Name of the Project
South Crofty tin project.
Location
Cornwall, UK.
Client
Strongbow Exploration.
Project Description
A preliminary economic assessment (PEA) on the South Crofty mine indicates that the project is potentially economically viable and technically feasible.
The mineralised material mined in the PEA indicates that 2.58-million tonnes at an average grade of 1.55% tin are amenable to mining.
The mine is expected to be accessed using the existing New Cook’s Kitchen shaft, which will serve as the primary access to the mine for personnel and materials, and for transporting mill feed to the plant site.
The existing Tucking mill decline will be extended in the second half of the mine life and eventually provide an alternative haulage route from the upper levels, as well as access and ventilation. The existing New Roskear shaft will provide ventilation and secondary egress during development and early mine life.
Mill feed of up to 350 000 t/y is planned, primarily using sublevel long-hole mining. Delayed thickened tailings will be used as backfill to support some mining areas.
Mining blocks will be about 60 m along strike and 20 m to 30 m high.
Mineralised material will be removed from the stopes using 3.5 t load-haul-dump vehicles and transported to the existing shaft hoisting infrastructure using 20 t trucks.
All development and rehabilitation work will be conducted using single-boom hydraulic jumbo drills to widen the existing access development from 2.4 m × 2.4 m to 3.0 m × 3.5 m to allow for trackless mining.
Potential Job Creation
The project has the potential to create about 110 new jobs during the 24- to 36-month dewatering and construction period, excluding construction personnel and contractors.
The mine has the potential to directly employ about 275 people in permanent positions.
Net Present Value/Internal Rate of Return
The project has an after-tax net present value, at a 5% discount rate, of $130.5-million and an internal rate of return of 23.4%, at assumed metal prices of $10.00/lb tin, $2.65/lb copper and $0.90/lb zinc, with a payback of 3.8 years.
Value
The project has an estimated preproduction capital cost, including contingency, of $118.7-million.
Duration
Not stated.
Latest Developments
The South Crofty tin mine has received the last permit – a permit to proceed with the construction of a mine water treatment plant (WTP) – required to render the project fully shovel ready.
The permit allows for the discharge of up to 25 000 m3/d of treated water from the South Crofty project and for Strongbow to start with construction, which will start immediately.
Strongbow has appointed UK-based Siltbuster Process Solutions to oversee the process design and commissioning of the WTP, which will use a high-density sludge process to recover suspended solids and dissolved metals from the mine water prior to discharge into the Red river.
Nomenca, a subsidiary of North Midland Construction, has been retained to complete the detailed design and engineering, and manage the construction of the WTP.
Key Contracts and Suppliers
Siltbuster Process Solutions and Nomenca (process specification and outline design works).
On Budget and on Time?
Not stated.
Contact Details for Project Information
Strongbow Exploration, tel +1 604 638 8005 or email info@strongbowexploration.com.