IPRI.TECHUHTP™

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Antamina (Compañía Minera Antamina S.A.)

NI 43-101 Technical Report on Antamina Mining Operation, Peru

Identity and ownership

Operator
Compañía Minera Antamina S.A. (Minera Antamina)highAntamina NI 43-101 (p.1-1), p.1-1 — as of 2024-12-31
Jurisdiction
Peru — San Marcos District, Huari Province, Ancash Department (~270 km north of Lima)highAntamina NI 43-101 (p.1-3), p.1-3 — as of 2024-12-31
Primary commodity
Copper and zinchighAntamina NI 43-101 (p.1-6 to 1-9), p.1-6 — as of 2024-12-31
Deposit type
Giant Cu-Zn(-Mo-Ag) skarn, zoned outward from porphyry centres (brown-garnet endoskarn through green-garnet skarn)highAntamina NI 43-101 (Section 7, p.7-1 to 7-23), p.7-1 — as of 2024-12-31
First production
2001highNS Energy — Antamina copper and zinc mine — as of 2001
Years in operation
25derived from first production year

Disclosed interests

Interest 1
BHP Group Ltd — 33.75%highAntamina NI 43-101 (p.1-1), p.1-1 — as of 2024-12-31
Interest 2
Glencore plc — 33.75%highAntamina NI 43-101 (p.1-1), p.1-1 — as of 2024-12-31
Interest 3
Teck Resources Ltd (via Teck Base Metals Ltd) — 22.50%highAntamina NI 43-101 (p.1-1), p.1-1 — as of 2024-12-31
Interest 4
Mitsubishi Corporation — 10.00%highAntamina NI 43-101 (p.1-1), p.1-1 — as of 2024-12-31

Byproduct and co-product commodities

Byproduct 1
Molybdenum, silver, lead/bismuthhighAntamina NI 43-101 (p.1-6 to 1-9), p.1-6 — as of 2024-12-31

Reported production

MetalQuantityBasisPeriodSource
Copper85900 tattributableFY2025 (year to 31 Dec 2025) (Teck 22.5% attributable share)Teck 2025 Production and Sales Updatehigh
Zinc in concentrate102300 tattributableFY2025 (year to 31 Dec 2025) (Teck 22.5% attributable share)Teck 2025 Production and Sales Updatehigh

Public technical reporting

NI 43-101 (primary)NI 43-101 Technical Report on Antamina Mining Operation, Peru, 2025, filed by Teck Resources Limited (filed on SEDAR+ 19 Feb 2025) on SEDAR+highNI 43-101 Technical Report on Antamina Mining Operation, Peru

Canada (TSX / TSX-V) · expected language: Mineral Resource / Mineral Reserve

Reported mineral resource and reserve

CategoryTonnesGradeContainedCut-offAs ofSource
Proven198 Mt (Cu; 100% basis; Zn 0.12%; Ag 8.1 g/t; Mo 0.029%)0.82 % Cu2024-12-31Antamina NI 43-101, Table 1-3, Table 1-3
Proven50 Mt (Cu-Zn; 100% basis; Zn 1.88%; Ag 18.1 g/t; Mo 0.011%)1.02 % Cu2024-12-31Antamina NI 43-101, Table 1-3, Table 1-3
Probable190 Mt (Cu; 100% basis; Zn 0.15%; Ag 9.4 g/t; Mo 0.03%)0.91 % Cu2024-12-31Antamina NI 43-101, Table 1-3, Table 1-3
Probable113 Mt (Cu-Zn; 100% basis; Zn 1.99%; Ag 19.2 g/t; Mo 0.008%)1.07 % Cu2024-12-31Antamina NI 43-101, Table 1-3, Table 1-3
Proven+Probable550 Mt (Combined; 100% basis; Zn 0.67%; Ag 11.7 g/t; Mo 0.023%)0.92 % Cu2024-12-31Antamina NI 43-101, Table 1-3, Table 1-3
Measured86 Mt (Cu; 100% basis; Zn 0.09%; Ag 6.5 g/t; Mo 0.014%; exclusive/inclusive basis per report Table 1-1)0.66 % Cu2024-12-31Antamina NI 43-101, Table 1-1, Table 1-1
Indicated150 Mt (Cu; 100% basis; Zn 0.13%; Ag 8.6 g/t; Mo 0.021%)0.78 % Cu2024-12-31Antamina NI 43-101, Table 1-1, Table 1-1
Inferred587 Mt (Cu; 100% basis; Zn 0.14%; Ag 8.3 g/t; Mo 0.024%)0.88 % Cu2024-12-31Antamina NI 43-101, Table 1-1, Table 1-1
Inferred282 Mt (Cu; 100% basis; Zn 0.2%; Ag 10.8 g/t; Mo 0.017%)1.23 % Cu2024-12-31Antamina NI 43-101, Table 1-2, Table 1-2

Figures are quoted from the filing named beside each row and are not restated, converted or aggregated here.

Processing and metallurgy

Process route
not stated
Reported recovery
92% Cu, 79% Ag, 46% Mo
Processing language used in the filing
none of that family used
Deleterious elements named
none stated

Cu geometallurgical ore: average recovery 92% Cu, 79% Ag, 46% Mo. Cu-Zn ore: 83% Cu, 84% Zn, 60% Ag. Overall Cu recovery range 73.72-93.40%, Zn 72.48-83.70%.

