Name of the Project
South Crofty tin project.
Location
Cornwall, UK.
Project Owner/s
Cornish Metals, formerly Strongbow Exploration.
Project Description
South Crofty has one of the highest-grade tin mineral resources in the world not currently in production and has the potential to be among the lowest-cost producers globally. Having previously operated, there is significant mine infrastructure still in place, most notably several mine shafts that can be used for future production and ventilation purposes. The operation is located within an industrial area with access to the national electricity grid and existing transport infrastructure.
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.
Capital Expenditure
The project has an estimated preproduction capital cost, including contingency, of $118.7-million.
Planned Start/End Date
The project is expected to take 48 months to implement.
Latest Developments
The completion of the £40-million financing in May, including an investment by Vision Blue Resources, has opened a new chapter for Cornish Metals.
The company aims to advance South Crofty to a construction decision within 30 months of closing the offer.
Cornish plans to build a 25 000 m3/d water treatment plant in the first half of 2023 to dewater the mine over an 18-month period.
A feasibility study is slated for completion by the end of December 2024.
Key Contracts, Suppliers and Consultants
Siltbuster Process Solutions and Nomenca (process specification and outline design works).
Contact Details for Project Information
Cornish Metals, tel +1 604 200 6664 or email info@cornishmetals.com.