Silver-Gold-Prices.com News and Information about Investing in Gold & Silver Bullion Coins and Precious Metals

Today is Thursday September 09, 2010 Home Page Precious Metals Gold Silver Platinum

Gold Refining Impure gold, as it usually occurs in natural deposits, has a density of 16 to 18, whereas the associated waste rock (called gangue) has a density of about 2.5. The difference in density enables gold to be concentrated by gravity and allows the separation of gold from silt, clay, sand, and gravel by various agitating and collecting devices including the gold pan, rocker, and sluicebox. Mercury (also called quicksilver) has a chemical affinity for gold. When mercury is added to gold-bearing ore, the two metals form an amalgam. Mercury is then separated from amalgam by a process of retorting. Extraction of gold or other types of precious metals from their ores by treatment with mercury is called amalgamation. Gold will dissolve in aqua regia, a mixture of hydrochloric and nitric acids, and also in sodium or potassium cyanide. The latter solvent is the basis for the cyanide process that is employed to extract gold from low-grade ore. Disclaimer: While Silver-Gold-Prices.com seeks to provide accurate information, it is provided without warranty or claim of reliability. Site visitors must agree that errors or omissions shall not be made the basis for any claim, demand or cause for action. The information has been obtained from sources believed to be reliable, but we do not guarantee its accuracy. We offer information and links for informational purposes only and do not make recommendations regarding the purchase of gold bullion or other precious metals from any particular business or government entity. This site contains information and news from third party business and government web sites as well as links to advertisers. We make no claim of reliablity or accuracy in regard to these web sites.