by Greg Klein | March 23, 2016
Metallurgical tests point to a simplified flowsheet and improved recovery for Copper North Mining’s (TSXV:COL) Carmacks copper-gold-silver deposit in south-central Yukon. The results will be incorporated into a new leach and development plan for an updated PEA expected in early May, the company announced March 23.
Tests showed an increase in the leach temperature to 80 degrees centigrade improved copper recovery, eliminated one circuit and simplified the cyanide circuit for leach recovery of gold and silver.
The new PEA will be based on the project’s 1, 4 and 7 zones, which were estimated to have a seven-year lifespan. Copper North said three other zones, which produced a maiden resource in January, call for further infill drilling for possible inclusion in a later mine plan.
“Furthermore, the substantial increase in sulphide mineral resources at shallow depth warrants additional metallurgical test work to confirm the potential to process that material to produce either concentrate or cathode copper,” the company added.
The resource for zones 1, 4, 7 and 7A used a 0.25% total copper cutoff, showing oxide mineral resources as follows:
- measured and indicated: 11.98 million tonnes averaging 1.07% total copper (0.86% acid-soluble copper and 0.21% sulphide copper), 0.456 grams per tonne gold and 4.578 g/t silver
- inferred: 90,000 tonnes averaging 0.73% total copper (0.53% acid-soluble copper and 0.2% sulphide copper), 0.128 g/t gold and 1.809 g/t silver
The sulphide mineral resources show:
- measured and indicated: 4.34 million tonnes averaging 0.75% total copper (0.03% acid-soluble copper and 0.73% sulphide copper), 0.221 g/t gold and 2.369 g/t silver
- inferred: 4.03 million tonnes averaging 0.71% total copper (0.01% acid-soluble copper and 0.7% sulphide copper), 0.179 g/t gold and 1.9 g/t silver
The road-accessible project lies about 190 kilometres north of Whitehorse and 38 kilometres northwest of the town of Carmacks. The region’s first reported copper discovery, 12 kilometres north of the property, was made in 1887 by George Dawson as he surveyed the Yukon prior to the Klondike Gold Rush and the creation of a city named after him.
Copper North also holds a 100% option on the Thor porphyry copper property in British Columbia and an historic resource at its Redstone copper-silver project in the Northwest Territories.