It gives information about extraction of iron metal from hematite ore and also extraction of copper metal from copper pyrite ore

1. By Anuja r. kamthe

2. Native State Combined state
Occurrence of metals
The noble metals(less active
metals )like gold, silver and
platinum exist in nature in native
or free or metallic state
Almost all the metals exist in nature
in combined state in the form of
their compounds like oxides,
sulfides, sulfates, carbonates ,
hydroxides etc. These natural
compounds of metals are called as
minerals.

3. Ore: - A minerals from which the metal can be extracted easily and
economically is known as ore.
for Example:-Clay [Al2 Si2O5 (OH)4 ] and bauxite [Al2 O3 ] are two
minerals of aluminum but aluminum can be profitably extracted only
from bauxite not from clay, hence bauxite is an ore while clay even
though it contains Al it can not be used as ore of aluminum.
Mineral: - A naturally occurring
substance present in earth's crust
which contains metal in the free or
combined state is known as mineral.

4. Type of the ore Name of the ore Chemical
formula
Metal
Extracted
Oxide ores Haematite Fe2O3 Fe
Magnetite Fe3O4 Fe
Limonite 2Fe2O3, 3H2O Fe
Cuprite Cu2O Cu
Sulphide ore Zinc blende ZnS Zn
Iron pyrite FeS2 Fe
Carbonate ore Siderite FeCO3 Fe
Limestone CaCO3 Ca
Sulphate ore Gypsum salt CaSO4 , 2H2O Ca
Epsum salt MgSO4 , 7H2O Mg

5. Gaunge or matrix:- The
unwanted earthy impurities like
dust particles, sand particles,
small rocks etc. present in the
ore are called as gangue or
matrix
Metallurgy:-
Metallurgy is a process of extraction of metals from their ores
economically & profitably. It has four steps
Ore Metal
Metallurgy
1. Crushing
2. Concentration
3. Reduction
4. Refining
Steps of Metallurgy-

6. Flow chart for extraction of metal

7. Combustion type Electric type
Types of Furnaces
It is used for smelting purpose to
produce industrial metals and their
alloys like iron, lead, copper etc
It is used for high temperature
applications such as fusing glass,
creating enamel coatings, ceramic
articles , soldering and brazing
articles
Charge is heated with the help of
heat obtained by burning the coal
Charge is heated with the help of
electric current
Example- Blast furnace,
Reverberatory furnace
Example- Muffle furnace

8. The blast furnace is a huge, cylindrical furnace made up of steel and
internally lined with refractory bricks. In the body of blast furnace the
mixture of iron ore, coke and limestone are introduced from the top,
and preheated air is blown from the bottom. The molten metal & molten
slag formed removed from bottom of the furnace

11. Muffle furnace –It is front
loading box type oven which
can reach high temperatures
using electric current . It
contains heating chember,
temperature controller and
safty door The furnace
achieves the high-temperature
on the basis of the insulating
material which is fitted inside
the chamber. The insulating
material which is provided in
the chambers acts as a muffle
(wrap or cover for warmth) and
stops the heat from escaping out of the chamber. Muffle furnaces are
used for the applications where there is huge demand of testing the
sample at high temperature and to determine the percent of ash content
in those materials.

12. Type of the ore Name of the ore Chemical formula
Oxide ores Hematite Fe2O3
Magnetite Fe3O4
Limonite 2Fe2O3, 3H2O
Sulphide ore Iron pyrite FeS2
Carbonate ore Siderite FeCO3
Ores of Iron metal :-
Extraction of Iron Metal from Hematite Ore:-
1.Processing of ore:- In this ore is converted into fine powdered
form by using jaw crushers and ball mill.
2.Concentration of ore:-The process of removal impurities is
called as concentration of ore.
a) Physical concentration:- Hematite ore is first concentrated by gravity
separation and then by magnetic separation .

13. Crushing of ore
Concentration of ore done by
Hematite ore
Smelting of ore
Refining of iron
wrought iron
1. Gravity sepration
2.Magnetic seperation
3.Roasting

14. Principle:-Gravity separation
method is based on the
difference between the densities
of the ore particle and gangue.
It is used for the concentration
of denser ores from the water
soluble and lighter impurities
(gangue).
a) Gravity separation method :-
Process :-In this method powdered ore is kept at the top of the
sloping platform or a vibrating table having depressions and is then
washed with the running stream of water. The light impurity particles
are washed away by water while heavy ore particles settle down in the
depressions due to gravitational force.

15. b) Electro magnetic separation:-
Principle- This method is based upon magnetism

16. Process –
Hematite ore contains non magnetic impurities which are removed
here. In this process powdered ore is allowed to fall through hopper on
leather or rubber belt which is constantly moving over two rollers one of
which is electromagnetic in nature. The magnetic particles present in the
ore when come in contact with the magnetic field of the electromagnetic
roller they get attracted towards the roller and hence get collected near the
roller, while non magnetic particles present in the ore are not attracted
towards the roller hence fall away from the roller.

17. c) Chemical concentration:- It is done by roasting . In this
process ore is strongly heated in presence of air in open heaps below its
M.P.
Following changes occurs during roasting:-
1.Moisture is removed
2.The impurities like C, S,P,As etc. are oxidized and removed in the
form of their oxides.
C + O2 CO2
2P + 5 O2 2 P2O5
3. The ferrous oxide impurity is oxidized to ferric oxide
4FeO + O2 2 Fe2O3
4. Ore becomes porous

18. Reduction of ore :- It is done by smelting . In this process roasted
ore is strongly heated with reducing agent coke and flux limestone in the
hearth of blast furnace
Role of flux :- It remove
matrix or gangue present in
the ore in the form of slag.
Role of coke :-
It acts as reducing agent and
reduces iron oxide to iron metal
Fe2O3 + 3C → 2Fe + 3CO
Flux + Gangue Slag

