Name of the Project
Island Gold mine Phase 3 expansion.
Location
Ontario, Canada.
Project Owner/s
Alamos Gold.
Project Description
A July 2020 expansion study has increased the Island Gold mine life to 16 years, double that of the current eight-year mineral reserve life.
The project will increase production from the mine from 1 200 t/d to 2 000 t/d, after the completion of the shaft, through various infrastructure investments such as the installation of a shaft and paste plant, as well as the expansion of the mill and tailings facility.
The addition of paste fill underground will allow for faster stope cycling, thereby supporting higher mining rates and providing increased geotechnical stability. It will also increase mining recovery, resulting in an additional 100 000 oz of gold recovered over the life-of-mine.
The expanded mill will be a conventional milling operation with a nominal capacity of 2 000 t/d, up from about 1 200 t/d. The expansion will include upgrading the crushing circuit, adding a second parallel ball mill, and a new elution and carbon-in-pulp circuit with carbon screens.
Following the completion of the shaft, the operation will transition from trucking ore and waste to skipping ore and waste to surface through the new shaft infrastructure, driving production higher and costs significantly lower.
Longhole open stoping will continue to be used as the primary mining method.
The expanded mill will include upgrades and expansions for the following major process operations: a new vibratory grizzly feeder, a new primary crusher, a new fine-ore stockpile and conveyors, an additional primary ball mill, a primary ball mill screen for both ball mill circuits, converting existing thickener to high-rate thickener, two additional leach tanks, a new elution plant and kiln, as well as tailings pumps.
Average production is estimated at 236 000 oz/y, starting in 2025 upon completion of the shaft. Total gold production is estimated at 3.1-million ounces.
Potential Job Creation
Not stated.
Net Present Value/Internal Rate of Return
The project has an after-tax net present value, at a 5% discount rate, of $1.02-billion and an internal rate of return of 17% using a base case gold price assumption of $1 450/oz.
Capital Expenditure
Growth capital for the shaft expansion is estimated at $514-million. This is expected to be spent over five years until the completion of the shaft and expansion of the mill in 2025. The bulk of this spending will occur between 2022 and 2024.
Planned Start/End Date
Not stated.
Latest Developments
Alamos Gold has been approved to ramp up construction activities on the Island Gold Phase 3 expansion, including the presink of the shaft, which will start by midyear.
Since the expansion study was completed, Alamos has increased the mineral reserves and resources by 37% to 5.1-million ounces at the end of 2021. This growth will be incorporated into an updated mine plan, which will be released in mid-2022.
Alamos has said that the optimised mine plan will incorporate higher-grade additions in proximity to the planned shaft bottom earlier in the mine life, further increasing the value of the operation.
Key Contracts, Suppliers and Consultants
Hatch (overall infrastructure design/engineering); Cementation (sinking engineering and design); Airfinders (ventilation engineering); Golder (paste fill plant and UDS design, water management and tails dam and environmental baseline monitoring and permitting support); Halyard (mill expansion); SRK (mine simulation consultant); and DMC Estimating (third-party master estimate review).
Contact Details for Project Information
Alamos Gold, tel +1 416 368 9932 or email info@alamosgold.com.