The 2023 technical report for the Matagami Mining Camp in Québec, Canada, proposes using the existing Matagami process plant to treat copper and zinc material from the Caber, Caber Nord, and PD1 deposits, with processing details based on the historical plant flowsheet.
Report context
The report, dated 2023, covers the Matagami Mining Camp in Québec, Canada, as a NI 43-101 Technical Report. It describes the recovery methods proposed for processing material from the Caber, Caber Nord, and PD1 deposits through the existing Matagami process plant. This plant has been in operation since 1962, is currently on care-and-maintenance, and has treated ore from 12 different mines since construction.
Processing route
Overall processing basis
The basis for processing material from the Caber, Caber Nord, and PD1 deposits is to treat copper- and zinc-bearing material through the existing Matagami process plant to produce separate copper and zinc concentrates. The tailings from the process plant will be deposited in a new tailings storage facility.
Existing plant description
The plant has a nominal throughput capacity of 3,000 t/d and was progressively upgraded and modernized, with the most recent upgrade occurring 2012-2013. The processing route consists of a conventional three-stage crushing and two-stage ball mill grinding circuit, followed by sequential copper and zinc flotation to produce separate concentrates. Copper and zinc concentrate products were dewatered through existing thickeners and pressure filters.
Crushing circuit
Mineralized material will be transported by truck from the deposits to the existing Matagami process plant and either dumped directly into the ROM bin or stored nearby. Material is withdrawn from the ROM bin and fed to a jaw crusher operating in open circuit. Crushed material discharges onto a conveyor feeding a primary single-deck sizing screen. Oversize from this screen feeds a secondary cone crusher, with discharge conveyed with primary screen undersize to a secondary single-deck sizing screen. Undersize from the secondary screen is conveyed to storage bins, while oversize feeds a tertiary cone crusher. There is a 1,000 t bin between the primary and secondary crushing circuits and three 3,000 t crushed material bins.
Grinding circuit
Crushed material is reclaimed by vibrating feeders and conveyed to a primary ball mill measuring 12.5 feet diameter by 16 feet long. The circuit includes three secondary ball mills and hydrocyclones for classification. The grinding circuit will produce a primary grind size of 80% passing 50-60 µm and operate at approximately 78% solids density. The recirculating load around the secondary ball mills will be 300%, with installed grinding capacity of 2.8 MW. Cyclone overflow is directed to a trash screen before copper flotation, and underflow returns to the secondary grinding circuit.
Copper flotation circuit
The copper flotation circuit consists of conditioning tanks, a flash flotation stage, a rougher stage, and four stages of cleaning. Slurry flows from the trash screen to two conditioning tanks then to the flash flotation circuit, which includes one 30 m³ and one 10 m³ forced air tank cells. Rougher concentrate is reground to approximately 80% passing 20 µm in a regrind ball mill with hydrocyclone classification. The cleaner circuit consists of four banks of Denver cells for first cleaning, two banks for second cleaning, one bank for third cleaning, and one column cell for fourth cleaning. Concentrate from the first cleaner, flash flotation product, and tails from the third cleaner are directed to the second cleaner circuit. Concentrate from the third cleaner is directed to the copper dewatering circuit or the fourth cleaner if required. Final copper concentrate is pumped to a dewatering circuit consisting of a conventional thickener and Larox vertical pressure filter to produce 8% moisture concentrate.
Zinc flotation circuit
The zinc flotation circuit consists of conditioning tanks, a rougher stage, and three stages of cleaning. From the copper flotation circuit, slurry flows to conditioning tanks then to the rougher flotation circuit, which consists of 5 banks of Gallagher forced air cells. Rougher concentrate is reground to approximately 80% passing 20 µm in a regrind ball mill with hydrocyclone classification. The cleaner circuit includes first cleaner, scavenger cleaner, second cleaner, and third cleaner banks. Concentrate from the first cleaner and tails from the third cleaner are directed to the second cleaner circuit, with tails sent to the scavenger cleaner circuit. Final zinc concentrate is pumped to a dewatering circuit with two conventional thickeners and a Larox vertical pressure filter to produce 8% moisture zinc concentrate.
Concentrate loadout and tailings handling
Final dewatered copper and zinc concentrates are either bagged for road transport or loaded into train cars for shipment. Tailings from the zinc flotation circuit are pumped to the tailings storage facility, with no current provision for further tailings handling or thickening.
Reagents and consumables
Hydrated lime will be used as a pH modifier, supplied dry and mixed into a slurry. The 3418A collector and MIBC frother will be delivered in intermediate bulk containers and dosed using diaphragm pumps. Copper sulphate will be used as an activator for zinc flotation, supplied as dry flake and mixed with raw water. SIPX collector will be supplied in 850 kg bulk bags and mixed with raw water. Flocculant will be a liquid polymer used in the copper and zinc thickeners, diluted with raw water and then process water before addition.
Services and utilities
The plant historically used raw water for all process needs, but water conservation will be implemented once the plant restarts. Raw water will be supplied from the river and stored in the existing raw water tank, used for gland seal water and reagent makeup. Process water will consist of thickener overflows and tailings storage facility return water. Potable water will be provided by the existing potable treatment plant. Fire water will be delivered using raw water from the existing fire water pump system.
