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 At the present time, cyanidation has superseded all previous leaching processes, particularly chlorination, because of its ability to effectively and economically treat ores containing as little as 1-3 g/ton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 language||Spanish (Mexico)|
|Title of host publication||NOBLE METALS|
|Place of Publication||Rijeka, Croacia|
|Number of pages||24|
|State||Published - 1 Feb 2012|
Valenzuela, J. L., Parga Torres, J. R., & Diaz, J. A. (2012). New Technology for Recovery of Gold and Silver by Pressure Cyanidation Leaching and Electrocoagulation. In Yen-Hsun Su (Ed.), NOBLE METALS (2011 ed., Vol. 4, pp. 71-94).  InTech Europe .