Gold extraction the purity of gold. The parting of gold from silver has been done since ancient times starting in Lydia in the 6th century BC. Various techniques have been practised; salt cementation from ancient times, parting using distilled mineral acids from medieval times, and in modern times using chlorination using the Miller process and electrolysis using the Wohlwill process. Gold extraction Gold extraction refers to the processes required to extract gold from its ores. This may require a combination of comminution, mineral processing, hydrometallurgical, and pyrometallurgical processes to be performed on the ore. Gold mining from alluvium ores was once achieved
Five Ways to Save the World Five Ways to Save the World Five Ways to Save the World is a British documentary film on environmental issues related to climate change, released in 2006. The film was made by Karen O'Connor, for the big screen and was shot in the English language to reach an international audience. It includes interviews with five environmental scientists and experts including Paul Crutzen, James Roger Angel, John Latham, Ian Jones, and Klaus Lackner. The "five ways" proposed are geoengineering techniques: Since the first three methods do not remove carbon dioxide from the atmosphere, they would only reduce global warming but not