• Bunney, Karl
• May, Peter
• Pleysier, Ron
• Kyle, James

Abstract

A literature review on the deportment of trace elements in gold processing by cyanidation is presented.This will support the development of computer models to predict the chemical speciation and deportment of these elements through the various stages of the gold cyanidation process.The review covers lead, cadmium, mercury, arsenic, antimony, bismuth, selenium, and tellurium.Presented in this paper is the first part of this review which is a collation of the relevant information on trace element mineralogy, aqueous solution chemistry and toxicity. Although there is much information available about basic solution chemistry of the trace elements, their chemistry in cyanide leach solutions remains largely unexplored.Chemical speciation modelling can assist in understanding the chemistry of the trace elements in gold cyanidation solutions, however, many significant differences exist between the predicted speciation of these trace elements for different types of modelling software.This is due to differences in the thermodynamic data used, the paucity of data that exists under appropriate non-ideal conditions, and the methods used by the software packages to estimate thermodynamic parameters under these conditions. The trace elements reviewed generally have significant toxicities to humans, and more so to plants and animals, especially the aqueous species.Cadmium, mercury and arsenic are classified as human carcinogens.Selenium is an essential trace element for human health but is toxic in excess.This review highlights that further understanding of their chemistry during cyanidation is required to better understand the health and environmental risks associated with the presence of these elements in gold ores.

Topics

• impedance spectroscopy
• gold
• toxicity
• trace element
• Arsenic
• Bismuth
• Mercury
• Antimony
• Cadmium
• Tellurium