History
According to de Lecerda and Salomons (1997) mercury was first in use for extraction at about 1000 BC., according to Meech and others (1998), mercury was used in obtaining gold until the latter period of the first millennia. A technique known to Pliny the Elder was extraction by way of crushing, washing, and then applying heat, with the resultant material powdered.
The solubility of gold in a water and cyanide solution was known by 1783 (Scheele), by Bagration in 1843 and Elsner in 1846 who recognized the necessity of oxygen in the process, (a method of exctraction by chlorination (Plattner) considered during 1848 proved uneconomical) this prior to the discovery of an economical method of treatment with potassium cyanide by J.S. MacArthur (with R. and, or, W. Forrest). Development of understanding from 1887 led to the discovery dated to 1888 (and elsewhere 1890) that is known as the MacArthur-Forrest process.
The method heap leaching was first proposed during 1969 by the United States of Americas' Bureau of Mines, in use by the 1970s.
Read more about this topic: Gold Extraction
Famous quotes containing the word history:
“There is nothing truer than myth: history, in its attempt to “realize” myth, distorts it, stops halfway; when history claims to have “succeeded” this is nothing but humbug and mystification. Everything we dream is “realizable.” Reality does not have to be: it is simply what it is.”
—Eugène Ionesco (b. 1912)
“The best history is but like the art of Rembrandt; it casts a vivid light on certain selected causes, on those which were best and greatest; it leaves all the rest in shadow and unseen.”
—Walter Bagehot (1826–1877)
“The thing that struck me forcefully was the feeling of great age about the place. Standing on that old parade ground, which is now a cricket field, I could feel the dead generations crowding me. Here was the oldest settlement of freedmen in the Western world, no doubt. Men who had thrown off the bands of slavery by their own courage and ingenuity. The courage and daring of the Maroons strike like a purple beam across the history of Jamaica.”
—Zora Neale Hurston (1891–1960)