19. Flux - A substance which is used to remove matrix or gangue is known
as flux.
Flux + Gangue Slag
Types of flux:-
1. Basic flux: CaO
2. Acidic flux: SiO2
In Smelting process flux and gangue are complimentary to each
other
1) SiO2 + CaO CaSiO3
Acidic Gangue Basic Flux Slag
2) FeO + SiO2 FeSiO3
Basic Gangue Acidic Flux Slag
Slag: - Flux combines with gangue to form easily fusible mass known as
Slag.
Flux + Gangue Slag

20. Composition of charge added in Blast furnace:-
It consist of
8 parts of roasted ore + 4 parts of coke +1 part of limestone
Zones of blast furnace :- Depending upon temperature range blast
furnace is divided into
1) Zone of reduction 3000C to 8000C
2) Zone of heat absorption 8000C to 12000C
3) Zone of fusion 12000C to 15000C

23. Chemical reactions in the reduction zone of blast furnace.
The reduction of iron oxide is done in the following stages:-
Fe2O3 Fe3O4 FeO Fe
i) In between 3000C – 5000C
3Fe2O3 + CO 2Fe3O4 + CO2
ii) In between 6500C – 7000C
Fe3O4 + CO 3FeO + CO2.
iii) At temperature between 7000C – 8000C
FeO + CO Fe + CO2
CaCO3 CaO + CO2
iv) Simultaneously, the limestone present in the charge is also
decomposed to produce lime.
lime
.
limestone

24. Chemical reactions in the zone of heat absorption blast furnace:-
Following reactions take place in this zone.
i) Any oxide of iron which has escaped from reduction is reduced by
red hot carbon
Fe2O3 + 3C → 2Fe + 3CO
ii) Carbon dioxide is reduced to carbon monoxide by heat absorption.
CO2+ C → 2CO + 39Kcal
iii) The hot spongy iron melts the ascending CO and decomposes a part
of it to produce finely divided carbon.
2CO → CO2↑ + C
iv) lime obtained in the zone of reduction forms slag with silica.
CaO + SiO2 → CaSiO3 (Slag)
v) At about 12000C, non-metallic and metallic oxides are reduced by
coke to respective elements.
1. SO2 + 2C → S + 2CO ↑ 2. SiO2 + 2C → Si + 2CO ↑
3. P2O5 + 5C → 2P + 5CO ↑ 4. MnO2 + 2C → Mn + 2CO ↑

25. Chemical reactions in the zone of fusion:-
The spongy iron metal formed in the zone of reduction and zone of
heat absorption is impure . It melts in this zone and get collected in the
furnace well. It is then removed from the lower tap hole
Similarly the slag formed in the zone of heat absorption melts in this
zone. Molten slag floats on the surface of the molten metal and thus
prevent its oxidation. It is removed from upper tap hole.
The blast furnace attains the maximum temperature in the zone of
fusion because in this zone the coke present in the charge gets
oxidized by hot blast of air introduced through twyers and forms CO2
along with the liberation of heat.
C + O2 CO2 + 97 KCal
Products of blast furnace:- i) Slag
ii) Flue Gases
iii) Pig Iron

26. Pig iron.
Composition:
Iron: 92-94% Carbon: 2.5- 4.5% Silicon: 0.7 – 3%
Phosphorus: 0.5 -1 % Manganese: 0.2- 1% Sulfur: 0.1 -0.3 %
Properties: It is neither malleable nor ductile.
•It can not be forged, rolled, tempered and welded.
•It can not be magnetized permanently.
•It is very brittle & has low tensile strength.
•It melts at 1150 0 c to 1250 0c
•It expands on solidification and does not rust easily
Applications.
i) It is used for casting metal objects such as stoves, lamp posts, drainage
covers , pipes, railings, fire gates etc.
ii)Used in casting various types of articles such as toys, radiators,
cooking ranges, water and drain pipes and agricultural implements
iii)used for making electric poles, Bunsen burners, bases.
iv) Used in making wrought and steel

27. Slag.
Composition:-It consists primarily of calcium silicates, alumino-
silicates, and calcium-alumina-silicates
Applications:-
1) It is used as filler for rail roads.
2) It is used in the manufacturing of cement lightweight aggregate for
Portland cement concrete.
3) Granulated blast furnace slag has been used as a raw material for
road making.
4) It is used as a fertilizer & for soil conditioning.
5) It is used in the manufacturing heat insulating material.
Flue gases
Composition:- N2 = 55.19%, CO = 20.78%,
CO2 = 21.27% and H2 = 2.76%
Blast-furnace gas is utilized as a fuel in metallurgical works.
Applications:-

28. Heat treatment of steel:-
Heat treatment of steel may be defined as the process of heating
steel to a certain high temperature and then cooling it at a controlled rate,
in order to develop certain desirable physical properties in it without
changing its chemical composition
Purposes of heat treatment of steel :-
To change the structure of steel,
To increase surface hardness.
To increase resistance to heat & corrosion.
To vary strength & hardness.
To make steel easily workable.
To remove the trapped gases.
To improve machinability & mechanical properties.
To alter magnetic properties of steel.

29. Hardening:-It is defined as heating the steel to a high temperature (800
– 9000C) & then suddenly cooled by dipping or quenching in some
suitable medium is called hardening.
Tempering :- The process of reheating quenched steel and cooling it
usually in air is called as tempering It is done to minimize hardness ,
brittleness & unequally distributed stresses..
Normalizing:-It is defined as heating the steel to a definite temperature
about 500C above the critical temperature. Then it is allowed to cool
freely in air. The cooling rate is generally about 50C per second is called
Normalizing.
Annealing:- It is defined as heating the steel to certain high temperature
& then cooling slowly at controlled rate in furnace is called annealing.
i)It improves machinability ii) It softens the steel.
iii) It increases ductility & shock resistance.
iv) It removes internal stress caused due to uneven contraction during
casting.

