The developer of the $800-million Grassy Mountain steelmaking coal project has launched a legal appeal after energy regulators last month denied its application to build a steelmaking coal mine, in Crowsnest, Alberta.

Benga Mining, a wholly owned subsidiary of Australian billionaire Gina Rinehart’s Riversdale Resources, on Monday announced that it had filed an application for permission to appeal to the Court of Appeal of Alberta.

A joint federal-provincial review panel (JRP), in its capacity as the Alberta Energy Regulator (AER), in June denied the permits needed by the Grassy Mountain mine, after ruling the environmental consequences would likely outweigh the economic benefits.

"After careful and thorough review of the JRP's report, Benga believes that the AER's conclusions and reasons contain material errors of law and contraventions of procedural fairness," said Benga CEO John Wallington in a media statement.

"Among the reasoning in its report, the AER dismissed the full support of the relevant First Nations without consultation, demonstrated a lack of familiarity with the provincial royalty regime, and gave preference to non-expert layman analysis over expert, science-based evidence. These errors must be addressed to not only deliver fairness to Benga and the Indigenous groups adversely affected by the decision, but to provide future guidance to any company considering an investment in Alberta and Canada, any participants in AER and JRP review processes, future AER and JRP panels, and Indigenous groups that support projects and can benefit economically and culturally from their approval."

Benga highlighted several issues which it considers to be errors that the JPR made in its press statement.

The company also said that it was unprecedented for Alberta’s energy regulator to deny a project after public hearing, stating that since 2009, 11 oil sands and coal mining projects had gone through the energy regulator’s hearing processes, with eight being approved, three withdrawn and none denied.

"The JRP could have addressed any valid concerns with the project by making an approval conditional on strict conditions. This well-established and proven approach ensures any development can only proceed with adequate protections in place. Unfortunately, for reasons unknown to us, the JRP imposed a decision that is based on a number of errors of law, leaving Benga no choice but to take the steps we announced today," said Wallington.

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

Environment Minister Jonathan Wilkinson has to issue a final decision on the project by November.