Metals

Question 1

What’s the most common ore ?

Answer 1

Aluminium is the most common ore followed by iron

Question 2

In general, the more rare a material is the more…

Answer 2

expensive it is

however a common ore like aluminium is still expensive because its expensive to process as you have to use electrolysis rather than heat to extract it from the ore

Question 3

Where do metals come from ?

Answer 3

ores which are found in the ground

Question 4

What percentage of the earths crust is made up of metal ores ?

Answer 4

25% of the earths crust is made up of metal ores

Question 5

The ores do not re-grow when we dig them up meaning that they are …

Answer 5

Non-renewable and unsustainable

Question 6

What ore does iron come from ?

Answer 6

Magnetite, haematite

Question 7

What ore does copper come from ?

Answer 7

Chalcopyrite

Question 8

What ore does aluminium come from ?

Answer 8

Bauxite

Question 9

What ore does Lead come from ?

Answer 9

Galena

Question 10

What ore does Tin come from ?

Answer 10

Cassiterite

Question 11

What ore does Zinc come from ?

Answer 11

Zinc blende

Question 12

What are the 3 categories of metals ?

Answer 12

Ferrous, non-ferrous and alloys

Question 13

What is the structure of the metal ?

Answer 13

All metals are made up of crystals. Each crystal has a boundary that is firmly bonded to the boundary of a neighbouring crystal

Question 14

What does the nature of the crystal depend on ?

Answer 14

The nature of the crystal depends very much on the material

for e.g. steel is made up from iron and carbon so these elements will be seen within the microstructure of the material

Question 15

How do you extract iron ?

Answer 15

We extract iron from magnetite ore using a blast furnace.

Question 16

How does a blast furnace work ?

Answer 16

1) Solid raw materials - iron ore, coke, limestone - are added from the top of the blast furnace

2) Hot air is blown in to the bottom of the blast furnace and provides the oxygen for the coke (carbon) to burn

3) Iron oxide in the iron ore reacts and changes to iron - molten iron trickles to the bottom of the furnace

4) Limestone reacts with impurities to form a slag that floats on the iron

5) Waste gases are removed to a treatment plant

Question 17

What are the properties of ferrous metals ?

Answer 17

• Ferrous metals contain iron
• They will corrode if unprotected
• Ferrous metals are magnetic

Question 18

What happens if you add carbon to iron ?

Answer 18

It forms steel

Question 19

Why is iron not commercially viable ?

Answer 19

Because iron is generally soft and ductile which makes it not commercially viable

Question 20

How do the properties of iron change when carbon is added to it ( when is becomes steel ) ?

Answer 20

When carbon ( a very hard and brittle element ) is mixed with iron the characteristics of iron are greatly improved - it becomes more harder and tougher

Question 21

What does increasing carbon content do to a material ?

Answer 21

• the material becomes harder
• toughness reduces - cast iron is brittle under impact
• Both medium and high carbon steel can be heat treated to make them harder and stronger

Question 22

What’s the most plentiful metal found in the earths crust

Answer 22

Aluminium

Question 23

Why is aluminium high in demand

Answer 23

Because its both light and strong

Question 24

How is aluminium extracted from aluminium oxide ( bauxite )

Answer 24

It is extracted by electrolysis - electricity passes between the electrodes and pure aluminium forms at the cathode

Question 25

Name some ferrous metals

Answer 25

• cast iron
• high speed steel
• low carbon steel
• medium carbon steel

Question 26

Name some Non-ferrous metals

Answer 26

• Aluminium
• Zinc
• Copper
• Sliver
• Gold
• Titanium
• Tin

Question 27

Name some ferrous alloys

Answer 27

• Stainless steel
• Die steel ( tool steel )

Question 28

Name some Non-ferrous alloys

Answer 28

• Brass
• Bronze
• Pewter
• Duralumin

Question 29

Name all the performance characteristics of metals

Answer 29

• hardness
• toughness
• malleability
• elasticity
• tensile strength
• density
• resistance to corrosion
• thermal conductivity
• electrical conductivity
• melting points
• ability to be alloyed
• ability to be joined with heat processes
• ability to take applied coating and finishes