Company: CENX
Filing Date: 2025-03-03
Form Type: 10-K
Source: 0000949157-25-000024
Chunk: 64

Company: CENTURY ALUMINUM CO
Filing Date: 2025-03-03
Form: 10-K
Item: Item 2
Chunk 64
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 2024 of $190.7 million is included in Property, plant and equipment, net on the Consolidated Balance Sheets. Jamalco has prepared capital projects to increase the proportion SML 169 bauxite to 55 % of the refinery feed. An overall capital investment of $70.5 million has been estimated to cover mine development and installation of the necessary equipment from 2025 to 2027.

Refer to the Jamalco TRS in Section 5 for more information on the property history and condition.

Mining Method and Processing Operations

Jamalco’s resources are based on exploration done by Jamaican Bauxite Institute (“JBI”). For an accessible deposit and planning production drilling, ArcGIS software is used to produce a background image showing the created grid, JBI grid and JBI drill holes, which is then uploaded to GPS receivers. This is utilized in the field by the drillers to peg production drillholes. Additionally, a 3-D outline is generated within the orebody outline. This process is also completed in AutoCAD, where both exploration and production drillhole coordinates are used to generate a surface from which the 3-D outline is produced.

Once the production drilling is completed with assays, AutoCAD plans are prepared with grades and thicknesses that are passed on to the mine operators. Production drilling is essentially quality control in-fill drilling. Parcel maps are created for the production crew, showing color-coded grade information which enables selection of mining for stockpiling.

Once mined, Jamalco utilizes the Bayer Process to extract alumina from bauxite. The processing plant is a fixed plan for ore crushing and washing.

Refer to the Jamalco TRS in Sections 12 and 14 for more information on the mining method and processing operations.

Bauxite Mineral Resources

The tables shown below of resources were prepared using the results of the procedures performed by Aluminpro. As stated above, Jamalco has no reportable mineral reserves.

Summary of Attributable Bauxite Mineral Resources Exclusive of Mineral Reserves at December 31, 2024: 

(tonnes shown in millions)Tonnes(1)AvAl2O3(2) (%)ReSiO2(3) (%)P2O5(4) (%)Measured mineral resources— — %— %— %Indicated mineral resources27.0 38.22 %3.03 %1.06 %Measured + Indicated mineral resources27.0 38.22 %3.03