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SEC Technical Report Summary

Mineral Resources

San Martín

Zacatecas, México

Effective Date: December 31, 2021

Report Date: February 25, 2022

Report Prepared for

Southern Copper Corporation

1440 East Missouri Avenue

Suite 160

Phoenix, Arizona 85014

Report Prepared by

SRK Consulting (U.S.), Inc.

1125 Seventeenth Street, Suite 600

Denver, CO 80202

SRK Project Number: 569000.020-USPR00783

Firmado Digitalmente por:

ALVARO BURGA VELASCO

Fecha: 08/03/2022 05:01:27 p.m.

SRK Consulting (U.S.), Inc.
SEC Technical Report Summary - San Martín	Page ii

Table of Contents

1	Executive Summary.....................................................................................................	1
	1.1	Property Description (Including Mineral Rights) and Ownership ........................................................	1
	1.2	Geology and Mineralization ................................................................................................................	1
	1.3	Status of Exploration, Development and Operations..........................................................................	1
	1.4	Mineral Resource Estimates ...............................................................................................................	2
	1.5	Conclusions and Recommendations ..................................................................................................	4
		Property Description and Ownership ......................................................................................	4
		Geology and Mineralization.....................................................................................................	4
		Mineral Resource and Mineral Reserve Estimates.................................................................	4
		Recommendations ..................................................................................................................	5
2	Introduction ..................................................................................................................	6
	2.1	Registrant for Whom the Technical Report Summary was Prepared.................................................	6
	2.2	Terms of Reference and Purpose of the Report.................................................................................	6
	2.3	Sources of Information........................................................................................................................	6
	2.4	Details of Inspection............................................................................................................................	7
	2.5	Qualified Person..................................................................................................................................	7
	2.6	Report Version Update .......................................................................................................................	7
3	Property Description....................................................................................................	8
	3.1	Property Location ................................................................................................................................	8
	3.2	Mineral Title, Claim, Mineral Right, Lease or Option Disclosure ........................................................	9
	3.3	Mineral Rights Description and How They Were Obtained ..............................................................	13
	3.4	Encumbrances ..................................................................................................................................	15
	3.5	Other Significant Factors and Risks..................................................................................................	15
	3.6	Royalties or Similar Interest ..............................................................................................................	15
4 Accessibility, Climate, Local Resources, Infrastructure and Physiography ........	16
	4.1	Topography, Elevation and Vegetation.............................................................................................	16
	4.2	Means of Access...............................................................................................................................	17
	4.3	Climate and Length of Operating Season.........................................................................................	18
	4.4	Infrastructure Availability and Sources..............................................................................................	19
		Water .....................................................................................................................................	19
		Electricity ...............................................................................................................................	19
		Personnel ..............................................................................................................................	19
		Supplies.................................................................................................................................	19
		Plant/Tailings.........................................................................................................................	19
5	History.........................................................................................................................	21

SanMartin_SEC_Report_569000-020-USPR000783_Rev05.docx

February 2022

SRK Consulting (U.S.), Inc.
SEC Technical Report Summary - San Martín	Page iii
5.1	Previous Operations..........................................................................................................................	21
5.2	Exploration and Development of Previous Owners or Operators.....................................................	24
6 Geological Setting, Mineralization, and Deposit .....................................................	25
6.1	Regional, Local and Property Geology .............................................................................................	25
	Regional Geology..................................................................................................................	25
	Local Geology .......................................................................................................................	27
	Property Geology ..................................................................................................................	30
6.2	Mineralization ....................................................................................................................................	35
	Mineralization and alteration .................................................................................................	35
	Structural Controls on Mineralization ....................................................................................	36
6.3	Mineral Deposit .................................................................................................................................	38
7 Exploration .................................................................................................................	40
7.1	Exploration Work (Other Than Drilling) .............................................................................................	40
	Procedures and Parameters Relating to the Surveys and Investigations.............................	40
	Sampling Methods and Sample Quality ................................................................................	42
	Information About the Area Covered.....................................................................................	45
	Significant Results and Interpretation ...................................................................................	45
7.2	Exploration Drilling ............................................................................................................................	46
	Drilling Type and Extent ........................................................................................................	46
	Drilling, Sampling, or Recovery Factors................................................................................	48
	Drilling Results and Interpretation .........................................................................................	54
7.3	Hydrogeology ....................................................................................................................................	57
7.4	Geotechnical Data, Testing and Analysis .........................................................................................	57
7.5	Property Plan View............................................................................................................................	62
7.6	Exploration Target.............................................................................................................................	62
8 Sample Preparation, Analysis and Security ............................................................	63
8.1	Sample Preparation Methods and Quality Control Measures ..........................................................	63
8.2	Sample Preparation, Assaying and Analytical Procedures...............................................................	63
	Density Analysis ....................................................................................................................	63
	Sample Preparation - Internal Laboratory ............................................................................	64
	Chemical Analysis - Internal Laboratory...............................................................................	66
	Sample Preparation - SGS Lab............................................................................................	66
	Chemical Analysis - SGS Lab ...............................................................................................	66
8.3	Quality Control Procedures/Quality Assurance ................................................................................	67
	Security Measures - Chain of Custody.................................................................................	67
	Mine Geology Department ....................................................................................................	68
	Exploration Department.........................................................................................................	68