For air supply, high-pressure air at approximately 700 kPa(g) will be provided by existing compressors in a lead-lag configuration, dried and distributed via the main plant air receiver. Low-pressure air at 50 kPa(g) supplies the flotation circuit.
The performance of the flotation circuit will be monitored by the existing on-stream analysis system, allowing operators to make air, level, or reagent changes based on real-time assays. All major streams will be monitored for percent solids, copper, zinc, gold, and silver assays, with cumulative shift samples collected for laboratory analysis.
Key reported parameters
| Parameter | Unit | Value | Basis |
|---|---|---|---|
| Nominal annual throughput | Mt/yr | 1.1 | Design |
| Nominal daily throughput | t/d | 3,000 | Design |
| Crushing plant availability | % | 65 | Design |
| Wet plant availability | % | 90 | Design |
| Average copper feed grade | %Cu | 0.96 | Design |
| Average zinc feed grade | %Zn | 8.66 | Design |
| Average gold feed grade | g/t Au | 0.11 | Design |
| Average silver feed grade | g/t Ag | 14.57 | Design |
| Material hardness, BWI | kWh/t | 11-12 | Reported |
| Primary grind size, P80 | µm | 50 | Design |
| Copper rougher regrind size, P80 | µm | 20 | Design |
| Zinc rougher regrind size, P80 | µm | 20 | Design |
| Copper concentrate moisture | % | 8 | Design |
| Zinc concentrate moisture | % | 8 | Design |
| Recovery to copper concentrate | %Cu | 88.4 | Design |
| Recovery to copper concentrate | %Zn | 1.2 | Design |
| Recovery to copper concentrate | %Au | 22.0 | Design |
| Recovery to copper concentrate | %Ag | 37.5 | Design |
| Recovery to zinc concentrate | %Cu | 4.3 | Design |
| Recovery to zinc concentrate | %Zn | 93.7 | Design |
| Recovery to zinc concentrate | %Au | 17.6 | Design |
| Recovery to zinc concentrate | %Ag | 19.8 | Design |
| Copper sulphate usage | kg/t | 0.2 | Reported |
| 3418A collector usage | kg/t | 0.3 | Reported |
| SIPX collector usage | kg/t | 0.3 | Reported |
| MIBC frother usage | kg/t | 0.3 | Reported |
| Flocculant usage | g/t | 20.0 | Reported |
| Grinding media usage | kg/t | 0.4 | Reported |
| Average power demand | MW | 12.4 | Reported |
| Raw water requirement | m³/h | 35 | Reported |
| Process plant personnel | persons | 74 | Reported |
Project website: https://nuvauminerals.com/matagami-mining-district/
Technical qualifications
The report identifies several limitations and recommendations specific to the process plant. A detailed plant inspection is required prior to restarting the existing Matagami process plant to qualify any upgrades and refurbishments that may be required. A full metallurgical test work program on core samples from Caber, Caber Nord, and PD1 is needed to confirm the use of the Matagami flowsheet. The report also recommends implementing a water conservation program and considering installing a tailings thickener or water decant from the tailings storage facility. Optimizing the configuration of the copper and zinc flotation circuits is suggested to improve processing efficiency, and installing a pyrite flotation circuit to desulphurize flotation tailings is proposed to potentially extend the life of the tailings storage facility.
Source: Matagami Mining Camp, Québec, Canada, NI 43-101 Technical Report, 2023, Section 17.0 Recovery Methods and Section 17.3 Process Description.
Consolidated report summaries
The following former standalone pages about this operation were consolidated here in October 2026. They are retained for source traceability; dates and figures reflect each report’s own effective date and may be superseded by the current information above.
Caber Complex PEA Would Restart the Matagami Plant for 3,000 t/d of Sequential Copper and Zinc Flotation
The May 2024 preliminary economic assessment for the Caber, Caber Nord and PD1 deposits in Québec proposes reusing a 1962 concentrator with three-stage crushing, four ball mills, four-stage copper cleaning and three-stage zinc cleaning.
The Caber Complex is a group of copper and zinc deposits, Caber, Caber Nord and PD1, in the Matagami mining camp of Québec, Canada. The NI 43-101 preliminary economic assessment (PEA) was prepared for Nuvau Minerals Corp. and Aardvark 2 Capital Corp. with an effective date of May 24, 2024. The basis for processing is to treat the copper and zinc bearing material through the existing Matagami process plant to produce separate copper and zinc concentrates. Tailings would go to a new tailings storage facility (TSF). The existing plant has operated since 1962 and is currently on care and maintenance. It has treated ore from 12 different mines, has been progressively upgraded and modernized, and had its most recent upgrade in 2012 to 2013.
