Modern Mining February 2018

GOLD

period and has a total estimated value of US$112 million. Hummingbird said at the time of announcing the award of the contract that it represented an approximately 5 % improve- ment on the DFS estimate. The Yanfolila ore is non-refractory and the simple process plant design utilises gravity and CIL processes for the recovery of the gold. Designed to achieve a recovery of 92,8 %, the

within the timeframe originally set down.” Nearly 2 million man-hours were expended on the construction phase of the project, which also saw the erection of over 1 600 tonnes of structural steel and mechanical equipment, the pouring of over 4 000 m 3 of concrete and the installation of over 20 km of piping. Located in the Sikasso region of south-west Mali close to the border with Guinea, Yanfolila is a low-cost, high-grade, open-pit mine. It has 710 koz of reserves at 3,14 g/t but an overall 2,2 Moz resource at 2,4 g/t. The average annual production over a life of mine (LOM) of 7,5 years is 107 000 oz at an AISC of approximately US$700/oz. The first active pit, Komana East, is about to be joined by a second pit, Komana West, and these two will account for the bulk of ore production at the mine for the next sev- eral years. Three further pits – Guirin West and Sanioumale East and West – will be exploited starting in year 5. The LOM strip ratio is 11,9:1. To undertake the mining, AMS – which started producing ore in August last year – has deployed a fleet of four Liebherr 9150 excava- tors, one Liebherr 9250 excavator, 18 Cat 777F 100-ton mining trucks and four drill rigs. Blasting is carried out using non-electric down- hole delay detonators with ammonium nitrate fuel oil (ANFO) for dry holes and emulsion explosives for wet holes. AEL is providing an explosive storage and supply service to AMS. AMS’s contract is for an initial three-year

Mining operations underway in the Komana East pit at Yanfolila.

The process plant is designed to achieve a recovery of 92,8 % and has a capacity of 1,24 Mt/a.

February 2018  MODERN MINING  27