Coronado CEO Gerry Spindler said in a company presentation that the company had also optimised its mine plan to integrate the Stanwell Reserve Area into its Curragh North project as part of its expansion project.

"Curragh has improved efficiency in the coal handling and preparation plant to improve operating hours," he said.

"It has completed an upgrade train loadout system to reduce train load time."

Coronado's mine plan for its Curragh complex is expected to deliver 15 million tonnes of annual saleable production by 2023 at a cost of up to US$108.5 million.

Phase one of Curragh's expansion plan focuses on integrating the 82Mt of reserves from the Stanwell Reserve Area into the plan, which will let Coronado exploit the benefits of the incremental tonne.

It allows an optimised mine plan and sequencing at Curragh North, while extending the mine life.

Current installed infrastructure will be used to support the production uplift with no additional material investment, such as box cuts, needed.

Spindler said a proposed integration of an intermediate circuit in the CHPP was in the study phase.

The company is also devising ways of improving stacking infrastructure and automating the train loadout system.

Spindler said Coronado had secured an extra haulage capacity contract from Aurizon Operations and Pacific National.