The Syama gold deposit lies on the northern margin of the Archaean-Proterozoic Leo Shield which forms the southern half of the West African Craton. The Syama tenements straddle the regional boundary between interbedded basalt and argillite of the Kadiana–Madinani terrain with polymict conglomerate and sediments of the Kadiolo terrain.

From west to east the stratigraphy contains an un-mineralised hangingwall zone consisting principally of basalt and andesite, a 200m to 300m thick mineralised sequence of altered and pyritic basalt, greywacke and intrusive rocks. On the footwall side polymict andesitic conglomerate forms the eastern boundary of the sequence.

The Syama Bananso Fault Zone is an extensive regional structure located on the sharp contact with the conglomerate. While the mine stratigraphy dips at 60° toward the west it is in an overturned position with younger rocks toward the east. The spatial distribution, geometry and character of lamprophyre units intruding the sequence is considered an important factor in the mineralising event as they display an intimate geometric relationship with alteration and mineralisation.

Within the mineralised zone pyrite is the dominant sulphide mineral accompanying gold. It is found as disseminations in highly altered basalt and sediment, within breccia matrix and in sheeted quartz veinlets. The pyrite content can be up to 15% but generally represents less than 5% of the rock mass. Gold occurs in three forms comprising native gold, electrum and solid solution gold in pyrite. The majority of gold present is refractory while the reduced amount of free gold observed is up to 300µm in size but predominantly fine grained.

Mining at the main Syama open pit was completed in May 2015 with ore for the sulphide circuit currently being sourced from previously stockpiled sulphide ore, underground development ore and satellite operations.

Mining was conducted in the BA-01, Beta and Alpha pits during FY18. These satellite pits are located approximately 4-6km north of Syama and form part of a series of northern satellite deposits, including the A21 deposits mined between FY15-17. Total waste material mined from the satellite pits for the financial year was 2.70m bank cubic metres (BCM) of material (FY17: 4.20m BCM). Total ore mined was 0.78m BCM at a grade of 2.09g/t Au (FY17: 1.13M BCM at 2.35g/t Au) and a (waste:ore) strip ratio of 3.5:1 (FY17: 3.7:1).

Resolute is continuing to ramp up the Syama underground mine for commercial production in the September 2019 quarter.

The planned transition of Syama to an underground mining operation has provided an opportunity to fundamentally review all aspects of the Syama operation.

Through the various stages of mining evaluation, it was determined that Sub Level Caving (“SLC") represented the optimal mining method to develop the extensive sulphide orebody beneath the open pit. This mining method will provide controlled, high productivity ore delivery from the deposit. Industry experts from Snowden Mining Industry Consultants outlined the following advantages of SLC at Syama:
• SLC is highly mechanised, well understood and used in many locations around the world and is able to deliver the required production rate to replace open pit production at a comparable cost.
• The orebody geometry and geotechnical conditions are suited to SLC.
• The subsidence zone will not affect critical infrastructure.

Resolute operates two processing plants at Syama: a 2.4 million tonnes per annum (Mtpa) sulphide processing circuit and a 1.5Mtpa oxide processing circuit. Due to the refractory nature of the sulphide ore, it is treated using conventional three-stage crushing, ball milling, sulphide flotation, roasting, calcine leaching and elution. The oxide processing circuit is a conventional crushing, SAG milling, and leaching circuit.

Syama Oxide Operation – Gravity Circuit
During the September Quarter 2018, work progressed on the installation of a gravity gold recovery circuit within the oxide
processing plant. The new gravity circuit, which comprises a Knelson concentrator and Acacia reactor, will allow Resolute to efficiently recover coarse gold which is expected to occur in the Tabakoroni oxide deposit.

Additional metallurgical testwork was developed to confirm gold extraction characteristics of future underground ore to ensure it was able to be processed through the current flowsheet. The current processing plant is designed to treat the primary Syama ore where the gold is dominantly refractory and located within sulphides. The sulphides require roasting to oxidise and release the gold ahead of the routine carbon in leach (“CIL") process. The product from roasting, the calcine, is then fed to the CIL circuit. The roasting process also oxidises the majority of the organic carbon which would otherwise cause preg-robbing in the cyanide leach train.

Processing of the ore will be via the following stages:
• Crushing and grinding.
• Flotation to produce a sulphide rich concentrate.
• Concentrate thickening.
• Roasting, followed by calcine quench and wash.
• CIL.
• Tailings disposal.
The crushing, grinding and flotation circuit has a designed capacity of 2.4 Mtpa and the roaster will process 196,000t of concentrate per annum. The CIL circuit has a designed capacity sufficient to process all of the roasted concentrate.