Mineral Resource and Ore Reserve – Summary

Responsible management of our Mineral Resource and Ore Reserve, our exploration programme and related planning, is vital in optimising the operating lives of our portfolio.

AngloGold Ashanti strives to actively create value by growing its major assets – the Mineral Resource and Ore Reserve. This drive is based on active, well-defined brownfield and greenfield exploration programmes, innovation in both geological modelling and mine planning, and continual optimisation of the asset portfolio. Ensuring a viable Mineral Resource and Ore Reserve pipeline enables delivery of sustained value-adding growth in the long term.

Responsible management of our Mineral Resource and Ore Reserve, our exploration programme and related planning, is vital in optimising the operating lives of our portfolio. In so doing, AngloGold Ashanti ensures that it is able to deliver on its strategy and the related strategic objectives in particular, namely, to maintain long-term optionality and improve the quality of our portfolio. See also Exploration and planning for the future in this report.

Reporting compliance

AngloGold Ashanti’s Mineral Resource and Ore Reserve are reported as at 31 December 2021, in accordance with the minimum standards described by the South African Code for the Reporting of Exploration Results, Mineral Resources and Mineral Reserves (The SAMREC Code, 2016 edition) and Section 12.13 of the JSE Listings Requirements (as updated from time to time).

We achieve this by ensuring the principles of integrity, transparency and materiality are central to the compilation of the <R&R> and by using reporting criteria and definitions as detailed in the SAMREC Code. In complying with the SAMREC Code the changes to AngloGold Ashanti’s Mineral Resource and Ore Reserve have been reviewed and it was concluded that none of the changes are material to the overall valuation of the Company.

AngloGold Ashanti has therefore once again resolved not to provide the detailed reporting as defined in Table 1 of the SAMREC Code, apart from the maiden Mineral Resource declaration for Silicon. The Company will continue, however, to provide the high level of detail it has in previous years to comply with the transparency requirements of the SAMREC Code.

Price assumptions

The SAMREC Code requires the use of reasonable economic assumptions. These include long-range commodity price and exchange rate forecasts. These are reviewed annually and are prepared in-house using a range of techniques including historic price averages. AngloGold Ashanti selects a conservative Ore Reserve price relative to its peers. This is done to fit into the strategy to include a margin in the mine planning process. The resultant plan is then valued at a higher business planning price.

In the case of Sunrise Dam, the 2021 Ore Reserve estimate reflects that the mine is two years into a three-year “growth through exploration” phase that aims to unlock the value of the asset, with Ore Reserve growth the initial step in a move towards realising the full asset potential. The Ore Reserve has been estimated using a mine-constrained break-even cut-off determined at a $1,200/oz gold price under budget cost conditions across the six-year Ore Reserve life.

This has meant that significant marginal material was included in the plan in order to keep the plant operating at full capacity.

The Ore Reserve has been evaluated economically and shown to be cash flow positive at a $1,500/oz gold price. It is AngloGold Ashanti’s opinion that there is sufficient margin between this price and the current spot price of gold for this to define an Ore Reserve.

Gold price

The following local prices of gold were used as a basis for estimation in the December 2021 declaration, unless otherwise stated:

Local prices of gold
Gold price
$/oz
Australia
AUD/oz
Brazil
BRL/oz
Argentina
ARS/oz
Colombia
COP/oz
2021 Ore Reserve 1,200 1,633 6,182 134,452 3,849,000
2020 Ore Reserve 1,200 1,604 5,510 119,631 4,096,877
2021 Mineral Resource 1,500 2,072 7,940 173,065 5,336,250
2020 Mineral Resource 1,500 2,170 7,682 142,507 5,094,827

Copper price

The following copper price was used as a basis for estimation in the December 2021 declaration:

Copper price
$/lb COP/lb
2021 Ore Reserve 2.90 9,302
2020 Ore Reserve 2.65 9,047
2021 Mineral Resource 3.50

