Name: Asanko mine.

Location: The Asanko concessions are located in the Amansie West district of the Ashanti region of Ghana.

Mine Owner/s: Asanko Gold and Gold Fields.

Brief Description: The Asanko gold mine is a large-scale, multideposit complex with two main orebodies – Nkran and Esaase – and nine satellite deposits jointly owned by Asanko Gold and Gold Fields.

Satellite orebodies within 10 km of the Nkran pit include Adubiaso, Asuadai, Dynamite Hill and Akwasiso.

Brief History: The Asanko project area was previously owned by Resolute’s Amansie Mining Operations, commonly known as the Obotan mine.

Initial mining started at Nikran in early 1997 and first gold was poured by May 1997. The Nkran mine closed in 2001 and was dewatered and reopened in 2015/16 by Asanko Gold as a deeper opencast operation, with an estimated life-of-mine at that time of 12 years.

The Esaase deposit was previously mined by alluvial mining company Bonte Resources. The concession was returned to the government of Ghana after the company went into liquidation, whereafter it was bought by private Ghanaian company Sametro. In May 2006, Asanko Gold, then called Keegan, signed a letter of agreement with Sametro to earn 100% of the Esaase mining concession over a three-year period. The concessions were subject to a systematic exploration and drilling programme.

Gold Fields acquired a 50% stake in Asanko Gold’s 90% interest in the Asanko gold mine in 2018.

Primary Metals/Minerals: Gold.

Secondary Metals/Minerals: None stated.

Geology/Mineralisation: Although each gold occurrence within Asanko has its own local mineralisation style, geological and geophysical studies have profiled a similar mine scale setting for all the deposits discovered to date. There is an underlying structural relationship between reactivated WNW basement structures and the dominant north-east to south-west shears that have juxtaposed the sandstone, siltstone and lesser shale metasedimentary packages, coupled with north to south structures, which may control flexures in the steeply dipping sediments. All deposits have intrusive tonalitic − porphyritic granite dykes.

Episodic gold mineralisation has occurred at least twice during distinct deformational events.

Gold occurs largely as free particles. It is deposited in economic concentrations predominantly around zones of rheological contrast between sandstone (porous) and siltstone facies (nonporous) that are subvertical shear zones, as well as in late, shallow dipping conjugate quartz vein arrays that transgress rheologically contrasting metasedimentary units and the later granite intrusives.

Reserves: Total proven and probable reserves as at December 31, 2019, were estimated at 26.7-million tonnes grading 1.38 g/t gold.

Resources: Total mineral resources as at December 31, 2019, were estimated at 35.52-million tonnes grading 1.69 g/t gold.

Mining Method: Contract mining and conventional openpit truck-and-shovel methods are used at the four active orebodies.

Major Infrastructure and Equipment: Three openpits and one carbon-in-leach gold plant, with a capacity of 5.4-million tonnes a year.

The plant consists of primary crushing, semiautogenous grinding/ball milling circuit, gravity recovery circuit, followed by a conventional carbon-in-leach circuit. Plant tailings are deposited into a single tailings storage facility, which has been built with downstream designed embankments and is high density polyethylene lined.

Prospects: Gold Fields is working with Asanko on near-mine and extensional exploration of the Asanko mining and prospecting leases. Exploration is to be undertaken on two fronts. The first is to extend existing life-of-mine (LoM) openpits and near-mine targets to add mine plan flexibility. The second objective is to extend the mine life by bringing new projects into the LoM plan through phased field programmes.

Contact Details:
Gold Fields
Tel +233 302 770 189/90/91
Email investor@goldfileds.com
Website http://www.goldfields.com