Project
Project
Project
This is to certify that the project entitled “BLAST FURNACE IRON MAKING OPERATION
PRACTICES”, being submitted by :
1. Aasir Rashid Bhat
2. Faizan Mir
3. Junaid Ahmad
4. Sabit Amin
5. Saqib Khaliq
6. Sayib Khaliq
7. Shah Fuhaid
Students of B.Tech (3rd year), Metallurgy and Materials Engineering 3rd year National
Institute of Technology Srinagar, during the academic year 2016-2017 and it has been
worthy of acceptance.
ACKNOWLEDGEMENT
We are thankful to Vizag Steel Plant for providing us this opportunity to visit the plant and help us in
understanding the practical aspects of steel making.
Lastly we would like to thank all the employees of VSP for their kind cooperation ,without whom this
project would not have been possible.
INTRODUCTION:
Steel comprises one of the most important inputs in all sectors of economy. Steel industry is both a
basic and a core industry. The economy of any nation depends on a strong base of iron and steel
industry in the nation. Iron and steel making, as India has known craft for a long time, the growth of
steel industry in India can be conveniently studied by dividing the period into pre and post
independent era. By 1950, the total installed capacity for ingot steel production was 1.5 million tons
per year. The capacity increased by 11 times to about 16 million tons by nineties. Presently in India
steel products are being produced from 4 different sources , namely integrated (interlinked) steel
plant, Mini steel plants Re-rolling mills, Alloy and special steel plant. In Integrated steel plants,
naturally occurring raw materials are processed into finished products in various stages. These plants
are highly capital intensive. It needs approximately Rs. 25000 crores for the establishment of steel
plant producing 1 million tons per year. VSP’s product mix comprises Wire rods, Bars, Angles,
Channels/Beams, Rounds and Billets. About nearly 60 type of products are produced in the steel
plant. The Plant also produces Pig iron, Granulated Slag and Coal chemicals. Coils and Rods are
mainly for reinforced concrete work for housing, construction, of dams, buildings, factories,
manufacture of agricultural implements an fabrication of light engineering components.
The soviet design organization, GIPROMEZ designed the coke oven and coal chemical plant, sinter
plant and blast furnace. MECON of Ranchi designed the seven-meter tall coke oven batteries with
dry quenching. The remaining facilities have been designed by DASTUS & Co., who is the principal
consultant for VSP.
VSP won many accolads and won the prestigious silver trophy for turnaround category from SCOPE
for the year 2000-01, National Energy conservations Award-2002, Green Tech Environment
Excellence award , silver award in steel sector are few to name among many. The Vishakapatnam
steel plant strikes every one with a tremendous sense of awe, wonder and amazement as it
presents a wide array of excellence in all its facets in scenic beauty , in technology , in man power , in
management and above all in product quality.
Quality holds the keys to pride , productivity and profit ability. The economics of recent times has
spawned the need to have the right resources to improve quality and reduce cost and at VSP, the
quality is the responsibility of one and all. It is a matter of pride that VSP is the only integrated steel
plant in the country to be certified for ISO 9001-2000,ISO 14001:2004 and OSHAS 1800:1999.
The main by-product in the process of coke making is crude coke oven gas and this has a lot of
valuable chemicals. Coal Chemical Plant recovers Ammonia (NH3), Tar and Benzol from CO-Gas. The
primary by-products from Crude CO Gas are Ammonium Sulphate (NH4)2SO4, Crude Tar, Crude
Benzol and cleaned coke oven gas. The cooled coke from CDCP (Coke Dry Cooling Plant) is
separated into 3 fractions, BF Coke i.e. +25-70 mm, which is sent to Blast Furnaces, Coke Breeze i.e.
+0-15 mm, which is sent to Sinter making and nut coke i.e., +15-25 mm, which is also used in the
Blast Furnaces.
