Name of the Project
Tuvatu gold project.

Location
Located near the Nadi International Airport in Fiji.

Client
Lion One Metals.

Project Description
Tuvatu is a fully permitted high-grade underground gold project and the largest undeveloped gold project in Fiji.

A National Instrument 43-101 preliminary economic-assessment technical report, completed in 2015, envisages a low-cost underground gold mining operation producing 352 931 oz of gold over seven years at head grades of 11.30 g/t gold.

Access to the mineralisation at Tuvatu will be made from two declines from surface and internal declines, with two ventilation raises to surface. Level access drives are designed at dimensions sufficient to use medium-sized loaders for improved productivity and truck loading close to the stoping area.

The primary planned mining method is shrinkage stoping, with limited breast stoping for flat-dipping lodes. Shrinkage stoping is a manual overhand method that relies on broken mined material being left in the stope to provide a ‘working floor’ and support for the stope walls. Man and material access into the stope is from predeveloped raises. 

Production drilling is performed using air-legs (jacklegs). Mineral extraction is from crosscuts driven at closely spaced intervals into the bottom of the stope. 

During the mining cycle only 30% to 35% of the blasted material is extracted, equivalent to the broken swell factor. When mining to the top horizon is completed, the remaining material is extracted. These mining methods provide the greatest control to allow for commercial-scale selective mining that minimises dilution and maximises ore recoveries and grade.

The processing facility has been designed as a conventional two-stage crushing and screening circuit, followed by two-stage grinding to achieve a target grind P80 of 75μm. The grinding circuit, which includes gravity recovery, then feeds flotation where a sulphide concentrate is produced and reground to 80% passing 20μm before entering the carbon-in-leach (CIL) circuit. 

The flotation tails and concentrate are leached, with the concentrate CIL tails recirculating to the feed of the flotation tails CIL circuit, the combined discharge being pumped to detoxification and dry tails deposition.

The process facility is designed with a nominal capacity of 219 000 t/y for a nominal design rate of 600 t/d based on an overall availability of 91%, with a life-of-mine average feed grade of 11.3 g/t gold. The plant is designed to operate 365 d/y, 24 h/d. 

The crushing circuit is designed with a mechanical equipment availability of 75%, but has been sized to process 1 000 t/d to accommodate any future expansion.

Potential Job Creation
Not stated.

Net Present Value/Internal Rate of Return
The PEA estimates a net present value, at a 5% discount rate of $116.99-million and an internal rate of return of 67.1%, with a payback of 1.5 years.

Value
The 2015 PEA estimates underground costs at $123.20-million.

Duration
Not stated.

Latest Developments
Lion One Metals secured a $40-million finance facility with Sinosteel Equipment & Engineering, and mining and smelting group Baiyin in June this year.

Lion One will engage Sinosteel as the project engineering, procurement and construction contractor (EPC), and Baiyin as the offtake partner. The facility will have a five-year term, a yearly interest rate of 7.5% and a net smelter return royalty of 2.25% on the first 350 000 oz of gold produced at Tuvatu.

Key Contracts and Suppliers
Sinosteel (EPC) and Baiyin (doré offtaker).

On Budget and on Time?
Not stated.

Contact Details for Project Information
Lion One Metals, tel + 1 604 998 1250 or email info@LionOneMetals.com.