Palmer being studied for "critical" barite

Constantine Metal Resources Ltd. Feb. 27 said it has initiated a metallurgical test program to determine if a marketable barite concentrate can be produced as a co-product from the Palmer copper-zinc-gold-silver project in Southeast Alaska.

In a report published earlier this year, the U.S. Geological Survey named barite among 23 minerals considered "critical" to the economic and national security of the United States.

Palmer hosts a volcanogenic massive sulfide (VMS) deposit with 8.1 million metric tons of inferred resource grading 1.41 percent copper, 5.25 percent zinc, 0.32 grams per metric ton gold and 31.7 g/t silver, according to a resource calculated in 2015.

This low-sulfide VMS – more accurately, massive sulfide-sulfate – deposit has an unusually high Barite content. The resource area contains 13 to 15 percent barium, which equates to roughly 22 to 25 percent barite by weight.

"Barite constitutes about a quarter of the rock mass of the defined mineralized zones, and if recoverable has the potential to materially enhance the value of the already high-value mineralization. It's recovery as a potential ore-mineral would also reduce ore processing waste," said Constantine President and CEO Garfield MacVeigh.

One of the primary uses of barite is a weighting agent in drilling mud for oil and gas exploration and development drilling.

Key parameters that determine viability of barite for drilling fluids include density, grind size, presence of impurities based on standards set by the American Petroleum Institute and distance to market.

Constantine said long term market price for drilling mud-grade barite is expected to average more than US$100 per metric ton.

Currently, roughly 80 percent of the barite used in the United States is imported.

Situated a few miles from the coastal community of Haines, barite from Palmer could easily be transported to markets in the U.S., Canada and around the Pacific Rim.

"The projects excellent location, 60 kilometers (37 miles) by road from deep tidewater facilities enables low-cost shipping to markets," said MacVeigh.

–SHANE LASLEY