ore reserves and mineral resources 2011 report - Anglo American ...

SECURING OUR FUTURE
ORE RESERVE AND MINERAL RESOURCE ESTIMATES
as at 31 December 2011
Ore Reserve footnotes
General
Rustenburg mines
Rounding of figures may result in computational discrepancies. 4E grade reported: sum of platinum, palladium, rhodium and gold grades.
Rustenburg consists of five mines and owing to benefits of time/extraction, internal boundaries change year-on-year. However, for reconciliation
purposes the entire Rustenburg area will be compared.
Merensky Reef
The total Ore Reserve tonnage decreased by 38% to 32.9 Mt (2010: 53.0 Mt) and the 4E ounce content decreased by 35% to 5.6 Moz (2010:
8.6 Moz). This was mainly owing to the following:
Thembelani Mine – conversion of previously reported Ore Reserves back to Mineral Resources owing to economic assumptions: -17.7 Mt -2.9 Moz.
Production depletion: -3.0 Mt -0.5 Moz.
As a consequence of the conversion reallocation the total Proved Ore Reserves tonnage decreased by 28% to 29.9 Mt (2010: 41.7 Mt) and the
4E ounce content decreased by 24% to 5.2 Moz (2010: 6.9 Moz).
UG2 Reef
The total Ore Reserve tonnage increased by 22% to 186.9 Mt (2010: 153.3 Mt) and the 4E ounce content increased by 23% to 21.8 Moz (2010:
17.7 Moz). This was mainly owing to additional conversion of Mineral Resources to Ore Reserves at the following mines:
Thembelani Mine: +26 Mt +3.5 Moz.
Siphumelele Mine: +9.2 Mt +0.9 Moz.
Khomanani Mine: +3.1 Mt +0.5 Moz.
The increase in tonnage is offset by production depletion: -6.0 Mt -0.6 Moz.
Owing to conversion of Mineral Resources to Ore Reserves the total Proved Ore Reserves tonnage increased by 23% to 165.8 Mt (2010: 134.5 Mt)
and the 4E ounce content increased by 25% to 19.2 Moz (2010: 15.4 Moz).
Tumela Mine
Previously reported Ore Reserves have been reallocated back to Mineral Resources in the following areas:
Portions of 4-shaft area as a result of mining engineering-related issues.
In areas with complex geology causing unsafe conditions.
Additionally, owing to the reduction in confidence for portions of 4-shaft area, the Reserve classification has been affected and the Proved Ore
Reserves have been reclassified to Probable Ore Reserves.
Merensky Reef
The Ore Reserve tonnage decreased by 12% to 26.2 Mt (2010: 29.9 Mt) and the 4E ounce content decreased by 13% to 4.9 Moz (2010: 5.6 Moz).
This was mainly owing to the following:
Portions of 4-shaft owing to mining engineering-related issues (layout and design): -3.2 Mt -0.6 Moz.
Production depletion: -0.5 Mt -0.1 Moz.
The Proved Ore Reserve tonnage decreased by 92% to 1.0 Mt (2010: 11.9 Mt) and the 4E ounce content decreased by 91% to 0.2 Moz (2010:
2.2 Moz).
UG2 Reef
The Ore Reserve tonnage decreased by 15% to 126.6 Mt (2010: 149.4 Mt) and the 4E ounce content decreased by 15% to 19.4 Moz (2010:
22.7 Moz). This was mainly owing to the following:
Portions of 4-shaft owing to mining engineering-related issues (layout and design) and owing to complex geology: -19.6 Mt - 2.8 Moz.
Production depletion: -3.3 Mt -0.5 Moz.
The Proved Ore Reserve tonnage decreased by 54% to 57.2 Mt (2010: 123.1 Mt) and the 4E ounce content decreased by 52% to 8.9 Moz
(2010: 18.6 Moz).
As a consequence of the reclassification of Proved to Probable Ore Reserves, the Probable Ore Reserve tonnage increased by 163%.
Dishaba Mine
Merensky Reef
The Ore Reserve tonnage decreased by 2.7% to 15.5 Mt (2010: 16.0 Mt) but the 4E ounce content increased by 7.2% to 2.9 Moz (2010: 2.7 Moz)
as a result of a change in the modifying factors; the Ore Reserve grade increased by 0.54 g/t from 5.25 g/t to 5.79 g/t.
UG2 Reef
The Ore Reserve tonnage decreased marginally by 0.6% but the 4E ounce content increased by 3.8% owing to changed modifying factors; the overall
Ore Reserve grade increased by 0.20 g/t from 4.58 g/t to 4.79 g/t.
Union Mine
Amplats’ attributable interest is 85% of the Mineral Resources and Ore Reserves. The figures quoted are for the attributable interest only. Figures
provided by Amplats.
Merensky Reef
The Ore Reserve tonnage decreased to 0.03 Mt owing to production depletion. The Ore Reserves will be mined out during 2012.
UG2 Reef
The Ore Reserve tonnage increased by 8.0% to 51.6 Mt (2010: 47.8 Mt) and the 4E ounce content increased by 15% to 7.3 Moz (2010: 6.3 Moz) as
a result of additional converted Ore Reserves: +6.5 Mt +1.3 Moz.
The increase in Ore Reserves is offset by production depletion: -2.7 Mt -0.4 Moz.
26 ANGLO AMERICAN PLATINUM LIMITED 2011