The mine is entering phase three of its restart plan, which aims to safely return the operation to historical levels of production, South32 CEO Graham Kerr told the Bank of America Merrill Lynch Global Metals, Mining & Steel Conference in Florida.
He said the leadership team had reconfigured Appin Area 9 and potential future mining areas and optimised underground development plans.
"[We are] continuing to improve our safety performance and the way we work," Kerr said.
Phase two of the mine's plan focused on a safe start of staged ramp-up, gas drainage and ventilation, and transforming the way mine personnel worked.
"Appin is focusing on lowering the cost base by improving development and longwall productivity and implementing strategic sourcing to reduce spend," Kerr said.
Unit costs at Appin are expected to reduce to be less than US$110 per tonne and production is forecast to reach 6 million tonnes in FY2019.
The mine is anticipated return to historical rates above 8Mtpa from H2 FY2020 with the progressive return from one to six development units.