Critical Data
| Parameter | Value | Unit | Notes |
|---|---|---|---|
| Nominal throughput | 3,000 | t/d | 1.1 Mt/y |
| Crushing plant availability | 65 | % | Existing surge bins and feeders |
| Wet plant availability | 90 | % | Existing bins and standby equipment |
| Average feed grade, copper | 0.96 | % Cu | Design |
| Average feed grade, zinc | 8.66 | % Zn | Design |
| Average feed grade, gold | 0.11 | g/t Au | Design |
| Average feed grade, silver | 14.57 | g/t Ag | Design |
| Bond work index | 11 to 12 | kWh/t | Material hardness |
| Primary grind | 50 | µm P80 | 50 to 60 µm in the process description |
| Copper and zinc regrind | 20 | µm P80 | Each rougher concentrate |
| Concentrate moisture | 8 | % | Copper and zinc |
| Copper recovery to copper concentrate | 88.4 | % | Plus 22.0% Au and 37.5% Ag |
| Zinc recovery to zinc concentrate | 93.7 | % | Plus 17.6% Au and 19.8% Ag |
| Installed grinding capacity | 2.8 | MW | Existing |
| Raw water requirement | About 35 | m3/h | Process |
Overview
The selected flowsheet is the existing Matagami flowsheet. It includes primary, secondary and tertiary crushing, storage bins with reclaim, primary and secondary grinding with classification, copper flash flotation, copper rougher flotation with regrind and four stages of cleaning, zinc rougher flotation with regrind and three stages of cleaning, concentrate thickening and filtration, and tailings pumping to the TSF. The plant has modern automated metallurgical and process control sampling and on-stream analysis (OSA) equipment, and updated instrumentation.
Key Process Stages
Crushing
Trucks bring material from Caber, Caber Nord or PD1 to a ROM bin or nearby storage. A Nordberg C125B jaw crusher runs in open circuit and feeds a single deck sizing screen. Oversize goes to a Symons 5 1/2 inch standard cone crusher, and its discharge with the screen undersize goes to a second sizing screen. Its oversize feeds a Symons 5 1/2 inch short head cone crusher, which returns to that screen. Undersize goes to storage. A 1,000 t bin sits between the primary and secondary crushing circuits, and there are three 3,000 t crushed material bins.
Grinding
Vibrating feeders reclaim crushed material to a primary ball mill, 12.5 ft by 16 ft. Three secondary ball mills, two of 11 ft by 15 ft and one of 11 ft by 13 ft, work with 12 Cavex hydrocyclones at 78% solids and 300% recirculating load around the secondary mills. Cyclone overflow passes a trash screen to the copper flotation circuit and underflow returns for secondary grinding.
Copper flotation
Slurry flows to two conditioning tanks and then to flash flotation, which has one 30 m3 and one 10 m3 forced air tank cell. Flash concentrate goes to the second cleaner. Tailings go to five banks of sixteen 1.13 m3 Gallagher forced air rougher cells. Rougher concentrate is reground to about 20 µm in a 9 ft by 11.5 ft ball mill with hydrocyclones. The cleaning circuit is four banks of Denver cells for the first cleaner, two for the second, one for the third and a column cell as an optional fourth cleaner. The first cleaner concentrate, flash product and third cleaner tails feed the second cleaner, and third cleaner tails go to the zinc circuit. Final copper concentrate is thickened and filtered in a Larox vertical pressure filter to 8% moisture, using 3418A collector and MIBC frother.
Zinc flotation
Zinc flotation follows with conditioning tanks, a rougher stage, a rougher concentrate regrind to 20 µm and three stages of cleaning, which are a first cleaner with a scavenger and then second and third cleaners. Copper sulphate activates zinc, SIPX is the collector, and lime controls pH. Zinc concentrate is thickened and filtered to 8% moisture.
Reagents and services
Reagents are lime, 3418A, MIBC, copper sulphate, SIPX and flocculant, delivered by road in bulk containers or bags and dosed with diaphragm pumps. Raw water is supplied from the river, though water conservation will be implemented at restart, and process water comes from thickener overflow and TSF return water. High-pressure air at about 700 kPa is dried and shared as plant and instrument air, and low-pressure air at 50 kPa supplies the flotation circuit.
Additional Interesting Data and Summary
The OSA system monitors all major streams for percent solids and copper, zinc, gold and silver assays, which lets the operator change air, level or reagent additions based on real-time assays. Cumulative shift samples for laboratory analysis are collected through the OSA sampling system, which has its own control, calibration and reporting system.
The report notes that the plant's crushing capacity relies on existing surge bins and dedicated feeders for choke feeding the cone crushers, and that grinding and flotation availability depends on reliable grid power supply. The design aims for enough automated plant control to minimize the need for continuous operator intervention.
Key Processes
- Three-stage crushing with jaw and cone crushers
- Primary and three secondary ball mills with hydrocyclones
- Copper flash and rougher flotation with regrind
- Four-stage copper cleaning
- Zinc rougher flotation with regrind and three-stage cleaning
- Thickening and Larox pressure filtration of concentrates
- Tailings disposal in a new tailings storage facility
Source: NI 43-101 Technical Report, Matagami Mining Camp, Québec, Canada, Preliminary Economic Assessment for the Caber Complex Project, May 24, 2024.
Project website: Caber Complex Project
