Alcoa Corp

Alcoa Corporation’s principal executive office, located at 201 Isabella Street, Suite 500, Pittsburgh, Pennsylvania 15212-5858, is leased. Alcoa also leases several office facilities and sites, both domestically and internationally. In addition, Alcoa owns or has an ownership interest in its production sites, both domestically and internationally. Alcoa owns active mines and plants classified under the Alumina and Aluminum segments of its business. These include facilities and assets around the world used for Alcoa’s bauxite mining and alumina refining, aluminum smelting and casting production, and energy generation. Capacity and utilization of these facilities varies by segment and the level of demand for each product. See Part I Item 1 of this Form 10-K for additional information, including the ownership, capacity, and utilization of these facilities, used in the Alumina and Aluminum segments. A discussion of our bauxite mining properties is below.

The following map shows the locations of our operations as of December 31, 2023:

Alcoa Locations and Properties.

Although Alcoa’s facilities vary in terms of age and condition, management believes that its facilities are suitable and generally adequate to support the current and projected operations of the business. See Part II Item 8 of this Form 10-K in Notes B and K to the Consolidated Financial Statements for more information on properties, plants, and equipment.

Bauxite Mining Properties

Alcoa has access to large bauxite deposit areas with mining rights that extend, in many cases, more than 15 years from the date of this Form 10-K. The Company obtains bauxite from its own resources and from those belonging to AWAC, located in the countries listed in the table below, as well as pursuant to both long-term and short-term contracts and mining leases. Tons of bauxite are reported on a zero-moisture basis in millions of dry metric tons (mdmt) unless otherwise stated.

As of December 31, 2023, the Company’s individually material mining properties, as determined in accordance with subpart 1300 of Regulation S-K, are our bauxite mining properties in the Darling Range of Western Australia (Darling Range) and Juruti, Brazil (Juruti).

As used in this Form 10-K, the terms “mineral resource,” “measured mineral resource,” “indicated mineral resource,” “inferred mineral resource,” “mineral reserve,” “proven mineral reserve” and “probable mineral reserve” are defined and used in accordance with subpart 1300 of Regulation S-K. Under subpart 1300 of Regulation S-K, mineral resources may not be classified as “mineral reserves” unless the determination has been made by a qualified person (as defined under subpart 1300 of Regulation S-K) that the mineral resources can be the basis of an economically viable project. Part or all of the mineral deposits (including any mineral resources) in these categories may never be converted into mineral reserves. Further, except for the portion of mineral resources classified as mineral reserves, mineral resources do not have demonstrated economic value. Estimates of inferred mineral resources have too high of a degree of uncertainty as to their existence and may not be converted to a mineral reserve. Therefore, it should not be assumed that all or any part of an inferred mineral resource exists, that it can be the basis of an economically viable project, or that it will ever be upgraded to a higher category. Likewise, it should not be assumed that all or any part of measured or indicated mineral resources will ever be converted to mineral reserves. Management relies on estimates of our recoverable mineral reserves, which estimation is complex due to geological characteristics of the properties and the number of assumptions made and variable factors, some of which are beyond our control.

The following table shows the AWAC and/or Alcoa share (proportion) of annual production tonnage at each of our bauxite mining properties and in the aggregate for each of the last three fiscal years.

Summary of Attributable Annual Bauxite Production (mdmt) for the years ended December 31, 2023, 2022, and 2021, respectively:

(1)

Amounts shown for the years ended December 31, 2022 and 2021, represent production prior to the Company’s sale of its interest in the MRN mine in April 2022. Related mining operations were not material to the Company’s business or financial condition after consideration of both quantitative and qualitative factors assessed in the context of the Company’s overall business and financial condition.

The following tables summarize certain information regarding our bauxite mining properties. The information that follows relating to Darling Range and Juruti is derived, for the most part, from the technical report summaries relating to such properties prepared in compliance with Item 601(b)(96) and subpart 1300 of Regulation S-K. Portions of the following information are based on assumptions, qualifications, and procedures that are not fully described herein. Reference should be made to the full text of the Technical Report Summary for Darling Range, Western Australia, dated February 21, 2024, with an effective date of December 31, 2023, filed as Exhibit 96.1 to this Form 10-K (the Darling Range TRS), and the Technical Report Summary for Juruti, Brazil, dated February 24, 2022, with an effective date of December 31, 2021, incorporated by reference as Exhibit 96.2 to this Form 10-K (the Juruti TRS), which are incorporated by reference herein.

