A joint federal and provincial panel in June found that the likelihood of significant adverse environmental effects on water and wildlife resulting from the Grassy Mountain steelmaking coal mine outweighed economic gains.

Privately held Benga Mining is a unit of Riversdale Resources, owned by Australian billionaire Gina Rinehart’s Hancock Prospecting Pty Ltd.

Benga said the panel’s conclusions “contain material errors of law and contraventions of procedural fairness.”

Riversdale has said the C$800 million ($648 million) Grassy Mountain project would generate C$1.7 billion in taxes and royalties over the 23-year mine life, and employ 400 people.

At its peak, the mine, to be situated near Crowsnest Pass, Alberta, would produce 4.5 million tonnes of steelmaking coal a year.