12,451

2020 Mineral Resource 3.30 11,209

Mineral Resource

Gold

The AngloGold Ashanti Mineral Resource reduced from 124.5Moz in December 2020 to 123.2Moz in December 2021. This annual net decrease of 1.3Moz includes depletion of 2.9Moz, the relinquishment of the lease for Obuasi’s Anyankyirem open pit of 0.4Moz, changes in economic assumptions of 2.3Moz and other factors of 1.4Moz (including the write-off of 0.6Moz for AGA Mineração Nova Lima Sul). This decrease is partially offset by additions due to exploration and modelling changes of 5.7Moz. The Mineral Resource was estimated using a gold price of $1,500/oz, unless otherwise stated (2020: $1,500/oz).

Mineral Resource – Gold

Moz
Mineral Resource as at 31 December 2020 124.5
Disposal At Obuasi, the Anyankyirem open pit mining lease was relinquished. (0.4)
Sub-total 124.1
Depletions   (2.9)
Sub-total 121.2
Additions Due to:  
Silicon A maiden Mineral Resource was declared after the completion of a positive conceptual study based on the greenfield exploration success. 3.4
Geita Increase due to ongoing grade control and successful exploration activities. Following a review of mining cost for 2021 the resultant reduction in cost led to further increases. 0.9
Sunrise Dam Increase due to ongoing advanced grade control and exploration activities partially offset by minor local changes in gold price and an overall increase in costs 0.7
Kibali Changes were largely as a result of exploration, with gains seen from the open pits, specifically from Oere, Pamao, KCD and Gorumbwa as well as from the initial Inferred Mineral Resource definition of the 11000 lode in the underground. 0.6
Other Additions less than 0.5Moz 0.3
Sub-total 127.1
Reductions Due to:  
Obuasi Changes primarily due to model changes in the historic mining areas in the north of the mine which accounted for an overall reduction. (2.2)
Iduapriem New grade control drilling at Block 3W resulted in a decrease in model grade and re-interpretation of the intrusives in the deeper portions of Blocks 7 and 8 resulted in further losses. These were partially offset by lower costs resulting from a new long-term contract resulting in additions. (0.6)
Other Reductions less than 0.5Moz (1.1)
Mineral Resource as at 31 December 2021 123.2

Copper

The AngloGold Ashanti Mineral Resource reduced from 4.39Mt (9,677Mlb) in December 2020 to 4.26Mt (9,384Mlb) in December 2021 due to methodology changes of 0.13Mt (293Mlb). The Mineral Resource was estimated at a copper price of $3.50/lb (2020: $3.30/lb).

Mineral Resource – Copper

Mt Mlb
Mineral Resource as at 31 December 2020 4.39 9,677
ReductionsDue to:    
Quebradona Decreases resulted from the remodelling of the orebody including three new drill holes. (0.13) (293)
Mineral Resource as at 31 December 2021 4.26 9,384

Ore Reserve

Gold

The AngloGold Ashanti Ore Reserve increased from 29.7Moz in December 2020 to 29.8Moz in December 2021. This annual net increase of 0.1Moz includes additions due to exploration and modelling changes of 4.1Moz. This increase was partially offset by depletion of 2.6Moz and reductions due to other factors of 1.4Moz. The Ore Reserve was estimated using a gold price of $1,200/oz, unless otherwise stated (2020: $1,200/oz).

Ore Reserve – Gold

Moz
Ore Reserve as at 31 December 202029.7
Depletions   (2.6)
Sub-total27.1
Additions Due to: (2.9)
Iduapriem The net increase is primarily due to the decrease in costs resulting from signing a new mining contract and operational changes. 0.9
Geita The significant increase is mainly due to ongoing drilling exploration success resulting in larger pit designs. The open pit shell and underground slope design changes contributed to an increase of 27% and 3% to the Ore Reserve respectively. 0.8
Kibali The increase in Ore Reserve was primarily as a result of the conversion of the 3000 and 9000 lode extensions in the KCD underground, and the addition of the Oere pit and growth in the Pamao pit due to exploration successes. The price used for pit optimisation at Pakaka and Gorumbwa also changed from $1,000/oz to $1,200/oz which contributed to the increase seen. 0.5
Sunrise Dam The increase in the reported Ore Reserve is due to exploration success and a revised methodology for underground stope optimisation offset by more conservative extraction ratios and increased unit costs. 0.4
Other Additions less than 0.3Moz 0.5
  Sub-total 30.2
Reductions Due to:  
Obuasi Operational changes primarily associated with design reviews in historically mined areas to eliminate low confidence stopes resulted in a net decrease which was partially offset by methodology changes. (0.4)
Other Reductions less than 0.3Moz (0.0)
Ore Reserve as at 31 December 2021 29.8