Bauxite Interests and Operators:

(1)

Owners’ Mining Rights reflects AWAC’s and/or Alcoa’s ownership interest(s) in the properties and related share (proportion) of the mineral resources and reserves and annual production.

(2)

For more information, see Individual Property Disclosure—Darling Range below.

(3)

For more information, see Individual Property Disclosure—Juruti below.

(4)

Brazilian mineral legislation does not limit the duration of mining concessions; rather, the concession remains in force until the deposit is exhausted. These concessions may be extended later or expire earlier than estimated, based on the rate at which these deposits are exhausted and on obtaining any additional governmental approval, as necessary.

Bauxite Mine Types and Facilities:

(1)

For more information, see Individual Property Disclosure—Darling Range Mines below.

(2)

For more information, see Individual Property Disclosure—Juruti below.

Bauxite Mineral Resources and Mineral Reserves

In accordance with subpart 1300 of Regulation S-K, management engaged SLR International Corporation as the qualified persons to prepare technical report summaries for the disclosure of mineral resources and reserves at Darling Range and Juruti. The tables shown below of resources and reserves by mining property were prepared using the results of the procedures performed by the qualified persons, which have no affiliation with or interest in Alcoa or our mining properties.

Summary of Attributable Bauxite Mineral Resources Exclusive of Mineral Reserves at December 31, 2023:

(1)

This table shows only the AWAC and/or Alcoa share (proportion) of mineral resources. The reference point for the mineral resource is the in situ predicted dry tonnage and grade of material to be delivered to the refinery stockpile following the application of mining design parameters. Metallurgical recovery factors are not applicable to the mineral resource estimate as the Darling Range operations do not include a conventional processing plant, only crushing. The metallurgical recovery of the three refineries (Kwinana, Pinjarra, and Wagerup) are beyond the boundaries of the mining operations. Certain totals may not sum due to rounding.

(2)

Alumina for the Darling Range is stated as Available Alumina (as A.Al 2 O 3) and Silica is stated as Reactive Silica (as R.SiO 2). Further, mineral resources are estimated using a reasonable market expectation of arms-length sales of bauxite from Darling Range, approximately $21 per ton. Darling Range mineral resources are estimated at a ≥ 27.5% A.Al 2 O 3 and ≤3.5% R.SiO 2 cut-off grade and at a minimum mining thickness of 1.5 m.

(3)

Alumina for Juruti is stated as Available Alumina (as A.Al 2 O 3) and Silica is stated as Reactive Silica (as R.SiO 2). Juruti mineral resources are estimated at a pit discard cut-off value based on a benefit calculation that determines whether a block is economically viable and has a minimum thickness of 1 meter (m). Further, mineral resources are estimated using a long-term bauxite price of approximately $35 (wet-base) per ton, representing a 30% increase over the mineral reserve bauxite price.

(4)

Alumina for Poços de Caldas is stated as Available Alumina (as A.Al 2 O 3) and Silica is stated as Reactive Silica (as R.SiO 2). Poços de Caldas mineral resources are estimated at a pit discard cut-off value based on a benefit calculation that determines whether a block is economically viable.

(5)

Alumina for Boké is stated as Total Alumina (as T.Al 2 O 3) and Silica is stated as Total Silica (as T.SiO 2). Boké resources are estimated at a ≥ 41% T.Al 2 O 3 and ≤10% T.SiO 2 cut-off grade. Tonnage reported on a 3% moisture basis.

(6)

Alumina for Al Ba’itha is stated as Total Available Alumina (as TAA) and Silica is stated as Total Silica (as T.SiO 2). Al Ba’itha mineral resources are estimated at a ≥ 40% TAA cut-off grade and a minimum mining thickness of 1.0 m.

The following table shows only the AWAC and/or Alcoa share (proportion) of mineral reserves. These estimates are periodically updated to reflect past bauxite production, updated mine plans, new exploration information, and other geologic or mining data. Given the Company’s extensive bauxite resources, the abundant supply of bauxite globally, and the length of the Company’s rights to bauxite, it is not cost-effective to establish bauxite reserves that reflect the total size of the bauxite resources available to the Company. Certain totals may not sum due to rounding.

