Have you ever wondered where metals such as iron, copper or nickle come from?
We can buy them from hardware store, right?
Well, how did they get to the store then?
Turns out a lot of metals can simply be found in soil.
Try this simple extraction experiment.
What you need
- soil from your backyard
- neodymium magnet
- a piece of paper
Warning: Magnets, especially neodymium which is rare earth metal, are very hazardous if swallowed.
Please keep them away from children who still put everything into their mouths.
- Put soil on a piece of paper.
- Place the magnet underneath the soil and the paper.
- Move the magnet around and see what happens.
- As you move the magnet around, some of the soil will move with it. If there is enough magnetic soil, you can see the pieces align with the magnetic field of the magnet.
- See how much magnetic soil you can collect in a sample of backyard soil.
- Find soil from other sources (e.g. school playground) and see if they produce a different amount.
- What is the color of the magnetic soil found?
- What metal do you think the magnetic soil contains?
Turns out pure iron is actually quite hard to find in nature. Iron mostly exists in the form of iron oxide, e.g. hematite (ferrous oxide).
So what you found is mostly likely one of the 16 iron oxides known on earth.
Of course the iron used to make our tools in everyday life doesn’t come from backyard soil.
Instead, iron is more economically extracted in large scale from iron ores using heavy equipment.
The mined iron ore is then processed to give molten iron.