30. Type of ore Name Chemical
formula
Oxide Cuprite or ruby copper Cu2O
Sulphide Copper glance Cu2S
Copper pyrite CuFeS2
Carbonate Malachite CuCO3,Cu(OH)2
Azurite 2CuCO3,Cu(OH)2
Ores of Copper metal:-

31. Crushing of ore
Concentration of ore done by
Copper Pyrite ore
Smelting of ore
Bessemerisation
Electro refining
pure copper
1. Gravity sepration
2.Froth flotation
3.Roasting

32. 1. Processing of ore:- In this ore is converted into finely powdered
form by using jaw crushers and ball mill.
2.Concentration of ore:-The process of removal impurities is called as
concentration.
a) Physical concentration:- Copper pyrite ore is first concentrated by
gravity separation and then by froth floatation.
Gravity separation:- In this method powdered ore is
kept at the top of the sloping
platform or a vibrating table
having depressions and is then
washed with the running stream
of water. The light impurity
particles are washed away by
water while heavy ore particles
settle down in the depressions
due to gravitational force

33. Froth Floatation Process :-
Principle- This method is based upon differential wetting
characteristics. Here ore particles are selectively wetted by oil while
gangue particles are selectively wetted by water

34. Process :-
In this process, the powdered sulfide ore is mixed with water & pine oil.
The whole mixture is then stirred vigorously by passing compressed air.
The oil forms a froth with air bubbles. The sulfide ore particles get
attached with the Froth & Floats on the surface, while the gangue or
earthy impurities are wetted by water & sink to the bottom of the tank.
The floating froth is then skimmed off into settling basins from where by
filter press a concentrated ore is recovered.

35. Chemical concentration:- It is done by roasting . In this process
ore is strongly heated in the hearth of reverbaratory furnace in presence
of air at a temperature just the below its M.P.
Following changes occurs during roasting:-
1.Moisture is removed
2.The impurities like S, Sb ,As etc are oxidized and removed in the
form of their oxides.
S + O2 SO2
2As + 3 O2 2 As2O3
2Sb + 3O2 2 Sb2O3
3. The copper pyrite decomposes to form cuprous and ferrous sulfide.
2 CuFeS2 + O2 2 Cu2S + FeS + SO2
4. A part of these sulfides get oxidised to corresponding oxides
2 Cu2S + 3 O2 2 Cu2O + SO2
2 FeS + 3 O2 2 FeO + SO2

36. Smelting process:-

37. Process: i) Roasted copper ore is then mixed with coke & sand particles
& then strongly heated at high temp. in a water jacketed blast furnace.
ii)At high temperature ferrous sulfide (FeS) is oxidized & converted
into ferrous oxide (FeO) which further reacts with sand particles to form
a fusible slag (FeSiO3)
2FeS +3O2 2FeO + 2SO2
FeO + SiO2 FeSiO3
iii) Further cuprous oxide (Cu2O) formed during roasting combines
with ferrous sulfide (FeS) to form ferrous oxide (FeO) & cuprous
sulfide (Cu2S). The ferrous oxide (FeO) formed futher react with silica
particles to form slag.
Cu2O + FeS FeO + Cu2S
iv)Thus during smelting process most of the ferrous sulfide impurity is
converted into the fusible slag (FeSiO3)which is then removed from the
upper slag outlet.
v)The molten mass containing mostly cuprous sulfide (Cu2S) & little
quantity of ferrous sulfide (FeS) is called as matte which is then
removed from the lower outlet.

38. Bessimerization process:-
Bessemer converter
After smelting the molten matte
is then transferred to a
Bessemer converter which is a
pear shaped furnace made up of
steel and internally lined with
lime or magnesia. It is mounted
on turnnions and can be tilted in
any position. Furnace is
provided with pipes known as
twyers through which sand and
hot air is blown into it.
Following chemical reactions
takes place in the Bessemer
converter

39. (a) Conversion of FeS to slag
2FeS +3O2 2FeO + 2SO2
FeO + SiO2 FeSiO3
(b) Partial oxidation of Cu2S to Cu2O
(c) Reduction of Cu2O by Cu2S to metallic copper
2Cu2O + Cu2S 6Cu + SO2
The molten metal obtained from the Bessemer converter is then poured
into sand moulds and allowed to cool. On cooling dissolved SO2
escapes out causing blisters on the surface of copper hence it is called
as blister copper. It is 96 to 98% pure.
2Cu2S +3O2 2Cu2O + 2SO2

40. Electro-refining of copper :-Blister copper contains 3 to 4 % of
impurities like Ag, Au, Pt, Cr, Ni, Fe, S etc. Presence of all these
impurities in copper reduces its electrical conductivity. So when copper
metal is to be used for preparation of electrical wires & cables it is electro
refined because this process gives 99.99% pure copper metal.

41. 1. It is carried out in the large lead lined tank.
2. Impure Copper is placed into large plates which are suspended into
tank at intervals & acts as anode.
3. Cathodes are thin plates of pure copper & each is suspended between
two plates of anode.
4. The electrolyte is 15% CuSO4 containing 5-10% free H2SO4 solution.
5. By the passage of electric current, Cu from the anode with traces of
more active metals like Zn, Fe, Ni present as impurities go into the
solution as metallic ions, whereas less active metals like Ag, Au & Pt are
not ionized but crumbles down from the anodes & settle below the anode
as anode mud.
6. At the applied voltage, Cu++ ions alone are discharged at the cathode &
thus pure copper is deposited on the cathodes.
7. Electro – refined copper is about 99.99% pure.

