1. MADE TO BE MADE AGAIN
CHEMISTRY FOR A CIRCULAR ECONOMY
Metals in a circular economy, Part 1
Lesson objectives:
Give reasons for the uses of aluminium, titanium and their alloys.
Explain the importance of materials recovery.
Discuss the limitations of aluminium recycling and how product design could be improved.

2. What do you think this image means?

3. Aluminium and titanium
Extraction
Aluminium and titanium exist in the earth as ores.
Most aluminium exists as aluminium oxide in bauxite.
Most titanium exists as titanium dioxide often in combination with other metals like iron (ilmenite).
Unlike iron, they cannot be extracted from their oxides by reduction with carbon. WHY NOT?
Extraction from the ores by electrolysis is expensive because:
the process has many stages
large amounts of energy are needed

4. Aluminium and titanium
Properties and uses
Low density = light weight = soft
Commonly used as alloys to increase strength
Corrosion resistant
A thin layer of oxide on the surface stops corrosion by H2O + O2
Uses:
Aluminium: aircraft, trains, overhead power cables, saucepans, cooking foil and cans
Titanium: fighter aircraft, artificial hip joints and pipes in nuclear power station
Can you name another alloy?

5. Aluminium and titanium
Alloys
Aluminium commonly used as an alloy of 93% Al mixed with Si and Fe
How do the iron and silicon atoms make aluminium stronger?

6. Task 1: Aluminium and titanium
Name of ore
How it is extracted
Physical properties
Uses
Complete the table. How much can you remember?

7. Task 1: Aluminium and titanium
Name of ore
Bauxite
(aluminium oxide) (Al2O3)
Rutile (TiO2) Ilmenite (FeTiO3)
How it is extracted
Electrolysis
(many processes, uses a lot of energy)
Physical properties
Soft, low density, light, corrosion resistant (used as alloys)
Uses
Aircraft, trains, overhead power cables, saucepans, cooking foil and cans
Fighter aircraft, artificial hip joints and pipes in nuclear power stations

8. Task 2: The lifecycle of a can
Metals like aluminium can be viewed as technical nutrients which we need to make the products we use. We need to design out waste so that the nutrients are recovered

9. Task 2: The current lifecycle of a can
Organise your cards around the wheel to illustrate the lifecycle of an aluminium can.

10. Task 2: The current lifecycle of a can
End of life
Manufacture
Use
Recycle
Extract

11. Task 3: Why recycle?
Turn over your cards. Sort them into two groups to explain why recycling aluminium is better than extracting it from its ore.
Recycling is a good idea but in a linear system it simply slows down the loss of valuable materials.

12. Task 4
1) Look at the cards from the previous exercise.
2) What would have to change to make aluminium recovery work better?
3) Write a letter to a packaging company describing the advantages to the industry of adopting clean ‘technical’ and ‘biological’ materials flows.

13. Quiz time: question 1
1. Bauxite is an example of…
An element
A compound
An ore
A solution

14. Quiz time: question 2
2. Aluminium is extracted by…
Reduction
Distillation
Thermal decomposition
Combustion

15. Quiz time: question 3
3. Aluminium cannot be extracted from aluminium oxide using carbon because…
Aluminium is more reactive than carbon
The density of aluminium is too low
Carbon is higher in the reactivity series than aluminium
Aluminium is covered in a layer of aluminium oxide

16. Quiz time: question 4
4. Aluminium is often recycled. Which answer(s) are true and which indicate(s) that aluminium production is still essentially ‘take-make- dispose’
Recycling of short cycle products (cans, packaging) is always wasteful even at high recycling rates.
World aluminium production from bauxite is increasing year on year.
Recycling reduces the amount of energy used to make aluminium and makes it cheaper than extracting from bauxite.
Recycled aluminium is not suitable for all uses of the metal.

17. Homework
Coca-Cola is developing a bottle called PlantBottle as an alternative to aluminium cans. It is currently made from 30% plant material and the company’s aim is to make a bottle from 100% plant-based waste.
Research this product on the internet. Explain why plantbottle packaging is a ‘technical nutrient’. Comment on the impact of this choice on the environment. Consider biological nutrient based packaging.