New Technology for Recovery of Gold and Silver by Pressure Cyanidation Leaching and Electrocoagulation

Jesus L Valenzuela, Jose Refugio Parga Torres, Jose A Diaz

Research output: Chapter in Book/Report/Conference proceedingChapterpeer-review


The present chapter describes a new technology of pressure oxidation/cyanidation leaching for the dissolution of gold and silver and the recovery of the precious metals by using the electrochemical process of Electrocoagulation (EC). The novel method demonstrates that the oxidation and dissolution of gold and silver in alkaline cyanide solution can be conducted simultaneously in the same reactor in less than 90 minutes with a recovery that exceeds 96%. Then, the pregnant cyanide solution with gold and silver is sent for recovery of precious metals by using a very promising electrochemical technique (EC) that does not require high concentrations of silver and gold in cyanide solutions. Gold is classed as a noble metal because of its inertness to most chemical reactions under ordinary conditions. At the present time, cyanidation has superseded all previous leaching processes, particularly chlorination, because of its ability to effectively and economically treat ores containing as little as 1-3 g/ton gold. Cyanidation processes are especially suitable for treatment of gold/silver-bearing sulphidic materials
Original languageSpanish (Mexico)
Title of host publicationNOBLE METALS
Editors Yen-Hsun Su
Place of PublicationRijeka, Croacia
PublisherInTech Europe
Number of pages24
ISBN (Print) 978-953-307-898-4
StatePublished - 1 Feb 2012

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