Photo by: Ascot Resources
Name of the Project
Premier gold project (PGP).
Location
British Columbia, Canada, adjacent to the border with Alaska, in the US, in the Golden Triangle gold mining district.
Project Owner/s
Gold and silver explorer Ascot Resources.
Project Description
An independent feasibility study has outlined a low-capital restart plan for the project, based on a proven and probable reserve of 6.2-million tonnes grading 5.9 g/t gold and 19.7 g/t gold.
The study is based on four underground mining operations – Silver Coin, Big Missouri, Premier and Red Mountain – feeding a centralised 2 500 t/d processing facility at the project. The mining operations will be sequenced over eight years to initially produce 1.1-million ounces of gold and three-million ounces of silver.
Mining will start from the Silver Coin and Big Missouri deposits, which will be followed by the Red Mountain deposit in Year 3, and then the Premier deposit.
In the four planned operations, access for production will be through new and existing adits (side hill portal access) using a combination of new ramp development and the refurbishment of existing underground infrastructure.
Mining methods will largely comprise low-cost longhole stoping for most of the ore, with limited use of inclined undercut longhole, room-and-pillar and cut-and-fill mining methods in specific shallow or flat-lying stopes. Ore will be trucked to the processing facility and mining waste will be used underground as a combination of rockfill and cemented rockfill.
The existing processing facility will be refurbished within a construction period of about 40 weeks. The process plant will use conventional crushing, grinding and gravity circuits, followed by a standard carbon-in-leach process to produce gold doré.
The plant refurbishment will comprise a combination of existing, new and repaired equipment and supporting plant infrastructure. Prior to ore from the Red Mountain project being treated, the plant will add an energy efficient, fine grinding mill, as well as an additional preleach thickener, to accommodate the processing of harder-ore feed and the finer grind required for recovery purposes.
The project has an existing tailings storage facility (TSF) and water treatment plant. The independent feasibility study proposes two key enhancements to the existing infrastructure:
- the tailings dam will be raised using centreline lifts throughout the mine life, with about 1.2-million cubic metres of nonacid-generating rock excavated from a nearby quarry; and
- the water treatment plant will be modified to nearly double the existing capacity to accommodate additional water treatment from the Big Missouri and Silver Coin operations, and will also include an ammonia treatment plant, a water clarifier and a lime high-density sludge system.
Potential Job Creation
Not stated.
Net Present Value/Internal Rate of Return
The April 2020 feasibility study highlighted an after-tax net present value (NPV), at a 5% discount rate, of C$341-million and an internal rate of return (IRR) of 51% at $1 400/oz gold.
The project has an estimated after-tax NPV, at a 5% discount rate, of $546-million and an IRR of 73% at current gold prices of $1 740/oz gold.
Capital Expenditure
C$224-million.
Planned Start/End Date
First gold pour would be in early 2023.
Latest Developments
Ascot has made considerable progress on outdoor areas, such as the TSF earthworks, the new water treatment plant (WTP) and the electrical substation at PGP.
Underground development and ore stockpiling has resumed at the Big Missouri deposit at the PGP, coinciding well with record-high gold grades recently intercepted from drilling in that deposit.
The surface work has also been completed for the new Premier portal, and underground development will start shortly and advance towards the Prew zone of the Premier deposit by early 2024, which will enable Ascot to source production from two portals when milling operations start.
At the end of the third quarter ended September 30, 2023, overall construction, excluding mine development, was 66% complete (73% as of October 31), compared with 48% complete at the end of the second quarter.
Detailed engineering and procurement are substantially complete. The company expects the first gold pour to occur by the end of the first quarter in 2024.
In August, excavation work started on the new Premier portal close to the mill, including establishing the start of an access road for waste disposal in the historic Premier pit. Dewatering of the existing Big Missouri development and re-establishing surface infrastructure also started.
Key items for the remainder of the year include completing the earthworks on the TSF and Cascade Creek Diversion Channel by the end of November.
There is also an increase in the number of piping contractors at the mill to finish the piping, systems and controls at the process plant to mitigate the impact of the delay in earthworks at the TSF.
Ascot will also aim to complete the new temporary camp in Stewart, fully commission the WTP, energise the new substation by fully connecting it to the Long Lake power plant in mid-December, advance the mining development at Big Missouri and at Premier, and continue to ramp up the operating team personnel.
It will also focus on ensuring that it has sufficient capital to complete the project and provide the working capital for startup at the end of first quarter 2024.
Key Contracts, Suppliers and Consultants
Sacre-Davey Engineering (overall coordination, infrastructure and the economic evaluation in the independent feasibility study); InnovExplo Inc and Mine Paste (mining); Sedgman Canada (metallurgy and processing); Knight Piésold (tailings and water management); SRK Consulting (water treatment plant); Paul Hughes Consulting (site geotechnical); McElhanney (access roads); Prime Engineering (electrical substation); Palmer Environmental Consulting Group (geochemistry, hydrology and water quality modelling); Falkirk Environmental Consultants and EcoLogic Consultants (environmental studies); Farnell-Thompson Applied Technologies (SAG ball mills and related parts); and Procon Mining & Tunnelling (underground mining services).
Contact Details for Project Information
Ascot Resources, tel +1778725 1060 or email info@ascotgold.com.