Minera Alamos metallurgical work augurs well for increased La Fortuna economic potential

TORONTO (miningweekly.com) – TSX-V-listed development company Minera Alamos on Tuesday reported that ongoing metallurgical testwork at the La Fortuna project, in Durango, Mexico, pointed to the company potentially being able to consider processing methods other than heap leaching, possibly increasing the economic potential of the project significantly.

The company was working on a prefeasibility study for its La Fortuna project, scheduled for publication later this year, and announced gold recoveries of more than 90%.

Minera Alamos president Darren Koningen explained that metallurgical testwork targeting gold recovery optimisation at La Fortuna had resulted in a 50% increase in potential gold production from the La Fortuna gold resource, when compared with typical heap leach recoveries.

Further, the ability to pre-concentrate the gold before leaching would allow for further reductions in the scope and capital required for downstream processing equipment, Koningen stated.

Ongoing work conducted by consulting engineering firm SGS Canada had found that gold was mainly found in the form of free grains that were readily recoverable. Based on the samples tested, recoveries averaging about 98% were achieved through direct cyanidation of the ground mineral samples.

Further, gravity recoverable gold results demonstrated that more than 80% of the gold from the sample materials could be achieved through centrifugal gravity concentration alone.

According to the company, 97% to 98% of the gold reported a high-grade bulk flotation concentrate, representing only 10% (by mass) of the initial sample material, while high gravity/flotation recoveries were maintained at relatively coarse grind sizes larger than 200 microns.

Minera Alamos acquired the project earlier this year from Argonaut Gold and was working aggressively to formalise a construction decision.

The project hosted measured plus indicated resources of 4.8-million tonnes grading 2 g/t gold and containing 308 100 oz of gold, with additional silver credits, currently excluded from the resource calculations. The company expected to release a new resource estimate in the coming months.