Antamina NI 43-101 (p.1-6 to 1-7), p.1-6
Process route
not stated
Reported recovery
Molybdenum recovery is comparatively low (~46% in Cu ore); no Mo recovery reported from Cu-Zn ore
Processing language used in the filing
none of that family used
Deleterious elements named
As, Bi

Deleterious elements bismuth and arsenic, managed by selective campaigning of geometallurgical ore types. Molybdenum recovery is comparatively low (~46% in Cu ore); no Mo recovery reported from Cu-Zn ore.

Antamina NI 43-101 (p.1-6 to 1-7), p.1-6
Process route
flotation
Reported recovery
not stated
Processing language used in the filing
none of that family used
Deleterious elements named
none stated

Processing method: SAG + ball mill comminution then flotation, producing separate Cu, Zn, Mo and Pb/Bi concentrates; Cu/Zn concentrate piped 302 km to Punta Lobitos (Huarmey). Tailings impoundment adjacent to the mill; reclaim water reused.

NS Energy — Antamina

Assessment

The 2024 NI 43-101 (effective 31 Dec 2024, filed by Teck on SEDAR+) reports 550 Mt of proven and probable reserves at 0.92% Cu, 0.67% Zn, 11.7 g/t Ag and 0.023% Mo, with plant recoveries of ~92% Cu and ~46% Mo in copper ore and ~84% Zn in copper-zinc ore. Public resource reporting characterises grade, tonnage and bulk-flotation recovery; it is not designed to resolve element deportment by mineral phase, nor where the unrecovered molybdenum, the unrecovered silver, or byproduct metals such as bismuth and selenium report across the concentrate, tailings and residue streams. Whether value resists conventional flotation or reports to tailings at a skarn of this scale is a testable question that a DETECT characterisation is built to answer. Element deportment by mineral phase is not resolved in the public reporting located, and the figures here are machine-extracted from the cited filings and not yet independently verified.

Screening signals

Each item below is something a cited source states. Nothing here asserts that unrecovered material is present.

Reported metallurgical recovery

Reported metallurgical recovery is 92% Cu, 79% Ag, 46% Mo.

92% Cu, 79% Ag, 46% Mo

Antamina NI 43-101 (p.1-6 to 1-7), p.1-6
Reported metallurgical recovery

Reported metallurgical recovery is Molybdenum recovery is comparatively low (~46% in Cu ore); no Mo recovery reported from Cu-Zn ore.

Molybdenum recovery is comparatively low (~46% in Cu ore); no Mo recovery reported from Cu-Zn ore

Antamina NI 43-101 (p.1-6 to 1-7), p.1-6
Deleterious element named

The filing names As among the deleterious elements in the feed.

As

Antamina NI 43-101 (p.1-6 to 1-7), p.1-6
Deleterious element named

The filing names Bi among the deleterious elements in the feed.

Bi

Antamina NI 43-101 (p.1-6 to 1-7), p.1-6
Byproduct without a reported grade

Molybdenum, silver, lead/bismuth is named as a byproduct or co-product commodity, and the resource statement located carries no grade or contained-metal figure for it.

Molybdenum, silver, lead/bismuth

Antamina NI 43-101 (p.1-6 to 1-9), p.1-6
Documented deposit-type association

The deposit is described as Giant Cu-Zn(-Mo-Ag) skarn, zoned outward from porphyry centres (brown-garnet endoskarn through green-garnet skarn). Porphyry systems are documented as commonly carrying molybdenum, gold, silver, rhenium and tellurium as byproduct or unrecovered constituents.

Giant Cu-Zn(-Mo-Ag) skarn, zoned outward from porphyry centres (brown-garnet endoskarn through green-garnet skarn)

Antamina NI 43-101 (Section 7, p.7-1 to 7-23), p.7-1

Open technical questions

Public resource reporting characterises grade and tonnage to a code standard. It is not designed to resolve element deportment by mineral phase. These are the questions this operation’s public reporting was not built to answer.

  1. The resource statement reports contained Copper and zinc but no deportment for the molybdenum, silver, lead/bismuth carried in the concentrate; in which mineral phase that value resides is not resolved by the assays disclosed.

    Grounded in: Molybdenum, silver, lead/bismuth is named as a byproduct or co-product commodity, with no separate grade in the located resource statement. source

  2. Reported metallurgical recovery is 92% Cu, 79% Ag, 46% Mo; where the unrecovered fraction reports across concentrate, tailings and residue is not resolved by the disclosed assays.

    Grounded in: The filing reports a metallurgical recovery of 92% Cu, 79% Ag, 46% Mo. source

  3. The filing names As, Bi among the deleterious elements in the feed; the host phase of each in feed and residue is not resolved by the disclosed assays.

    Grounded in: The filing names As, Bi as deleterious element(s). source

  4. The deposit is described as Giant Cu-Zn(-Mo-Ag) skarn; public code-compliant reporting characterises grade and tonnage to a code standard but is not designed to resolve element deportment by mineral phase in this material.

    Grounded in: The deposit type is reported as Giant Cu-Zn(-Mo-Ag) skarn, zoned outward from porphyry centres (brown-garnet endoskarn through green-garnet skarn). source

How those questions get answered

These are testable questions about element deportment by mineral phase, which code-compliant public reporting is not designed to resolve. A DETECT™ characterisation of a representative physical sample is the instrument built to answer them: it measures which phases host the value and how much is locked. It does not assume a result.

What was sought and not found

This profile is compiled from public sources, is indicative, and is not a mineral resource estimate. It is not affiliated with, endorsed by, or prepared on behalf of the named owners or operators. Figures are quoted from and linked to the filings named beside them; those filings remain the authoritative statements. Where no public source was located, that is stated rather than inferred.