Name and Location
Mt Todd gold project, Northern Territory, Australia.

Client
Vista Gold.

Project Description
The Mt Todd property contains several known occurrences of gold, which have been explored and/or exploited to various degrees.

The largest and best-known deposits are the Batman and Quigleys deposits, both of which have been mined by prior operators.

The prefeasibility study on Mt Todd envisages a base-case mine plan at 50 000 t/d, which contains ore mined from the Batman openpit and the ore from the existing heap-leach pad.

The base-case mine plan envisages 209.5-million tonnes at 0.84 g/t of gold mined from the Batman openpit and 13.4-million tonnes at 0.54 g/t of gold from the existing heap-leach pad that will be processed through the mill at the end of the mine life.

Together, an estimated 222.8-million tonnes of ore containing 5.901-million ounces of gold at an average grade of 0.82 g/t is processed over the 13-year operating life.

Total gold recovered is expected to be 4.808-million ounces.

Average yearly gold production over the life-of-mine (LoM) is estimated at 369 850 oz.

During operating years 1 through 5, gold production will average an estimated 481 316 oz/y; Year 1 production is estimated at 580 472 oz.

The project is designed to be a conventional, owner-operated, large openpit mining operation that will use large-scale mining equipment in a blast/load/haul operation.

The flowsheet entails primary crushing, closed-circuit secondary crushing, closed-circuit tertiary crushing using high-pressure grinding rolls, ball milling, cyclone classification, preleach thickening, leach and adsorption, elution electrowinning and smelting, carbon regeneration, tailings detoxification and disposal to a conventional tailings storage facility.

Planned infrastructure for the site includes:
• an ammonium nitrate and fuel oil (Anfo) facility;
• mine support facilities – a heavy-vehicle workshop, a lube farm, a washdown and tyre change, a warehouse, a fuel farm, mining offices and a core storage facility;
• a heap-leach facility;
• an accommodation camp;
• a water treatment plant;
• power supply;
• pit dewatering;
• mine services;
• communications;
• a gatehouse; and
• a future tailings dam/decant dam.

Net Present Value/Internal Rate of Return
The project has a pretax net present value of $1.094-billion and an internal rate of return of 22%; with a post-tax payback period of 3.5 years.

Value
$1.046-billion.

Duration
Commercial production will begin following two years of construction and commissioning, subject to receipt of all regulatory approvals.

Latest Developments
Australia’s Northern Territory Environmental Protection Authority (NT EPA) has approved Vista Gold’s environmental-impact statement (EIS) for the Mt Todd gold project, subject to several recommendations outlined in an assessment report.

The company has based its EIS on a 50 000 t/d operation, which will result in the largest possible environmental impact. This will allow for flexibility, enabling the company to scale the project down initially, if the economics of a smaller project prove to be more compelling, and to expand the project at a later date, if justified.

The NT EPA assessment report includes 28 recommendations that will have to be dealt with as part of the MMP, of which four pertain directly to the Gouldian Finch. Vista estimates that approval under the Environmental Protection and Biodiversity Conservation Act 1999 (EPBC Act) will take three to four months from the submission date and that approval for the mine management plan (MMP) will take about six months.

Vista’s next steps will focus on obtaining the necessary approvals under the EPBC Act from the federal government (as these relate to the Gouldian Finch). It will turn its efforts to obtaining the mine operating permit and the MMP from the NT Department of Mines and Energy.

The company has started planning with regard to the submissions of the documents required for authorisation under the EPBC Act and approval of the MMP.

Vista intends to undertake studies in the second quarter of 2015 for the EPBC Act approval. MMP preparation will continue in-house and the company plans to have it ready for submission when there are signs of sustained recovery in the gold market.

With the successful completion of the EIS process, the permitting risk has been substantially reduced and the development timeline at Mt Todd is well defined.

Key Contracts and Suppliers
None stated.

On Budget and on Time?
Not stated.

Contact Details for Project Information
Vista Gold, tel +1 720 981 1185.