The new measured, indicated and inferred resource estimate is 1.335 billion gross in situ tonnes, up from 713 million tonnes.
The updated resource covers around 40% of the total project area, with a further resource upgrade to incorporate the remaining 60% is expected before the end of the year.
“The upgrade confirms our view that the Makhado project is capable of becoming a very substantial long life producer of high-quality hard coking coal,” Coal of Africa managing director Simon Farrell said.
The quality of the product is expected to be coking coal at 12% ash (air dried) with a weighted average sulphur content of 0.97%.
The design of the mine has been completed and a scoping study level schedule and an operation cost estimate are expected to be completed within the next month.