Summary of Attributable Bauxite Mineral Reserves at December 31, 2023:

(1)

This table shows only the AWAC and/or Alcoa share (proportion) of mineral reserves. The reference point for the mineral reserve is the refinery processing plant gate, with crushing, washing (as applicable), and transportation being the only process employed. Metallurgical recovery factors are not applicable to the mineral reserve estimate as the Darling Range operations do not include a conventional processing plant, only crushing. The metallurgical recovery of the three refineries (Kwinana, Pinjarra, and Wagerup) are beyond the boundaries of the mining operations. Certain totals may not sum due to rounding.

(2)

Alumina for the Darling Range is stated as Available Alumina (as A.Al 2 O 3) and Silica is stated as Reactive Silica (as R.SiO 2). Darling Range mineral reserves are estimated at variable cut-off grades, dependent on operating costs and ore quality for blending to meet refinery target grades. Mineral reserves are estimated using a reasonable market expectation of arms-length sales of bauxite from Darling Range, approximately $21 per ton.

(3)

Alumina for Juruti is stated as Available Alumina (as A.Al 2 O 3) and Silica is stated as Reactive Silica (as R.SiO 2). Juruti mineral reserves are estimated at a pit discard cut-off value based on a benefit calculation that determines whether a block is economically viable. Further, mineral reserves are estimated using a one-year weighted average bauxite price of approximately $27 per ton, based on contractual agreements with an Alumina segment refinery.

(4)

Alumina for Poços de Caldas is stated as Available Alumina (as A.Al 2 O 3) and Silica is stated as Reactive Silica (as R.SiO 2). Poços de Caldas mineral reserves are estimated at a pit discard cut-off value based on a benefit calculation that determines whether a block is economically viable.

(5)

Alumina for Boké is stated as Total Alumina (as T.Al 2 O 3) and Silica is stated as Total Silica (as T.SiO 2). Boké reserves are estimated at a ≥ 45% T.Al 2 O 3 and ≤10% T.SiO 2 cut-off grade. Tonnage reported on a 3% moisture basis.

(6)

Alumina for Al Ba’itha is stated as Total Available Alumina (as TAA) and Silica is stated as Total Silica (as T.SiO 2). Al Ba’itha mineral reserves are estimated at a ≥ 40% TAA cut-off grade.

Individual Property Disclosure—Darling Range

Property Location and Description

The Darling Range bauxite deposits comprise the mining centers of (i) Huntly, located approximately 80 kilometers (km) to the southeast of Perth and 30 km northeast of Pinjarra, Western Australia, Australia, and (ii) Willowdale, located approximately 100 km south-southeast of Perth and 20 km southeast of Waroona, Western Australia, Australia. The Huntly and Willowdale mining centers/regions are separate open pit, surface mines and are both located within Mining Lease ML1SA. Darling Range is owned and operated by Alcoa through AofA.

All spatial data used for mineral resource and reserve estimation are reported using a local grid based on Australian Map Grid 1984 system (Zone 50) and using the Australian Geodetic Datum 1984 coordinate set. The approximate coordinates of the mining areas are 410,000 m East and 6,390,000 m North (Huntly) and 410,000 m East and 6,365,000 m North (Willowdale).

Darling Range Location, Lease Area, Mining Centers, and Mining Regions

Refer to the Darling Range TRS in Sections 2.0 through 5.0 for more information on the Darling Range mining centers – their history, location, accessibility, and other relevant details.

Infrastructure

The figure above illustrates the relative location of each of the individual mining areas within the Huntly and Willowdale centers. These areas include, but are not limited to, Myara, Larego, Orion, and Arundel.

Mining infrastructure in the Darling Range is generally concentrated in the Myara area in the northwest of the Huntly mining center, and at the Larego area (20 km southeast of the Wagerup refinery) in the center of the Willowdale mining center. Both infrastructure areas include:

•

Ore crushing and handling facilities;

•

Ore stockpile stacker/reclaimer;

•

Maintenance facilities;

•

Sampling stations;

•

Site offices including a production tracking room;

•

Haul road networks;

•

Overland conveyors, as illustrated on the above map;

•

Water supplies consisting of abstraction from licensed surface water sources supplemented with treated wastewater from vehicle washdowns, stormwater runoff, and maintenance workshops; and,

•

Power supply lines direct from certain of the Company’s refineries.

