The new system, which works in conjunction with existing gold cyanide CIP/CIL circuits, enables cyanide to be reclaimed and reused. Cyanide costs - including the cost of destroying it, which can be as much as its purchase price - can make or break copper-gold projects with high cyanide demand.

But it's not only the economic benefits that make Oretek's technology particularly attractive.

Spills like the Baia Mare disaster in Romania, which spread cyanide 2000km to the mouth of the Danube River, highlight the inherent envrionmental dangers in treating gold ore with cyanide. If the cyanide can be removed from the system and reused, it greatly reduces the inherent risks.

"Oretek's technology reduces the quantity of cyanide being transported to mine sites, enables the cyanide to be retained within the plant where it is able to be safely handled, reduces the volume of water required to be stored in tailings ponds, and enables previously uneconomic copper-gold ores to be mined using sodium cyanide," says Oretek director Dr Bill Jay.

The system being developed by Oretek involves capturing the copper ions after the gold has been removed using patented "polychelators" which displace the attached cyanide ions, then passing the solution through a membrane to separate the copper-polychelator complex from the cyanide.

The copper is recovered using electolysis and the cyanide and polycheating reagents are recycled.

"No changes are made to the solution chemistry of the gold mine, no hydrogen cyanide gas is generated and no lime or other chemicals are needed to change the acidity or alkalinity of the tailings slurry," said Jay.

Pilot plants and in-house studies are to be conducted over the next six months with a number of gold miners to develop the technology further.

"We are quietly confident that everything will go well," Jay said.