Download Topic 3: Metals and Metal Extraction

Topic 3: Metals and Metal
Extraction
(3 weeks)
Topics to cover
•
•
•
•
•
•
•
Minerals
Metals and their uses
Mine to Metal – the processes involved
The activities series
Metal ores
The extraction process of iron and aluminium
Precipitation reactions
Key Idea 1: Minerals are natural
resources that are important to
Australia’s economy
• Define the term mineral
• State how minerals are mined from the
ground in the form of an ore
• Discuss the economic considerations of
mining an ore deposit
The natural occurrence of metals
• Most metals occur in the earth’s crust as compounds
called minerals.
• Minerals are substances formed naturally in the Earth.
• They are solid, inorganic and have a definite chemical
composition and structure.
• There are over 3000 minerals known.
Some are rare and precious
such as gold and diamond,
while others are more ordinary,
such as quartz.
Mineral - Definition
1.
2.
3.
4.
Naturally occurring
Inorganic
Definite chemical composition
Solid with a crystal structure due to
internal arrangement of atoms
1. Naturally occurring in the earth
Mineral formation
• Mineral formation can occur during the
cooling of a melt.
• Magma cools slowly as it rises to earth
and solid rocks form with large crystals.
• Lava is on the Earth's surface so it cools
quickly compared to magma in Earth. As a
result, rocks form quickly and mineral
crystals are very small
1. Naturally occurring in the earth
Mineral formation
• Minerals are deposited from salty water
solutions on Earth's surface and underground
called crystallisation. In order for a mineral to
crystallise, ions from the nearby environment
must be brought together and link together to
form mineral crystals.
• The size and texture of the crystals formed
depends on the rate of change in
temperature and pressure which essentially
determines how much time is available for
the crystals to develop.
2. Minerals are Inorganic
That is to say, they are not organic
compounds!
(formed form biological processes)
3. Minerals have a definite
chemical composition
• Each mineral is made of a particular mix of
chemical elements and can be written as a
chemical formula.
E.g. Limestone (CaCO3)
4. Minerals have a solid, crystalline
structure
Minerals are solid substances with a
crystalline structure. To be crystalline means
that the atoms within the solid are arranged
in a in an ordered, three-dimensional,
structure. The distances and angles
between an individual atom and the
neighbours it is bonded to are constant.
4. Minerals have a solid, crystalline
structure
The result of this is that the structure of a
crystal is both geometrical and highly
symmetrical, forming a pattern unique to
each mineral.
Mineral Formation
• The crystal structure that is formed is
based upon the chemical composition and
the type of bonding.
• Ionic bonding: The electrostatic forces
between the positive and negative ions
(usually metal and non-metal) as in halite
(formed from NaCl).
• Covalent bonding: The atoms share
electrons, as in diamonds (made of C).
Minerals - Polymorphs
• Polymorphs are minerals that have the
same elements in the same proportions,
but the atoms are arranged differently.
For example:
diamond and graphite
both are pure carbon.
Classification of Rock-forming Minerals
• There are two classifications of minerals:
– Silicate minerals, and
– Non-silicate minerals.
• Silicate minerals make up more than 90%
of the Earth’s crust.
• Silicate minerals are made up of silicon
(Si) and oxygen (O) atoms along with
other elements (Al, Mg, Fe, Mn, and Ti).
Identifying Minerals
• Properties which are used to identify
minerals include:







Colour
Lustre
Streak
Cleavage and fracture
Hardness
Density
Any special properties
Mineral
Hardness
CRYSTAL
SHAPE (FORM)
• Ability to scratch another mineral 
• Mohs scale from 1 (talc) to 10
(diamond)

• Quartz (most common mineral and
most dust particles) is 7
LUSTRE
COLOUR



How light reflects off the surface
Main categories are “metallic” &
“non-metallic”
For example:
Metallic/glassy – shiny
Non-metallic - dull
External structure
due to internal arrangement of
the atoms
Six basic groups of shapes,
with about three dozen
variations


Colour results from the ability to
absorb some wavelengths & reflect
others
some minerals have characteristics
colors
others vary due to chemical
differences or impurities - unreliable
Streak
MINERAL CLEAVAGE/
FRACTURE
• Color of the powder when
rubbed on a “streak plate”
(unglazed porcelain)
• May be same as handspecimen or different
• Some paint is based on
powdered minerals (streaks).