43. Tensile Strength: - Is the ability to carry a load without breaking.
Or A tensile strength of a metal is its ability to resist pull without
breaking
Machinability: - Is the property due to which a material can be easily
cut by cutting tools to produce a desired shape & surface finish on its
surface.
.
Ductility: - It is the property of metal which allows it to be drawn into
wires without breaking.
Malleability:- It is the property of metal which allows it to be converted
into thin sheets without breaking.
Hardness:- It is the property of metal to resist wear, abrasion and
penetration
Toughness:- It is the property of metal to resist repeated shocks and
vibrations without breaking (deformation).
Properties of metal :-

44. Soldering: - A method of joining the metals surfaces by introducing a
molten non-ferrous alloy with melting point below 4000C between them,
is known as soldering.
Brazing: - A method of joining the metals surfaces by introducing a
molten non-ferrous alloy with melting point above 4000C between them,
is known as soldering
Castability:- The process of pouring molten metal into a mould &
allowing it to solidify is known as casting and the ability of metal to get
casted is called as castability.
Weldability: - Is the property of metal due to which two metal pieces
can be joined easily by means of heat.

45. Mrs A R Kamthe
Alloy:- It is defined as a homogeneous mixture of two or more elements
in which one must be a metal. It is always in solid state hence also called
as solid solutions in which base metal(major component which acts as
solvent ) and alloying elements (minor component which acts as solute)
.When alloy contain mercury as a one of the component
Base metal:- It is the major component of alloy
Alloying elements:- These are the minor component of alloy
Examples: steel alloy, plain carbon steel, magnetic steel, stainless steel
Brass, Bronze, Duralumin etc.
When alloy contain mercury as a one of the component then it is called as
amalgam
Examples: Sodium amalgam ( alloy of Na & Hg)
Aluminum amalgam ( alloy of Al & Hg)

46. Purposes of making alloy:-
1. To improve the hardness of metal:-
e.g. Pure gold & silver are soft. Hence they are hardened by
the addition of a small amount of copper in them.
2. To lower the melting point:- Pure metals are having high
melting point. It can be lowered by addition of alloying
elements.
e. g. Wood’s metal has the M.P. 710C which is much lower
than those of its constituents.
3. To increase the tensile strength:-
e. g. The addition of 1% carbon increases the tensile strength
of pure iron by about 10 times.

47. 4. To increase corrosion resistance:-
e. g. Pure iron is corroded fastly but its alloy stainless
steel resists corrosion.
5. To get good castings:-
e. g. Bronze possesses good casting property.
6. To modify color:-
e. g. Brass is an alloy of Copper (red) and Zinc
(silvery white) and is yellow in colour.
7. To reduce malleability and ductility:-
e. g. A small amount of Copper is added to gold and
silver to reduce their malleability and ductility.

48. Preparation of alloy:-
1. Fusion
2. Reduction
3. Compression
4. Electro deposition
Fusion Method:- It is used for preparation of binary alloys (two
component alloy)

49. Mrs A R Kamthe
Process:
1) The component metal having higher M.P. is melted first in a crucible
& the other having lower melting points are added to in it.
2) The molten metals are at high temp & hence may react with
atmospheric oxygen to form oxide. So in order to prevent oxidation the
molten mass is covered with charcoal powder.
3) The molten mixture is stirred using graphite rods to get uniform alloy.
4) The molten mass is then allowed to cool which gives required alloy.

50. Mrs A R Kamthe
For example :
preparation of brass alloy (Cu+Zn)by fusion method
1) The copper metal having higher M.P. (10890C) is melted first in a
crucible & then zinc metal having lower melting point ( 4190C) is
added into it in definite proportion.
2) ) The molten mixture is stirred using graphite rods to get uniform
mixture.
3) In order to prevent oxidation the molten mass it is covered with
charcoal powder.
4)The molten mass on cooling gives required brass alloy

51. 2.Compression Or Powder metallurgy:-
Process:
In this method intimate mixture of component metals in powdered
form is compressed in a mould and then heated to a temperature just
below the melting points of the alloy. It is carried out in following
steps
1. Preparation of metal powders:- It is done by using mechanical,
chemical or electro chemical methods
2. Mixing:- Metal powders of component elements are mixed together
in definite proportion to form intimate mixture.
3. Compacting:-The intimate mixture of component elements in filled
in a suitable mould under pressure.
4. Sintering:-The moulded article is then heated in a furnace at a
temperature just below the melting point of the alloy.
Example:- Alloys like Wood’s metal, solder, Alnico

52. 3. The Electro-Deposition Method
This method involves simultaneous deposition of different component
metals at cathode by passing direct electric current through the
electrolyte which contains the mixture of component elements salts .
4. Reduction Method
In this method the Metal oxide of one component element is reduced in
presence of other component element in a furnace
Exam – While preparing aluminum bronze (Al+ Cu) alloy aluminum
oxide is reduced in presence of copper metal in electric furnace

53. Ferrous alloys Non-ferrous alloys
Types of Alloys
The alloy which contains iron as
a major component iscalled as
ferrous alloy. They are commonly
called as steels
The alloy which does not contain
iron as a major component is
called as non ferrous alloy
Exam.:-
Plain carbon steels, spring steels,
stainless steels, tool steels, high
speed steels, magnetic steels
Exam.:-
Brass, bronze, duralumin, wood’s
metal

54. Ferrous alloys (Steels):- Contain iron as a major component
Example:- Plain Carbon steel
Classification of Plain Carbon steel:
It is classified on the percentage of carbon present in it.
a) Mild or low carbon steel – 0.05 to 0.3% carbon.
b) Medium carbon steel – 0.3 to 0.6% carbon.
c) High carbon steel – 0.6 to 1.5% carbon.

55. Mrs A R Kamthe
a) Mild or low carbon steel:
Composition: 0.05 to 0.3% carbon , remaining is Fe
Properties:
1. It is Soft, tough, malleable& ductile
2. It responds to heat treatment
3. It is suitable for welding
4. It has low tensile Strength
Applications:
1. It is used for soft wires, wires for rope
2. It is used for chains, rivets, bolts, nails, boiler tubes etc.

56. Mrs A R Kamthe
b) Medium carbon steel –
Composition: 0.3 to 0.6% carbon , remaining is Fe.
Properties:
1. It is harder & tougher than low carbon steel
2. It can be hardened by heat treatment
3. It is fairly good for welding (not easily)
4. It has high tensile Strength than mild steel
5. It is shock resistant
Applications:
1. It is used for rail roads, wheels, axles, fish – plates
2. It is used for armature and crank shafts, turbine rotors springs
3. It is used for gun parts, machine parts etc.