Personnel are sourced from the area around Perth, Western Australia, which benefits from a skilled workforce due to the relatively large number of operating mines in the region.

Huntly is accessible from the South Western Highway via Del Park Road, which connects the town of North Dandalup in the north with Dwellingup in the south. From Del Park Road, a 3 km road following the route of the bauxite conveyor to the Pinjarra refinery provides access to the Huntly site administration offices. Willowdale is similarly accessible, 19 km from the South Western Highway via Willowdale Road, a road to the south of Waroona. There are several airstrips in the region, although the closest major airport is in Perth, approximately 70 km north of North Dandalup. The nearest commercial port is at the Kwinana refinery, approximately 40 km south of Perth.

While an extensive haul road network and overland conveyors transport crushed bauxite from the main mining hub to the Wagerup and Pinjarra refineries, bauxite is also transferred to the Kwinana refinery via the Kwinana freight railway system, using the Kwinana–Mundijong line.

Alcoa’s Darling Range mining operations do not produce mine waste in the same manner as conventional mining operations and waste dumps are not constructed.

Alcoa’s Darling Range facilities are in a well-maintained condition. Net book value of these facilities as of December 31, 2023 of $517 is included in Properties, plants, and equipment, net on the Consolidated Balance Sheet.

Refer to the Darling Range TRS in Sections 14.0 and 15.0 for more information on the surface infrastructure and facilities of the Darling Range.

Land Tenure and Permitting

Bauxite occurrences were first recorded in the Darling Range in 1902, with studies and exploration subsequently conducted by the Geological Survey of Western Australia until the 1950s. Commercial exploration took place from 1957 by Western Mining Corporation Ltd (later Western Australia NL, or WANL), across a large portion of southwest Western Australia within a Special Mineral Lease (ML1SA) granted in 1961. Commercial mining first took place within the Darling Range in 1963 at the former Jarrahdale mining center with WANL having joined with Alcoa. The Huntly and Willowdale mines commenced commercial production in 1972 and 1984, respectively. Huntly currently supplies bauxite to the Kwinana and Pinjarra refineries (approximately 25 Mtpa), while Willowdale supplies the Wagerup refinery (approximately 10 Mtpa).

The ML1SA lease allows for exploration and mining of bauxite within the tenement boundaries. ML1SA was granted in 1961, by the State Government of Western Australia under the Alumina Refinery Agreement Act, 1961 (the Act 1961), for four 21-year periods, and the current lease expires on September 24, 2045. The State Government concession agreement includes the provision for conditional renewal beyond 2045. Alcoa pays rent for each square mile of ML1SA in accordance with the Act 1961, providing exclusive rights to explore for and mine bauxite on all Crown Land within the ML1SA. The current lease covers an area of 702,261 hectares (ha).

There are certain annual requirements to maintain the existing permits and approvals associated with ML1SA, including:

•

Submission of annual mine plans for mining associated with the Wagerup refinery;

•

Maintain public Completion Criteria documentation for its bauxite mining operations;

•

Annual submission and approval of Mining and Management Programs (MMPs) that include five-year mining schedules;

•

Annual reporting of bauxite processed and any non-compliances to maintain environmental operational licenses; and,

•

Maintain compliance with environmental protection orders.

The ML1SA area includes sub-lease arrangements made between Alcoa and the Worsley Alumina joint venture participants (the Worsley Participants). The agreements, made in August 2001 and September 2016, provide bauxite mining concessions to the Worsley Participants. No mineral resources or mineral reserves attributable to the Darling Range mining areas have been declared within these sub-lease areas.

Constraints on mining activities within the ML1SA concession are in place, among others, which prevent mining within: 200 m of the top water level margin of any water reservoirs; Serpentine Pipehead Dam Catchment; 10 m of a Black Cockatoo nesting tree or Black Cockatoo significant tree; National Parks; Aboriginal Heritage Sites; Old Growth Forest; formal Conservation Areas; and 50 m of granite outcrop (greater than 1 ha), and Mining Avoidance Zones (MAZ) around the Western Australian forest towns of Dwellingup and Jarrahdale. Mineral resources and mineral reserves have not been defined in these restricted areas.

Additionally, the 2023-2027 MMP requires additional constraints including: a reduction in mining activities inside higher risk areas within drinking water catchments; no new pit clearing in areas with an average pit slope greater than 16 percent within any Reservoir Protection Zone (RPZ, 2 km from reservoir top water level); an acceleration of forest rehabilitation and a reduction in open mining areas; and a maximum annual clearing footprint of 800 ha.

