Positive tests at both EnviroLeach's Surrey facility and at Golden Predator's Yukon test plant at Watson Lake proved concentrate produced from the secondary recovery unit was responding well to the process, setting the scene for a larger five-tonne test to start.

"The plant and SRU are examples of the continuing ways that Golden Predator works to be innovative, testing new methods that have the ability to change how we operate at projects like 3 Aces," said CEO Janet Lee-Sheriff.

"Working with EnviroLeach provides us with a unique opportunity to lead the way for safe and responsible new cyanide-free extraction methods in processing gold bearing concentrates which has immediate value on our 3 Aces project as well opening up other commercial opportunities."

To date the EnviroLeach method produced a 91.3g button of gold from a 55.9kg sample, a 77.8g button from a 30.4kg sample, and 255g gold from 121kg sulphide ore.

Significantly, in the latest test completed at the Watson Lake facility, the sample was processed in 21 hours, returning 96.2% recovery, followed by 14 hours of electrowinning.

The plant has now demonstrated the ability to recover both coarse-grained gold from a closed system gravity circuit and to extract gold from a sulphide concentrate in an environmentally conscious manner.

The company's shares (TSXV:GPY) is trading at par compared with a year ago at C27.5c, which capitalises it at $42.6 million (US$32 million).