57. Mrs A R Kamthe
c) High carbon steel –.
Composition: 0.6 to 1.5% carbon, remaining Fe
Properties:
It is quite hard; resistant to wear hence it can produce a keen cutting
edge.
It can be imparted desired hardness by heat treatment.
It is un-weldable
It has highest tensile Strength
Applications:
It is used for wooden working tools; making files, chisels, saws,
drills etc.
It is used for metal cutting tools for lathes: cutters, knives, saws,
blades, razors etc.

58. Effect of alloying element on steel Or Iron
Effect of alloying element Carbon:-
i) It increases the hardness.
ii) It increases tensile strength of steel, but reduces its ductility.
Effect of alloying element Chromium:-
i) It increases hardness, toughness and tensile strength.
ii) It increases wear resistance and resistance to corrosion.
Effect of alloying element Ni:-
i) It improves corrosion & heat resistance.
ii) It also improves hardness, toughness, strength, elasticity & ductility.
Effect of alloying element Co:-
i) It also imparts strength & hardness to the steel which persists at red
heat.
ii) It also helps to retain permanent hardness.
.

59. Non-Ferrous alloys :- Do not contain iron as a major component
Example:- Brass, Bronze, Duralumin, Wood’s metal
Brass:-
Composition: Cu = 60 to 90 %
Zn= 40 to 10 %
Properties:
1.It has low melting point than pure copper and zinc.
2.It is highly malleable, ductile, good conductor of heat and electricity
3. It has high strength and good corrosion resistance
Applications:
1.It is used for making rivets, screws, plumbing fittings, hardware,
gears, battery caps etc.
2 It is used for making utensils, musical instruments,
3. It is used for artificial jewellery and decorative articles

60. Bronze:-
Composition: Cu = 88 %
Sn= 12 %
Properties:
1.It can be easily casted and machined
2.It is highly malleable, ductile, good conductor of heat and electricity
3. It has high strength and good corrosion resistance
Applications:
1.It is used in architecture for making structural and design elements
2 It is used for making utensils, statues, coins and bearings
3. It is used for musical instruments like saxophones, piano, singing
bowls, gong balls, cymbals

61. Tinmann’s solder:
Composition:- Sn = 66 % and Pb = 34 %
Properties:- It melts at 1800C .
Applications:- It is used for joining articles of tin.
Rose metal
Composition: Bi = 50%
Pb = 28%
Sn = 22%
Properties:
1.It is easily fusible alloy.
2. Its melting point is 890C
Applications:
1.It is used for making fire – alarms.
2 It is used in electrical fuse wires,
3. It is used for casting for dental works
4. It is used in automatic sprinkler system.

62. Wood’s metal.
Composition:-
Bi=50% ,
Properties:
1.It is easily fusible alloy.
2. Its melting point is 800C
Applications:
1.It is used for making fire – alarms.
2. It is used in electrical fuse wires,
3. It is used for casting for dental works
4. It is used in automatic sprinkler system.
5. Safety plugs of pressure cookers
6. Safety plugs of Boilers
7. Soft solder
Pb = 25% , Sn = 12.5% , Cd = 12.5%

63. Al=95% , Cu=4% , Mg=0.5% , Mn=0.5%
Duralumin:-
Composition:-
Properties:
1.It is light in weight, tough .
2.It is highly malleable, ductile, good conductor of heat and electricity
3. It has high corrosion resistance
4. It is Strong as mild steel with good tensile strength
5. Easily castable
Applications:
1. Al clad sheets used in aircraft industry in which a plate of duralumin
is sandwiched between two layers of 99.5% pure Al.
2. It is used for making cables, surgical instruments and fluorescent
tube caps.
3. It is used for automobile and locomotive parts.
4. It is used for making rivets, bars, housing cases

64. Babbit metal
Composition:
Sn = 88%
Sb = 8%
Cu =4%
Properties:
i) It is silvery white, soft metal alloy.
ii) It has very low coefficient of friction.
iii) It has very high corrosion and wear and tear resistance.
iv) It can take high polish.
v) It does not tarnish easily
vi) It distributes the load uniformly.
Applications:
i) It is used for making engine bearing.
ii) It is also used as a common bearing metal in cast iron boxes.

65. Cement:-
Cement is a very important building material. Almost every construction
work requires cement.
It is a fine gray powder of alumina, silica, lime and other substances
which when mixed with water harden to form a rigid comprehensive
structure with a good compressive strength.

66. Mrs A R Kamthe
Portland Cement:-
It is defined as the finely divided greyish mixture of calcium silicates
and aluminates with a small amount of gypsum which are capable of
setting and hardening by chemical reaction with water.

67. Mrs A R Kamthe
1) Calcareous Rocks (CaCO3 > 75%) – Used as a source of calcium
Limestone
Marl
Chalk
Marine shell deposits
2) Argillocalcareous Rocks (40%<CaCO3<75%) – Used as a source of
both that is calcium and aluminum
Cement rock
Clayey limestone
Clayey marl
Clayey chalk
3) Argillaceous Rocks (CaCO3 < 40%) - Used as a source of Aluminum
Clays
Shales
Slates
Raw materials used for preparation of Portland Cement:-

68. Mrs A R Kamthe
Chemical Composition of Portland cement:-

69. Chemical Composition of Portland cement:-
Sr.
No.
Name of Constituent Percentage
1 Lime (CaO) 60 – 67%
2 Silica (SiO2) 17 – 25%
3 Alumina (Al2O3) 3 – 8%
4 Iron Oxide (Fe2O3) 0.5 – 6%
5 Magnesia(MgO) 0.1 – 4%
6 Sulpher trioxide (SO3) 1 – 2%
7 Soda and Potash (Na2O+K2O) 0.5 - 1.3%
8 Gypsum (CaSO4.2H2O) 3 – 4%

