Gold_amalgam Amalgam_(chemistry)

1 gold amalgam

1.1 gold extraction (mining)
1.2 gold extraction (ore processing)
1.3 gold extraction (retorting)

gold amalgam
gold extraction (mining)

gold amalgam has proved effective gold fines ( flour gold ) not extractable ore using hydro-mechanical methods. large amounts of mercury used in placer mining, deposits composed largely of decomposed granite slurry separated in long runs of riffle boxes , mercury dumped in @ head of run. amalgam formed heavy solid mass of dull gray color. (the use of mercury in 19th century placer mining in california, prohibited, has caused extensive pollution problems in riverine , estuarine environments, ongoing day.) substantial slugs of amalgam found in downstream river , creek bottoms amateur wet-suited miners seeking gold nuggets aid of engine-powered water vacuum mounted on float.

gold extraction (ore processing)

interior of deadwood terra gold stamp mill. crushed ore washed on mercury coated copper sheets, , fine gold particles form amalgam mercury. amalgam scraped off , gold separated amalgam heating , evaporating mercury recovered condenser reapplication plates

where stamp mills used crush gold-bearing ore fines, part of extraction process involved use of mercury-wetted copper plates, on crushed fines washed. periodic scraping , re-mercurizing of plate resulted in amalgam further processing.

gold extraction (retorting)

amalgam obtained either process heated in distillation retort, recovering mercury reuse , leaving behind gold. released mercury vapors atmosphere, process induce adverse health effects , long term pollution.

today, mercury amalgamation has been replaced other methods recuperate gold , silver ore in developed nations. hazards of mercurial toxic waste have played major role in phasing out of mercury amalgamation processes. mercury amalgamation still regularly used small-scale gold placer miners (often illegally) & particularly in developing countries.