Alcoa 2015 Annual Report Download - page 29

1This table shows only the AWAC and/or Alcoa share (proportion) of reserve and annual production tonnage.
2This entity is part of the AWAC group of companies and is owned 60% by Alcoa and 40% by Alumina Limited.
3Alumínio is owned 100% by Alcoa.
4Brazilian mineral legislation does not establish the duration of mining concessions. The concession remains in force
until the exhaustion of the deposit. The Company estimates that (i) the concessions at Poços de Caldas will last at least
until 2020, (ii) the concessions at Trombetas will last until 2046 and (iii) the concessions at Juruti will last until 2100.
Depending, however, on actual and future needs, the rate at which the deposits are exploited and government approval is
obtained, the concessions may be extended to (or expire at) a later (or an earlier) date.
5Alcoa World Alumina LLC (AWA LLC) owns 100% of N.V. Alcoa Minerals of Suriname (AMS). Suralco and AMS
are parts of the AWAC group of companies which are owned 60% by Alcoa and 40% by Alumina Limited.
6At the end of 2015, AWAC’s bauxite mineral and mining rights remained valid until 2033. The AWAC mines in
Suriname were curtailed in the fourth quarter of 2015. There are no plans for AWAC to restart these mines and there are
no reserves to declare.
7Alumínio holds an 8.58% total interest, AWA Brasil holds a 4.62% total interest and AWA LLC holds a 5% total
interest in MRN. MRN is jointly owned with affiliates of Rio Tinto Alcan Inc., Companhia Brasileira de Alumínio,
Companhia Vale do Rio Doce, BHP Billiton Plc (BHP Billiton) and Norsk Hydro. Alumínio, AWA Brasil, and AWA
LLC purchase bauxite from MRN under long-term supply contracts.
8AWA LLC owns a 45% interest in Halco (Mining), Inc. (Halco). Halco owns 100% of Boké Investment Company, a
Delaware company, which owns 51% of CBG. The Guinean Government owns 49% of CBG, which has the exclusive
right through 2038 to develop and mine bauxite in certain areas within an approximately 2939 square kilometer
concession in northwestern Guinea.
9AWA LLC and Alu˜mina Española, S.A. have bauxite purchase contracts with CBG that expire in 2033. Before that
expiration date, AWA LLC and Alu˜mina Española, S.A. expect to negotiate extensions of their contracts as CBG will
have concession rights until 2038. The CBG concession can be renewed beyond 2038 by agreement of the Government
of Guinea and CBG should more time be required to commercialize the remaining economic bauxite within the
concession.
10 Guinea—Boké: CBG prices bauxite and plans the mine based on the bauxite qualities of total alumina (TAl2O3) and total
silica (TSiO2).
11 Ma’aden Bauxite & Alumina Company is a joint venture owned by Saudi Arabian Mining Company (Ma’aden)
(74.9%) and AWA Saudi Limited (25.1%). AWA Saudi Limited is part of the AWAC group of companies and is owned
60% by Alcoa and 40% by Alumina Limited.
12 Kingdom of Saudi Arabia—Al Ba’itha: Bauxite reserves and mine plans are based on the bauxite qualities of total
available alumina (TAA) and total silica (TSiO2).
Qualifying statements relating to the table above:
Australia—Darling Range Mines: Huntly and Willowdale are the two AWAC active mines in the Darling Range of
Western Australia. The mineral lease issued by the State of Western Australia to AofA is known as ML1SA and its
term extends to 2024. The lease can be renewed for an additional twenty-one year period to 2045. The declared
reserves are as for December 31, 2015. The amount of reserves reflects the total AWAC share. Additional resources are
routinely upgraded by additional exploration and development drilling to reserve status. The Huntly and Willowdale
mines supply bauxite to three local AWAC alumina refineries.
Brazil—Poços de Caldas: Declared reserves are as for December 31, 2015. Tonnage is total Alcoa share. Additional
resources are being upgraded to reserves as needed.
Brazil—Juruti RN101, RN102, RN103, RN104, #34: Declared reserves are as for December 31, 2015. All reserves
are on Capiranga Plateau. Declared reserves are total AWAC share. Declared reserve tonnages and the annual
production tonnage are washed product tonnages. The Juruti mine’s operating license is periodically renewed.
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