Copper

The AngloGold Ashanti Ore Reserve increased from 1.41Mt (3,105Mlb) in December 2020 to 1.47Mt (3,250Mlb) in December 2021. This gross annual increase of 0.07Mt (145Mlb) is due to methodology changes. The Ore Reserve was estimated at a copper price of $2.90/lb (2020: $2.65/lb).

Ore Reserve – Copper

Mt Mlb
Ore Reserve as at 31 December 2020 1.41 3,105
AdditionsDue to:    
Quebradona Result of an update in the Mineral Resource model due to three new drill holes, in addition to an upgrade in Mineral Resource classification based on conditional simulation. 0.07 145
Ore Reserve as at 31 December 2021 1.47 3,250
Note:

The Mineral Resource, as reported, is inclusive of the Ore Reserve component, unless otherwise stated. Mineral Resource and Ore Reserve estimates are reported as at 31 December 2021 and are net of 2021 production depletion. Although the term Mineral Reserve is used throughout the SAMREC Code, it is recognised by the SAMREC Code that the term Ore Reserve is synonymous with Mineral Reserve. AngloGold Ashanti elects to use Ore Reserve in its reporting. To reflect that figures are not precise calculations and that there is uncertainty in their estimation, AngloGold Ashanti reports tonnage content for gold to two decimals and tonnage content for copper with no decimals.

By-products

Several by-products will be recovered as a result of processing of the gold Ore Reserve and copper Ore Reserve. These include 0.43Mt of sulphur from Brazil, 20.5Moz of silver from Argentina and 28.1Moz of silver from Colombia. Molybdenum, at present, is not planned for recovery at Quebradona. The Quebradona process plant has been designed to treat underground ore and to produce copper concentrate with provision of space in the plant site for a molybdenum plant in the future.

Corporate governance

AngloGold Ashanti has an established Mineral Resource and Ore Reserve Steering Committee (RRSC), which is responsible for setting and overseeing the Company’s Mineral Resource and Ore Reserve governance framework and for ensuring that it meets the Company’s goals and objectives while complying with all relevant regulatory codes. Its membership and terms of references are mandated under a policy document signed by the Chief Executive Officer.

The Audit and Risk Committee and Investment Committee review the Mineral Resource and Ore Reserve and make a recommendation to the board, which provides final approval for the publication of the Mineral Resource and Ore Reserve.

AngloGold Ashanti has developed and implemented a rigorous system of internal and external reviews aimed at providing assurance in respect of Mineral Resource and Ore Reserve estimates. In 2021, the following operations were subject to an external review in line with the policy that each operation or project will be reviewed by an independent third party on average once every three years:

  • Mineral Resource and Ore Reserve at Iduapriem
  • Mineral Resource and Ore Reserve at Obuasi
  • Mineral Resource and Ore Reserve at Kibali
  • Mineral Resource and Ore Reserve at Serra Grande
  • Mineral Resource and Ore Reserve at Sunrise Dam
  • Mineral Resource and Ore Reserve at Tropicana

The external reviews of the Mineral Resource and Ore Reserve were conducted by SRK Consulting for the mines operated by AngloGold Ashanti. Certificates of sign-off have been received for all AngloGold Ashanti managed operations and projects to state that the Mineral Resource and Ore Reserve estimates are reported in accordance with the SAMREC Code. In the case of Kibali, an independent technical review of the annual Mineral Resource and Ore Reserve estimates was undertaken by RSC Mining and Mineral Exploration on behalf of the managing partner Barrick. No significant flaws were identified.

