective plants. Then they are filled in stock bins with the help of
trippers.

Trippers
They are mechanical structures. The conveyer carrying burden splits into two
vertical, closed structures. The materials after passing through tripper pass
through series of screens and then are collected in the bins. The following
figure shows tripper floor:
Conveyers
There are three main conveyers that do the job of bin filling
 SC- Sinter Conveyer
 OAC- Ore/Additive Conveyer
 CC- Coke Conveyer
As a benefit from the above placement of bunkers and conveyers, OAC i.e. ore
conveyer can be used to carry sinter or coke in case of breakdown of other
conveyors. Hence it is referred to as substitute conveyer.
Only those materials, whose quality has been ascertained and found
corresponding to requirements are received to BF stock house. Quality
compliant consideration and rejection procedure is laid down at the BHS.
Quality check set-up is taken care of by responsible departments. The set-up
ensures constant monitoring of chemical composition, size and other
characteristic of sinter, coke and other materials when they come to stock
house. The off-grade material is stored in separate bin and is not used in
further operation.
Amount of materials within the bins can be assessed by means of level
indicators installed at all bins. They provide information on the level of

materials step-wise i.e. when upper, medium and lower fixed positions are
reached. Normally level is maintained between medium to upper level.
Dust Controlling
As large amount of raw materials are brought and dumped into the bins at the
stack house, there is emission of large quantities of dust particles into the
environments. So, to clean the dust laden air, Electrostatic Precipitator (ESP)
is installed. To maintain a healthy environment the dust content in air should
be less than 100 mg/m3.
It comprises of large parallel metallic plates of the same charge, surrounded
by a large closed shell. In the house, there are two large fans which create
suction and collect all the dust particles and send them to the closed shell via
large pipes. Under the influence of field inside the shell the dust particles
acquire negative charge and the large parallel plates acts as anode. Therefore,
the dust particles are attached to the plates. Now, there are large hammers
connected to rapping motors, which continuously beats the parallel plates.
This action leads to dust particles falling and they are collected large
containers and later disposed by the dumpers.
The above picture on left shows an ESP and the one on right shows one of the
large fans used to create the suction to collect the dust particles.

Day 4- Stock House
Sending charge to the furnace:
The burden is sent to the furnace via Main Belt (MB) conveyer. But there are
many size, quantity and quality parameters of the burden required at the
furnace. Following image shows the MB carrying burden to BF 3:
The principle iron-bearing material is sinter with 20% lump iron ore. Sinter
composition required in BF includes additives like limestone, dolomite,
quartzite, manganese ore etc. which are added to the burden through BHS
additive bins. The required composition of the charge otherwise known as
recipe is laid by operation department. It is prepared on the basis of
calculation, available raw materials, technological requirement and capacity.
Additives are added to the charge to maintain of a particular basicity of the
products formed.
 To increase the basicity
o LD Slag
o Limestone
 To decrease the basicity
o Quartzite
o Manganese Oxide (MnO)
Hence, according to need the amount of each additive is regulated.

In case of change of availability of raw material or technological modifications
there is change in the target sinter composition. But to be noted there is time
gap between taking decision and implementation of the change in
composition. This time is required to consume the old pile of charge and
prepare a new one. Coke received at the stock house is produced from a
mixture of local and imported coke subjected to dry quenching. With respect
to availability and strength characteristics the composition is laid, but coal
blend composition is not being changed for three months at least.
Some of the size requirements are as follows:
1. Sinter (Iron Bearing) should be +5 mm. Those below this size limit are
sent back to the sinter plant.
2. Coke should be of +25 mm in size. Surface coke is of size 25 to 60 mm
and center coke of +60 mm size. The center coke is introduced at the
center of the shaft of the furnace for easy bed formation and better
results.
Screening
To regulate the size factor of the materials as per parameters laid down,
sieves are introduced between trippers and bins. Accordingly to need sieving
is done when burden is filled into the bins with the help of series of screens.
 When sieving is done, materials above the screen are collected in
“Hopper”.
 Otherwise if sizing is not done, materials are collected in “Fill”.
Hence, according to requirement we can include or exclude hopper and fill
into the main belt carrying charge.
Efficiency of screening is ensured by
 Proper condition and reliable securing of sieve elements.
 Quality incoming of materials and uniform distribution i.e. bed
thickness.
 Proportion between amount of material outgoing from upper and lower
sieve.

