Name of the Project
Syama underground gold mine project.

Location
Syama is located in south-eastern Mali, about 280 km from Bamako.

Project Owner/s
Resolute Mining.

Project Description
A definitive feasibility study (DFS) on the project has confirmed the Syama underground mine as a long-life, low-cost mine that will continue to deliver strong operating margins for Resolute for more than a decade.

It has been determined that sublevel caving represents the optimal mining method to develop the extensive sulphide orebody beneath the openpit.

This mining method will provide controlled, high-productivity ore delivery from the deposit.

The prefeasibility study completed on the project in 2015 considered a two-million-tonne-a-year production rate using a single decline with truck haulage and direct truck-loading.

Industry experience suggests that production rates of more than two-million tonnes a year might be compromised by a single decline.

As a result, the DFS has used a twin-decline truck option and internal ore passes for more efficient loading.

The incorporation of a second decline provides distinct advantages for efficient trucking, with separate traffic directions to minimise congestion, allowing for improved spatial layout for ore passes, better ventilation and a second means of egress.

While the DFS has been based on the twin-decline truck option, there is sufficient flexibility in the design and timing to more comprehensively assess the option to include conveyor haulage as an alternative to trucks.

The twin access also enables Resolute to consider expansions in mine production rates in the future.

Current production from Syama is more than 200 000 oz/y of gold and development of the underground mine will result in production increasing to 250 000 oz/y.

Resolute will also implement a series of process upgrades to mainly increase the sulphide gold recovery from 78% to 85% (Project 85).

These upgrades will comprise:
• flotation tails carbon-in-leach (CIL), which entails that the current calcine CIL circuit be repurposed to treat the flotation tails;
• a new calcine CIL, which entails the design and installation of a new dedicated calcine CIL circuit;
• regrind, which will involve the coarse calcine product being reground prior to CIL; and
• the upgrade of the current flotation circuit, which entails a series of minor upgrades to improve the operational performance.

In addition, minor modifications to the crushing and grinding circuits will increase mill capacity to 2.4-million tonnes a year.

Resolute is also working with Outotec, the manufacturer of the roaster, to develop a new roaster technology that will produce a low-carbon calcine to further improve CIL recovery. This new technology will enable Resolute to modify the current single-stage circulating fluidised-bed roaster into a low-carbon roaster.

Through a series of improvements, the roaster has been running above nameplate capacity at 25 t/h. The roaster will allow for an increase to 33 t/h.

By significantly reducing the carbon in the calcine being fed to the calcine CIL circuit, the roaster will contribute to an increase in the overall sulphide gold recovery beyond the benefits already mentioned in Project 85. Consequently, life-of-mine (LoM) recovery will be 89%.

The Syama underground mine has an initial operating life of more than 12 years.

Currently delineated underground probable reserves are estimated at three-million ounces at 2.7 g/t gold.

Syama underground mineral resources are estimated at 5.9-million ounces at 3.2 g/t gold.

Potential Job Creation
Not stated.

Net Present Value/Internal Rate of Return
Not stated.

Capital Expenditure
Resolute has indicated that it will fund the preproduction capital requirement of $95-million from the current balance sheet and future operating cashflows.

Planned Start/End Date
Full commissioning of the underground operation has been targeted for the third quarter of 2019.

Latest Developments
Resolute Mining has announced the completion of the Syama sulphide plant shutdown, completing its A$7.5-million enhancement project at the gold plant.

The shutdown started on February 18, with the comminution circuits fully recommissioned by March 20, ahead of schedule.

Resolute told shareholders that flotation concentrate has been stockpiled in advance of the roaster restart to provide immediate gold concentrate feed. The full restart of the roaster was delayed by three days to account for revised recommendations from the refractory suppliers resulting in a more conservative refractory installation and curing process.

First gold concentrate was fed to the roaster on March 31, completing the restart of the entire sulphide processing circuit.

The entire sulphide plant is now expected to be more consistent and manageable, as measured by the overall plant availability, leading to improved production outcomes. Roaster capacity is also expected to increase, which will effectively advance the sulphide circuit ‘bottleneck’ from the roaster to the crusher.

Following a detailed review of the integrity of the roaster, use of condition monitoring controls and the properties of the newly installed refractory it should be possible to extend the next major shut and refurbishment of the roaster by up to seven years, improving the production profile of the Syama sulphide project and LoM fundamentals.

Key Contracts, Suppliers and Consultants
Sandvik (autonomous haulage and trucking).

Contact Details for Project Information
Resolute Mining, tel +61 8 9261 6100, fax +61 8 9322 7597 or email contact@rml.com.au.