Name of the Project
Mara Rosa gold project.

Location
The project is located in the state of Goias, central Brazil.

Client
Amarillo Gold Corporation.

Project Description
The project has proven and probable mineral reserves of 997 536 oz of gold.

The updated prefeasibility study (PFS) completed on the project indicates that the Mara Rosa project represents a robust, rapid-payback, single openpit mining operation, with key economic metrics showing a marked improvement, compared with the 2011 study.

Contract mining has been selected as the main base case for the project, owing to a significantly lower initial capital expenditure and a higher internal rate of return.

The project will employ contract mining, with conventional openpit mining using drill-and-blast methods, hydraulic excavators, haul trucks, and auxiliary mobile equipment to support a mining operation of a nominal 2.5-million tonnes a year of ore and a maximum of 20-million tonnes a year of waste.

Run-of-mine ore will be hauled from the openpit using 45 t haul trucks and dumped directly into a hopper that feeds the primary crusher. A small stockpile will be established at the primary crusher area. Two ore stockpiles are proposed for material grading between 0.3 g/t and 0.8 g/t of gold, which will be processed later in the mine life. Waste material will also be moved by 45 t trucks. Smaller locally made trucks will allow for simple switching between owner’s fleet and/or contract mining.

The PFS incorporates a conventional carbon-in-leach (CIL) circuit preceded by a pre-oxidation stage (Pre-Ox).

The plant consists of a conventional crushing circuit (including tertiary crushing) followed by primary and secondary milling in closed circuit with cyclones. After adding lime to lift the pH to 12 using 2 kg/t of lime, the final pulp (P80 @ 45 µ) will be sent to three Pre-Ox tanks, where it will be agitated for 12 hours using oxygen from a pressure swing absorption unit. The pulp will be moved to the CIL tanks, where it will come into contact with cyanide (0.24 kg/t of pulp) and activated carbon in a typical CIL circuit of six agitated tanks for 24 h.

Loaded carbon will be extracted daily from the CIL circuit and processed in a typical Zadra-style 4-t-capacity elution circuit. The eluted solution will be passed continuously through the electrowinning cells until efficient desorption has been achieved. At intervals, the gold will be removed from the cells and smelted into doré bars for sale. The activated carbon will be regenerated in a gas-fired rotating kiln before being returned to the CIL circuit.

Tailings from the CIL circuit will be thickened to recover some of the solution before the thickened pulp is subjected to detoxification using sulphur dioxide/air and a copper sulphate catalyst to destroy free cyanide before being pumped to a tailings storage facility (TSF). The water from the TSF will be recirculated to the plant under conditions of zero discharge.

Jobs to Be Created
Not stated.

Net Present Value/Internal Rate of Return
The updated PFS has estimated the project’s net present value, at a 5% discount rate, at $178-million and a post-tax internal rate of return at 35.2%, with a post-tax payback of 2.2 years.

Value
The updated PFS has estimated initial capital expenditure, including working capital, at $148-million.

Duration
Not stated.

Latest Developments
Amarillo is focused on completing the next stage of the permitting process, which includes continuous environmental monitoring, detailed engineering of the tailings dam, basic engineering at feasibility level and procuring surface rights, as well as other social and archaeological studies. This installation licence permit allows for mine construction to begin.

As a result of this updated PFS, the company also plans further resource definition drilling, which could potentially expand the mine’s life. The planned pit shell is controlled in part by the availability of indicated and measured resource blocks. The pit reaches a depth of 260 m in the south-east. It is possible that the pit could be extended at similar depths to the north-west, if inferred blocks are converted to measured and indicated resources with further drilling.

Key Contracts and Suppliers
SRK Consulting (updated PFS).

On Budget and on Time?
Not stated.

Contact Details for Project Information
Amarillo Gold Corporation, tel +55 31 3261 5974 or email info@amarillogold.com.