Mining on a day-only basis is conducted in “noise zones” where noise from the mining operations will potentially exceed allowable levels. The operation actively seeks to maintain lower noise levels than those mandated, thus mining in these areas is undertaken by contract miners on day shifts only.

The Company has all environmental permits and operating licenses required for current mining activities. Outcomes of and compliance with the management and monitoring programs are tracked within Alcoa’s Environmental Management System and reported within the Annual Environmental Review report.

Refer to the Darling Range TRS in Section 3.0 for more information on Land Permitting and Tenure for the Darling Range.

Geology and Exploration

The Darling Range comprises a low incised plateau formed by uplift along the north-south trending Darling Fault, a major structural lineament that extends for over 250 km, from Bindoon in the north to Collie in the south. Bauxite deposits have been identified throughout the Darling Range and generally occur as erratically distributed alumina-rich lenses. Lateralization and subsequent periodic activity of the Darling Fault has resulted in the current landform of scarps and deeply incised valleys on the western edge of the Darling Range.

Systematic exploration for bauxite within the region commenced in the 1960s and is currently conducted on a continuous basis to maintain sufficient mineral resources and mineral reserves to meet refinery supply. Current mine plans include further exploration throughout all areas where Alcoa has mining permits to sustain future production.

Refer to the Darling Range TRS in Sections 6.0 through 11.0 for more information on the geology, mineralization, and exploration history of the Darling Range, including Quality Assurance / Quality Control (QA/QC) procedures and data used in the current mineral resource estimate.

Mining and Processing

The Huntly and Willowdale mines employ conventional open pit surface mining practices and equipment. Following definition of mineral reserve blocks, vegetation is cleared after which Alcoa operations commence stripping topsoil and secondary overburden removal using small excavators, scrapers, and trucks. Soil is stockpiled at the site, away from the proposed pit, for rehabilitation purposes. After completion of mining, overburden is progressively backfilled into adjacent exhausted pits, topsoiled, and rehabilitated by re-establishment of native vegetation, creating a stable post-mining landform that replicates the pre-existing environment.

The process plant for the Darling Range operations consists of two separate crushing facilities at the Huntly and Willowdale mines, respectively. Both facilities crush the ROM ore and convey the crushed ore to three separate refineries located at Pinjarra, Kwinana, and Wagerup. The Pinjarra refinery is located adjacent to the east of the town of Pinjarra and is approximately 30 km southwest of the Huntly mining areas. The Kwinana refinery, also supplied by Huntly, is approximately 50 km northwest of Huntly in the city of Kwinana, approximately 40 km south of Perth. The Wagerup refinery, supplied by Willowdale, is located immediately adjacent to the east of the South Western Highway, approximately 8 km south of Waroona and 20 km west of the Willowdale mining area.

The process plant is a dry crushing operation and therefore water is not required as a consumable for the plant. Alcoa’s Darling Range mining operations do not produce mine waste in the same manner as conventional mining operations and waste dumps are not constructed.

Refer to the Darling Range TRS in Sections 12.0 and 13.0 for a detailed description of the mineral reserves and mining methods used in the Darling Range.

Environmental and Social

Alcoa’s mine sites are monitored in accordance with the conditions of Government authorizations and its operational licenses at Huntly and Willowdale. Outcomes of and compliance with the management and monitoring programs are tracked within Alcoa’s Environmental Management System and reported within a Triennial Environmental Review report.

Alcoa works proactively with key regulatory agencies to address operational incidents and implement operational improvements to reduce releases to the environment.

In December 2023, the Western Australian government granted a section 6 exemption under the Environmental Protection Act 1986 that allows Alcoa to continue its mining operations while the WA Environmental Protection Authority (EPA) assesses the environmental impact of parts of the MMP, following a third party’s referral of the Company’s future and existing mine plans in existing mine regions to the WA EPA in the first quarter of 2023. Compliance against the section 6 exemption is monitored on a weekly basis by an independent compliance monitor and reported monthly to the Department of Water and Environmental Regulation. At the request of the Western Australian government, the Company has committed to provide a bank guarantee for approximately $68 (A$100) demonstrating Alcoa’s confidence that its operations will not impair drinking water supplies.

