Pan American Silver has announced an initial mineral resource estimate for the large polymetallic deposit discovered in 2018 at the company’s La Colorada mine in Zacatecas, Mexico. The initial inferred mineral resource totals 72.5 million metric tons (mt), averaging 44 grams/mt silver, 0.17% copper, 2.02% lead, and 4.40% zinc, assuming a cut-off value of $60/mt after accounting for transportation, smelting, and refining costs. The deposit remains open in nearly all directions for resource expansions.
Sixty-five diamond drill holes having a total length of 54,000 meters (m) were used for the geological interpretation and inferred resource estimate.
Metal contents in the deposit are estimated at 102 million ounces (oz) of silver, 3.2 million mt of zinc, 1.5 million mt of lead, and 121,000 mt of copper. The majority of the mineralization is contained within a larger polymetallic mineralized skarn covering an area measuring 500 meters (m) by 600 m. The deposit, as currently defined, is located between 600 m to 1,700 m below surface and east of the current La Colorada underground mine workings.
Initial laboratory bench-scale metallurgical testing of individual diamond drill core composite samples indicates encouraging selective polymetallic flotation recoveries generating high-quality, silver-rich copper, lead, and zinc mineral concentrates.
Pan American President and CEO Michael Steinmann commented, “This initial resource estimate is a very exciting development for Pan American Silver and our La Colorada operation. The substantial size and grades point to a world-class deposit, discovered with our near-site exploration program.
The company plans to invest $10 million in 2020 to drill 44,000 m at the deposit, focusing on infill and exploration drilling to further define, expand and add confidence to the inferred resource.