Antofagasta (40%) and Duluth (60%) are currently joint-venture partners in Twin Metals Minnesota, which is focused on developing a copper-nickelcobalt- platinum-palladium-gold-silver project in the Duluth Complex in northeast Minnesota. The acquisition of Duluth by Antofagasta consolidates Antofagasta’s ownership in Twin Metals Minnesota to 100%.

Aside from the Twin Metals Minnesota joint venture, Duluth Metals holds a 100% position on more than 40,000 acres (16,000 ha) of exploration properties adjacent to and near the Twin Metals project.

Antofagasta CEO Diego Hernandez said, “The acquisition of Duluth provides Antofagasta with a long-term option to develop a large, polymetallic resource in a stable and proven mining region. We believe that the Duluth Complex is an attractive deposit and upon closing of the offer, we will commence the process of re-evaluating the project’s design while also continuing with the permitting activities.”

On August 20, Duluth Metals reported the results of a draft pre-feasibility study (PFS) for the proposed Twin Metals underground copper, nickel and platinum group metals mine. The PFS assumes development of a 30-year underground mine, having an average production rate of 50,000 st/d of ore. Life-of-mine production of metal in concentrates is estimated at approximately 5.8 billion lb of copper, 1.2 billion lb of nickel, 1.5 million oz of platinum, 4 million oz of palladium, 1 million oz of gold, and 25.2 million oz of silver. Life-of-mine C1 cash costs are estimated at $0.76/lb of copper net of byproduct credits (C1 costs = cash costs net of byproducts).

The PFS estimates an initial capital cost for project development of $2.77 billion and a pre-tax payback period of 6.4 years from the start of production.