SINTER PLANT
Sintering is an agglomeration process of fine mineral particles into a porous mass by incipient
fusion caused by heat produced by combustion within the mass itself. Iron ore fines, coke breeze,
limestone and dolomite along with recycled metallurgical wastes are converted into agglomerated
mass at the Sinter Plant, which forms 70-80% of iron bearing charge in the Blast Furnace. The
vertical speed of sintering depends on the suction that is created under the grate. At VSP, two
exhausters are provided for each machine to create a suction of 1500 mm water column under the
Grate.
Facilities
Two Sintering machines of Dwight Lloyd type each having 312 M2 total grate area.
One Sintering machine of Dwight Lloyd type having 408 M2total grate area.
BLAST FURNACE
Iron is made in the Blast Furnaces by smelting iron bearing materials with the help of coke and air.
The solid charge materials like sinter, sized iron ore, coke etc. are charged in the vertical shaft of the
Blast Furnace at top and hot air blast is blown through the tuyeres located at the bottom. The
oxygen from the hot air combines with the carbon of the coke and generates heat and carbon
monoxide. The gases, while ascending upwards react with the descending charge materials.
Eventually, the charge melts, hot metal and slag are produced and tapped out. The cooled gas is
also used as fuel in the plant. The Paul-Wurth, bell less top system is installed for furnace charging.
Facilities
Three LD converters (One converter of 133 cum. volume and Two converters modernized
with increase in volume to 150 cum. each along with DOG House facility).
6 nos. of 4 - Strand Continuous Bloom Casting machines.
SMS-2:
Blooms from Continuous Casting Division are rolled into billets, some of which are sold and
rest are sent to Bar Mill/WRM. The continuous two-line Bar Mill comprises of 8 Stand Double
Strand roughing train, 2 nos. of 4 Stand Single Strand intermediate train & 2 nos. of 4 Stand
Single Strand finishing train. Loopers are provided in between the finishing stands for tension
free rolling in order to obtain good surface quality and tolerances. Housings are of closed top
type. Roll necks are mounted in anti friction bearings.
Facilities
Breakdown Mill
Bar Mill
The Mill is high speed 4 strand No-Twist continuous mill designed to produce 8,50,000 Tons
of wire rod coils per year. Rolled billets of 125 mm x 125 mm square cross section, length
ranging from 9.8 m to 10.4 m and weighing approximately 1250 kgs are used. The mill is
designed to roll steel stock of 0.9% max. carbon content.
WRM-2
The Mill is designed to produce 6,00,000 tons per year of rounds in coil form. The Mill is
designed to roll low, medium and high carbon steel, case hardening steel, cold heading
quality steel, electrode steel, spring steel, bearing steel and free cutting steel. The mill shall
use continuous cast billets of 150 mm X 150 mm square cross section, 12 m length and
weighing 2100 kgs approximately, are used as input material.
Facilities
WRM-1
WRM-2
The main purpose of BHS is to manage reception of raw materials from various sources and plants
(RMHP-iron ore, Sinter Plant-sinter, Coke Oven-Coke, etc) and supply it batch wise to Blast Furnace
continuously .
As we know the process in blast furnace is a continuous reaction not a batch process. Hence,
continuous feeding of the furnace with charge material is necessary. If burden sent is insufficient, it
would result in increase of pressure in the upper region of the shaft. Such irregularities may lead to
severe malfunctions or accidents. 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. Thus Burden handling System is designed to
perform a number of technological operations essential for proper running of BF process.
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 CB 1,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
These are mechanical structures. The conveyer carrying burden splits into two vertical closed
structures. The materials after passing through trippers pass through series of screens and are
collected in bins.
Conveyers
в1 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 characteristics of sinter, coke
and other materials when they come to the 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 stock 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 electric field inside the shell the dust particles
acquire negative charge and the large parallel plates act as anode and hence the dust particles get
attached to the plates. There are large hammers connected to rapping motors, which continuously
beat the parallel plates. This action leads to dust particles falling and they are collected in large
containers and later disposed off by the dumpers.