70. Mrs A R Kamthe
Mineral Oxide composition
Abbreviat
ion
%
Tricalcium silicate (alite) 3CaO.SiO2 C3S
45
Dicalcium silicate (belite) 2CaO.SiO2 C2S
25
Tricalcium aluminate 3CaO.Al2O3 C3A
10
Tetracalcium
aluminoferrite
4CaO.Al2O3
Fe2O3
C4AF
10
Calcium sulphate CaSO4
4
Calcium oxide(free) CaO
2
Magnesium oxide (free)
MgO
4
Compound Chemical Composition of Portland cement:-

71. Functions of different constituents of Cement:-
1.Lime (CaO) :This is the important ingredient of cement which
impart strength. It’s proportion is to be carefully maintained because
lime in excess makes the cement unsound and cause the expansion
and disintegration of the cement. On the other hand if the lime is
less (deficient) then it will decrease the strength of the cement
and will cause it to set quickly.
2.Silica (SiO2) : This is an important ingredient of the cement as it
imparts strength to the cement due to formation of di-calcium
silicate and tri-calcium silicate. If silica is present in excess quantity
its setting time is prolonged however strength is increased.
3.Alumina (Al2O3) : This ingredient imparts quick setting
property to the cement. It acts as a flux and it lowers the clinkering
temperature. However the high temperature is essential for the
formation of a suitable type of cement and hence in alumina should not
be present in excess amount as it weakens cement.

72. 4.Iron Oxide (Fe2O3) :This imparts color, hardness and strength to the
cement.
5.Magnesia (MgO) :This ingredient, if present in small amount, imparts
hardness and color to the cement. A high content of magnesia makes the
cement unsound.
6.Sulphur(S) :A very small amount of sulphur is useful in making sound
cement. If it is in excess, it causes cement to become unsound.
7.Soda or Potash :The most of the alkalis (Soda or Potash) present in raw
materials are carried away by the flue gases during heating of raw
materials and hence cement contains only a small amount of alkalis. If
cement excess of alkalis then, they cause a number of troubles such as
alkali-aggregate reaction, efflorescence (is the migration of a salt to the
surface of a porous material )and staining when used in concrete,
brickwork or masonry mortar.
8.Calcium Sulphate (CaSO4) :This ingredient is in the form of gypsum
and its function is to increase the initial setting time of cement.

73. Role of Gypsum in Cement:-
Tricalcium aluminate (C3A) present in cement combines with water very
rapidly with evolution of large amount of heat to form C3A. 6H2O
crystals.
C3A + 6H2O  C3A. 6H2O + Heat
( Crystals)
Formation of these crystals prevent the hydration reaction of other
constitute compounds of cement forming a barrier . Because of this, the
cement paste becomes stiff and causes flash or initial set.
To avoid this early initial set, gypsum is added in cement. The added
gypsum retards the dissolution of C3A by forming insoluble calcium
sulpho – aluminate which does not have quick hydration property.
C3A + x H2O + y CaSO4. 2H2O  C3A.y. CaSO4 . z H2O
This reaction prevents a high concentration of alumina in the cement
solution & there by decreasing the early initial set of the cement.

74. Setting and Hardening of cement: -
The setting and hardening of cement is due to hydration and hydrolysis
reaction taking place between the different constituents of cement and
water.
Anhydrous compounds undergo hydration forming insoluble gels and
crystalline products.
Setting: is defined as stiffening of the original plastic mass due to initial
gel formation.
Hardening: is the development of strength due to crystallization.
Following chemical reaction taking place during setting and hardening.
1] Hydrolysis:
C3S + ( x+ 1) H2O C2S. xH2O (gel) + C.H2O.
C4AF + 7 H2O C3A. 6H2O(crystal) + CF.H2O
2] Hydration:
C3S + xH2O C2S .x H2O(gel) + CaO.
C3A + 6 H2O C3A.6 H2O(crystal + Heat.

75. Meta stable gel
Un-hydrated cement
Stable gel
Crystalline
hydrated
products
Crystalline
products
hydration and hydrolysis reactions
+ H2O

76. Uses of Portland Cement:-
Portland cement is the most common type of cement in general use
around the world as a basic ingredient of concrete mortar. It has
great resistance to cracking and shrinkage but has less resistance to
chemical attacks
1.It is used for general construction purposes where special
properties are not required.
2.It is normally used for the reinforced concrete buildings, bridges,
pavements, and where soil conditions are normal.
3.It is also used for most of concrete masonry units and for all uses
where the concrete is not subject to special sulfate hazard or where
the heat generated by the hydration of cement is not objectionable.
4. It is also used for preparation of wall putty, solid concrete blocks
AAC blocks (Autoclaved aerated Concrete blocks) and other type
of cement.

77. Waterproof cement:- Waterproofing is the process of making an
object or structure waterproof or water-resistant
Properties of water proofing cement:-
1. Ingredients in it act as pore blocking agents.
2. These acts as water repelling agents.
3. They increase the resistance to the penetration of moisture.
Uses of water proofing cement:-
1. Water proofing cement is used to building structures like dams,
bridges, water proof roofs, basement water proofing, Waterproof
floors, basement, underwater constructions, water proof fabrics,
damp proofing
.

78. Plaster of Paris:- Plaster of Paris is a fine white powder of quick-
setting gypsum plaster , which hardens when moistened and allowed to
dry. Chemically it is calcium sulfate hemihydrate
Properties:-
1.When Plaster of Paris is mixed with water it forms a plastic mass
which quickly sets to a hard mass.
2.The mass formed after setting is water proof
3.It is an excellent molding and casting agent
Applications:-
1.Plaster of Paris is used as a building material by constructors and
architects.
2. It is often used as a protective coating on the walls and ceiling before
painting is done.
3. In hospitals and medical departments, it is often used in fracture
cases. Orthopedics uses it to put casts around bone fractures
4. Dentists use Plaster of Paris to make mould or casts of the teeth.