Alcoa is modernizing its environmental approvals framework for the Huntly bauxite mine and referred future mining plans to access Myara North and Holyoake to the WA EPA for assessment in 2020.

Refer to the Darling Range TRS in Section 17.0 for more information on the environmental, social, compliance, and permitting aspects of the Darling Range.

Mineral Resources and Mineral Reserves

In January 2024, Alcoa announced the full curtailment of the Kwinana refinery beginning in the second quarter of 2024. Current mine plans do not accommodate this curtailment but will be amended to include a staged reduction of supply to the refinery through the third quarter of 2024.

For information on Darling Range mineral resources and mineral reserves, refer to the tables above. For comparative purposes, measured and indicated mineral resources were 198.4 mdmt and 96.7 mdmt as of December 31, 2023 and 2022, respectively, representing an increase of 105 percent. Inferred mineral resources were 106.9 mdmt and 140.3 mdmt as of December 31, 2023 and 2022, respectively, representing a decrease of 24 percent. Probable reserves were 296.0 mdmt and 255.8 mdmt as of December 31, 2023 and 2022, respectively, representing an increase of 16 percent, and proven reserves were 48.0 mdmt and 145.8 mdmt as of December 31, 2023 and 2022, respectively, representing a decrease of 67 percent.

The increase in measured and indicated mineral resources from December 31, 2022 to December 31, 2023 is primarily attributable to the addition of lower grade material in Larego and Myara, exploration activities and changes in mine scheduling. The decrease in inferred mineral resources from December 31, 2022 to December 31, 2023 is attributable to Alcoa’s commitments to refrain from mining in areas within the MAZ around Dwellingup. The mineral reserves decrease from December 31, 2022 to December 31, 2023 is attributable to mining depletion in 2023, changes in mine scheduling, the depletion of ore in higher risk areas within drinking water catchments and Reservoir Protection Zones in Myara, and adjustment of the cut-off grades in Myara and parts of Larego.

Additionally, refer to the Darling Range TRS Section 17.1 for more information on the mineral resources and mineral reserves of the Darling Range mines.

Individual Property Disclosure—Juruti

Property Location and Description

The Juruti bauxite mine is located in the west of Para State in northern Brazil. The mine is approximately 55 km south from the town of Juruti on the southern shore of the Amazon River. The mine is owned and operated by Alcoa through AWAB. The Juruti bauxite mine represents an established mining operation which commenced commercial production of bauxite in 2009.

All spatial data used for the mineral resource and mineral reserve estimation are reported using a local grid based on SIRGAS 2000 (21S). The approximate coordinates of the mining area for the Capiranga Central, Mauari, São Francisco, Mutum and Santarém plateaus are 618,879 m East and 9,721,768 m North, and for the Nhamundá plateau are 521,657 m East and 9,773,299 m North.

Juruti Location and Bauxite Mine Permit Areas

Refer to the Juruti TRS in Sections 2.0 through 5.0 for more information on the Juruti mine – history, location, accessibility, and other relevant details.

Infrastructure

Infrastructure required for bauxite mining operations is well-established and available, the majority of which is located within the area of the Juruti bauxite mine. The required infrastructure includes the following:

•

Rail siding and loading equipment;

•

Bauxite beneficiation plant for ore crushing and washing;

•

Mine waste facilities including tailings thickening lagoons and tailings disposal ponds;

•

ROM and product stockpiles and materials handling conveyors;

•

Ancillary buildings (offices, warehouses, laboratory, workshops);

•

Fuel station;

•

Water supply intake raft, pumps, and approximate 9 km pipeline from the Juruti Grande stream;

•

Power generation via thermoelectric units at the mine and port;

•

Surface water management including drainage channels and pumps;

•

Off-site rail corridor between the mine and port; and,

•

Port facilities including rail siding, material handling equipment, ship loader.

The Juruti mining area is connected to Juruti town and port facilities by a road that joins to the PA-257 road near the town, and a dedicated railway between the mining area and port. There are very few major roads across the region and the only major road in this area is the PA-257.

The nearest major city to Juruti is Santarem, approximately 160 km to the east and is only accessible by boat or by air from Juruti Airport (JRT) to Santarem-Maestro Wilson Fonseca Airport (STM). National roads connect Santarem to wider Para State including the port city of Belem on Brazil’s northern coast, approximately 1,300 km by road via the 230 and PA-151 roads.

