Pulverising, baking and dissolving
It was only supposed to be a temporary solution. Twenty years ago, a German company unloaded 5,000 tonnes of waste containing zinc ferrite - a compound of zinc and iron - at the port of Rotterdam. The company went bankrupt and the mountain of waste is still there. Zinc is a valuable substance; separate the zinc atoms from the iron atoms and you are onto a winner. Unfortunately, a standard procedure using acids did not really work on this specific molecule.