79. Bio cements:- Bio cement is a self healing material used to enhance
durability of construction structure and for conservation of cultural
heritage. It is a Calcium carbonate deposits developed by soil based
bacteria. It can set a sand in solid rock like material
Properties:-
1. Bio-cement increase the shear strength and compressive strength of
the structure.
2 . Bio-cement fills the empty spaces between soil particles without
changing its volume
3.It has self healing property
4. Dry Bio cement can be dissolved to prepare a solution of low
viscosity which can be sprayed or injected in or percolated through the
porous soil or structure for its strengthening
Applications:-
1. It is used for enhancing stability of slopes, dams, for road
construction, prevention of soil erosion.
2. For construction of channels, aqua cultures, ponds, reservoirs
3. 3 For remediation (filling) of cracks in concrete

80. Mrs A R Kamthe
Concrete: It is the building & structural material obtained by mixing of
binding materials like lime or cement, aggregates, like sand, crushed
stones, gravel, broken bricks, slag & water in a suitable proportion (1:2:4)
which can be easily molded into any desired shape.
Properties:
1.It is compact.
2.It is rigid.
3.It is strong.
4.Durable.
5.It can be moulded into any desired shape.
Uses :
1) It is used for construction of roads, building, floors, columns, roofs,
arches, tanks, foundations.
2) Abutments, piers, reinforce works, water – proof structures etc.

81. Reaction:
CaCO3  CaO + CO2
lime stone Quicklime
Lime :-
Lime is a calcium-containing inorganic mineral which is primarily
composed of oxides, and hydroxide of calcium.
Commercially calcium oxide is known as quick lime . It is obtained
by calcination of limestone or chalk or marble or oyster shells which
contain CaCO3

82. Properties of quick Lime :-
1. Pure quick lime is white amorphous crystalline solid having the
specific gravity 3.2
2. It is very refractory as it melts at a high temperature of 25750C
3. It can be easily slaked with water. This slaking of lime is a
exothermic process hence a grate care is to be taken while slaking
the lime.
4. When the quick lime is exposed to air then it absorb the moisture as
well as CO2 from air and form air slaked lime and forms CaCO3
the mortar produce from such lime do not harden
Uses of quick Lime:-
1. Used in manufacturing of cement, refractory bricks, mortar
2. Used as a flux in metallurgy
3.Used in water softening process and in paper industry
4.Used in agricultural for liming the soil
5.Used in manufacturing of bleaching powder, sodium hydroxide ,
ammonia

83. What is slaking of lime?
The action of water on quick lime is known as slaking of lime. OR
When 3 parts quick lime & one part of water are mixed together to
form slaked lime the process is called slaking of lime. The resulting
product is a suspension of finely divided calcium hydroxide in water. It
is known as slaked lime.
Reaction:
CaO + H2O  Ca (OH)2 + Heat (15.9 Kcal)
Quicklime Slaked lime
We have to take more care during slaking of quick lime because it is an
exothermic reaction. The large amount of heat evolved in the reaction
cause entire mass to boil with hissing sound and lumps of it burst with
explosive force as the steam generated due to boiling escapes.

84. High
Calcium
lime/Fat
lime
Lean lime/
Poor lime
Types of lime
Dolomite lime
Hydraulic
lime
Feebly hydraulic
lime
Moderately
hydraulic
lime
Eminently
hydraulic
lime

85. Fat lime (High Calcium lime):
Composition of Fat lime:
1.CaO = 90 – 95%
2. Silica, Alumina, Iron oxide = less than 2%
3. Remaining consists of MgO, H2O & CO2
Properties:-
1. More expensive
2. It slakes vigorously
3. It hardens slowly hence produce hard mortar
4. It has large sand carrying capacity
5. It is perfectly white in color
Applications:-
1. In chemical and glass industry
2. For white washing and plastering walls
3. For water softening
4. In mortar form used to join brick works and stone works

86. Lean lime (Poor lime):
Composition :
1.CaO 75%
2. Clay  25%
Properties:-
1. It is cheap
2. It slakes slowly
3. It produce less hard (poor) mortar
4. It has very low sand carrying capacity
5. It has muddy white in color
Applications:-
1. For white washing
2. In mortar form used to construct inferior type of structures Drainage
covers, drainage manholes etc.

87. Dolomite lime:-
Composition :
1.CaO = 60 to 70 %
2. MgO = 30 to 40%
3. Very small amount of clay
Properties:-
1. More expensive
2. It slakes very slowly
3. It produce strong mortar which sets to form hard mass
4. It has low sand carrying capacity
Applications:-
1. In is used as flux in metallurgy.
2. For preparing special type of slag
3. For preparing basic refractories

88. Hydraulic lime (Inferior grade natural cement):
Composition :
1.CaO = 70-80 %
2. Clay= 5- 20 %
3. Very small quantity of MgO, Fe2O3
Feebly
hydraulic lime
Types of hydraulic lime
Moderately
hydraulic lime
Eminently
Hydraulic lime

89. Types of hydraulic
lime
Feebly
Hydraulic
Moderately
Hydraulic
Eminently
Hydraulic
Slaking time
Slakes slowly
5 to 60 min
Slakes very
slowly
1 to 2 hours
Slakes with
difficulty
Setting time
Requires
nearly 3 weeks
Requires nearly
1week
Requires
nearly 1-2
days
Quality of mortar Good Very good Excellent
Uses
For ordinary
masonry work
For superior
masonry work
For
foundation
work under
water

90. Setting and Hardening of lime: -
The setting and hardening of lime is due to dehydration, carbonation and
colloidal gel formation reaction.
a) Dehydration- It is the loss of water from slaked lime due to
evaporation.
b) Carbonation- It is reaction of lime with atmospheric CO2 to form
CaCO3.
c) Colloidal gel formation - A part of Ca(OH)2 in the mortar reacts
with CO2 to form CaCO3. which then gradually harden
CaO + CO2 CaCO3.
Ca(OH)2 + CO2 CaCO3 + H2O.

