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
Four Ways to Forgiveness Four Ways to Forgiveness Four Ways to Forgiveness is a collection of four short stories and novellas by American writer Ursula K. Le Guin. All four stories are set in the future and deal with the planets Yeowe and Werel, both members of the Ekumen, a collective of planets used by Le Guin as part of the background for many novels and short stories in her Hainish Cycle. In 2017 it was reissued as an e-book, augmented with a fifth related story by Le Guin, as Five Ways to Forgiveness. The stories in the book are set on two planets