“Production was negatively affected by the highest September rainfall on record, which disrupted production at open cut operations in Queensland,” Anglo American said.

“Production from the underground operations increased as a result of asset optimisation programs focused on improving longwall performance.

“This enabled the business to respond to continuing strong demand in the metallurgical coal market.”

Anglo’s met coal production reached 3.97 million tonnes for the September quarter, 5% higher than the previous quarter and up 26% year on year.

Anglo made 4.1Mt of met coal sales – roughly in line with the previous quarter but up 32% from a year ago.

The average free-on-board price received was $US205 a tonne, 27% better than the June quarter.

The company’s thermal coal production in Australia was down 14% from the previous quarter to 3.41Mt, mainly due to “lower domestic demand”

Anglo’s global export thermal coal production was 8.24Mt, down 2% year on year, with adverse geological conditions experienced at the Goedehoop mine in South Africa and above average rain hitting Colombia.

The 10.43Mt of Anglo’s South African domestic thermal coal output was on par with the corresponding period last year but was up 26% on the previous quarter.

Last year Anglo’s Moranbah North longwall mine in Queensland commissioned the world’s biggest powered roof supports and became one of the first operations to use LASC automation as part of a commercial installation.

Supplied by Joy Mining Machinery, each of the 2m-wide roof supports can handle 1750t each and are controlled by Joy’s RS20s control system.

The previous 980t-rated supports had face yielding 40-50% of the time, with support leaning issues, equipment damage and recovery operations.