Name of the Project
Syama underground gold mine project.

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

Client
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 currently 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 uprades 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 lift 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 (LCR).

Through a series of improvements, the roaster has been running above nameplate capacity at 25 t/h. The LCR 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 LCR 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.

Value
Resolute has indicated that it will internally fund the preproduction capital requirement of $95-million from current balance sheet and future operating cash flows.

Duration
Not stated.

Latest Developments
An update to the DFS has delivered a significant reduction in the LoM all-in sustaining cost to $746/oz to $881/oz.

The DFS update presents the results of an ongoing effort by Resolute Mining to critically examine and pursue improvements in all aspects of its flagship operation.

A key focus has been the redesign and rescheduling of the underground mine, following the 39% increase in mineral resources.

The adoption of autonomous mining will result in substantially lower average mining costs, while improvements to site power generation facilities will deliver significant reductions in processing costs.

The sublevel cave mine plan at Syama lends itself to automation, MD and CEO John Wellborn has explained, noting that the miner’s partnership with engineering company Sandvik to deliver autonomous haulage and trucking enables major productivity and cost improvements over the original DFS.

An upgrade of the Syama power station supports a further cost reduction in sulphide processing. Collectively these improvements support LoM production at an AISC of about $746/oz, a material improvement on the original mine design.

Wellborn further notes that the company’s investment in technology and exploration is resulting in a substantial expansion to the scale, operating margins and value of Syama.

“Reducing operating costs and increasing production at Syama is consistent with our journey to build an operation that utilizes best-in-class technology while maintaining flexibility to incorporate further advances in mining and processing. We aim to make Syama the best mine of its type in the world and to ensure that we unlock the full potential of this outstanding orebody”.

Wellborn has elaborated that the pursuit of world-class mining and processing has been accompanied by a renewed commitment to, and investment in, exploration.

“The exceptional drill results achieved over the past two years have been followed by a sophisticated and rigorous mine design and evaluation process, which has resulted in an increase of nearly one-million ounces in contained gold in the Syama underground probable reserve.”

In addition, Resolute has discovered and started the delineation of a new ore zone at Nafolo. Wellborn has cited this as a breakthrough in the understanding of the size and potential of the Syama mineralised system.

The miner remains confident of further growth in the resource base.

“The growing reserves at Syama, and our commitment to new technologies, offer significant opportunities for further optimisation, expansion and unit cost reduction,” Wellborn has added.

The DFS update is based on maintaining the planned mining rate of about 2.4-million tonnes yearly.

“Our study focus at Syama will now turn to identifying the optimal future mining rate based on the improved automated infrastructure we have developed, and the significant progress being made on our processing capabilities,” Wellborn has indicated.

There is “obvious scope” to increase the current planned mining rate to about four-million-tonnes yearly, he has noted.

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

On Budget and on Time?
The project is on track to begin sublevel caving in December 2018.

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