Simple instrument could save miners millions

Dr Kathryn Hindmarsh with the cost-saving equipment she developed.

A simple instrument costing less than $10,000 could save gold miners millions of dollars in cyanide costs, and minimise the amount of cyanide in the tailings.

The instrument, in its final testing stage at Murdoch University, provides instantaneous analyses of the amount of cyanide used in solution to extract gold — thereby saving significant costs in this effective but expensive process.

Murdoch's BankWest Fellow, Dr Kathryn Hindmarsh, has developed the on-line technique which provides an accurate analysis of the amount of active cyanide available to extract the gold.

"The current challenges facing the gold industry make it imperative for minerals processing to be as efficient as possible," Dr Hindmarsh said.

"A simple, quick reading of the analyser will let operators monitor the amount of cyanide present at any time, and show when there is too much or too little cyanide in the solution.

"The system can be connected to the gold plant's automated process control system to provide automatic adjustment of cyanide added to the leach tanks.

"It works by reacting cyanide solutions from the leach tanks with colloidal gold (gold in solution). By using three standard cyanide solutions the concentration of cyanide is automatically calculated.

"The analyser can test one sample every two minutes. It's simple to use and will provide a very cost-effective way of controlling the over-use of this very expensive chemical, and minimising the amount of cyanide in the tailings."

Dr Hindmarsh expects the analyser to be commercially available later this year, once the fine-tuning has been completed. It is being evaluated in collaboration with a working goldmine.

Dr Hindmarsh is conducting her research under the tutelage of Murdoch's world-renowned Professor of Mineral Science, Mike Nicol, in conjunction with the AJ Parker CRC for Hydrometallurgy. Their work provides a strong boost to the university's excellent credentials in minerals processing and confirms Murdoch's national leadership in the quest to extract minerals more cheaply from their ores.

The recipient of the 1997 BankWest Centenary Grant, Dr Hindmarsh was funded for her research under the BankWest Research Fellowship project to assist research into hydrometallurgy in Western Australia.