First Quantum's March 2019 technical report for Cobre Panamá in Colón Province, Panama, was written as plant start-up neared. Copper concentrate is piped about 25 km to a filter plant at the Punta Rincón port.
The Cobre Panamá Project, Colón Province, Republic of Panamá, NI 43-101 Technical Report is dated March 2019 and was prepared by qualified persons of FQM (Australia). Its recovery methods section is largely reproduced from Rose et al. (2013), with updates by FQM. Ore from several open pits is treated in a conventional plant that makes a copper concentrate and a separate molybdenum concentrate. After start-up in 2019, the concentrator was to treat nominally 202,000 t/d from the Botija pit, rising to 232,000 t/d by 2020. From 2023 the scheduled rate is a nominal 246,575 t/d, with design capacity of up to 274,000 t/d to allow for daily fluctuations. The plant is designed for head grades of up to 0.65% Cu and 0.023% Mo. The highest sustained scheduled grades are 0.46% Cu in 2023 and 88.40 ppm Mo in 2029.
Critical Data
| Parameter | Value | Unit | Notes |
|---|---|---|---|
| Report date | March 2019 | Not applicable | First Quantum Minerals Ltd |
| Throughput | 202,000 t/d (2019), 232,000 (2020), 246,575 (from 2023) | Not applicable | Design up to 274,000 t/d |
| Design head grade | Up to 0.65% Cu, 0.023% Mo | Not applicable | Sustained peaks 0.46% Cu, 88.40 ppm Mo |
| Primary crushing | Four semi-mobile in-pit gyratory crushers | Not applicable | Botija pit |
| Coarse ore stockpile | 2.5 days, 16 h live without dozing | Not applicable | Up to four secondary crushers |
| Grinding lines | Three 28 MW SAG mills | Not applicable | Gearless drives |
| Ball mills | Four 16.5 MW, plus a 22 MW mill on the third train | Not applicable | Closed with hydrocyclones |
| Pebble crushing | Up to four cone crushers | Not applicable | Next to the secondary crushers |
| Gravity | Two gravity gold plants on ball mill discharge | Not applicable | Gravity gold upgraded to bullion |
| Cleaning | Columns for first-cell concentrate; three regrind mills, two mechanical stages and a column stage for the rest | Not applicable | Installed for ultimate capacity |
| Molybdenum | Differential flotation, copper depressed | Not applicable | Can be bypassed |
| Copper concentrate | Filtered to 8 to 9% moisture at the port | Not applicable | 140,000 t covered storage |
Overview
Ore is crushed in pit and conveyed on dual overland conveyors to secondary crushers or directly to a coarse ore stockpile. Three SAG mills and their ball mill circuits grind the ore, with pebble crushing and two gravity gold circuits. Bulk rougher and cleaner flotation recovers copper, molybdenum, gold and silver into a bulk concentrate. The bulk concentrate is thickened without flocculant and separated by differential flotation. Molybdenite is floated while the copper minerals are depressed. The molybdenum concentrate is filtered, dried and containerized for offshore roasters. The copper-gold concentrate is pumped to the port, filtered, stored and loaded onto bulk carriers. Tailings go to a centreline/downstream tailings management facility (TMF), and later to the mined-out Botija pit.
Key Process Stages
Crushing and stockpiling. A transfer point on surface can also take crushed ore from future sources such as Colina. Two trains of six apron feeders under the stockpile feed the two original grinding lines. A third train feeds the third SAG mill, which is linked to the other ball mills. By the end of 2019 it gains its own 22 MW ball mill.
Grinding. Trommels and washing screens close the SAG mills. Oversize passes metal removal to the pebble crushers, and reject balls are recycled. Each SAG mill's discharge is cycloned, and the unfinished product is split between two ball mill circuits. Finished product passes in-stream particle and chemical analyzers and goes to flotation surge tanks. Part of the ball mill discharge feeds scalping screens and centrifugal gravity concentrators.
Flotation. The first rougher cell's high-grade concentrate is cleaned directly in columns. The rest of the rougher concentrate is reground in three mills and cleaned in two mechanical stages and a column stage. On-stream chemical and particle analysis covers the flotation circuits.
