The process flow sheet for the Yanfolila Gold Project. Image courtesy of Hummingbird Resources.
A layout of the Yanfolila mine incorporating the infrastructure facilities. Image courtesy of Hummingbird Resources.
The Yanfolila Gold Project will involve the development of the Komana East (KE) and Komana West (KW) pits in the first phase. Image courtesy of Hummingbird Resources.

The Yanfolila Gold Project is located 40km west of the town of Yanfolila, in the Sikasso region of Mali. The optimisation study for the project was completed in March 2015, following which the initial earthworks were initiated and completed by September 2015. The definitive feasibility study (DFS) was completed in January 2016.

The project is 85% owned by Hummingbird Resources (HUM), who acquired it from Gold Fields in November 2014. Private Malian company Société Malienne de la Petite Mine owns 5% share in the project, while the Mali Government owns the remaining 10% and has an option to increase its stake by an additional 10%.

The Malian gold project has an estimated production life seven years and aims at developing a 1.24Mtpa processing plant and producing approximately 121,000oz of gold a year. It is expected to generate approximately 900 jobs during the construction phase and 800 jobs during the production phase.

Geology and mineralisation

The project is located within the Yanfolila Greenstone Belt on the eastern boundary of the greater Siguiri Basin, which forms part of the Birimian Volcano-Sedimentary series of the West African Craton. The belt hosts a number of sub-basins, including the Komana Mafic Sub-Basin (KMSB) and the Kabaya Sub-Basin (KSB).

Most of the deposits at the project site are hosted within the KMSB and the mineralisation has a stratigraphic sequence of basalt, polymictic conglomerate, feldspathic sandstone, siltstone and greywacke, with mineralised mafic intrusive rocks present at certain locations.

Reserves at the Malian gold mine

As of February 2016, the project is estimated to hold probable reserves of 7.039Mt grading 3.14g/t, containing 709,800oz of gold.

Mining and processing at the Yanfolila gold project

The project involves the development of five open-pits, namely Komana East (KE) and Komana West (KW) in the first phase, and Guirin West (GW), Sanioumale East (SE) and Sanioumale West (SW) in the second phase.

The mining method envisaged for the project is the open-pit mining using conventional drill and blast, and load and haul operations.
The proposed conventional processing plant will primarily integrate a two-stage crushing facility, a closed-circuit ball mill with gravity concentration, a carbon in leach (CIL) circuit, an elution column, a gravity electrowinning circuit and a gold sludge smelting facility to produce doré.

Infrastructure for Hummingbird Resources’ gold project

The power required for the project during the construction phase will be met by generators, whereas during the production phase, the power will be supplied by an independent power provider (IPP). The required water will be sourced from the Sankarani River.

“The project is 85% owned by Hummingbird Resources (HUM), who acquired it from Gold Fields in November 2014.”

Access to the project site is provided by an existing 29km road connecting the town of Yanfolila to the Kona Bridge near the project site. This existing road will be upgraded and a new 8km-long access road will be constructed from the Kona Bridge to the processing plant area. A 1,300m laterite airstrip is also proposed to be constructed to transport the personnel and the gold.

Other major infrastructure at the site will include a tailings storage facility (TSF), water and sewage treatment plants, fuel storage facilities, fire protection systems, an assay lab, a change house building integrating the security office and the first-aid room, a control room building on top of the CIL tanks, and two reagents store buildings.

The project will use the existing accommodation facilities located at Komana. The facilities will be expanded and upgraded to provide a capacity for 152 people.

Key players involved

The DFS was compiled by DRA Projects with contributions from CSA Global for the reserves and resources estimates, SENET for the metallurgical testwork, process design and engineering, the capital and operating cost estimates for the processing plant and the associated plant infrastructure. Schlumberger Water Services (SWS) performed the detailed hydrology and hydrogeological studies, and Ausenco Engineering Canada (Ausenco) provided the design and cost estimates for the TSF.

DRA and SENET have been retained to serve as the project manager, and the engineering, procurement, construction and management (EPCM) contractor respectively.

Financing for the Yanfolila gold project

The overall investment to bring the project into production is estimated to be $79m. Taurus Mining Finance Fund is providing a $75m loan to finance the construction of the project.