The PolyMet and Teck American joint venture recently launched an $18 million project in Hoyt Lakes, beginning the transformation of an old taconite plant into a copper-nickel operation.

NewRange Copper Nickel — as the joint venture is called — earlier this month started salvage work at the former LTV Steel taconite plant, which closed in 2001. The project is expected to take 13 months and employ up to 120 union workers.

PolyMet bought the sprawling taconite plant in 2005. There, the company plans to process copper, nickel and other metals from what would be Minnesota's first hard rock mine.

Still, PolyMet's three key mining permits remain on hold, tied up in court and regulatory battles with environmental groups.

"We are just waiting for decisions right now," said Bruce Richardson, a spokesman for NewRange Copper Nickel.

Any further investments into the $1.2 billion copper-nickel project couldn't occur until permit issues are settled.

"Minnesotans should know that courts and agencies have struck down or suspended several permits that PolyMet would need to begin construction," said Aaron Klemz, chief strategy officer for the Minnesota Center for Environmental Advocacy.

Environmental advocates say PolyMet's mine plans threaten to pollute water with toxic acids and metals.

St. Paul-based PolyMet, which is controlled by Swiss mining giant Glencore, earlier this year completed the 50-50 joint venture — dubbed NewRange — with Teck American. Teck has a copper-nickel project next door to PolyMet, which is still in its early stages and has not begun the permitting process.

PolyMet and Canada-based Teck have each sunk $85 million into the joint venture; the cleanup project is the partnership's first major investment.

The Hoyt Lakes plant was the first of eight large taconite operations built in Minnesota between the mid-1950s and the mid-1970s.

Much of the plant's monolithic equipment remains in place, from mills that crushed taconite boulders into powder to machines that turned that powder into marble-size balls made primarily of iron.

Work at the old LTV plant began in recent weeks with the restoration of electrical service, and is expected to pick up in the coming months, Richardson said.

NewRange Copper Nickel said it plans to salvage and recycle more than 19,000 tons of structural steel and 40,000 cubic yards of concrete. The plant's crane will be refurbished, and its roof replaced.