Household waste contains many metals, especially aluminum. What do others think about the idea of extracting these metals through electrolysis?
Passing the collected household waste through a bath with electrolyte does not seem to me to be a difficult technical problem. One could take as electricity the nightly production that is currently used (wasted?) with a ridiculously low efficiency to pump an artificial lake in Coo.
The benefit would not only be an amount of recovered aluminum (or other metal) but also a smaller amount of it that ends up in the environment through incineration of household waste.
Answer
Hi Francois,
I’m not a specialist in this matter, but since the question has been open for a while, I’d like to give it a try.
If everyone sorts their waste properly, there will of course be little metal in the residual waste. Electrolysis is certainly not the most appropriate way to recover metals from residual waste. The problem is, of course, that waste consists of many different substances, and electrolysis usually does not give good results. Moreover, electrolysis is an expensive technique.
It is much simpler (and as far as I know it is done that way) to incinerate the waste (with heat recovery). The metal can then be recovered quite easily from the ash residue. For iron, this is simply done with a magnet. The non-ferrous metals all have different densities, and can be separated with a hydrocyclone or the like.
Electrolysis is actually only used to purify metals from unwanted alloying elements.
Answered by
Dr Etienne Jooken
Chemistry
Old Market 13 3000 Leuven
https://www.kuleuven.be/
.