In addition, numerous internal Mineral Resource and Ore Reserve process reviews were completed by suitably qualified Competent Persons from within AngloGold Ashanti and no significant deficiencies were identified. The Mineral Resource and Ore Reserve governance framework is underpinned by appropriate Mineral Resource Management processes and protocols that ensure adequate corporate governance. These procedures have been developed to comply with the guiding principles of the US Sarbanes- Oxley Act of 2002 (SOX).

AngloGold Ashanti makes use of a web-based group reporting database called the Resource and Reserve Reporting System (RCubed) for the compilation and authorisation of Mineral Resource and Ore Reserve reporting. It is a fully integrated system for the reporting and reconciliation of Mineral Resource and Ore Reserve that supports various regulatory reporting requirements, including the U.S. Securities and Exchange Commission (SEC) – under Subpart 1300 of Regulation S-K (Regulation S-K 1300) – and the JSE under the SAMREC Code. AngloGold Ashanti uses RCubed to ensure a documented chain of responsibility exists from the Competent Persons at the operations to the Company’s RRSC.

AngloGold Ashanti has also developed an enterprise-wide risk management tool that provides consistent and reliable data that allows for visibility of risks and actions across the group. This tool is used to facilitate, control and monitor material risks to the Mineral Resource and Ore Reserve, thus ensuring that the appropriate risk management and mitigation plans are in place.

Where technical experts involved in the estimation of Mineral Resource or Ore Reserve feel that their technical advice has been ignored and may represent a risk to the Mineral Resource or Ore Reserve to be published, they are obliged to inform the Mineral Resource and Ore Reserve Steering Committee in writing. AngloGold Ashanti’s Whistle Blowing Policy and links can be found at https://www.anglogoldashanti.com/sustainability/governance/ethics/ and can also be used if the person deems they will be compromised in the process.

Competent persons

The information in this report relating to Exploration Results, Mineral Resource and Ore Reserve is based on information compiled by or under the supervision of the Competent Persons as defined in the SAMREC Code. All Competent Persons are employed by AngloGold Ashanti, except for Kibali (which uses a Competent Person employed by Barrick) and have sufficient experience relevant to the style of mineralisation and type of deposit under consideration and relevant to the activity which they are undertaking. The legal tenure of each operation and project has been verified to the satisfaction of the accountable Competent Person and all the Ore Reserve has been confirmed to be covered by the required mining permits or there exists a realistic expectation that these permits will be issued. This is detailed in the <R&R>. The Competent Persons consent to the inclusion of Exploration Results, Mineral Resource and Ore Reserve information in the <R&R> report, in the form and context in which it appears.

Accordingly, the chairperson of the Mineral Resource and Ore Reserve Steering Committee, Mr. VA Chamberlain, MSc (Mining Engineering), BSc (Hons) (Geology), MGSSA, FAusIMM, assumes responsibility for the Mineral Resource and Ore Reserve processes for AngloGold Ashanti and is satisfied that the Competent Persons have fulfilled their responsibilities. Mr. VA Chamberlain has 34 years’ experience in exploration and mining and is employed fulltime by AngloGold Ashanti and can be contacted at the following address: 112 Oxford Road, Houghton Estate, Johannesburg, 2198, South Africa.

A detailed breakdown of our Mineral Resource and Ore Reserve and backup detail is available on the AngloGold Ashanti website www.anglogoldashanti.com. The full comprehensive <R&R> is available for download.

