Day 5: What is aluminum foil? How is it made?
1) Video: Share with your students this short video of how bauxite, the base material containing about 10% of alumina, is mined.
Recap: Aluminum is mined in large,shallow open pits mainly in the tropics. A very work intensive process to get aluminum foil.
2) Math: Bauxite contains about 10% of alumina (the precursor of aluminum), how much bauxite is needed to make 100 lbs of aluminum? The video says one ingot weighs 7,500 kg and it can make 12.7 km long stretch of aluminum foil. How many ft or cm can be made out of 1 kg of aluminum? Aluminum sells for $1,900,00 per ton.
3) Social Studies: The video talks about mining in the tropics. What do you need to do before you get to the Bauxite containing layers of soil? (Answer: Clear all the trees first)
The material needs to be transported (roads need to be built) , then crushed, then extracted (what does that mean and how do you think that happens?), then refined and then smelted to turn Alumina into Aluminum. What does smelting mean (melting it at very high temperatures)? Only then the liquid aluminum is pure enough to be cast into ingots to be then sold.
What happens to the left overs, called tailing?
Think about it: How much work did it take just so we can wrap our sandwich in aluminum foil? Is there a better way?
This is an abandoned bauxite mine in Brazil.