D1 Conveyer
The burden is sent to the furnace via Main Belt (MB) conveyer. 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 the
operations department. It is prepared on the basis of calculation, available raw materials,
technological requirement and capacity.
Additives are added to the charge to maintain a particular basicity of 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. The coke received at the stock
house is produced from a mixture of local and imported coke subjected to dry quenching.
Screening
To regulate the size of the materials sieves are introduced between trippers and bins. Accordingly
sieving is done when burden is filled into the bins with the help of a 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
sieves.
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 affects blending too.
It is to be noted that bins are operationally never emptied below the
lower level other than in case of furnace shutdown.
Stove
BF 1 Stoves
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 by burning gas and combustion of
air within chamber the heat is absorbed into the brick wall, this mode is called Caledon-gas. Coke
Oven gas(C.O) and Blast Furnace(B.F) gas are used to produce heat . Cold air (about 100°C) coming
from Thermal Power Plant (TPP), is passed through pre-heated stove and absorbs heat to become
hot blast. Hot Blast comes out at a Temperature of about 1100°C. Cold air is then mixed in small
amounts to achieve the desired temperature (1000°C),and is then forced into the blast furnace via
tuyeres. Commonly there are three or four stoves. A stove has two modes, heating mode and blast
mode. At a time when one is on blast mode 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. Heating stops when “Flue
Temperature” i.e the temperature of flue gases coming out reaches 400 °C. The stove is then ready
for blast. Blast mode continues till the “Flue Temperature” drops below 110°C.
The Figure shows the four stoves . Out of the four , only three are functional . Stove 1 is out of use.
Stove 4 is in blast mode and in use. Stove 2 and Stove 3 are in heating mode and will be used
subsequently .The Hot blast coming out from the Stove 4 is mixed with some amount of cold blast
to get the desired temperature (about 1000°C) and it is finally sent to the furnace.
1. Mudgun mass
2. Runner mass
3. Water mass
Mud gun mass chiefly consists of clay, coke breeze, bauxite and Oil (Wash oil, Binder, Liquid resin,
etc.). 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.
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.
Cast House
Introduction
Blast furnace (BF) is a tall vertical furnace which is used to produce hot metal (pig iron). Preheated
air is blown from the bottom at high pressure and temperature. It is because of this blast of air
which is blown, this furnace is known as ‘Blast Furnace’. In VSP there are three blast furnaces (BF 1,
BF 2, BF 3). BF 1 and BF 2 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. BF 3 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 63m3. BF cooling system consists of
cast iron & copper staves .The tapholes 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.
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
Hearth acts as the container for hot metal and slag. It is constructed using fire bricks but now-a-days
carbon blocks are used. It comprises of three layers, viz. refractory layer, water cooled layer and
steel plate layer. 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
Tuyeres are located just above hearth which is used to blow hot air blast into the furnace for the
combustion of fuel. 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
At the top of the bosh is the widest inside dimension of the refractory lining. Just above the bosh of
the same diameter there is a straight vertical section connected to the furnace called the ‘belly’.
Stack
This section is above the belly and has inward slope. Charge is deposited at the uppermost region of
the stack and is at an angle of 80°.
1. Charging
2. Tapping
1. CHARGING
Charging is the process of pouring of Iron bearing material and Coke into the furnace through two
bins. One charge is composed of one batch of Iron bearing material (sinter and additives) and one
batch of coke. The burden is sent to the furnace via D1 conveyer.
The main constituents of charge are:
Iron Bearing Material (Iron ore, Sinter),pellets,additives
Coke
Iron Bearing Material:-
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, agglomeration of iron ore fines, coke, silica,
metallurgical waste (VSP). Pellets are durable and ship well while sinter is 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).
Some new techniques used are ‘Pulverised Coal Injection (PCI)’ and Oxygen Enrichment which
increases the production and also decreases the overall cost of fuel consumption.
Additives:-
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 sulphur 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.