Mineral Resource by region, inclusive of Ore Reserve (attributable)

Gold

Tonnes Grade Contained gold
as at 31 December 2021 Category million g/t Tonnes Moz
Africa Measured 56.44 3.38 191.03 6.14
Indicated 361.14 2.52 909.64 29.25
Inferred 179.17 3.43 613.98 19.74
Total 596.75 2.87 1,714.66 55.13
Americas Measured 114.47 1.33 151.88 4.88
Indicated 1,203.75 0.90 1,085.22 34.89
Inferred 767.87 0.75 576.86 18.55
Total 2,086.08 0.87 1,813.96 58.32
Australia Measured 56.08 1.35 75.74 2.44
Indicated 58.45 1.73 101.24 3.26
Inferred 50.07 2.53 126.83 4.08
Total 164.59 1.85 303.82 9.77
AngloGold Ashanti Measured 226.98 1.84 418.66 13.46
Indicated 1,623.33 1.29 2,096.11 67.39
Inferred 997.11 1.32 1,317.67 42.36
Total 2,847.42 1.35 3,832.44 123.22

Copper

Tonnes Grade Contained copper
as at 31 December 2021 Category million %Cu Tonnes million Pounds million
Americas Measured 86.74 0.95 0.82 1,814
Indicated 227.33 0.87 1.97 4,338
Inferred 305.94 0.48 1.47 3,231
Total 620.02 0.69 4.26 9,384
AngloGold Ashanti Measured 86.74 0.95 0.82 1,814
Indicated 227.33 0.87 1.97 4,338
Inferred 305.94 0.48 1.47 3,231
Total 620.02 0.69 4.26 9,384

Mineral Resource by region, exclusive of Ore Reserve (attributable)

Gold

Tonnes Grade Contained gold
as at 31 December 2021 Category million g/t Tonnes Moz
Africa Measured 13.16 3.98 52.32 1.68
Indicated 179.46 2.36 422.86 13.60
Inferred 179.17 3.43 613.98 19.74
Total 371.79 2.93 1,089.15 35.02
Americas Measured 64.29 1.50 96.24 3.09
Indicated 1,035.46 0.87 897.36 28.85
Inferred 767.37 0.75 576.25 18.53
Total 1,867.11 0.84 1,569.85 50.47
Australia Measured 29.92 1.25 37.49 1.21
Indicated 33.13 1.42 47.21 1.52
Inferred 50.07 2.53 126.83 4.08
Total 113.12 1.87 211.52 6.80
AngloGold Ashanti Measured 107.37 1.73 186.05 5.98
Indicated 1,248.04 1.10 1,367.43 43.96
Inferred 996.61 1.32 1,317.06 42.34
Total 2,352.02 1.22 2,870.53 92.29

Copper

Tonnes Grade Contained copper
as at 31 December 2021 Category million %Cu Tonnes million Pounds million
Americas Measured 45.15 0.69 0.31 684
Indicated 148.91 0.68 1.01 2,218
Inferred 305.94 0.48 1.47 3,231
Total 500.01 0.56 2.78 6,134
AngloGold Ashanti Measured 45.15 0.69 0.31 684
Indicated 148.91 0.68 1.01 2,218
Inferred 305.94 0.48 1.47 3,231
Total 500.01 0.56 2.78 6,134

Ore Reserve by region (attributable)

Gold

Tonnes Grade Contained gold
as at 31 December 2021 Category million g/t Tonnes Moz
Africa Proved 41.33 2.58 106.54 3.43
Probable 183.69 2.72 499.29 16.05
Total 225.02 2.69 605.84 19.48
Americas Proved 11.11 2.70 29.99 0.96
Probable 203.74 0.98 199.60 6.42
Total 214.86 1.07 229.60 7.38
Australia Proved 26.41 1.46 38.43 1.24
Probable 25.31 2.13 54.04 1.74
Total 51.73 1.79 92.47 2.97
AngloGold Ashanti Proved 78.86 2.22 174.97 5.63
Probable 412.74 1.82 752.93 24.21
Total 491.60 1.89 927.90 29.83

Copper

Tonnes Grade Contained copper
as at 31 December 2021 Category million %Cu Tonnes million Pounds million
Americas Proved
Probable 120.01 1.23 1.47 3,250
Total 120.01 1.23 1.47 3,250
AngloGold Ashanti Proved
Probable 120.01 1.23 1.47 3,250
Total 120.01 1.23 1.47 3,250