The revised figures come after an extensive study by SRK Consulting that boosted resource figures by 39% on previous amounts to 176 million tonnes in the measured and indicated categories.

The mine's reserve jumped 38% to 23.6Mt.

"This latest study by independent consultants has added a further four years of mining to our mid-term mine plans, with substantial further upgrades to come in future years as drilling continues," said Caledon chief operating officer Peter Seear.

"Caledon has taken the unusual step of planning its long-term mine design and has now developed the mine plan out to 2020 with substantial additional expansion to come.

"In the short term we continue to focus on the implementation of the Magatar mining system as soon as possible."