Another important method to be followed in BHS is blending of materials in
order to average their qualitative parameters. It is achieved through
sequential dumping of materials in batches from all bins. Sequential pattern in
which bins are charged with coke and sinter effects the blending too. The
image below shows the shed where the final burden to be sent is prepared:
This is way bins are being emptied on the main belt for effective charge to the
furnace. It is to be noted that bins are operationally never emptied below the
lower level other than in cases of repairing of furnace shutdown.

Day 5- Cast House
Introduction
Blast furnace (BF) is a shaft i.e. tall vertical furnace which is used to produce
pig iron or commonly referred to as hot metals in industries. Blast furnace is
named so as it runs with preheated air blown form the bottom at high
pressure and temperature.
Blast Furnace Structure
Blast Furnace structure comprises of mainly of these parts:
 Foundation
 Hearth
 Tuyeres
 Bosh
 Belly
 Stack

Foundation
It is a massive steel structure reinforcing concrete mass, partially embedded
below the ground level. It should be strong enough to stand the loaded
furnace weight, which may about 10000 tones. It is about 1500 mm in
diameter and 600-800 mm thick upon which lies the furnace bottom i.e. 400-
500 mm thick fire bricks.
Hearth
Also referred to as the crucible, hearth acts as the receptacle to collect hot
metal and slag. It is constructed using fire bricks but now-a-days carbon
blocks are used. It comprises of three layers, the carbon wall with inner lining
or refractory and to protect it water cooled copper/steel plates. The carbon
wall is more than 1 m uniformly thick and stadium like structure. 0.3-0.6 m
above the hearth bottom level lays the iron tap hole of 12-15 cm diameter and
above that at 1.2-1.6 m lays the slag notch. If not in use, these taps are closed
with masses coming from the Masses and Compound Shop (MCS). At the top of
the hearth lies the tuyeres uniformly distributed over the entire cross-section.
Tuyeres
Immediately above the hearth are located the tuyeres. They are used to blow
hot air blast into the shaft for fuel combustion. Depending on the furnace size
number of tuyeres is decided and is uniformly distributed over the periphery.
Air from the stove house is supplied to a huge circular pipe encircling the

furnace at the bosh level called the bustle pipe. The uniform distribution of
tuyeres along the bustle pipe equalizes the pressure of the blast throughout
the furnace.
Bosh
The region just above the tuyeres is outward sloping at an angle of 80° and
going up. The slope provides a smooth and uniform movement of the burden
material. The top of bosh is the maximum diameter of the furnace and a zone
of intense heat. Bosh is built tight up in a gas tight steel shell of thickness
about 50 mm. The shell plate is cooled with water sprays or enclosed water
panels.
Belly
The widest inside dimension of the refractory lining, is at the top of the bosh.
Just above the bosh of the same diameter there is a straight vertical section
connected to the stack called the ‘belly’.
Stock
This section above the belly is inward sloping. At the uppermost of the stack
charge material is deposited and is at an angle of 80°.

