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

General
Ore Reserve pay limit
The pay limit is based on Cost 4 which consists of ‘Direct Cash Cost’ (on- and off-mine), ‘Other Indirect Costs’ and ‘Stay-in-Business Capital’ (on- and
off-mine). The range is a function of various factors including depth of the ore body, geological complexity, infrastructure and economic parameters.
The Merensky and UG2 Reef Ore Reserve pay limit varies across all operations between 1.8 g/t and 3.7 g/t. The pay limits for the Platreef varies
between 1.0 and 1.7 g/t 4E.
Merensky Reef The global Ore Reserve tonnage decreased by 19% to 113.0 Mt (2010: 140.2 Mt) and the 4E ounce content decreased by 18% to 18.5 Moz (2010:
22.5 Moz), mainly owing to the following:
Thembelani Mine: Conversion reallocation of previously reported Ore Reserves back to Mineral Resources owing to economic assumptions:
-17.7 Mt -2.9 Moz.
Tumela Mine: Portions of 4-shaft area owing to mining engineering-related issues (layout and design) resulted in the reallocation of previously
reported Ore Reserves back to Mineral Resources: -3.2 Mt -0.6 Moz.
Production depletion -5.7 Mt -0.9 Moz.
These decreases were partially offset by the increase in Ore Reserves from Siphumelele Mine where additional Mineral Resources have been
converted to Ore Reserves: +1.9 Mt +0.6 Moz.
It must be noted that the global Ore Reserve grade increased by 0.10 g/t from 5.00 g/t to 5.10 g/t owing to the optimisation of the modifying factors
especially at Dishaba and Siphumelele mines.
Total Merensky Reserves (4E Moz)
Changes between 2010 – 2011 (Amplats attributable)
Reserves Moz
23.5
23.0
22.5
22.0
21.5
21.0
20.5
20.0
19.5
19.0
18.5
18.0
17.5
22.5 (0.9)
Production
0.6
Conversion:
+0.9 Moz
0.4 (2.9)
Economic
assumptions
Thembelani
(0.1)
(0.6)
(0.1) (0.2)
Reallocation Reserves to Resoures:
-4.0 Moz
(0.0) 18.5
Securing
our future
Opening balance
Production
Conversion:
Siphumelele
Conversion:
Dishaba
Conversion reallocation:
Thembelani
Conversion reallocation:
Khomanani
Conversion reallocation:
Tumela
Conversion reallocation:
BRPM
Conversion reallocation:
Bokoni
Conversion reallocation:
Khuseleka and Union
Closing balance
Reduction of 4.0 Moz (-18%)
The Proved Ore Reserve tonnage decreased by 28% to 63.9 Mt (2010: 89.2 Mt) and the 4E ounce content decreased by 27% to 10.4 Moz
(2010: 14.3 Moz) mainly owing to the following:
Tumela Mine: 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: -11.0 Mt -2.0 Moz.
Thembelani Mine: Owing to economic assumptions previously reported Proved Ore Reserves have been reclassified back to Measured Mineral
Resources: -10.1 Mt -1.7 Moz.
UG2 Reef The global Ore Reserve tonnage increased by 1.7% to 640.7 Mt (2010: 630.2 Mt) and the 4E ounce content increased by 2.5% to 89.9 Moz (2010:
87.6 Moz) mainly owing to the conversion from Mineral Resources to Ore Reserves at:
Thembelani Mine: +26.0 Mt +3.5 Moz.
Siphumelele Mine: +9.2 Mt +0.9 Moz.
Union Mine: +6.5 Mt +1.3 Moz.
Twickenham Platinum Mine: +4.4 Mt +0.8 Moz.
Khomanani Mine: +3.1 Mt +0.5 Moz.
These increases were partially offset by the decrease in Ore Reserves mainly from the following:
Production depletion: -20.1 Mt -2.4 Moz.
Portions of Tumela’s 4-shaft area owing to mining engineering-related issues resulted in the reallocation of previously reported Ore Reserves back
to Mineral Resources: -19.6 Mt - 2.8 Moz.
ANGLO AMERICAN PLATINUM LIMITED 2011
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