21. How is gold recycled?
Scrap gold from jewellery and old coins and bars is melted in special furnaces that heat the metal to above the melting temperature. A kind of glass is added to the gold to which all the dirt sticks. After everything has melted and been poured into a container again, the glass containing the dirt can be separated from the gold and other metals. The gold is then dissolved in royal water, where it is separated from other precious metals.
A company like Umicore also processes gold from electronic waste. Printed circuit boards are finely ground and chemical processes and heating are also used to separate the metals.
