Once reached, operations will be producing at a 1.5Mtpa annualised rate, the company said.
“This ramp up has been delivered with zero lost time injuries and environmental incidents,” it said.
“BNU Operations has now reached 1.34 million man hours without an LTI and remains focused on delivering further ramp up in volumes safely.”
BNU Operations has delivered the increased coal volumes at direct mining costs of $US1.85 per cubic metre of material in Q3 2015.
This is estimated to place the operation within the bottom end of first quartile mining unit costs compared to global coal producers, according to the company.
The direct cash cost positive margin on the hard coking coal product is forecast to be between $9/t and $11/t for the last quarter of 2015.
“Strong operational performance has maintained forecast margins despite continued weakness in coking coal markets,” the company said.
“While the market continues to remain soft there are some positive signs and there is still strong buyer interest for the BNU coking coal and Guildford remains committed to developing its Mongolian business in the most capital and cost efficient methods.”