Alcoa 2015 Annual Report Download - page 28

globally and the length of the Company’s rights to bauxite, it is not cost-effective to invest the significant funds and
efforts necessary to establish bauxite reserves that reflect the total size of the bauxite resources available to the
Company. Rather, bauxite resources are upgraded annually to reserves as needed by the location. Detailed assessments
are progressively undertaken within a proposed mining area and mine activity is then planned to achieve a uniform
quality in the supply of blended feedstock to the relevant refinery. Alcoa believes its present sources of bauxite on a
global basis are sufficient to meet the forecasted requirements of its alumina refining operations for the foreseeable
future.
Bauxite Resource Development Guidelines
Alcoa has developed best practice guidelines for bauxite reserve and resource classification at its operating bauxite
mines. Alcoa’s reserves are declared in accordance with Alcoa’s internal guidelines as administered by the Alcoa Ore
Reserves Committee (AORC). The reported ore reserves set forth in the table below are those that Alcoa estimates
could be extracted economically with current technology and in current market conditions. Alcoa does not use a price
for bauxite, alumina, or aluminum to determine its bauxite reserves. The primary criteria for determining bauxite
reserves are the feed specifications required by the customer alumina refinery. In addition to these specifications, a
number of modifying factors have been applied to differentiate bauxite reserves from other mineralized material. Alcoa
mining locations have annual in-fill drilling programs designed to progressively upgrade the reserve and resource
classification of their bauxite.
Alcoa Bauxite Interests, Share of Reserves and Annual Production1
Country Project
Owners’
Mining
Rights (%
Entitlement)
Expiration
Date of
Mining
Rights
Probable
Reserves
(million
bdmt)
Proven
Reserves
(million
(bdmt)
Available
Alumina
Content
(%)
AvAl2O3
Reactive
Silica
Content
(%)
RxSiO2
2015
Annual
Production
(million
bdmt)
Australia Darling Range
Mines ML1SA
Alcoa of Australia
Limited (AofA)2
(100%)
2024 28.5 150.0 33.0 0.9 31.7
Brazil Poços de Caldas Alcoa Alumínio
S.A. (Alumínio)3
(100%)
202040.9 1.3 39.6 4.4 0.3
Juruti4
RN101, RN102,
RN103, RN104,
#34
Alcoa World
Alumina Brasil
Ltda. (AWA
Brasil)2(100%)
210048.7 26.5 47.7 4.1 4.7
Suriname Coermotibo and
Onverdacht
Suriname
Aluminum
Company, L.L.C.
(Suralco)2(55%)
N.V. Alcoa
Minerals of
Suriname (AMS)5
(45%)
203360.0 0.0 N/A N/A 1.6
Equity interests:
Brazil Trombetas Mineração Rio do
Norte S.A. (MRN)7
(18.2%)
204643.7 10.4 49.5 4.5 3.0
Guinea Boké Compagnie des
Bauxites de
Guinée (CBG)8
(22.95%)
2038959.5 23.2 TAl2O310
48.5
TSiO210
1.7
3.4
Kingdom of
Saudi Arabia
Al Ba’itha Ma’aden Bauxite
& Alumina
Company
(25.1%)11
2037 33.8 19.3 TAA12
49.4
TSiO212
8.6
0.6
4