Principle components of the charge to a blast furnace:
• Iron Ore
• Coke
• Fluxes
Iron Ore:
Iron ore can be hematite (Fe2O3), magnetite (Fe3O4) or taconite (a colloquial
term used for Minnesota ores which can refer to either hematite or
magnetite). Iron ore is beneficiated to 65 -72% Fe, and pelletized to form
pellets 3/8 inch to 5/8 inch in diameter. In some operations, concentrated
fines may also be sintered, that is, fused into porous lumps that are broken
into one or two inch pieces. Pellets are durable and ship well, and sinter does
not. Pelletizing plants are therefore often built near the mine and pellets are
transported to the blast furnace by rail or ship, while sinter is usually
produced at the steel mill.
Coke:
Coke serves three functions:
• Supply chemical reactants for reducing iron ore to metallic iron.
• Act as a source of carbon in the pig iron and eventually in the steel.
• Provide a source of heat in the blast furnace (fuel).
Fluxes:
When metal is smelted, the metal is separated from its impurities by melting,
with the impurities forming a molten slag on top of the metal. Many of the
impurities associated with iron ore are difficult to melt, and so they will not
form a proper slag easily, which retards the smelting process.
To make these impurities easier to melt, fluxes are added.
Limestone (CaCO3) or dolomite ((Ca, Mg) CO3) are two typical fluxes used in
blast furnaces. When a large amount of sulfur needs to be removed from the
furnace charge, limestone is the preferred flux. Limestone is also a better flux
to use if slag from the blast furnace is to be used as a raw material for cement
manufacture. An important criterion for flux selection is availability and cost,
and dolomite is often more readily available and less expensive than
limestone.

Day 6- Cast House
Stove House
The hot blast air produced by passing the atmospheric air through preheated
chambers known as ‘Stoves’, at a temperature 1000°C. The stove is first
heated up burning gas and combustion of air within chamber the heat is
absorbed into the brick wall, this mode is called Caledon-gas. In this mode, no
combustion takes place; but cold air is passed through pre-heated stove and
absorbs heat to become hot blast. It is then mixed with cold blast to bring it to
the right temperature and is then forced into the blast furnace via tuyeres.
Commonly there are three or four stoves. So at a time when one is on blast
other can be boxed and sealed. While sealed, the stove is prepared by heating
and sealed, so that it is ready to go on-blast. The following figure shows the
stove changeover system:
Assume stove 2 is on –blast and boxed ready for use. Valve 1 of stove is
opened first, allowing cold blast into the stove to pressurize it. Valve 2 of stove
1 is opened, so that stoves 1 and 2 are now on blast. Stove 2 now come off-
blast by shutting valves 1 and 2 of stove 2. Now stove 2 is put on-gas to heat
up and store energy again. Meanwhile, valve 3 and 4 of stove 2 are opened
allowing gas and air enter the stove. When required temperature is reached it
is sealed and boxed.

There are three control modules for stoves combustion:
 Dome temperature control- The O2 reading trims the air/ fuel ratio,
until the dome temperature nears its required value- Then the dome
temperature controller output replaces the O2 trim signal activated by
the dome controller high target temperature. This allows increment of
air flow to the stove, while gas flow is constant. This helps in heat
distribution in the stove while cooling the stove dome. This on-gas
phase continues until the stove has absorbed enough heat, when it can
boxed and put back on blast.
 Gas flow control- Gas flow into the stoves is measured and controlled to
a local set point.
 Air flow control- The gas flow reading is used as a set point for air flow
ration controller.
Gas Enrichment
The water gas produced by the furnace is used as fuel in many areas of the
steel works. Generally, however its calorific value is very low and it requires
the addition of natural gas or coke oven gas. The figure shows how gas flow
rate is inferred by subtracting the natural gas and coke oven gas from the total
mixed gas flow rate. This calculated value is then used as ratio set point for
the natural gas and coke oven gas control blocks, keeping the proportion of
each type of gas entering the stove constant and achieving the desired calorific
value of the total mixed gas.

Oxygen enrichment of cold blast: It is proven that slight increase in the oxygen
gas content of cold gas improves the efficiency of the furnace. The cold blast
flow is measured and oxygen is injected into the main, controlled by a ratio
control block with the control blast flow as a rationed PV. And a constant
value of O2 is maintained.
Bell-less top charging system
Bell-less top charging (BLT) is of modern design with chute feeder and blower
charging throttle valve. The proposed BLT has high productivity, so it can
carry out as multi-ring or one-ring charging of materials into the furnace,
spiral charging as well as point charging. Charge regulating throttle valve
provides accurate and constant distribution of burden materials.
On large furnaces like in VSP, as a rule, two –hopper charging systems are
applied that raises productivity, maintainability and life-time of BLT. But as a
drawback increases complexity, expenses and dimension i.e. height.
Main parts of BLT:
 Receiving hopper
 Upper bank of valves
 One or two material hoppers
 Lower bank of valves
 Bellow arrangement
 Distributing device (DD) with a drive
 Distributing chute
 Pressure equalizing system
 Hydraulic system

 Lubrication system
 Cooling system
 Monitoring and cooling systems.