Juruti began production in 2009 and the facilities are in a well-maintained condition. Net book value of these facilities as of December 31, 2023 of $512 is included in Properties, plants, and equipment, net on the Consolidated Balance Sheet.

Refer to the Juruti TRS in Sections 14.0 and 15.0 for more information on the surface infrastructure and facilities of the Juruti mine.

Land Tenure and Permitting

All exploration and mining activities are managed by the National Mining Agency, Agencia Nacional de Mineracao (ANM), under the Mining Code (1967). Permits are granted by the ANM and fall into two categories:

•

Exploration Permits: granted to support ongoing exploration activities. On submittal of an approved Exploration Report, the holder is then granted one year to present a Mining Plan as a precursor to obtaining a Mining Concession. Exploration Permits require:

o

Initial application fee and submission by a registered professional geologist or mining engineer;

o

Annual fee payment to the ANM;

o

Declaration of exploration expenditures on an annual basis; and,

o

Survey visit fee payment to the ANM.

•

Mining Concession: following a successful Mining Plan submission, enabling exploitation once Environmental Licenses are granted. Concession holders are required to:

o

Commence mining activities within 6 months of being granted;

o

Submit annual reports on all mining / processing activities (Relatorio Annual de Lavra, or RAL) to the ANM;

o

Make compensation payments to landowners in line with the agreements made for mining easement; and,

o

Make Brazilian Mineral Royalty payments (Compensacao Financeira pela Exploracao de Recursos Minerais, or CFEM).

At Juruti there are three continuous mining concessions for an aggregated 29,410 ha, where current mineral reserves are determined. Brazilian mineral legislation does not limit the duration of mining concessions and instead the concession remains in force until the deposit is exhausted. These concessions may be extended later or expire earlier than estimated, based on the rate at which the deposits are exhausted and on obtaining any additional governmental approval, as necessary, such as operational licenses and environmental approvals.

In addition to the mining rights, there are thirteen requests for mining concessions, fourteen exploration permits, and two requests for exploration permits. The aggregated area for these permits is 197,866 ha.

The mining operations at Juruti take place on third-party land and, in accordance with the Mining Concession requirements, Alcoa currently has agreements in place with respective landowners. Agreements form a “mining easement,” which grants Alcoa access to the mining areas in exchange for compensation payments. As a result, there are no other titles, claims, leases, or options applicable to the exploration or mining permit areas which may limit Alcoa’s rights. Similarly, there are no liens or encumbrances.

The Company has all environmental permits and operating licenses required for current mining activities; there are no liens or encumbrances.

Refer to the Juruti TRS in Sections 3.0 and 17.0 for more information on Land Permitting and Tenure for the Juruti mine.

Geology and Exploration

The bauxite deposit of the Juruti bauxite mine consist of several lateritic bauxite plateaus which exist over a large lateral extent (several km) in comparison to the total thickness of the deposit (typically up to 20 m below surface).

Systematic exploration for bauxite within the region has persisted since Alcoa’s ownership and is currently conducted on a continuous basis to establish optimal mine plans to achieve a uniform quality of bauxite production. Current mine plans include further exploration throughout all areas where Alcoa has mining permits to sustain future production.

Refer to the Juruti TRS in Sections 6.0 through 11.0 for more information on the geology, mineralization, and exploration history of the Juruti mine, including QA/QC procedures and data used in the current mineral resource estimate.

Mining and Processing

Juruti is an active mining operation using surface strip mining methods over a total of eight plateaus whereby land clearance, topsoil removal, and overburden stripping is followed by bauxite deposit excavation and stockpiling. Waste is subsequently backfilled, and overburden and topsoil are re-instated for surface rehabilitation.

Juruti produces both a washed and unwashed bauxite product; however, all tonnage is presented on a zero-moisture basis. Bauxite processing takes place at a dedicated plant facility located at the Juruti mine site which has been operating since 2009 and comprises a simple comminution (crushing, screening) and washing circuit designed to remove fine particles from the ore.

Fine materials removed from ore are deposited in a thickening pond for settling and water reclamation, after which solid tailings are discarded into separate tailings ponds. There is currently one thickening pond and seven disposal ponds.

Refer to the Juruti TRS in Sections 12.0 and 13.0 for a detailed description of the mineral reserves and mining methods used in the Juruti mine.