Size requirements
Sinter : +5mm
Coke : +25mm (Surface Coke :20-60mm, Centre Coke: +60mm)
Charging system used at VSP
Paul Wurth /Bell-less top charging system
Paul Wurth or 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 ensures uniform distribution and allows manual control of the
burden into the furnace.
The furnace is divided into 11 rings into which the charge is distributed using chute which is
computer-programmed.
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.
Charging Observations :
Time Char Coke Nut Sin Iron LS/L MnO Quartz/Si Pellet BR %sinte
ge Coke ter Ore D lica Brick s r
No.
⎿ 23.0 - 46. 16 - - - 6.0 2.9 67.65
0 6
9:30 SKB 23.0 - 44. 14 1.0/2 - - 10.0 2.9 64.71
nd
0 6
10:30 SKB 23.0 - 48. 20.0 - - - - 2.9 70.59
0 6
2. TAPPING
The molten metal formed during the blast furnace operation is tapped at regular intervals by
opening the ‘tap-hole’ in the bottom of furnace. The hot metal from the furnace is collected in
‘ladles’ and specially constructed railway containers, called ‘torpedo cars’. The torpedo cars
carry the molten iron to the steel melt shop. The tap holes are opened using drillers. The tap
hole is closed when the furnace is in dry condition i.e. air starts coming out of the tap hole. Tap
holes are closed by mud gun which uses mud gun mass from MCS. The hot metal and slag are
separated from a single tap hole using ‘Skimmer plate’ arrangement.
Time:- 9:30-11:30
Amount of Metal Tapped:- 600T
Length of Tap Hole:- 2m
Diameter of Tap Hole:- 2’’
Mud Gun Mass used:- 250 litre/tap hole
Time Charges Stock Level Blower No.II
Blast
L R V P T Ste
3
(Nm (Kg/ ( ⁰C) am
/min) cm2) (T
/hr)
7 05 0.67 1.12 5769 3.05 955 12.6
8 11 0.52 0.93 5855 2.90 955 12.5
9 17 0.78 1.40 5531 2.50 955 11.6
10 22 0.65 1.26 5610 2.60 955 10.40
11 28 0.54 1.06 5674 2.70 955 11.90
S1+34.20 S2+37.8
Pr Temp. L U T 1 2 3 4 1 2 3 4
1 2 3 4
1.6 20 24 207 21 1.1 0.2 1.4 213 185 277 227 159 143 - 177
5 1 7 4 5 5 0
1.5 21 23 209 23 1.0 0.3 1.4 210 210 303 243 161 141 - 192
0 3 1 6 5 5 0
1.1 18 19 196 21 1.1 0.3 1.4 211 211 274 279 164 108 - 154
0 4 7 2 0 0 0
1.2 16 16 161 16 1.1 0.3 1.4 182 182 238 211 159 106 - 150
0 2 5 0 0 0 0
1.3 14 16 149 16 1.1 0.2 1.4 232 177 232 191 161 127 - 169
0 2 9 2 1 9 0
1.5 13 15 105 12 1.1 0.2 1.4 134 184 285 206 177 160 - 193
0 1 2 7 2 8 0
Stoves Temp.
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.
The analysis of raw materials and products are conducted using two
instruments:
Optical Emission Spectrometer (OES)
X-Ray Flouro-Spectrometer (XRF)
OES :
Picture: OES
The main process in this instrument is generation of spark using high voltage
with the help of which electron is removed from the inner-shell and the
characteristic wavelength is emitted which is detected using detector at
characteristic angle. This instrument can only be used for metals(cooled hot
metal) because conduction of sample is necessary.
The main components of OCS are:
Tungsten (Primary Electrode)
Sample (Secondary Electrode)
Argon (Inert Environment)
OES Observations:
XRF:
XRF machine
The process in XRF is same as OCS . The only difference is that electron is
emitted using X-rays unlike in OCS where it was done using spark. XRF is used
for non-metals which is reduced to the size -10µm (oxides, iron-ore, Sinter).
The process can also be used for metals but that is more energy and time
consuming because of size reduction. Vacuum environment is maintained.
Sample in XRF