Overview
The Constancia Mine in Cuzco, Peru, operates a sophisticated mineral processing facility designed for the recovery of copper and molybdenum through bulk flotation and separation. The plant features a comprehensive circuit including crushing, grinding, flotation, thickening, filtration, and tailings management.
Key Process Stages
- Primary Crushing: Ore is reduced to manageable sizes using primary crushers.
- Crushed Ore Stockpile & Reclaim: Crushed ore is stored and systematically reclaimed for further processing.
- Grinding: Ore is ground to liberate valuable minerals for flotation.
- Cu-Mo Bulk Flotation: Copper and molybdenum are floated together in a bulk concentrate.
- Molybdenum Separation: Molybdenum is separated from the bulk concentrate through additional flotation steps.
- Copper Concentrate Thickening & Filtration: Copper concentrate is dewatered for storage and transport.
- Molybdenum Concentrate Processing: Molybdenum undergoes thickening, filtration, and loadout.
- Tailings Disposal: Waste material is managed in an engineered tailings storage facility.
Critical Data
| Parameter | Value |
|---|---|
| Throughput | Not specified (refer to report) |
| Primary Crushing Capacity | Not specified (refer to report) |
| Grinding Circuit Type | Not specified (refer to report) |
| Copper Recovery Efficiency | Not specified (refer to report) |
| Molybdenum Recovery Efficiency | Not specified (refer to report) |
Note: For exact operational parameters, consult the full 43-101F1 Technical Report.
Technical report and processing history
The following archived source profiles have been consolidated here to preserve the project’s processing history and study context.
Constancia Mine — Technical Report
Constancia Mine — Technical Report
| Company | Hudbay Minerals |
| Mine | Constancia Mine |
| Date | 2021 |
| Region | Cuzco, Peru |
| Commodities | Copper, Molybdenum, Gold, Silver |
Executive Summary
The Constancia Mine is a large-scale copper-molybdenum operation located in the mountainous terrain of the Cuzco region of Peru. The facility utilizes a traditional grinding and flotation flowsheet designed to process sulphide ore. The plant is engineered to leverage natural topography to minimize pumping requirements through gravity-fed circuits and optimized facility placement.
Operations focus on continuous process optimization, including the integration of pebble crushing circuits, advanced process control (APC) systems, and metallurgical upgrades to increase copper and molybdenum recovery. Recent initiatives include the transition to centralized control rooms and the implementation of geometallurgical characterization to adapt to varying ore hardness from the Constancia and Pampacancha deposits.
Reports
Website: https://hudbayminerals.com/peru/default.aspx
Report Date: 2021
Region: Cuzco, Peru
Project Status:
Commodity: Copper, Molybdenum, Gold, Silver
Throughput:
Mine Life:
Mine Type:
Ore type:
Constancia Project — Technical Report
Constancia Project — Technical Report
| Company | Not Specified |
| Date | Not Specified |
| Region | Peru |
| Commodities | Copper, Molybdenum |
| Throughput | 85,000 tpd |
| Mine Life | 15 years |
| Status | Development |
Executive Summary
This technical report section outlines the recovery methods for the Constancia and San José ore bodies. The projected throughput rate is 85,000 tpd of ore. Annual concentrate production is expected to ramp up from 350,000 tpa in the first year to a peak of 450,000 tpa in Year 3, stabilizing before declining towards mine closure in Year 15.
The processing plant is designed to operate outdoors for major equipment like crushers and mills, with filters and concentrate storage housed in clad structural steel buildings. The circuit includes a gyratory crusher, SAG mills, and ball mills in closed circuit with cyclones. Flotation circuits are dedicated to recovering copper and molybdenum into separate concentrates, utilizing column cells and Jameson cells.
Tailings management involves thickening to 58% solids before disposal in a tailings dam. The plant operates in automatic mode via a DCS system monitored from a central control room. Concentrate is filtered to 9-15% moisture and transported via truck to the Matarani port.
Website: https://hudbayminerals.com/peru/default.aspx
Report Date: Not Specified
Region: Peru
Project Status: Development
Commodity: Copper, Molybdenum
Throughput: 85,000 tpd
Mine Life: 15 years
Mine Type:
Ore type:
Mineral Processing Circuit of Constancia Mine
Processing and Recovery Methods Overview
The Constancia Mine employs a conventional copper-molybdenum flotation circuit designed to process 30.8 Mt/a of ore, with average feed grades of 0.39% Cu and 105 g/t Mo. The plant was designed by Ausenco, incorporating a SABC (SAG-ball mill-pebble crusher) comminution circuit, bulk Cu-Mo flotation, molybdenum separation, and concentrate dewatering.
