This report outlines the proposed processing design for the North Island Copper and Gold Project, which will produce copper/gold and molybdenum concentrates by flotation at a nominal capacity of 75,000 dry metric tonnes per day.
Report context
This technical report, dated 18 March 2021, describes the North Island Copper and Gold Project (the “Project”) located approximately 27 km west of Port Hardy, British Columbia, Canada, along the north shore of Holberg Inlet in Northern Vancouver Island. The Project will consist of an open pit mine, mineralized material processing facility, and miscellaneous infrastructure and support facilities. Copper, gold and molybdenum mineralized material will be mined.
Processing route
Proposed flowsheet design
The Project mineralized material facility will produce copper/gold and molybdenum concentrates. The nominal capacity of the mineralized material processing facility is 75,000 dry metric tonnes per day (dmtpd) or 27,375,000 dry metric tonnes per year (dmtpy). The plant capacity will fluctuate according to the hardness of the mineralized material type being milled, up to a maximum of 84,000 tonnes per day (t/d) when soft mineralized material is being milled.
The milling process will sequentially extract the Cu-Au and sulfide minerals into separate Cu-Au and molybdenum mineral concentrates via the flotation process. The Cu-Au concentrate will be loaded onto trucks for shipment to the port of export and the molybdenum concentrate will be sent to a packaging system and bagged in super sacks for shipment by trucks to market. Rhenium is considered in the financial analysis as a credit to the treatment charges.
The overall process flowsheet is summarized in Figure 17-1 of the report. Process unit operations that will be used include:
- Primary crushing
- SAG mill grinding
- Ball mill grinding
- Bulk rougher flotation
- Pyrite scavenger rougher flotation
- Bulk flotation concentrate regrinding
- Bulk 1st, 2nd, and 3rd cleaner flotation
- Copper-moly separation flotation
- Moly cleaner flotation
- Cu-Au concentrate dewatering
- Moly concentrate dewatering
- Tailings handling and disposal
Key reported parameters
| Parameter | Value | Basis |
|---|---|---|
| Nominal processing capacity | 75,000 dmtpd | Design |
| Annual processing capacity | 27,375,000 dmtpy | Design |
| Maximum capacity (soft mineralized material) | 84,000 t/d | Design |
| Mine life at this production rate | approximately 22 years | Design |
| Life-of-Mine copper grade | 0.19% Cu | Design |
| Life-of-Mine gold grade | 0.24 g/t Au | Design |
| Life-of-Mine molybdenum grade | 0.008% Mo | Design |
Project website: https://www.northisle.ca/news/northisle-provides-corporate-and-exploration-update-and-2026-execution-plan/
Technical qualifications
This report is a Preliminary Economic Assessment under Form 43-101F1. The processing design presented is proposed and not based on operating plant data. No historical operating data or testwork results are reported in the recovery methods section of this document. The report does not present actual performance data for the unit operations described.
*Source: North Island Copper and Gold Project , 2021 Technical Report, M3-PN200319, 18 March 2021, Revision 0, Sections 17 and 17.1.*
