Matagami Mining Camp — 2023 Technical Report

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 Material is withdrawn from the ROM bin and fed to a jaw crusher operating in open circuit.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

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.