This report presents the feasibility study for the Quebrada Honda I and II mine, located in the Pascua Lama District, III Region of Atacama, Chile, describing the proposed processing plant design and supporting metallurgical testwork.
Report context
The NI 43-101 Technical Report for Quebrada Honda I & II Mine, Chile, was issued July 20, 2020, as Version 2.0 Final (Report Number LB30571, Job Number ZT61-3404). The report was prepared for Barrow Mining SpA, based at 80 La Capitanía Street office 108, Las Condes, Santiago, Chile. The project is located in the San Félix area, III Region of Atacama, Pascua Lama District, Chile, in the «La Vega» Ravine and «El Rosario» Ravine sectors. UTM mine location is N: 6,811,610 meters, E: 354,900 meters, at a mine geographic height of 2,000 meters above sea level. The geodetic reference data uses the 1924 International ellipsoid reference, Origin Datum «La Canoa 1956», Spindle 19, Provisional South American.
Processing route
Existing Operation
The report references an existing operation with a process flowsheet that forms the basis for the proposed QH1-2 plant design. Specific historical operating performance data for the existing operation are not detailed in the processing sections of the report.
Proposed QH1-2 Process Flowsheet
The feasibility study proposes a flowsheet designated QH1-2. The process route consists of the following unit operations as described in Section 17.0 Recovery Methods:
- Primary Crushing: Run-of-mine ore is fed to a primary crusher.
- Coarse Ore Handling: Crushed material reports to a coarse ore conveyor, which delivers feed to a coarse ore stockpile.
- Storage and Grinding Feed: Ore is reclaimed from the stockpile into storage bins that feed the grinding circuit.
- Grinding Circuit: The grinding circuit is designed as the primary comminution stage downstream of the storage bins.
- Pebble Crushing: A pebble crushing circuit is included in the flowsheet.
- Flotation and Regrind: The ground product reports to flotation. A regrind circuit is incorporated for the flotation concentrate.
- Concentrate Thickening: Flotation concentrate is thickened in a dedicated concentrate thickener.
- Reagent Facilities: Reagent facilities are included for flotation and process requirements.
- Tailings Thickening: Tailings from the flotation circuit are thickened in a tailings thickener.
- Power and Water: The report notes that power and water supply are addressed in the plant design, though specific consumption data are not provided in the processing sections.
Metallurgical Testwork
Section 13.0 Mineral Processing and Metallurgical Testing describes the testwork program:
- Sample Selection: Samples were selected for metallurgical testing.
- Mineralogical Characterization: Mineralogical characterization of the samples was completed.
- Comminution: Comminution testwork was performed.
- Flotation: Flotation testwork was conducted.
- Ancillary Tests: Ancillary tests were carried out as part of the program.
Recovery Estimates
The report provides recovery estimates separately for different ore types:
- Enriched Material: Recovery estimates were developed for enriched material.
- Transitional and Primary Material: Recovery estimates were developed for transitional and primary material.
Metallurgical Variability and Deleterious Elements
Metallurgical variability testing was conducted. The report also addresses the assessment of deleterious elements in Section 13.5.
Resource and Reserve Estimation Methodology (NSR)
Mineral resource estimates were calculated using Net Smelter Return (NSR). The methodology involved:
- Calculation of the NSR using a base rate and variable price components.
- A description of the NSR% rate base and base rate is provided.
- Variable pricing was incorporated into the NSR calculation.
Mineral reserves were estimated for exploitation by conventional extraction methods. Two sectors are identified: Sector “La Quebrada 1” and Sector “La Quebrada 2”.
Key reported parameters
| Parameter | Reported Value / Description | Basis |
|---|---|---|
| Project name | Quebrada Honda I and II | Feasibility study designation |
| Location | San Félix, III Region of Atacama, Pascua Lama District, Chile | Report location |
| UTM coordinates | N: 6,811,610 m; E: 354,900 m | Mine location |
| Mine elevation | 2,000 m above sea level | Geographic height |
| Geodetic datum | 1924 International ellipsoid, La Canoa 1956, Spindle 19 | Reference system |
| Proposed main process route | Primary crushing, grinding, pebble crushing, flotation, regrind, concentrate thickening, reagent addition, tailings thickening | Proposed design (QH1-2 flowsheet) |
| Comminution testwork | Conducted | Metallurgical testing |
| Flotation testwork | Conducted | Metallurgical testing |
| Recovery estimates – Enriched | Estimated | Testwork-based |
| Recovery estimates – Transitional and Primary | Estimated | Testwork-based |
| Metallurgical variability testing | Conducted | Variability program |
| Deleterious element assessment | Undertaken | Section 13.5 |
| NSR calculation | Uses base rate and variable price | Estimation methodology |
| Exploitation method | Conventional extraction (open pit) | Proposed mining method |
| Mine sectors | “La Quebrada 1” and “La Quebrada 2” | Reserve sectors |
Technical qualifications
The report is an NI 43-101 Technical Report (Feasibility Study 2020) for the Quebrada Honda I and II mine. The processing sections do not provide specific design throughput rates, operational performance data for the existing operation, or detailed equipment specifications. Comminution, flotation, and ancillary testwork were performed, but full testwork results, including specific recovery percentages and reagent consumption rates, are not included in the sections excerpted. The report does not present economic analysis, project ownership details, current status of construction or operation, or hyperlinks to additional resources.
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Source: NI 43-101 Technical Report for Quebrada Honda I & II Mine, Chile, Barrow Mining SpA, July 20, 2020, Version 2.0 Final, Report Number LB30571. Relevant sections: 13.0 Mineral Processing and Metallurgical Testing, 14.0 Mineral Resource Estimates, 15.0 Mineral Reserves Estimates, 16.0 Mining Methods, 17.0 Recovery Methods.
