Gold mining has been an on-going activity in Kenya even before independence, with artisanal gold mining being the most dominant type. A number of international gold mining firms have been granted exploration licenses by the Kenyan government in the recent past to help professionalize the sector and increase yields. Some of their finds point to a bright future as far as gold mining is concerned. Mining of gold in Kenya can be traced back to 1882 when the first gold was discovered in western Kenya at Lolgorian on the border of the defunct Rift Valley and Nyanza provinces. Up until now most of the gold findings have not been commercialized.
Rosterman Gold Mines, a British company in 1935 was given the first license to prospect for gold in Kakamega. It struck gold and ended up conducting its activities there up to 1952 when the company closed. It had mined about 259,000 ounces of gold. Once this company exited, the mining of gold in Kakamega and several other places in western Kenya continued on small scale. This was and still is undertaken by the residents of those areas. The next commercial prospecting of gold was done in 1992, which resulted in the discovery of more gold deposits in Nyanza province.
One of the areas identified was the Migori Greenstone belt (MGB). This forms part of the Nyanzian supergroup, itself part of the northern extension of the gold-enriched Archaean Tanzanian craton. The granite-greenstone terrain to the south of the MGB is host to world class producing gold mines. The area is covered by volcano-sedimentary sequences and intrusive rocks of the Migori Greenstone Belt. Gold is hosted in quartz veins and also it is associated with massive sulphides ;pyrrhotite, pyrite, chalcopyrite, and galena.
The Tanzanian craton is of a similar age to other significant orogenic gold belts such as the Yilgarn in Australia and the Lake Superior province in Canada. The mineralization and stratigraphy of the MGB is similar to that of the Lake Victoria Greenstone belts in Tanzania and other Archaean greenstone deposits such as Red Lake in Canada.
Gold enrichment within the MGB is predominantly found in and around shear zones associated with quartz-carbonate veining and significant alteration, as well as banded iron formations (BIFs) and poly-metallic Volcanogenic Massive Sulphides (VMS). The dominant lithologies are felsic and mafic intrusive, BIFs and metasediments of the Nyanzian system, overlain by younger Kavirondian volcaniclastic sediments and intruded by younger granitic intrusions.
Kilimapesa Gold, Kenya’s first commercial gold mine since independence in 1963 was put into commission in 2009. The Kilimapesa Gold mine is located in the Migori Archaean greenstone Belt in western Kenya. The mine has a total resource of 8,715,291 tonnes at 2.40 g/t of gold for a total of 671,446 ounces of gold at 1 g/t. The mine project was initially a partnership between International Gold Exploration Company and Goldplat but it is now wholly owned by the Goldplat. Goldplat began commercial gold mining at the mine in 2012 once the commercial mining license was granted. The first gold poured out of the mine in 2012. This Company is focused on increasing production at the mine through a new processing plant and a tailings deposition facility. The new plant was commissioned in February 2017 at a site in close proximity to the Kilimapesa Hill underground mine and has a designed capacity of 200 tonnes per day. The plant has been uniquely designed to maximise production volumes by incorporating a crusher circuit, mills, a thickener, leach tanks, the existing elution plant as well as a tailings deposition facility.
Another important company involved in gold mining in Kenya is Stockport, which is involved in gold exploration of the Nyanza-Sotik project. The Stockport project is a joint venture between East Africa Pure Gold and the B&M mining. The exploration begun in early 2000 and there has been a number of successes especially in the Kamwango area.
The Red Rock company also plays an important role in gold mining in Kenya. Its key exploration is on the border between Kenya and Tanzania in Migori gold belt. The area has great potential given the fact that gold has been mined there on small scale by the locals for years. The company works through its subsidiary the Mid Migori mining Company that controls prospecting licenses to the region. This is the company associated with Macalder mines in Nyatike.
Another player is Acacia. The Africa-focused gold producer Acacia Mining declared early 2017 that an inferred mineral resource of about 1.31m ounces of gold at 12.1 grams per tonne was available on its Liranda Corridor at its West Kenya project. With six drill rigs currently active on site, and two more to follow soon, Acacia expects to increase the resource to 2 million ounces by the end of the year.
The company, which is majority owned by Canada’s Barrick Gold the world’s No.1 gold miner — said all inferred material is located on the Acacia prospect with multiple lodes open laterally and at depth. It also noted its Bushiangala prospect, “which has known mineralization”, had not yet been incorporated to the resource.
Further gold deposits have been discovered in parts of Narok, Kakamega, Transmara and Migori counties. A number of the new discoveries are of commercially viable quantities and it is believed that some can support large-scale mining for between 10 and 20 years.