The non-cyanide industrial recovery of silver utilizing nitrous-sulfuric acid catalyzed pressure oxidation

摘要

In the majority of industrial operations recoveringgold and silver by hydro-metallurgical means, cyanide is thepredominant lixiviant. However, as an alternative, production ofmassive quantities of silver chloride was done on an industrialscale in the nitrous-sulfuric acid pressure leaching of a refractoryprecious metals concentrate. This proven process required nocyanide. Thus, because of the large volumes encountered duringday-to-day plant operation, the need for efficient and low costmethods of silver chloride precipitation, reduction and materialshandling was mandatory. As such, this paper covers the evolutionof plant scale precipitation, filtration, washing, reduction andcontrol of silver chloride processing. As well, an in –depthdescription of the unique leaching system is included.