By Angel Dudley The final stage in the production of yellow metal is the refining one. Impurities are removed after smelting. The process of refining is executed by help of a furnace or with acid treatment. Most refiners are left with scarp or bars that have to be melted in the furnace. A gold refiner adds soda ash to the metal which is melted to distinguish the pure material from the metals of lesser value. A jeweler can also be a smelter...