Day 7- Cast House
Blast Furnace Operation
The furnace is charged with iron ore lumps, pellets, and/or sinter; coke; and
possibly extra flux. These are carried to the top of the furnace with skips or
conveyors, and are tipped, or charged, into the furnace. Meanwhile, air
preheated to 900°C is injected through the tuyeres, which are nozzles at the
bottom of the furnace. The coke is partially burned by the injected air both to
produce heat, and to generate carbon monoxide. Since coke is relatively
expensive, some furnaces inject coal or oil along with the air as supplemental
fuels to reduce coke usage. The carbon monoxide travels upward through the
column, and removes oxygen from the iron ores on their way down, leaving
metallic iron. By the time the charge reaches the base of the furnace, the heat
generated there melts the iron. The resulting molten “hot metal” is tapped at
regular intervals by opening the “tap hole” in the bottom of the furnace so that
it can flow out. The fluxes combine with impurities in the coke and ore to form
the slag, which floats on the iron and is removed through the “cinder notch”.

The hot metal from the furnace is collected in specially-constructed railway
containers, called “torpedo cars”. The torpedo cars carry the molten iron to
the steelmaking furnace.
Blast furnaces are operated continuously without shutdown for ten years or
more. If the furnace were allowed to cool, thermal stresses can cause damage
to the refractory bricks. Eventually, the refractory bricks in the furnace will
wear away, and at that point the furnace is emptied and shut down so that it
can be relined with new bricks. The period between shutdowns is referred to
as a “campaign”.
Iron taken directly from the blast furnace contains about 4 - 4.5% carbon, as
well as a number of other elements. This is referred to as “pig iron”, and if it is
allowed to solidify it is brittle, difficult to work with, and has poor structural
properties. The pig iron can be converted to steel by refining in the
steelmaking process, which reduces the carbon content and removes other

impurities, to make a stronger, tougher, and more generally useful product.
Blast furnaces in VSP
Blast Furnace 1 and 2 (BF1 & BF2)

These furnaces are of 3200 m3 each with four tap hole and 34 tuyeres. These
furnaces are equipped with double-bin bell less top with conveyer charging
system, four stoves, Slag Granulation Plant and air-lift system. The cast house
is also equipped with Mud-gun and drilling machine for each tap-hole.
Currently BF1 is shut down and is undergoing a capital repair.
Blast Furnace 3 (BF 3)
This furnace is of useful volume 3800 m3 and hearth diameter 13 m. There are
four tap holes and 34 tuyeres. The tuyeres stock is of double carded type. The

furnace is equipped with New Generation Parallel Hopper Bell Less Top of 63
m3. BF cooling system consists of cast iron & copper staves are having three
closed circuit of soft water & one open circuit of industrial water. The tap-
holes are equipped with Hydraulic Clay Gun, Drilling Machine & Cover
Manipulator. Annular Gap Scrubber does the dust cleaning. The furnace is
equipped with special probes for measurement like above burden probe, in
burden probe, profilometer, radar stack line etc. There is also Pulverized Coal
Injection with Dense phase system at a rate of 60t/h. There are three stoves
with ceramic burners to supply blast of 12500 C at 5.5 Bar.
BF 3:

Day 8- Gas Cleaning Plant (GCP)
Main components of GCP are:
 Scrubber
 Adjustable Ventures
 Two Cyclone Mist Separator (2600 mm)
 One Cyclone Separator (4000 mm)
 Throttle Assembly (3700 mm)
Scrubber
The purpose of scrubber is to cool the gasses released from the blast furnace
and remove the dust particles from them.
The collected gas is re-circulated with water. The process is characterized by
evaporation i.e. the sprayed water evaporates and in turn makes the medium
sized dust particles heavy and they settle down.
Gas is supplied to the scrubber from BF top via 2800 mm Raw (Dirty) gas pipe
with refractory lining.
The upper part of scrubber is spherical in shape and has two outlet gas pipes
(1600 mm) which supply gas to the venture tubes. Each gas pipe is provided
with 300 mm atmospheric valves, pressed tight to seal by loads. The lower
part of the scrubber has a conical bunker.
The water circulation in the scrubber is done with the help of two water
collection rings. Each ring has 12 nozzles, directed upward and is of size 62.5
mm. They are evenly distributed throughout the scrubber so that the whole
inside area is covered with sprayed water. Near the nozzle branch pipe there
is a purging branch pipe cocks of 125 mm gates to purge the nozzles.
Now there are four overflow pipelines with 500 mm gate valves and the
vertical part of each pipe has a 400 mm throttle valve controlled from a float.
This system keeps the water level inside the scrubber under check.

The float shaft mentioned above is connected to the throttle shaft by means of
a turn buckle. The movement of float in the chamber is checked by a screw in
upper position and a special support in the lower position.
The float assembly is installed near the throttle valve and connected to the
scrubber with the help of two pipes- one for the water and other for the gas.
Each pipe is provided with gate to cut-off the float chamber if necessary.
The accumulated dust in float chamber is done via drain cock provided at the
bottom of each chamber. The water is drained out of scrubber by means of
600 mm * 500 mm slime gate and 150 mm branch pipe with gate.
Adjustable Ventures
GCP has one automatic adjustable venture and one manual adjustable venture.
The purpose is of final cleaning of gas.
Each venture pipe has three nozzles and water is sprayed through them. Each
venture is adjustable and the throat area is adjusted with a sphere head.
The sphere is controlled by electric dive or by manual operation. It is
vertically mounted on the body and the shaft actuates through water seal of
clean water, which constantly is supplied to water seal chamber.
Water sprayed through nozzle and incoming gas proceeds to nozzle neck
where high speed of gas flow atomizes water drops into mist. This thoroughly
mixes with fine dust present in the gas. The fine dust and gas is categorized
and collected along water in bottom of cyclone mist eliminator after venture.
The slurry is collected in the water seal of scrubber.
Cyclone Mist Eliminator (CME)
It serves to separate the water drops which are carried out by BF gas during
the process of cooling and cleaning.
 Two CME of diameter 2600 mm
Each CME has one nozzle with 25 mm outlet for flushing of slurry
pocket and one nozzle for washing of blades. Mist Eliminators drain is

directly connected to scrubber seal via 300 mm pipeline and overflow of
pocket washing is also connected to this line.
 One CME of diameter 4000 mm
In this type there are three nozzle of 25 mm outlet for flushing slurry
pocket and one nozzle for cleaning of blades. It has a conical bunker
where water seal is maintained by simple overflow line. Pocket washing
overflow line joins to this seal by a separate line.
Important parameters:
1. Maintain the clean gas temperature between 40°c and 45°c.
2. Maintain differential pressure across the ventures between 1500 and
2500 mm.
3. Maintain water seal level at scrubber from 300 to 700 mm.
4. Monitor water pressure throughout the GCP.
5. Inspect individual components and parameters.