Environmental and Social

Alcoa submits an Annual Environmental Report in compliance with the Juruti operating licenses and approvals. This report includes detailed descriptions of activities undertaken for the year and environmental and social monitoring. No significant compliance issues were identified in the 2021/2022 and 2022/2023 Annual Environmental Reports, although certain environmental incidents were recorded in December 2020 and February 2021 which involved siltation of downstream watercourses following extreme rainfall events. In addition, during 2023, Alcoa reported to the state environmental agency that the volume of ore shipped from the port exceeded the permitted volume at times over the last three years. This issue was resolved in January 2024 when the agency amended the operating permit for the port to allow up to 12 Mtpa of ore to be shipped.

Additionally, Alcoa works proactively with key regulatory agencies to address operational non-compliances and implement operational improvements to reduce releases to the environment. None of the reportable non-compliances represent a risk that could adversely affect its license to operate.

Refer to the Juruti TRS in Section 17.0 for more information on the environmental, social, compliance, and permitting aspects of the Juruti mine.

Mineral Resources and Mineral Reserves

For information on Juruti mineral resources and mineral reserves, refer to the tables above. For comparative purposes, measured and indicated mineral resources of 64.2 mdmt did not change from 2022. Inferred mineral resources were 563.6 mdmt and 563.7 mdmt as of December 31,2023 and 2022, respectively, representing a marginal decrease of 0.1 percent. Proven reserves were 46.2 mdmt and 48.6 mdmt as of December 31,2023 and 2022, respectively, representing a decrease of 5 percent. Probable reserves were 34.7 mdmt and 36.8 mdmt as of December 31,2023 and 2022, respectively, representing a decrease of 6 percent.

Mineral resources were consistent with 2022. The decrease in mineral reserves from December 31, 2022 reflects mining depletion during 2023. Refer to the Juruti TRS for more information on the mineral resources and mineral reserves of the Juruti mine.

Internal Controls

Alcoa has a long history of mining bauxite, with the majority of bauxite production having been used to supply Alcoa refineries.

Internal controls used by the Company are informed by internal reviews, representation on Technical Committees of Joint Venture operations, and by reviews, audits, and studies performed by third-party mining consultants. The controls include: surveying of drillhole collar locations, drill sample logging, collection and security, database verification and security, QA/QC programs, internal and third-party qualified person statistical analysis, internal and third-party qualified person model validation, and reconciliation. Modelling and analysis of the Company’s resources is completed internally and reviewed by a qualified person, with the exception of Al Ba’itha where modelling and analysis is completed by a third-party consultant.

As the ore bodies are shallow and generally horizontal, two-dimensional seam modelling has been the standard practice; however, many operations are implementing more conventional 3D block modelling using geostatistical interpolation methods. Mineral resource estimation is validated internally through visual comparison of drillholes and model blocks as well as through the use of swath plots and statistical distributions. Mineral resource estimation is reviewed and adopted by a qualified person. Mineral reserve estimation is completed internally and reviewed by a qualified person, with the exception of Boké and Al Ba’itha where reserve estimation is completed by a third-party consultant.

Labelled samples from the drill site are securely transported for logging or temporary storage by the drilling contractor or Alcoa personnel. Additional transport to internal or external laboratories is controlled and completed, as necessary, by Alcoa personnel or by courier.

Drillhole databases are all site specific; most sites use industry standard drillhole database software, applications, and processes with security and backup protocols in place. Prior to modelling, secondary validation and cleansing of the modelling datasets is performed. Wherever possible, data collection is digital to allow direct loading into the database.

The Company has well-established QA/QC programs that are site specific. Although some programs are limited to laboratory protocols only covering analysis of duplicate pulps and standards, others involve, to varying degrees, the range of activities from twin hole drilling and collection of field duplicates, submission of blind duplicates and standards and submission of duplicate samples to umpire laboratories. Regardless of the level of QA/QC, all sites have well established and documented sampling and analysis regimes. QA/QC practices and available data are reviewed by a qualified person.

As discussed above, management relies on estimates for our mineral reserves and these estimates could change due to a number of factors, including future changes in: permitting requirements, geological conditions, ongoing mine planning, macroeconomic and industry conditions, and regulatory disclosure requirements. See Part I Item 1A of this Form 10-K for more information on risks.