Key Processing Stages & Equipment
1. Primary Crushing:
– Equipment: FLSmidth 63” x 118” gyratory crusher (1,000 kW motor).
– Output: ROM ore crushed to <125 mm.
– Layout: Hillside location for gravity drainage and reduced ROM pad construction costs.
2. Grinding Circuit:
– SAG Mills: Two 36’ x 26.5’ FLSmidth mills (16 MW total power, twin 8 MW motors each).
– Ball Mills: Two 26.5’ x 41’ FLSmidth mills (16 MW total power, twin 8 MW motors).
– Cyclones: FLSmidth Krebs hydrocyclones (26” diameter, 17 per cluster).
– Target Grind: 80% passing 130 µm.
– Pebble Crushing: Installation deferred to 2023–2024 due to softer Pampacancha ore.
3. Bulk Cu-Mo Flotation:
– Rougher Flotation: Two banks of seven Outotec 300 m³ forced-air cells (pH ~10).
– Regrinding: Glencore IsaMill M10,000 (3 MW) for regrinding rougher concentrate.
– Cleaning Circuit:
– 1st cleaner: Four Outotec 130 m³ cells.
– 2nd cleaner: Three Outotec 130 m³ cells.
– 3rd cleaner: Two Eriez CPT column cells (4.88 m diameter x 12 m tall).
– Recovery Targets: ~88–90% Cu recovery (nominal), with optimization projects targeting +3% recovery via froth crowders and regrind upgrades.
4. Molybdenum Separation:
– Conditioning: NaHS (6,500 g/t) and diesel emulsion (10 g/t) for Cu depression/Mo promotion.
– Flotation Stages:
– Rougher: Ten 10 m³ WEMCO cells.
– Cleaners: Five stages (1st to 5th), including a Jameson cell for final cleaning.
– Final Concentrate: Thickened to 60% solids, filtered (LAROX pressure filters), and dried to 5% moisture.
5. Concentrate Handling:
– Copper Concentrate:
– Thickened in a 24 m diameter thickener.
– Filtered via LAROX horizontal plate filters (91.2 t/h capacity, <8.5% moisture).
– Transported by truck (140 trailers, 36 t capacity) to port.
– Molybdenum Concentrate:
– Bagged in 1 m³ bulk bags for transport.
6. Tailings Management:
– Thickening: 75 m diameter thickener (58% solids underflow).
– Pumping: Five centrifugal pumps in series with HDPE-lined steel pipeline.
– Disposal: Gravity-fed to TMF with 12% max pipeline slope to prevent plugging.
Operational Parameters
– Reagents:
– Lime: 1,000 g/t (grinding), pH 11 in cleaners.
– Collectors: Matcol 251M (17 g/t), D101 (12 g/t).
– Frother: RE-100 (30 g/t).
– Power Consumption: 636,000 MW-h/year.
– Water Usage: 0.88 Mm³/year (average).
Innovations & Challenges
– Pebble Crusher Deferral: Softer ore allowed postponement of pebble crusher installation, saving capital.
– Recovery Optimization: Froth crowders, regrind mill upgrades, and column cell adjustments aim to boost Cu recovery by ~3%.
– Safety Measures: NaHS handling protocols (H₂S risk) and molybdenum plant isolation (downwind location).
Throughput & Capacity
– Design Capacity: 30.8 Mt/a (84,400 t/d).
– Grinding Circuit: 1,875 t/h per train (two parallel trains).
– Copper Concentrate Production: ~12,000 t live storage capacity (7 days).
Technical Challenges & Solutions
– Ore Variability: Geometallurgical studies (500 samples) guide pebble crusher installation timing.
– Tailings Pipeline: Low-slope design (12%) prevents blockages during shutdowns.
– Regrind Limitations: IsaMill power draw increase planned to reduce contaminant locking.
This comprehensive circuit integrates robust equipment selection, gravity-driven layouts, and advanced control systems to maximize recovery while addressing operational and safety challenges.
