I am in the jewellery business and we get a lot of old jewellery against the sale of new jewellery. We melt the old jewellery and use it to make new jewellery.
This is the cycle most of the jewellers use in the trading business. In the picture, silver ornaments are melting in the furnace. The furnace is old fashioned as it is made up of brick and clay and uses coal to light the furnace. Nowadays, electric furnace have come in the market which melts the metal at a much faster speed.