Gold refining use Aqua regia from Electronic scrap gold

Aqua regia is a mixture of nitric acid and hydrochloric acid, optimally in a molar ratio of 1:3.[note 2] Aqua regia is a yellow-orange (sometimes red) fuming liquid, so named by alchemists because it can dissolve the noble metals gold and platinum, though not all metals. Gold refining use Aqua regia from Electronic scrap gold@Archimedes Channel