One of the most abundant elements on

Earth.

Give rise to civilizations.

Key ingredient in Steel.

Said to have originated from explosion of

stars.

Formation – most violent process

Star – Red Giant – Turn helium in C and

O2 atoms

C and O2 atoms – turn into Iron atoms

Star becomes Supernova.

Supernova explodes – showering space

with Fe, C and O2 atoms.

Earth’s core – molten iron

Earth’s crust – 10% Iron

Life on Earth also contains iron (from

plants to humans)

Asteroids – entered Earth’s atmosphere

Meteorite fragments – did not burn in

atmosphere – more iron to Earth’s

surface.

Producing iron into usable implements –

2000 B. C.

Iron age – South-Central Asia

Key metal until 1850s

Innovators learnt –

More C + Fe = Durable Metal STEEL

1870s – Steel took over – Mass production

Physical

Lustrous

Ductile

Malleable

Silver-grey

Rusts in damp air; not in dry air

Melting Point : 1536 degree Celsius

Boiling Point : 3000 degree Celsius

Density : 7.87 gms/cubic cm

Chemical Properties

Very active metal

Combines with O2 in moist air

Reacts with hot water, produces H2 gas

Dissolves in acid

Other reactions

What is a Blast Furnace?

•The purpose of a blast furnace

is to reduce and convert iron

oxides into liquid iron called "hot

metal".

•The blast furnace is a huge,

steel stack lined with refractory

brick.

•Iron ore, coke and limestone

are put into the top, and

preheated air is blown into the

bottom.

Why does Iron have to be extracted in

a Blast Furnace???

•Iron can be extracted by the blast furnace

because it can be displaced by carbon.

•This is more efficient method than electrolysis

because it is more cost effective

Three substances are needed to enable to extraction of iron from its ore.

The combined mixture is called the charge:

Iron ore, haematite - often contains sand with iron oxide, Fe2O3.

Limestone (calcium carbonate).

Coke - mainly carbon

The charge is placed a giant chimney called a blast furnace. The blast

furnace is around 30 metres high and lined with fireproof bricks. Hot air is

blasted through the bottom.

The Method

•Oxygen in the air reacts with coke to give carbon dioxide:

C(s) + O 2(g) CO2(g)

•The limestone breaks down to form carbon dioxide:

CaCO3(s) CO2 (g) + CaO(s)

•Carbon dioxide produced in 1 + 2 react with more coke to

produce carbon monoxide:

CO2(g) + C(s) 2CO(g)

Several reactions take place before the

iron is finally produced...

• The carbon monoxide reduces the iron in the ore to give molten

iron:

3CO(g) + Fe2O3(s) 2Fe(l) + 3CO2(g)

• The limestone from 2, reacts with the sand to form slag (calcium

silicate):

CaO(s) + SiO(s) CaSiO3(l)

•Both the slag and iron are drained from the bottom of the furnace.

•The slag is mainly used to build roads.

•The iron whilst molten is poured into moulds and left to solidify - this is

called cast iron and is used to make railings and storage tanks.

•The rest of the iron is used to make steel.

Pig iron

C- 3.5% -4.5%

Si – 0.5% - 1.2%

Mn -0.4% - 1%

P – 0.15%

S – 0.04%

GREY CAST IRON

C -2.5 TO 4.0% Si – 1 – 3% Mn – 0.5 – 0.8% P – 0.2% S – 0.1%

WHITE CAST IRON C – 2.5 – 4.0% Si – 0.2 – 0.6% Mn – 0.5 – 0.8% P – 0.2%

S – 0.1% MALLEABLE IRON C – 0.08 – 0.5% Si – 1 – 3% Mn – 0.5 – 0.8%

P – 0.2% S – 0.1%

C:0.05-0.25%

Fe:99-99.8%

Si:0.02-0.2%

Mn:0.01-0.1%

P:0.05-0.2%

S:0.02-0.1%

Magnetite- 72.4% Fe,magnetic,black

Carbonate-<30% Fe+C+P

Hemetite-40-65%Fe,reddish

Limonite-20-55%

Pyrite-50% Fe and 50% S

Taconite-25-30% Fe,reddish or blackish

Sulphate-50% S,golden

Silicate-50%Si

Siderite-30% Fe,yellow brownish

C – 3.3 – 3.4%

Si – 2.2 – 2.8%

Mn – 0.1 – 0.5%

Mg – 0.03 – 0.05%

P – 0.005 – 0.04%

S – 0.005 – 0.02%

Wrought iron

Cast iron

Sheet iron

Steel

For minor structural and decorative

elements in 18th century.

Until mid-19th,used as tie rods,straps,etc.

Decorative ironwork in

balconies,fencings,etc.

Structural use became more widespread

around 1850.

Iron mills began to roll rails,bulb-tees and

eventually I-beams.

Ornamental balconies or hardware.

Brittle, but strong in compression.

Structural Purposes:Columns,domes,building

fronts,etc.

Decorative Purposes:

Stairs,elevators,lintels,railing,balconies,et

c.

Commissioner’s house at Bermuda,

designed by Edward Holl and built in

1820s is considered to be the first

residence that used cast iron in its

structural framework.

It was the standard support structure in

greenhouses and led to crystal palace in

London, built in 1851.

Glass and cast iron structure was much

imitated around the world.

Nowadays used for plumbing fixtures

and piping.

Structural and decorative use is used

occasionally through historic

preservation practices.

Can be subjected to rapid corrosion

Pressed decorative sheet iron used for

ceilings,called a ‘tin ceiling’.

Generally not used indoors

Development of structural steel in mid-

19th century gave rise to tall buildings.

Stronger than cast iron in compression

and wrought iron in tension.

Bridges, railroads, skyscrapers

All structural steel must be fireproofed.

Cladding of terra-cotta can be

utilized,tile,plaster-

poured,concrete,sprayed concrete or

insulation.

Steel wire+concrete=reinforced

concrete[ferro concrete]

Stainless steel

18%chromium and 8-12%nickel

Corrosion free

Expensive

Used primarily as non-structural

component or where probability of

corrosion is very high

15-25% copper.

Develops increased resistance to

atmospheric corrosion.

Forms an uniform deep brown coloured

oxide coating

Eero Saarinen experimented with the

material in the Deere and

Company building in 1964

Wikipedia.org

Essar Steel Pvt. Ltd. Authorities

TATA Steel official website

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