A high-powered Chilean delegation's visit to Minnesota last week signals strongly that a controversial new type of Iron Range mining isn't a matter of if, it's a matter of when. That should give Minnesotans pause, especially during this landmark election year.

Ferried about in a fleet of limousines were the Chilean ambassador and the executive team from one of the world's leading mining companies -- Antofagasta, which is run by Chile's wealthy Luksic family. The delegation met with the governor, legislators and members of the Star Tribune Editorial Board, among others, attempting to generate support for a large underground copper-nickel mine near Ely.

Operations like this are often referred to as "nonferrous" mining because metals other than iron are sought. Copper, nickel and palladium are increasingly valuable in electronics manufacturing and clean-energy technology. But nonferrous mining also carries a substantial environmental risk: acid runoff from pulverized waste rock.

Northeastern Minnesota is home to some of the world's richest metal deposits, as well as the beloved Boundary Waters Canoe Area Wilderness. Seven companies are pursuing nonferrous projects in the region. The $600 million PolyMet copper-nickel surface mine proposed near Babbitt so far is the only one that's formally begun the lengthy review and permitting process. The underground mine proposed by Antofagasta and its joint venture partner Duluth Metals is far larger. Total investment could exceed $2 billion.

The presence of Jean-Paul Luksic in Minnesota last week indicates how serious the firm is about making the project a reality. Antofagasta didn't just send its top brass: It sent its top guy. Luksic's billionaire father Andronico built a sprawling banking, mining and manufacturing empire in South America. He was one of the world's richest men when he died in 2005.

Jean-Paul Luksic is Antofagasta's chairman. In 2009, the company posted profits of $667.7 million, down from $842.9 million the year before. You've heard of Big Oil: This is Big Copper. The firm's interest in Minnesota isn't inherently bad, as some environmentalists believe, but it should spur Minnesota voters to start asking questions about the role of mining in economic development. Nonferrous mining has been a nonissue in the gubernatorial campaign to date. Voters deserve to know where their politicians stand.

Few other industries have the potential to fire the state's economic engine for decades. The Antofagasta/Duluth Metals venture -- which is not seeking public aid -- alone could generate several thousand permanent jobs and employ up to 5,000 during construction.

The state desperately needs these jobs, but this issue is far more complex than that. Politicians and firms like Antofagasta need to understand that Minnesotans will not trade the state's soul -- the BWCA, Lake Superior, the North Shore forest -- for economic gain. The Antofagasta/Duluth Metals project's eastern edge is just a few miles from the BWCA. Older nonferrous mines have an abysmal environmental track record. While technological strides certainly have been made, assurances that things are better now aren't going to cut it.

Nonferrous mining companies don't just need to win over the regulators. They need to win over the public. Facts, openness and a willingness to work with their critics will serve them well, but the task ahead of them is formidable.