Name of the Project
Rothsay gold project.

Location
The project is located 300 km north-east of Perth, in Western Australia’s midwest region.

Client
Egan Street Resources (EganStreet).

Project Description
The Rothsay gold project hosts high-grade mineral resources of 262 000 oz grading 11.6 g/t gold, with 399 000 t grading 11.9 g/t in the indicated category and 303 000 t at 11.3 g/t gold in the inferred category. The project has an initial 5.5-year mine life, with significant exploration potential.

A prefeasibility study (PFS) completed on the project has confirmed the potential for the project to be developed as a new high-grade, high-margin Australian gold project capable of delivering strong financial returns for shareholders. The PFS forecasts life-of-mine (LoM) production of 936 000 t grading 7 g/t gold for about 200 000 oz of gold, up from the 493 000 t grading 6.7 g/t gold for 106 000 oz indicated in the December 2016 scoping study.

Two mining methods have been selected.

The bulk of the production target is mined using longhole open stoping (LHOS) with cemented rock fill (CRF) pillars – a top-down method that premines the pillars and fills with high-strength CRF before starting with stoping. The high-grade nature of the orebody more than justifies the additional cost associated with CRF for higher mining recoveries.

Bench stoping will be undertaken in the southern upper zone above the 1225RL. This is a bottom-up method, where stopes are extracted and filled with rockfill. Working off the rockfill, the above level is then extracted.

LHOS and benching methods were chosen as the preferred option in the PFS; however, the hand-held shrinkage method should not be discounted as an option in the future, specifically in the narrower stopes.

The design of the 200 000 t/y gold plant comprises:
• a three-stage crushing and screening circuit to handle a top feed-size of 0.6 m and producing a P80 of 8 mm. The circuit is designed to operate on one shift at 50 t/h.
• a single-stage ball milling and classification circuit producing a final product size of P80 106 μm. The grinding and carbon-in-leach (CIL) circuit is designed to operate at 91.3% overall utilisation.
• a gravity recovery circuit consisting of a Falcon concentrator and Gemini table.
• a CIL circuit of two leach tanks and six adsorptions tanks for a 24-hour residence time.
• a high rate tailings thickener.
• a one-tonne Anglo American Research Laboratories elution circuit, with separate acid wash column and elution columns capable of stripping every 24 h, six days a week.
• a secure gold room with a tilting furnace, calcine oven and associated gold room equipment.

The tailings storage facility will meet the PFS LoM, with relatively low levels of construction materials required. A staged approach is envisaged, requiring 35 000 m3 of fill being required for the first two years of the project and a further 90 000 m³ for the LoM.

Jobs to Be Created
Not stated.

Net Present Value/Internal Rate of Return
The PFS estimates a net present value, at an 8% discount rate, of $58.1-million and an internal rate of return of 57%, with a payback of 23 months.

Value
The project is estimated at $33.9-million, including a $3.3-million contingency and $8.9-million of working capital. This represents a slight increase on the $28.1-million forecast in the scoping study, owing to additional mine capital development required to deliver the expanded LoM production target.

Duration
First gold production is targeted for mid-2018.

Latest Developments
The results of the PFS will form part of a fast-tracked feasibility study on the Rothsay project, which is well under way and targeted for completion in the third quarter of 2017.

Key Contracts and Suppliers
None stated.

On Budget and on Time?
Too early to state.

Contact Details for Project Information
EganStreet, email info@eganstreet.com.au.