The document describes the process of forming iron and steel using a blast furnace. It involves the following key steps: 1. Sinter is added to the top of the blast furnace. Air is blasted into the bottom to fuel reactions that melt the iron out of the sinter. 2. Molten iron collects at the bottom of the furnace and is tapped out periodically. Slag floats on top and is also tapped out. Wasted gases exit from the top. 3. The iron produced contains carbon and impurities, making it cast iron. Steel is made by removing carbon from cast iron through oxidation, then adding other metals to produce alloys with specific properties.

1. The Formation of Iron and
Steel
The Blast Furnace

2. Step 1 - the formation of sinter

3. Step 2 - the Blast Furnace
The outer case is a
water cooled steel
casing that provides
the main support for
the 30 m high
furnace.

4. Step 2a - the Blast Furnace
The sinter is added
through a hopper at
the top of the Blast
Furnace.
The design of the
hopper stops gases
escaping through the
top as sinter is added.

5. Step 2b - the Blast Furnace
The inner lining is
made of insulating
bricks, designed to
reduce heat loss
through the outer
walls of the furnace.

6. Step 2c - the Blast Furnace
The furnace is run
continuously for up to
2 years.
Air is blasted in at the
bottom at point A.
AA

7. Step 2d - the Blast Furnace
When running
continuously, iron is
run out through a tap
hole, drilled into the
furnace at the
bottom, B.
AA
B

8. Step 2e - the Blast Furnace
Slag is less dense
than iron and floats
on the surface.
Slag is run out
through a second tap
hole labeled C.
AA
B C

9. Step 2f - the Blast Furnace
Wasted gases pass
out through the top of
the furnace, at point
D.
The hot gases are
used to pre-heat the
incoming gases at A.
AA
B C
D D

10. Step 2g - the Blast Furnace
Iron that forms in the
furnace melts at the
temperature of 1700
°C.
The iron drips down
to the bottom.
AA
B C
D D

11. Equations for the reactions
carbon oxygen
carbon
dioxide
+ →
C(s) O2(g) CO2(g)+ →
This reaction is exothermic and provides the energy
needed to heat the furnace.

12. Equations for the reactions
carbon
dioxide
carbon
carbon
monoxide
+ →
CO2(g) C(s) 2CO(g)+ →
The carbon monoxide produced from the carbon dioxide,
is the reducing agent which takes the oxygen from the
iron(III) oxide.

13. Equations for the reactions
Iron(III)
oxide
carbon
monoxide
iron
carbon
dioxide
+ +→
Fe2O3(s) 3CO(g) 2Fe(s) 3CO2(g)+ +→
The iron(III) oxide is reduced. Reduction means the
iron(III) oxide loses oxygen. The Fe3+
ions gains 3
electrons to form Fe atoms.

14. Cast Iron
The iron from the furnace contains
up to 5 % carbon along with other
impurities.
Cast iron is brittle and has only
limited uses such as engine blocks.

15. Cast iron into steel
Steel is made from cast iron. The
carbon is removed by passing
oxygen through the molten cast
iron.
When the carbon content has fallen
to the required level, other metals
are added to form a number of
alloys.

22. Alloys of Steel

23. Alloys of Steel