91. Refractories:-A refractory material or refractory is a material that is
resistant to decomposition by heat, pressure, or chemical attack, and
retains it’s strength and form at high temperatures
Or it is a material which withstands high temperature.
Acid
refractories
Types of refractories
Basic
refractories
Neutral
refractories

92. Characteristics of good refractories: 1) Refractory materials should be
chemically and physically stable at working temperature. 2) It should
withstand thermal shock. 3) It should be chemically stable or inert. 4) It
should have high refractoriness. 5) It should be able to withstand various
loads at service conditions. 6) It should be impervious to solids, liquids
and gases. 7) It should have high mechanical strength even at operating
temperature, to bear load without breaking. 8) It should resist the
abrasive action of materials in contact with and gases slag.
Materials used in the manufacturing of refractory: 1) The oxides
used are: Aluminium (Al2O3 ), Silicon (SiO2 ), Magnesium (MgO),
Calcium (CaCO3 ). 2) Fire clay is also used in the manufacturing of
refractories.

95. Acid Refractories:-
1. They are acidic in nature
2. They are not affected by acidic materials but are affected by basic
materials
3. They mainly contains Silica and alumina.
Example- Fire clay, quartz, ganister (close-grained, hard siliceous
rock)
Basic Refractories:-
1. They are basic in nature
2. They are not affected by basic materials but are affected by acidic
materials
3. They mainly contains basic oxides like CaO , MgO.
Example- Magnesia, Dolomite

96. Neutral Refractories:-
1. They are neutral in nature
2. They are not affected either by acidic materials or by basic materials
3. They mainly contains oxides like Al2O3 , Cr2O3 .
Example- Bauxite, Chromite, Zirconia

97. 2) On the basis of fusion temperature:
a) Refractory: 1580-1780º C temperature. Example: Fire clay
refractory
b) High refractory: 1780-2000º C temperature. Example: Chromite
refractory
c) Super refractory: Temperature greater than 2000º C. Example:
Zircon refractory.
3) On the basis of oxide content:
a) Single oxide refractories: Example: Alumina, Magnesia and
Zirconia
b) Mixed oxide refractories: Example: Spinel, Mullite
c) Non-oxide refractories :Example: Silicides, borides, Carbides

98. Properties of Refractories:-
1.Refractoriness:-
It is the property of refractory material to withstand high temperature
without any sign of softening (fusion)
2. Refractories under load (R.U.L. value) :-
It is a measure of the deformation behaviour of refractory ceramic
products subjected to a constant load and increasing
temperature. RUL is a critical property for refractory bricks, which
basically reflects the service temperature of the bricks, raw materials, etc.
3.Thermal Expansion:-
It is a property of refractory material to expand with increase of
temperature. A good refractory material should have low thermal
expansion and contraction.

99. 4.Thermal conductivity:-
It is a property of refractory material to transfer the heat under normal
conditions. A good refractory material should have low thermal
conductivity
A refractory material of high thermal conductivity and low thermal
conductivity is required for industry, depending upon the requirement.
The refractory material used reduces the heat loss during industrial
operation. Therefore, in most cases, furnaces are lined with refractory
material of low heat conductivity to reduce the heat loss to the outside.
Fire-clay and silica refractories are good insulators, whereas carbon and
silicon carbide refractories are poor insulators. Thermal conductivity
depends on the porosity of refractory material. As the porosity increases,
thermal conductivity decreases because in porous bricks the entrapped
air in the pores acts as a non-heat conducting material. A good refractory
should have low thermal conductivit

100. 5 .Porosity:-
Porosity or void fraction is a measure of the void (i.e. "empty") spaces
in a material. Porosity is defined as the ratio of the volume of pores to
the volume of bulk material and is usually expressed as a percentage.
Refractories should not be porous because if it is porous then molten
slag enters into the pores and weaken the structure.
Porosity is the important property of refractory because porosity of
refractory material effects on chemical stability, strength, abrasion
resistance and thermal conductivity of refractory. In a porous refractory,
molten mass, flue gases, slag etc. easily enter to a depth and it reduces
the life of refractory material, strength of refractory. Porous refractory
reduces the resistance to abrasion, resistance to corrosion etc. But
porosity also increases the thermal shock resistance. In general a good
refractory should have low porosity.

101. Load bearing strength: The refractories used in industry charged with
varying amount of load during operation at high temperature. Therefore,
it is required that a refractory must have high mechanical strength, so
that it can withstand maximum possible load without breaking or
fracturing at operating temperature. Generally, a fireclay refractory
collapse below their fusion temperature. On the other hand, Silica brick,
refractories withstand good load even at high temperature, close to their
fusion temperature.
Electrical character: The electrical character of the refractory depends
on the composition of refractory material. All the refractory materials
are poor conductor of electricity except graphite. A good refractory
should have low electrical conductivity.

102. Thermal spalling:
Thermal spalling is the breaking, cracking, fracturing, peeling off a
refractory material at high temperature. Thermal spalling of refractory
takes place due to sudden change in temperature. Due to sudden change
in temperature, the refractory material undergo uneven expansion and
contraction which results in development of stresses and strain in the
material. Thermal spalling also results due to the slag and gases which
penetrate in the refractory material pores. A good refractory must show a
good resistance to thermal spalling.
Chemical inertness: The different types of chemicals are usually used
into the furnace lined with a refractory material. The environment in
most of the furnace is either acidic or alkaline. A good refractory should
be chemically inert so that it does not react with reactants, molten slags,
flue gases, the products etc

103. Applications of Refractory
1) Refractory materials are used in linings of furnaces, kilns, reactors
etc.
2) These are used to make crucibles and moulds for casting metals and
glass.
3) These are used for surfacing flame deflector systems for rocket
launch structures.
4) These are used in chemical industries that require high temperature
for production of chemicals.