MADE TO BE MADE AGAINCHEMISTRY FOR A CIRCULAR ECONOMYMetals in a circular economy, Part 2

Lesson objectives:•Review the importance of materials recovery.•Use this information to write an extended answer to a GCSE question.

Is recycling aluminium linear or circular?

Review: The current lifecycle of a can

End of life

Manufacture

Use

Recycle

Extract

http://www.youtube.com/playlist?list=PLD2C43638C526D33F

The six-mark question

Recycling reduces the loss of valuable materials to landfill and saves energy needed to make something new. Aluminium is a good example: it has the highest recycling potential of all recyclable materials. Every 1kg of recycled aluminium saves 8kg of bauxite, 4kg of chemical products and 14kW of electricity. But even with a recycling rate of 90% for aluminium cans, you still lose 10% of the aluminium each time you recycle and, if most cans only have a life of three months before being recycled, that’s only four years before it’s all gone. Recycling is a good idea but in a linear system it simply slows down the loss of valuable materials.

Task 1: Highlight and annotate

Describe how aluminium is extracted and its importance as a metal. Use your own knowledge and the information above to explain the benefits and limitations of recycling aluminium.

The quality of written communication will be assessed in your answer to this question.

• What is the examiner looking for?• On your A4 sheet highlight information that your answer must include to get six marks.

Task 1: Highlight and annotate

Tip: Always annotate the question. It shows you understand and you will write a better answer.

Describe how aluminium is extracted and its importance as a metal. Use your own knowledge and the information above to explain the benefits and limitations of recycling aluminium.

The quality of written communication will be assessed in your answer to this question.

Task 2: Write an answer structure

• Write down an answer structure showing how you think the marks will be allocated.

• List all the key scientific words you could use.

Describe how aluminium is extracted and its importance as a metal. Use your own knowledge and the information above to explain the benefits and limitations of recycling aluminium.

The quality of written communication will be assessed in your answer to this question.

Task 2: Write an answer structure

Answer structure:• extraction of aluminium from bauxite by

electrolysis (1 mark)• physical properties and uses (1 mark)• benefits of recycling aluminium (2 marks)• limitations of recycling aluminium (2 marks)

Key scientific words:

bauxite, ore, extraction, quarrying, energy, electrolysis, reduction, density, pollution, recyclingTIP: Examiners love ‘nominalisation’ (where

you use one noun to describe a scientific process)

Task 3: Write a list of points

• Bauxite, ore, open-cast mining• Expensive, lots of electricity, many steps in the process• Al too reactive, so can’t reduce with carbon

• Low-density, corrosion resistant (Al oxide)• Aircraft, saucepans, cans, foil, overhead cables• Used as alloy (increase strength)• Saves 95% energy

• Less damage to environment by mining and electricity production• Bauxite non-renewable• Reduced transport costs (China, Russia)

• Rapid loss at each stage in short cycle product• Eventually all Al is lost – recycling postponed the inevitable• Recycling needs electricity• Product and systems should be redesigned to eliminate waste

TIP: Try to make 1 point for ½ mark

Task 4: Write your own answer

• Write scientifically.• Use specialist terms appropriately.• Include a clear, detailed description of the

extraction process.• All information in the answer must be relevant,

clear, organised and presented in a structured and coherent format.

• Few, if any, errors in grammar, punctuation and spelling.

Review: Metals in a circular economy, Part 2

• 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✓• Use this information to write an extended answer

to a GCSE question✓