MINNEAPOLIS — The parent company for the proposed Twin Metals copper-nickel mine near Ely expects to reach a key milestone in the coming months.

Duluth Metals Limited says its “pre-feasibility” study is progressing well and is scheduled for completion by mid-year. The study will form the basis for a detailed plan for the mine before government environmental reviews and the permit process begin.

The company also expects to complete an updated estimate this spring on the extent of the nonferrous metals deposits at its site, which it has already called one of the world’s largest untapped reserves of copper, nickel and precious metals.

Twin Metals is expected to be larger than the proposed PolyMet mine near Babbitt, which would be Minnesota’s first copper-nickel mining operation if it wins all the necessary approvals.