Gold and silver

Gold and silver are two of the world's most well known precious metals. Gold and silver produced by Rio Tinto are sold to fabricators, who use the metals in manufacturing. Some gold also goes to investors such as large banks and gold traders.

How gold and silver is produced
Gold and silver is extracted as impurities during the final stage of refining copper. More information about this process can be found in the product page for copper.

In this final stage of the refining process, copper ends up in large, thick plates called copper anodes, which are 99.6 per cent pure copper. The anodes are put through one last process at the refinery where they are lowered into an acid solution just inches away from the cathodes at each side. An electric current runs through the plates, causing the copper ions to migrate from the anode to the cathode, while all other impurities - including gold and silver - drop off into the solution and settle to the bottom.

This residue is then collected and taken to the precious metals plant where a series of chemical processes is used to separate the gold and silver.

Uses for gold
Gold is used for jewellery more than any other industrial application. It is also used in electronics as it is an excellent conductor and does not corrode or tarnish, making it highly reliable for printed circuitry and electrical devices. Gold is also used in dentistry as fillings and tooth restoration. As gold has an excellent ability to reflect light, it is used in glass manufacturing.

Other uses for gold include: medicine, aerospace, the arts, porcelain dinnerware, decorations in architecture, medallions, coins, and gold bars purchased as investments.

Uses for silver
Silver is used primarily in photography, in the development of film and photographs. Silver is the best known conductor of electricity, hence is widely used in electrical contacts and switches.

Other uses for silver include: chemistry, jewellery, mirrors, silver plating, dental supplies, sterling silverware, medallions, catalysts in manufacturing, medical and scientific equipment, magnet windings, brazing alloys, and solder.

More information about Rio Tinto's silver and gold operations in North America can be found at the Kennecott Utah Copper website. For more information on our other products, see our corporate fact sheets.