Day 9- Slag Granulation Plant (SGP)
The slag produced in the blast furnace (BF) in the process of iron reduction is
sent to Slag Granulation Plant (SGP). In this unit the entire slag is granulated
and then transferred to the Slag Storage Yard.
Molten slag is received to SGP through slag runner. The runner is coated with
runner mass to avoid accumulation of slag and damage of the runner. In this
plant a reservoir is maintained 13 m deep below the ground level, containing

clean and cool water. This water is sent to water jets with the help of high-
tensile pumps. This setup is used as granulator of the hot slag.
Granulation takes place under the action of high-pressure water jets. The
water coming off the jets hits the falling slag from the runner at high speed.
This results in instant cooling and granulation. The steam and gases generated
during this process is released into the atmosphere via chimney.
The falling water and granules forms a mixture called slurry and is collected
into large container called receiving bins which is also 13 m deep. In the bin at
a depth of 10 m there is opening which is used to transfer the slurry into an
air-lift chamber.
In this chamber a hydro-pneumatic system is used, with the help of a
compressed air at pressure 50.7 Pa provided by the Air-Separation plant. The
air creates a suction to pull the slurry off the chamber so that most of the
water is separated in this step. The remaining slurry is slowly poured into the
dehydrator from the top via a conveyer.
In the dehydrator the remaining of the moist slag is dried with the help of high
speed rotations and screens. At the bottom of the dehydrator container there
is a bin where all the dry is collected after the dehydration.
From the dehydrator bins the slag is dumped into two conveyers i.e. slag
conveyers which carries the material to slag storage yard. From these yards
slag is transported to outside, other industries for various purposes like
cement making etc.

Day 10- Pig Casting Machine (PCM)
Due to exhaustion of rich ores in the recent years new methods were devised
to utilize impure ores. Hence pig iron is used where rough, tough and strong
metals are required like steel furnaces. This led to formation of various
industries that require pig iron for many important applications. PCM does
the work of converting the hot metal coming from the Blast Furnace (BF) into
pig cast iron which would be easy to transport to the above mentioned
industries.
In this unit the ladle full of hot metal is tilted so that the molten metal passes
through the runner to a rotating conveyer. The runner is prepared with mass
coming from the Mass and Compound Shop (MCS) so that the high
temperature liquid does not coagulate at the surface and damage it. The
conveyer has moulds coated with lime which help in sticking of the metal on
the moulds surface. As the conveyer is moves forward water is poured over it,
which does the further cooling and solidification.

The PCM is provided with a Lime Preparation Plant which provides the
required lime for cooling and sends it to the conveyers.
Later the solids are dumped into wagons for transportation or dumped into
yard to be transported either help of cranes and trucks. After dumping when
empty moulds return lime is sprinkled over it to form the lime layer again for
protection.

Day 11- Masses and Compound Shop (MCS)
MCS serves the vital function of preparation of various refractory materials
required in the BF department, namely used to for closing of tap hole in the
furnace and in the runners of the Pig Casting Machine (PCM).
Mainly there are three type of masses prepared at MCS
 Mud gun mass/ Oil mass
 Runner mass
 Water mass
The composition of the masses required depends on the furnace/ runner
condition.
Main constituents Mud gun mass is clay, coke breeze, bauxite and Oil (Wash
oil, Binder, Liquid resin). Clay and bauxite are received from outside and
stored in bunkers via conveyers, while coke and oils are received from the
Coke Ovens and the Coal Chemical Plant (COCCP).
Runner mass comprises of Coke, Pitch and Clay. And water mass has fine coke,
clay and pitch as constituents.
The process of mass formation is carried out by Pan-Mixture and Kneader
Machine. Pan-Mixture comprises of two rollers running in counter-direction
which helps in mixing of various components thoroughly. The binder and

other oils are used to increase the adhesion force between the particles
resulting in formation of clay-like mass. The product is pushed out, cut into
regular sizes and packed before they become too hard for use. The amount of
binder oil and resin oil depends on the atmospheric condition, which causes
easy evaporation and hardening of mass. The Kneader Machine works
similarly; along with it there is also cutting and packing machine which gives
us final product.
The masses are then sent to Pig Casting Machine and Cast House as per
requirements.

Day 12- Ladle Repair Shop (LRS)
In VSP Open Top Ladles are used to carry hot metal from Blast Furnace to Pig
Casting Machine or Steel Melt Shop via means of rail lines. Over time these
ladle tend to degrade under the influence of high temperature and various
other chemical phenomenon.
LRS does the work of repairing of damaged ladle with all necessary means and
make them use full again for service.

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