• What Are Ores ?
• Metal Ores
• How To Extract Metals From Ores ?
• Reduction Of Metal Ores
• Effects On Environment
3. WHAT ARE ORES ?
• An ore is any naturally-
occurring source of a metal
that you can economically
extract the metal from.
• Aluminium, for example, is the
most common metal in the
Earth's crust, occurring in all
sorts of minerals.
4. METAL ORES
• Metals are usually found in ores
• They are combined with Oxygen or
Sulphur to form Oxides or Sulphides.
• Sulphide Ores are converted to Oxides
by heating them in air (called roasting)
• Eg : Zinc Sulphide to Zinc Oxide
Zinc Zinc Sulphur
ZnS (s) 1 ½ O2 (g) ZnO (s) SO2 (g)
5. HOW TO EXTRACT METALS FROM
• To obtain a metal , it’s ore , a reducing
agent is used to remove the Oxygen , in a
reduction reaction .
• Examples of some reducing agents :
An impure form of Methane and
6. REDUCTION OF METAL ORES
• Iron , Manganese And Copper
Carbon and Carbon monoxide
are the reducing agents in the
extraction of Fe , Mn & Cu
These are cheap because coke
can be used which is cheaply
produced by heating coal in
absence of air
Extraction of Iron is done in a
blast furnace which reaches
temperatures of 2000K
7. Haematite Fe2O3(s)
Carbon 3 CO2
8. Manganese is produced by the reduction
of its Oxide with Carbon.
2MnO(s) C(s) 2MnI(s) CO2(g)
Copper used to be produced this way but
nowadays some ores are converted into
solutions containing Cu2+ ions.
The copper is extracted by reducing with
9. This is greener as no CO2 is produced
and scra p iron is cheap and readily
Also , solution can be made from low
grade ore so it is readily available
10. • Extracting O ther Metals
Some metals can’t be extracted using carbon
reduction such as Aluminium , Titanium , and
Aluminium cannot be extracted because it is
more reactive than metals.
Titanium and Tungsten also can’t because they
will form a metal carbide which would make the
11. • Extraction Of Aluminium
Aluminium is extracted from purified
bauxite ore (mainly Al2O3)
Oxide is dissolved in molten cryolite
, which forms a solution which melts at
around 1240K (Al2O3 melts at 2435K)
Therefore less energy is required
12. Alumi nium is produced at negative
Oxygen is produced at positive electrode
This gives us an equation :
Al2O3(I) 2Al(I) 1 ½ O(g)
13. • Extraction Of Titanium
As Titanium can’t be reduced by Carbon it
is reduced by Sodium or Magnesium.
It is an expensive process as Titanium
Oxide is first converted to Titanium
Chloride by reacting it with coke and
Chlorine at 1173K
14. Titanium Chloride is then reduced by
Sodium or Magnesium int o Titanium under
an inert argon atmosphere at 1300K
15. • Extraction Of Tungsten
Tungsten is extracted from it’s Oxide ,
WO3 by redu ction with H2 at high temp.
However , there is some risk as H2 is a
flammable gas , so using it as a reducing
agent is a last resort
16. EFFECTS ON ENVIRONMENT
• Recycling scrap metals has many
environmental and economic advantage.
• It reduces the amount of scrap metal in
landfill and it has already been extracted
from its ore so energy is not required