OBJECTIVES

Gold losses from carbon-in-pulp or carbon-in-leach circuits can result from fouling of the activated carbon used to adsorb the leached gold from solution. Carbon fouling by either organics or inorganics reduces the carbon’s ability to recover gold. Previous work had developed a method that accurately measures residual frothers (from the flotation stage for mineral concentration) in the gold cyanide slurry. Frothers are organics that can contaminate the carbon. The ability to analyse for organic foulants offers the opportunity to improve the operation of existing circuits to reduce gold losses in the solution tails.

A recent development in the Australian context is the use of pump cells in an adsorption circuit. This equipment utilises high energy to increase adsorption rates. Gaining an understanding of the mechanism of the processes occurring in pump cells should lead to improved design of adsorption circuits.

Therefore this project’s objectives include:

• measuring the adsorption rate of frothers, and their degradation products, onto carbon, and assessing the impact this adsorption has on gold adsorption rates
  
• investigating copper (an inorganic foulant) adsorption on carbon and its impact on gold adsorption
  
• assessing the impact of high energy (high agitation intensity) adsorption cells on the adsorption of selected foulants and on gold adsorption
  
• incorporating the impact of foulants and agitation energy into a flowsheet model of carbon adsorption.

INDUSTRY BENEFITS

• reduced losses of gold from carbon-in-pulp or carbon-in-leach circuits into the solution tails through improved operation of adsorption circuits
  
• lower capital expenditure for expansions and greenfield carbon-in-pulp or carbon-in-leach installations.

RESEARCH TEAM
Mr Ron Pleysier (Project Leader)
Mr Patrick Merrigan
(CSIRO Minerals)

PROJECT DURATION
2005-2008