Roberts added that, "Unfortunately, some environmental groups didn't like the result and filed for an injunction to block the settlement.
"The federal judge blocked the settlement and scheduled a hearing on the injunction for September," Roberts said.
"If the company concludes that it will never be allowed to mine those reserves and withdraws the equipment from the mine, those miners may never go back to work," he said.
Chief U.S. District Judge Charles Haden II has not issued an injunction to block the settlement. Coal companies have gone to court to challenge the settlement agreement.
Environmentalists challenged an expansion permit for Arch Coal Inc.'s Dal-Tex mine after the U.S. Army Corps of Engineers exempted it from the additional scrutiny called for in the settlement.
In response, Haden issued a preliminary injunction that halted the expansion until a full trial in the case, scheduled for September. Less than a week later, Arch Coal announced it would close Dal-Tex and lay off nearly 400 miners who work there.
Doug Gibson, a press spokesman for the mine workers, said the "settlement" that Roberts referred to wasn't the lawsuit settlement, but instead was federal agencies' decision to exempt the Dal-Tex permit from additional scrutiny.