Some minerals split along flat
surfaces when struck hard--this is
called mineral cleavage
Other minerals break unevenly
along rough or curved surfaces-this is called fracture
A few minerals have both cleavage
and fracture
Other special properties
• Magnetism is a distinctive property in a few minerals
(magnetite)
• Some minerals fluoresce under UV light (calcite and
fluorite).
• Some minerals are radioactive (radium and uranium).
Ores
• Elements are the building blocks of minerals
• Minerals form the building blocks of rocks.
are made of
Rocks
minerals
elements
are made of
• An ore deposit is a small region in the crust where
the concentration of metal is high enough to make
it financially viable to extract it.
• Some unreactive metals such as gold can be found
as the metal itself and chemical separation is not
needed.
Ores are rocks containing valuable minerals
Gold in quartz
Galena - lead
Hematite – iron ore
Malachite - copper
Mineral Summary
A mineral is a naturally occurring substance that
is solid and stable at room temperature,
represented by a chemical formula.
Minerals are different from rocks,
which can be any combination of minerals
or non-minerals,
and do not have a specific
chemical composition.
Mineral Summary
• Minerals have an orderly arrangement of
atoms.
• Rocks are aggregates (mixtures) of minerals.
• Most minerals are compounds of two or more
elements.
• The properties of a mineral are derived from
the elements it is comprised of.
• Minerals have Ionic or Covalent lattices.
• Generally considered inorganic.
Key Idea 1: Minerals are natural
resources that are important to
Australia’s economy
Define the term mineral
Minerals in Australia
• Minerals are Australia's largest export. The Australian Bureau of
Statistics reports that at June 2012 the mining industry
employed around 266 000 people directly.
• Australian mining companies trade freely in the global
marketplace, exporting goods on a commercial basis around the
world with principal markets in China, Japan, South Korea and
India.
• Australia has the world's largest resources of gold, iron ore,
lead, nickel, rutile, uranium, zinc and zircon as well as the
second largest resources of bauxite, cobalt, copper, ilmenite,
niobium, silver, tantalum and thorium. Australia's resources of
black coal, brown coal, magnesite, tungsten, lithium,
manganese ore, rare earths and vanadium are ranked in the top
five in the world.
Minerals in Australia
• Australia is one of the top mineral producers in the
world and has a large resource inventory of most of
the world's key minerals commodities.
• Australia is the world's leading producer of
bauxite, ilmenite, iron ore, rutile and zircon;
• The second largest producer of gold, lead, lithium,
manganese ore and zinc;
• The third largest producer of uranium;
• The fourth largest producer of black coal (also the
largest exporter), nickel and silver;
• The fifth largest producer of cobalt, copper and
diamond
Australian Government, Geoscience Australia
http://www.ga.gov.au/scientific-topics/minerals/basics
Some common metals
• Gold? 0.0000004%
Mining Techniques
• Surface mining
– Remove surface vegetation,
dirt & layers of bedrock
– Open-pit mining:
• Recovery of materials from
an open pit.
• Quarrying: gathering
building materials from an
open pit mine
– Strip mining:
• Stripping surface layers off
to reveal ore/seams
underneath
– Mountain top removal
• Common for coal mining
• Taking the top of a
mountain off to reach ore
deposits at depth
Open-pit mining of diamonds
Mining Techniques
Subsurface mining
– Digging tunnels or shafts into the earth to reach
buried ore deposits
– Ore (for processing) and waste rock (for disposal)
are brought to the surface through the tunnels
and shafts.
– Drift mining
• Horizontal access tunnels
– Slope mining
• Diagonally sloping access tunnels
– Shaft mining
• Vertical access shafts
Mining in Australia
• The mining industry is important to Australia.
It brings in billions of dollars of export income.
It provides work for over 750,000 Australians.
It supports communities all across the
country, today and into the future. Many
different ores and minerals are mined
throughout the country.
• Mining has had a substantial environmental
impact in some areas of Australia. Although
mining services, equipment and technology
are being exported, the mining sector
employs 2.2% of the total labor force.
Australian Pink Diamonds
The Argyle Diamond Mine (far north of Western Australia) is
the only known significant source of pink diamonds, producing
over 90% of the world's supply. It additionally provides a large
proportion of other naturally coloured diamonds, including
champagne, cognac and rare blue diamonds. Argyle is
currently transitioning from an open pit mine to an
underground mine.
Key Idea 1: Minerals are natural
resources that are important to
Australia’s economy
• Define the term mineral
• State how minerals are mined from the
ground in the form of an ore
• Discuss the economic considerations of
mining an ore deposit
Key Idea 2: Many metals are
extracted from minerals
• State the uses of some common metals
and their importance to our everyday life
Aluminium
• Packaging
• Transport
• Building
Copper
•
•
•
•
•
Electrical wires and cables
Plumbing pipes
Switches
Pots and pans etc
Coins (as an alloy)
Nickel
• Coins
• Batteries
• Hardener in alloys such
as armour plating and
machine parts
• Anti-corrosion coating
Iron
•
•
•
•
Buildings
Magnets
Automobiles
Household implements
Key Idea 2: Many metals are
extracted from minerals
• State the uses of some common metals
and their importance to our everyday life






Aluminum--packaging, transport, building
Beryllium--gemstones, fluorescent lights
Copper--electric cables, wires, switches
Feldspar--glass and ceramics
Iron--buildings, automobiles, magnets
Calcite--toothpaste, construction
Reaction of alkali metals with water
https://www.youtube.com/watch?v=HvVUtpdK7
xw
The activities series song
https://www.youtube.com/watch?v=DLlykUHH
AcQ
Topic 3: Metals and Metal
Extraction
(3 weeks)
Topic 3: Metals and Metal
Extraction
Kahoot
https://kahoot.it
https://getkahoot.com/