After 15 long and trying years of scientific study, environmental safeguarding, exhaustive public review, and more — all in accordance with state law — PolyMet, understandably, was “disappointed” this week after the Minnesota Court of Appeals stripped away key permits it needs to open Minnesota’s first copper-nickel mine.

Yes, legal challenges can be expected as part of the due diligence and scrutiny for such a complicated and controversial project. But in addition to sending the dam safety permits and permit to mine back to the Minnesota Department of Natural Resources, the court also ordered a contested case hearing. That additional review hadn’t been a part of the process PolyMet and everyone else long ago agreed to follow. It’s a new barrier insisted on by opponents. It’s an additional hurdle thrown in front of an industrial endeavor in a state that already has a reputation for being less than friendly to business and industry — never mind the abundance of good-paying, economy-boosting jobs industries provide.

“We obviously are disappointed in the court’s decision,” PolyMet said in a statement. “We and the regulatory agencies have strictly followed (the) process. … The NorthMet deposit is abundant in metals that address climate change in the way of renewable and clean-energy technologies. We are confident that we can produce these high-demand metals responsibly, with Minnesota workers, and in compliance with all applicable regulations.”

The company wasn’t the only one rightly disappointed.

“I applaud the Minnesota DNR for issuing permits based on sound science. It is unfortunate that the Minnesota Court of Appeals overruled these experts at our state agencies. I remain hopeful this misguided decision will be reversed, so that Minnesota’s hardworking union members can begin construction on the PolyMet mine and responsibly source the copper, nickel, cobalt, and platinum group elements that are necessary for everyday life, our national security, and increased demand for renewable energy,” U.S. Rep Pete Stauber said in a statement Monday. “I am incredibly disappointed as today’s decision will again needlessly delay a project that will bring decades of prosperity to northeast Minnesota. Families in our region have been waiting fifteen years for mining to begin at the NorthMet ore body and it is incredibly unfair to force them into another year of waiting. ...

“With 21st century technology, mining and preserving the environment are not mutually exclusive. My constituents will mine these critical minerals under the strongest labor and environmental standards in the world,” Stauber further stated. “Rather than putting forward harmful anti-jobs lawsuits, let’s support projects that will put our union members back to work. Instead of relying on countries with little or no labor and environmental standards, let’s support our national and energy security by responsibly developing these critical resources here at home.”

Stauber and others immediately urged PolyMet to push back, to “pursue all avenues to move this project forward,” as the pro-mining group Jobs for Minnesotans said in a statement.

But PolyMet’s next move is unclear: “We are reviewing the decision and exploring all of our options, including filing a petition for review to the Minnesota Supreme Court,” the company said.

Encouragingly, “We remain firmly committed to putting people to work in northern Minnesota and will continue pushing forward on the project,” the company also said.

After so many years and such extensive review, PolyMet can be confident in its ability to prevail in a contested case hearing. But if an administrative law judge verifies at the end of the hearing that the company’s mining plans are responsible and safe, will opponents then bring some other review or requirement? Every addition to the process means more delay for what’s already the most-scrutinized project in state history.

The PolyMet mine promises to be an economic boon for the Iron Range, the Duluth port, and all of Minnesota. It promises to responsibly extract minerals all of us need and use every day in our cellphones and elsewhere, minerals that now too often are mined in dangerous and unscrupulous ways.

The prospect of losing all that promise: that would be the most disappointing of all.