OBJECTIVES

Preg-robbing is the term used to describe the loss of gold by the re-adsorption of dissolved gold cyanide onto carbonaceous ore components. This robbing of gold from the pregnant liquor (ie the gold cyanide solution) can be a significant cause of low gold recovery in conventional carbon-in-pulp processes.

Development of a rapid and reliable surface analysis technique for characterising the carbonaceous matter, coupled with the ability to predict the preg-robbing potential of different types of carbonaceous mineralogy and determination of the effectiveness of various treatment options on these different types, would assist the gold industry to address this problem.

Gold producers would then be able to characterise their preg-robbing deposits into different types and apply the most appropriate, cost-effective treatment option for each type. Gold losses could be minimised by modifying the processing on a daily basis.

This project is building on previous research conducted through CRC-funded projects and the AMIRA P420 “Gold Processing Technology” project series. It will undertake fundamental studies to support more applied work in the current AMIRA P420C project. The aims of this project include:

• gaining a greater understanding of the process chemistry and surface science of the adsorption of gold cyanide on carbonaceous ore components
  
• understanding and predicting gold losses during cyanide leaching of preg-robbing ores in terms of the mineralogy of the carbonaceous components (characterised using a range of surface analysis techniques)
  
• undertaking laboratory-based investigations of treatment options based on a review of current and proposed industry practices for dealing with preg-robbing gold ores.

INDUSTRY BENEFITS

• a technique for differentiating between different types of carbonaceous mineralogy in preg-robbing gold ores, allowing separation of low preg-robbing mineralogy from high preg-robbing mineralogy
  
• identification of the best treatment method for specific preg-robbing ore types to maximise gold recovery and minimise cost for each ore type.

RESEARCH TEAM
Mr Bill Staunton (Project Leader)
Dr Jim Avraamides
Mr Troy Banks
Associate Professor Jeff Vaughan
Ms Michelle Helm (PhD student)

RESEARCH COLLABORATION
Curtin University
Department of Industry and Resources (WA)
Murdoch University
Advanced Mineral Technology Laboratory (Canada)

PROJECT DURATION
2006-2008