Syama underground gold mine, located in Mali, is the first fully-automated gold mine in the world.

Sociêtê des Mines de Syama (SOMISY), a subsidiary of Resolute Mining (RML), is the project developer. Resolute holds 80% interest in SOMISY, while the Malian government holds the remaining.

Definitive feasibility study (DFS) for the underground mine was completed in June 2016. Underground development works at Syama were started in September 2016, while mining operations were commenced in December 2018. Full-scale automation and production ramp up to 2.4Mtpa is anticipated to be reached by June 2019.

The mine is expected to produce more than 300,000oz of gold a year through its estimated mine life beyond 2032.

Syama underground gold mine development details

BHP originally developed the Syama open-cast gold mine in the 1980s, but sold it to Randgold Resources in 1996. Since acquiring the mine in 2004, RML conducted a number of studies to begin underground mining to supplement the open-pit operations.

The underground project comprises fiber-optic network, installed as part of automation process. Resolute has connected the fiber-optic network to the cloud data with the help of SES Networks’ fiber-like service.

The fully-automated underground mine employs AutoMine® and OptiMine® automation control systems along with automated fleet.

First development ore from Syama was delivered to the surface during the March 2017 quarter, while the first long-hole stoping ore was produced during the September 2018 quarter. The underground mine produced 256,009t of ore and produced 37,256oz of gold till the end of December 2018.

Ore extraction from the 1105 level of the sublevel cave began in December 2018.

Syama gold mine location, geology, and mineralization

Syama Gold mine is located approximately 300km from the capital city Bamako in south-eastern Mali. The mine is situated on the northern edge of the Achaean-Proterozoic Leo Shield, which is the southern portion of the West African craton.

The project tenements are hosted near basalt and argillite of Kadiana–Madinani terrane and polymictic conglomerate and sediments of the Kadiolo terrane.

Pyrite is the most abundantly found sulphide mineral within the Syama mineralized zone. Mineralization is disseminated in highly altered basalt and sediments, within breccia matrix and in sheeted quartz veinlets.

Ore reserves at Syama underground gold mine

As of June 2018, the Syama underground mine was estimated to hold 35.2Mt of probable ore reserves graded at 2.7 grams per tonne (g/t). It is expected to contain three million ounces (Moz) of gold.

Mining and ore processing at Syama underground gold mine

Open-pit mining at the Syama gold mine was completed in 2015, while previously stockpiled sulphide ore is currently being treated to produce gold. Other sources of ore for the oxide circuit include satellite deposits, including BA-01, Nafolo, Beta, Alpha, and Tabakaroni.

Sub-level caving method of mining is being used at the Syama underground project, which employs automated mining fleet including long hole production drilling units, trucks, and loaders.

Ore is processed at two processing plants, a 2.4 million tonnes per annum (Mtpa) sulphide plant, and a 1.5Mtpa oxide plant.

The sulphide ore is treated using conventional three-stage crushing, ball milling, sulphide flotation and dewatering, roasting, calcine leaching, and elution. The oxide processing circuit is a conventional crushing, semi-autogenous (SAG) milling, and leaching circuit.

Infrastructure facilities

Syama gold mine is accessed through a gravel road off the Côte d’Ivoire Highway to Sikasso via Kadiolo and Fourou.

Power supply for the mine is currently provided by a 28MW diesel-fired power station. A new 50MW hybrid power plant will be constructed by Ignite Energy, under a joint development agreement with Resolute, which will replace the existing power station upon commencing operations in 2020.

Contractors involved

Snowden Mining conducted the pre-feasibility study (PFS) for the Syama underground mine.

Optiro prepared the independent mineral resource estimates for the project, while the consultants of WorleyParsons conducted the tailings strategy study.

Byrnecut Offshore was awarded the underground mine development contract at Syama. Sandvik supplied mobile equipment and automation control systems for the Syama gold mine, in addition to providing complete maintenance services.