Recover metals in a jacuzzi?

What might sound stupid is actually done for ages and even really effectively. One of the most important processes to recover valuable minerals is called flotation. Imagine you through a lot of particles (together with some reagents) in a jacuzzi and then turn on the air. Some of the particles are hydrophobic, which means that they do not like to stay in the water and they much more prefer to cuddle with the air bubbles, while other particles are hydrophilic and rather enjoy a nice bath. Based on these differences in the particle property of what we call wettability, the different particles can be separated, since the hydrophilic particles stay in the suspension and the hydrophobic particles float on the surface of the jacuzzi as part of the froth. The froth can then be recovered and along with it you get all the valuable minerals containing the metals. Of course for this to work some chemistry is needed, for example a frother, which reduces the surface tension of the solution so that you really get a nice bubbly bath.

Nowadays, several gigatonnes of ore are processed by flotation worldwide and the amount is even about to increase. And this is why research on this topic is really important, especially now, since raw materials are more and more critical.