Concentrate handling. The molybdenum circuit tails are the copper concentrate. It is thickened and piped about 25 km to Punta Rincón. There, automatic filter presses dry it, a mechanical reclaimer recovers it, and closed conveyors load it. Filtrate is treated at the port or returned by pipeline to the TMF.
Tailings and water. Most rougher tailings are cycloned, and the coarse fraction builds the TMF embankments. Fines and unused coarse material are beached upstream. Cleaner tailings, which contain iron sulphides, are deposited underwater to prevent acid drainage. After about 14 years, cleaner tailings go to the depleted Botija pit. Rougher tailings continue to the TMF long enough to form a cover and are then also diverted. Reclaim water is pumped from the TMF to the process water tank, and excess water overflows by decant tower and tunnel to the Del Medio River.
Additional Interesting Data and Summary
At the end of 2018, inching and lining of one SAG mill and two ball mills was complete. The port and the first power station generator were running under operations control, and start-up was planned for the first quarter of 2019. The milling trains and coarse ore stockpile were sited on fresh rock in a valley south of a central ridge.
In summary, the 2019 Cobre Panamá report describes one of the largest copper concentrators, built with three SAG-ball lines, gravity gold recovery, column cleaning and optional molybdenum separation. It plans in-pit underwater storage of cleaner tailings once the Botija pit is depleted.
Key Processes
- In-pit gyratory crushing with secondary and pebble cone crushing
- Three-line SAG and ball milling with gearless drives
- Gravity gold recovery on ball mill discharge
- Bulk rougher flotation, regrind, mechanical and column cleaning
- Copper-molybdenum differential flotation
- Concentrate pipeline to port, pressure filtration and ship loading
- Cycloned tailings embankments and subaqueous cleaner tailings disposal
Source: Cobre Panamá Project, Colón Province, Republic of Panamá, NI 43-101 Technical Report, First Quantum Minerals Ltd, March 2019.
Earlier report summaries
Earlier versions of this profile, based on older technical reports, are retained below for source traceability. Dates and figures reflect each report’s own effective date and are superseded by the current information above.
Cobre Panamá Project — 2015 Technical Report
This technical report details the proposed conventional mineral processing route for the Cobre Panamá copper-molybdenum project, including crushing, grinding, flotation, and tailings disposal.
Report context
This June 2015 technical report for the Cobre Panamá Project describes the proposed mineral processing facilities for treating ore from multiple open pits to produce copper and molybdenum concentrates. The processing plant is designed with a staged expansion capability, starting at 190,000 t/day in 2018 and increasing to a nominal 246,575 t/day from 2023 onwards, with a design capacity up to 274,000 t/day allowing for 10% day-to-day fluctuations.
Processing route
Crushing and grinding
The processing route begins with semi-mobile in-pit primary gyratory crushers. Crushed ore is conveyed out of the pit to a surface transfer point, then via an overland conveyor to either secondary crusher feed bins or directly to a coarse ore stockpile at the concentrator. The coarse ore stockpile is designed to hold a 2½-day supply for the mill, with 16 hours available to reclaim feeders without bulldozer assistance.
Two trains of feeders and conveyors draw ore from below the coarse ore stockpile to feed two parallel wet-grinding lines, each comprising one semi-autogenous grinding (SAG) mill and two ball mills, all with gearless drives. A third train feeds a third SAG mill linked to the other ball mill trains, enabling maintenance of treatment rate and independent operation.
SAG mill circuits are closed by trommel screens followed by washing screens, with oversize conveyed to pebble crushers. The pebble crushing circuits include pebble bins, cone crushers, and a bypass arrangement, with crushed pebbles returned to SAG mills via stockpile feed conveyors. Discharge from each SAG mill is cycloned; finished product gravitates to a surge tank for pumping to flotation, while unfinished product splits evenly between two ball-mill circuits closed by hydrocyclones.
A gravity gold recovery plant is linked to the ball mill circuit. A proportion of ball mill discharge is pumped to a gravity gold circuit comprising scalping screens and centrifugal gravity concentrators, which recover free gold for upgrading to bullion. Tails from the gravity concentrators return to the milling circuit.
