The first step in refining gold is grinding it into a powder and mixing it with a substance called flux. Then the mixture is placed in a furnace and melted by intense heat. The alloys and impurities are drawn to the flux and rise to the surface. The gold (which is heavier) remains at the bottom. The impurities or dross (such as copper, iron, and zinc, combined with flux) is then removed, yielding a purer metal.