SanMartin_SEC_Report_569000-020-USPR000783_Rev05.docx

February 2022

SRK Consulting (U.S.), Inc.
SEC Technical Report Summary - San Martín	Page iv
	8.4	Opinion on Adequacy........................................................................................................................	73
	8.5	Non-Conventional Industry Practice .................................................................................................	74
9	Data Verification.........................................................................................................	75
	9.1	Data Verification Procedures ............................................................................................................	75
		Results of the Validation Samples ........................................................................................	75
	9.2	Limitations .........................................................................................................................................	78
	9.3	Opinion on Data Adequacy ...............................................................................................................	79
10	Mineral Processing and Metallurgical Testing ........................................................	80
	10.1	Testing and Procedures....................................................................................................................	80
	10.2	Sample Representativeness .............................................................................................................	80
	10.3	Laboratories ......................................................................................................................................	81
	10.4	Relevant Results ...............................................................................................................................	81
	10.5	Adequacy of Data and Non-Conventional Industry Practice ............................................................	84
11	Mineral Resource Estimates .....................................................................................	85
	11.1	Key Assumptions, Parameters, and Methods Used .........................................................................	85
		Mineral Titles and Surface Rights .........................................................................................	85
		Database ...............................................................................................................................	85
	11.2	Geological Model ..............................................................................................................................	85
	11.3	Mineral Resources Estimates ...........................................................................................................	87
		Data Compilation and Verification.........................................................................................	87
		Calculation of Weighted Averages Grades and Volume Calculation....................................	92
		Capping .................................................................................................................................	93
		Density...................................................................................................................................	93
		Documentation ......................................................................................................................	94
		Depletion ...............................................................................................................................	95
	11.4	Resource Classification and Criteria.................................................................................................	96
		Measured Resources ............................................................................................................	96
		Indicated Resources..............................................................................................................	96
		Inferred Resources................................................................................................................	96
	11.5	Uncertainty ........................................................................................................................................	99
	11.6	Cut-Off Grades Estimates...............................................................................................................	101
	11.7	Summary Mineral Resources..........................................................................................................	103
	11.8	Opinion on Influence for Economic Extraction................................................................................	105
12	Mineral Reserve Estimates......................................................................................	106
13	Mining Methods........................................................................................................	107
14	Processing and Recovery Methods .......................................................................	108

SanMartin_SEC_Report_569000-020-USPR000783_Rev05.docx

February 2022

SRK Consulting (U.S.), Inc.
SEC Technical Report Summary - San Martín	Page v
15	Infrastructure............................................................................................................	109
16	Market Studies .........................................................................................................	110
17	Environmental Studies, Permitting, and Plans, Negotiations, or Agreements with
	Local Individuals or Groups....................................................................................	111
18	Capital and Operating Costs...................................................................................	112
19	Economic Analysis ..................................................................................................	113
20	Adjacent Properties .................................................................................................	114
21	Other Relevant Data and Information.....................................................................	115
22	Interpretation and Conclusions ..............................................................................	116
	22.1	Geology and Mineralization ............................................................................................................	116
	22.2	Mineral Resource and Mineral Reserve Estimates.........................................................................	116
23	Recommendations...................................................................................................	118
	23.1	Mineral Resource and Mineral Reserve Estimates.........................................................................	118
	23.2	Recommended Work Programs......................................................................................................	118
	23.3	Recommended Work Program Costs .............................................................................................	118
24	References................................................................................................................	120
25	Reliance on Information Provided by the Registrant............................................	121

List of Tables

Table 1-1: San Martín Summary Mineral Resources at End of Fiscal Year Ended December 31, 2021 - SRK Consulting (U.S.), Inc.(1).........................................................................................................................4

Table 2-1: Site Visits...........................................................................................................................................	7
Table 3-1: Land Tenure at San Martín ...............................................................................................................	9
Table 5-1: Production Table Summary - San Martín 2002 - 2020...................................................................	22
Table 7-1: Comparison of Planned vs Real Tonnages and Grades for 2020 and 2021 ..................................	46
Table 7-2: Summary of RMR Values Determined Using Bieniawski's Method ................................................	60
Table 7-3: Summary of Hoek-Brown Parameters Determined from Mapping..................................................	61
Table 7-4: Summary of Point Load Strengths by Rock Type ...........................................................................	61
Table 7-5: Summary of Intact Rock Strength Parameters from Laboratory Testing Program .........................	61
Table 7-6: Comparison of Uniaxial Compressive Strength Test Results .........................................................	61
Table 8-1: Specific Gravity Measurements (2021) ...........................................................................................	64
Table 8-2: Detection Limits - Methods GE-ICP14B .........................................................................................	67
Table 9-1: Validation Rock Samples from Underground Workings..................................................................	76
Table 9-2: Results of the Validation Core Samples (Pulps) and the Original Data - Exploration Drilling ........	77
Table 10-1: Metallurgical Performance 2002 - 2020 ........................................................................................	81
Table 10-2: Metallurgical Performance 2020 to 2021 ......................................................................................	83
SanMartin_SEC_Report_569000-020-USPR000783_Rev05.docx	February 2022