Group Mineral Resources

As at 31 December 2019, Group Mineral Resources are estimated to contain 33.1 million ounces of gold (2.4 million ounces of gold from Tujuh Bukit and Wetar Operation and 30.7 million ounces of gold from Tujuh Bukit Copper and Pani Project), 9 million tonnes of copper (0.3 million tonnes of copper from Wetar Operation and 8.7 million tonnes of copper from Tujuh Bukit Copper Project), and 91 million ounces of silver (91 million ounces of silver from Tujuh Bukit and Wetar Operation).

This represents an increase of approximately 158 thousand ounces of gold (~0.5%), 93 thousand tonnes of copper (~1%) and 38 million ounces of silver (~42%), compared with the estimates as at 31 December 2018.

The Group Mineral Resources as at 31 December 2019 includes changes at numerous deposits following updated notional constraining shells and/or resource models. These include:

  • Mining depletion during 2019 was 7.3 Mt containing 262 koz of gold, 2,483 koz of silver and 69 thousand tonnes of copper.
  • A reduction in the cutoff grade for reporting Resources at Tujuh Bukit oxide operations from 0.3 g/t Au to 0.15 g/t Au in line with operational cutoff grades and gold price movements.
  • Updated resource models for Pit A and Pit C and Tujuh Bukit oxide operations.
  • Maiden Partolang Resource estimate.

Group Ore Reserves

As of 31 December 2019, Group Ore Reserves are estimated to contain 871 thousand ounces of gold (871 thousand ounces of gold from Tujuh Bukit Operation), 114 thousand tonnes of copper (114 thousand tonnes of copper from Wetar Operation) and 35.2 million ounces of silver (35.2 million ounces of silver from Tujuh Bukit Operation).

The Gold and Silver Ore Reserves do not include the Tujuh Bukit heap leach pad working inventory of 15 Mt at 0.43 g/t gold and 9 g/t silver containing 0.21 Moz of gold and 4.3 Moz of silver.

The heap leach pad is considered to be a working inventory because the active ore placement lift has a planned 150 day leach cycle to realise 100% of the estimated total recovery. In addition to this planned leach cycle, there is potential for additional recovery of metal as the leach solution percolates
through the underlying lifts. This potential additional recovery is not quantified or included within metal recovery or economic estimates. Grades are estimated from total metal stacked less metal extracted divided by total tonnes stacked on the heap leach pad.

The Copper Ore Reserves do not include the Wetar heap leach pad working inventory of 7.5 Mt at 1.5% copper containing 114 kt of copper. Grades are estimated from total metal stacked less metal extracted divided by total tonnes stacked on the heap leach pad. The heap leach pad is considered to be a working inventory because the active ore placement lift has a planned 720 day leach cycle to realize 100% of the estimated total recovery.

For more information, kindly read: Consolidated Mineral Resources & Ore Reserves Statement as of 31 December 2019.