Siguiri, Guinea

Overview and locality

Siguiri is AngloGold Ashanti’s only operation in the Republic of Guinea. The mine is 85% owned by AngloGold Ashanti and 15% by the government of Guinea.

Siguiri is currently a multi-pit fresh rock and oxide gold mining operation and is contractor mined using conventional open-pit techniques. The gold processing plant is designed to treat 12Mt annually on a 100% basis. A combination plant conversion allows the mine to treat 6Mt of sulphide ore and 6Mt of oxide ore.

A brief history

• First gold mining can be traced back to the first great West African Empire, the Sarakolle Kingdom
• Between 1931 and 1951, the French reported gold coming out of Siguiri, with figures varying between 1 and 3.8t annually
• Between 1960 and 1963, there was a phase of Russian exploration in the area that focused on the placer deposits along the major river channels in the area.
• In 1980, Société Minière Internationale du Quebéc (SOMIQ) gained the exploration rights for Siguiri and Mandiana. SOMIQ focused its work on the Koron and Didi areas. The Chevaning Mining Company Limited was then created to undertake a detailed economic evaluation of the prospect, with more intensive work beginning in the late 1980s.
• Société Aurifere de Guinea (SAG) took over from its predecessors and continued work on the placer deposits. Production on the Koron placer reached a peak in 1992 with 1.1t gold being produced, although due to a number of difficulties, the mine was shut down later that year.
• In the mid-1990s, Golden Shamrock acquired and operated the project as an open pit and heap leach.
• In October 1996, Golden Shamrock was acquired by Ashanti Goldfields Corporation which operated Siguiri as a heap leach until 2004.
• In 2004, Ashanti Goldfields Company Limited merged with AngloGold Limited to become AngloGold Ashanti Limited.
• The design and construction of the 8.5Mtpa saprolite soft rock treatment plant was completed and commissioned in 2005. Capacity was later increased to 12Mtpa
• A Siguiri combination plant feasibility study, based on the requirement to process fresh and transitional material in combination with existing oxide material, was completed in 2015. The combination plant conversion project began in 2017 to allow the mine to treat 6Mt of hard fresh rock ore and 6Mt of oxide ore. Construction was completed in March 2019, with the operation completing the optimisation and de-bottlenecking of the processing plant in 2021.