OBJECTIVES

As the free milling gold ore reserves are depleted, an increasing number of gold ore bodies are complex ores, containing copper and/or a high proportion of sulfide minerals. Complex ores require tailored treatment strategies to enable economic gold recovery from these ores.

Sulfide concentrates are traditionally smelted or roasted, but may also be treated by different hydrometallurgical pre-treatments, before the gold in most cases is recovered in a cyanide leach. High reagent consumption and poor gold recovery is often a feature of the treatment of such material. However, careful management and/or reagent recycle can increase gold recovery and reduce reagent consumption.

While gold ores with high copper levels leach well with cyanide, the copper also complexes with the cyanide, causing high cyanide consumption and the discharge of large amounts of copper and cyanide to the tails. Options for recovering both the cyanide and the copper would thus be beneficial.

This project aims to develop options for treating high copper ores/concentrates and for treating sulfide concentrates with cyanide. Specific objectives include:

• investigating options for recovering copper and recycling cyanide, including methods involving adsorption of the copper cyanide complex onto activated carbon (following gold recovery) or ion exchange resins
  
• improving reagent measurement in the processing of sulfide concentrates and investigating opportunities to increase the efficiency of gold leaching from sulfide concentrates by techniques such as intensive leaching and the use of lead(II).

INDUSTRY BENEFITS

• treatment options to enable the processing of complex gold ores (eg high copper ores and sulfide concentrates) that are currently considered sub-economic.

RESEARCH TEAM
Dr Paul Breuer (Project Leader)
Mr Karl Bunney
Dr Xianwen Dai
Ms Danielle Hewitt
Dr Matthew Jeffrey
(CSIRO Minerals)

PROJECT DURATION
2005-2008