English Deutsch Français Italiano Español Português 繁體中文 Bahasa Indonesia Tiếng Việt ภาษาไทย
All categories

9 answers

an element

2007-01-16 08:02:19 · answer #1 · answered by Anonymous · 0 1

Gold is found in several different geological settings. There are three principle geological environments :- 1) Archaean cratons; these are the basement rocks occuring on various continents where gold is both mined and explored for in Ontario, Quebec, Western Australia, Brazil and West Africa. 2) Active tectonic margins above subducting oceanic plates, or where such activity has formerly been taking place. It is this type of environment that is responsible for the gold deposits of the South American Cordilliera, British Columbia, the Philippines and Indonesia. 3) Aluvial and Palaeo-placer gold deposits; these are sedimentary in origin. Those palaeo-placer deposits of the Witwatersrand basin in South Africa being the largest in the world. Modern alluvial placers are found in the Klondyke in the Yukon, Canada and in various other parts of the world. Pure gold is seldom found in geological settings. Alluvial gold recovered from river gravels is often 92% pure, the remainder being composed largely of silver. The metal recovered from the mining is refined into bullion bars by companies such as Johnson Matthey at 99.99% purity. Gold from other sources is extracted from rock, which is first crushed and pulverised, using cyanide. Following further chemical processes, the gold is then recovered which is then refined as described above.

2016-05-25 02:34:53 · answer #2 · answered by ? 4 · 0 0

Four questions in the last 10 minutes, all from the same homework assignment.

DO THE WORK YOURSELF. These are easy questions...I bet the answers are all in your textbook. And I know almost all of them can be found with a simple online search.

2007-01-16 08:04:02 · answer #3 · answered by Qwyrx 6 · 1 0

less reactive.. it can't react with the elements present in the earth's crust

2007-01-16 08:04:42 · answer #4 · answered by Anonymous · 0 0

inert

2007-01-16 08:05:01 · answer #5 · answered by thubanconsulting 3 · 0 1

non-reactive

2007-01-16 08:17:32 · answer #6 · answered by science teacher 7 · 0 0

insoluble

2007-01-16 08:02:22 · answer #7 · answered by I hate friggin' crybabies 5 · 0 1

mineral? I don't know......

2007-01-16 08:10:57 · answer #8 · answered by cajunrescuemedic 6 · 0 1

a virgin.

2007-01-16 08:05:19 · answer #9 · answered by faversham 5 · 0 1

fedest.com, questions and answers