Modern Mining July 2019

GOLD

three WA800 loaders, three D375A-6 dozers and six HD465-7 water and service trucks. Multiple pits – which will reach depths of up to 210 m – are mined in parallel. The current active pits are Daapleu, Ity Flat and Bakatouo with additional tonnes being sourced from his- torical stockpiles. The LoM strip ratio is low at 1,9 and the maximum mining movement is anticipated to be 16 Mt/a. The processing plant – modelled on the Houndé facility – comprises a single stage primary crushing circuit and two-stage SAG (with pebble crusher recycle)/ball milling in closed circuit with hydrocyclones to produce a P80 grind size of 75 micrometres. A grav- ity concentrator and Intensive Leach Reactor (ILR) have been included in the design as per the Feasibility Study. The CIL circuit comprises eight CIL tanks containing carbon for gold and silver adsorption with oxygen sparged from two 25-tonne PSA oxygen plants and an 18-tonne split Anglo (AARL) elution circuit. Electrowinning and induction furnace smelting complete the gold doré production process. The Tailings Storage Facility (TSF), which is located 300 m from the plant, is a mixture of val- ley and paddock-style which optimises usage of waste and reduces reclamation and closure costs. Total design capacity for the LoM of the TSF is 57 Mt. The facility is made of compacted clay core, overlain by an HDPE geomembrane liner over the entire basin area (including the embankment face). It has a system of finger and

(compared to the design average LoM recovery rate of 86 %) and the overall plant availability at 96 % (compared to the 91 % design figure). Endeavour has determined that the plant can be easily modified to increase the plant nameplate capacity by 1 Mt/a to 5 Mt/a, at a minimal cost of US$10-15 million. The volu- metric upsize work mainly comprises an upgrade in pipes and pumps, and a second 50-tonne oxygen plant with no additional mining fleet required. These plant upgrades are expected to be completed during sched- uled plant maintenance shut-downs during the remainder of 2018. The Ity CIL project – which was officially inaugurated on 9 May by Cote d’Ivoire’s Prime Minister, Amadou Gon Coulibaly – was com- pleted below the initial budget of US$412 million. In addition to the initial scope, extra work was conducted and expenditure incurred, including the construction of a fuel farm, build- ing exploration facilities, and an additional US$7 million of crop and resettlement com- pensation in terms of prospective exploration grounds. Due to these additional works, and the US$10-15 million required for the plant upgrade to 5 Mt/a, the total project capex is expected to amount to approximately US$420 million. The mining is undertaken in-house by Endeavour with contractors being employed for grade control and production drilling. An all- Komatsu mining fleet is used which includes six PC1250 and five PC450 excavators, twenty- three HD785-7 dump trucks (100-ton payload),

Aerial view of the 4 Mt/a (currently being upgraded to 5 Mt/a) Ity CIL plant.

24  MODERN MINING  July 2019