Flotation
Ground slurry proceeds to a flotation circuit where a bulk sulphide concentrate containing copper, molybdenum, and gold values is collected and concentrated in rougher followed by cleaner flotation. A primary high-grade concentrate from the first rougher cell is cleaned directly in columns to produce a final product. The balance from remaining rougher cells is fed into regrind mills, then cleaned in two stages of mechanical cells followed by one column stage to produce a final bulk concentrate.
From 2025, an increase in rougher capacity is required to accommodate higher throughput, but no change to existing downstream regrind and cleaning capacity is needed since copper quantity remains the same. The bulk concentrate is thickened in conventional thickeners (with no flocculant) and pumped to a differential flotation plant, where copper minerals are depressed and molybdenite floated into a molybdenum concentrate.
Concentrates
Molybdenum concentrate is filtered, dried, and packaged in bulk bags for shipment to offshore roasters. Tailings from the molybdenum flotation circuit constitute the copper concentrate, which is thickened and pumped approximately 25 km to a filter plant at the port site. If molybdenum head grade is very low, the molybdenum separation plant can be bypassed.
Copper/gold concentrate piped from the plant site is filtered in automatic filter presses, reclaimed using a mechanical reclaimer, and loaded by closed conveyors onto bulk ore carriers. The dried concentrate (8% to 9% moisture) is stored in a covered building with a capacity of 140,000 t. Filtrate water is pumped through a return pipeline to the tailings management facility (TMF).
Tailings disposal and process water reclaim
For the first twenty years of operation, tailings from rougher and cleaning steps are deposited in the TMF located north of the mine and plant. The majority of rougher tailings are processed through cyclones, with the coarse fraction used to construct TMF embankments. The finer fraction and unused cyclone coarser tailings are deposited within the TMF on beaches upstream of the embankments. Cleaner circuit tailings are deposited underwater to prevent acid drainage generation.
In the original Inmet concepts, after twenty years the depleted Botija Pit would receive cleaner tailings deposited underwater, while rougher tailings would continue to the TMF for a period sufficient to form a cover, after which rougher tailings would also be diverted to the depleted Botija Pit and then ultimately to the depleted Colina Pit. Timeframes for tailings backfill will be revised as a function of new mining and processing schedules when production commences.
Reclaim water is pumped from the TMF to the process water pond north of the plant site, with a tee off providing water for the tailings cyclone plant. From the process water pond, water is used in the milling plant or boosted for general in-plant use. Excess water from the TMF overflows via a decant tower into the Del Medio River.
Key reported parameters
| Parameter | Design / Proposed | Scheduled / Actual | Testwork |
|---|---|---|---|
| Concentrator throughput (start-up, 2018) | , | 190,000 t/day | , |
| Concentrator throughput (2021) | , | 203,600 t/day | , |
| Concentrator throughput (from 2023) | Nominal 246,575 t/day; design up to 274,000 t/day | , | , |
| Design head grade (Cu) | 0.65% Cu | Highest sustained: 0.48% Cu (2027) | , |
| Design head grade (Mo) | 0.023% Mo | Highest sustained: 0.008% Mo (2021) | , |
| Copper concentrate moisture (after filtration) | 8% to 9% | , | , |
| Concentrate storage capacity (covered building) | 140,000 t | , | , |
| Concentrate pipeline length | ~25 km | , | , |
Project website: https://www.first-quantum.com/operations/cobre-panama/
Technical qualifications
The report notes that these processing descriptions largely reproduce information from a 2013 source with updates, and that the information shows proposed design parameters rather than operational results. The design head grades (0.65% Cu and 0.023% Mo) are stated to be higher than the highest sustained head grades scheduled in the mine plan (0.48% Cu in 2027 and 0.008% Mo in 2021), providing flexibility to accommodate a wide range of head grades over the project life. The original Inmet tailings concept timeframes are noted as subject to revision based on new mining and processing schedules produced when production commences.
Source: Cobre Panamá Project Technical Report, June 2015, Section 17 – Recovery Methods.
