Federal regulators have ordered coal producer Consol Energy to idle a Southwest Virginia mine. Pittsburgh-based Consol said the Mine Safety and Health Administration ordered it to stop production while new concrete seals cure to full strength at its Buchanan Mine near Mavisdale, Va. Consol says the seals should reach full strength by Oct. 6. The closure is another setback for Consol. Last week it lowered third-quarter production estimates to 15 million tons, from a range of 16.4 million to 18.4 million tons. The company said it was sticking with full-year production guidance of 17.8 million to 19.8 million tons from mines in Pennsylvania, West Virginia, Virginia, Kentucky, Ohio and Utah. Buchanan was closed nine months last year, but normally produces 14,300 tons daily.