Mining in Nigeria – First Account

25th November 2021

 

 

It is no news that Africa as a continent is blessed with abundant key mineral resources with a bunch of reserves underdeveloped and in most cases undeveloped. Much of the mining in Africa is done by artisans who prospect and exploit minerals including gold, diamonds, cobalt, iron ore, copper, galena, bauxite and salt. While this may still be the case in most countries in the region, government and private partnerships are paving the way for the rapid evolution of the industry, with hopes of providing local benefits and addressing environmental concerns while deriving value for the investors.

Nigeria, a major producer of critical metals and minerals, is the richest (by GDP) and most populous country in Africa, located on the western coast of Africa, in a position described as the trigger position of the gun-shaped African continent. Nigeria has a diverse geography with climate ranging from humid to arid.

Map of Nigeria
Map of Nigeria, relative to Africa (Source: internet geography).

Prior to the oil boom in 1970s which lead to a remarkable increase in foreign exchange earnings from petroleum exploration and exploitation, the mainstay of the Nigerian economy was mainly agriculture and mining, accounting for more than 80% of the gross revenue at the time. Mining activities in Nigeria started way back as 1903 after the set-up of the Mineral Survey agency by the then British colonial government. The major production at the time was limited to coal from the Enugu coal deposits, and cassiterite and columbite associated with the Pre-Cambrian granites widely exposed in the north central part of the country.

Due to the shift in focus to petroleum, the mining industry suffered a significant blow, relegating its economic contribution to about 0.03% of GDP. Recently, especially due to the fact that Nigeria’s ‘mono-economy’ is challenged by the world’s energy transition policies, there have been several initiatives and incentives to attract investors interested in pursuing mining ventures in Nigeria. This article shares valuable insights on the distribution and location of a number of minerals across Nigeria.

Coal

Coal was first discovered in Nigeria in 1909 at the Udi Ridge in Enugu. Coal is found in association with sedimentary successions with high organic contents that have been thermally altered in the absence of sufficient oxygen for decomposition. Nigeria still holds large coal reserves in various sedimentary basins, estimated to be at least 2 billion metric tons. The discovery of bituminous coal suitable for use in coke production for the iron and steel industries opens up potential new domestic markets.

Coal seems outcropping in Enugu (Source: Akinlagun A. 2018)

While the domestic market for coal has been negatively affected by the move to cleaner energies by organizations that were previously major coal consumers, the low-sulfur coal mined in Nigeria is desirable for international customers, who still import Nigerian coal. Recent financial problems have caused a near-shutdown of the Nigerian Coal Corporation mining operations, and the corporation has responded by attempting to sell off some of its assets while it waits for the government to complete privatization activities. Common mine sites include the Oyeama, Amansiodo, Ezinmo, Obwetti, and Ogbete mines in Enugu; Okaba and Ogboyoga in Kogi state, Ogwashi-Azagba in Delta; Owukpa Mine in Benue and Maiganga Mine in Gombe state. Part of the techniques being explored by the Eta-Zuma Group is the use of the coal deposits for power generation and the processing of lignite into low carbon yielding briquettes used for domestic purposes especially for the energy-starved parts of Northern Nigeria,

Gold

Gold deposits have been found in various grades, mostly associated with the basement complex of Nigeria. Major occurrences of gold have been found in predominantly two styles: the first are primary deposits associated with mineralized veins in the schist belts of northwest, central and southwestern Nigeria, and the second are placer gold deposits related to eroded veins which are transported over active streams or have been deposited alongside alluvial sediments and buried over time. Exploration activities in Nigeria are concentrated on finding the placer gold due to the ease of exploitation. Locals have been known to use traditional crude methods to pan eroded gold debris from the stream and river channels draining these mineralized zones.

The occurrence of gold in primary veins is common in several areas of the western half of Nigeria (Kankara and Darma, 2016). These primary gold mineralizations are associated with veins, stringers, lenses, and similar bodies of quartz, quartzo-feldspathic and quartzo-tourmaline rocks. In the Anka and Maru areas of Northwest Nigeria, these veins have varying thickness, ranging between several centimeters and a few meters, often displaying boundinage (pinch and swell) structures. They occur as isolated bodies, parallel and/or echelon vein systems.

Exploration for placer deposits is typically carried out using geochemical methods, employing the use of pathfinder elements in the search for gold. The presence of these pathfinders opens up the possibility of locating a nearby gold deposit, especially with a distributed pattern from the secondary and primary halo. Examples of minerals that are geochemical pathfinders for gold include silver, copper, lead, zinc, cobalt, nickel, arsenic, antimony, tellurium, selenium and mercury. Apart from Maru and Anka, other gold mine sites include Malele, Tsofon Birinin Gwari, Kwaga, Bin Yauri, Gurmana, Okolom-Dogondaji, and Iperindo in Ilesha. Tree Mines Global, an indigenous company with Gold assets in Kogi and Kwara states in Nigeria started new sets of explorations in the middle belts. Similarly, Moydow Holdings Limited announced the commencement of drilling in the Paimasa Gold Project located in the central part of Nigeria, about 115km north-northwest of the capital city, Abuja. The Dagma Project in the Benin-Nigerian shields which comprise of Archaean and Proterozoic basement rocks hosts several gold mineralizations as well. Kinsfield Resources operates two Gold fields located in the southwest around IsanluEsa, Yagba west area of Kogi state.

Locals panning eroded gold and niobium from streams (Extracted from Financial Times).

Cassiterite and Columbite

Columbite ores, which are typically found in association with tantalite, are sources of niobium and tantalum. In Africa, this association is collectively known as ‘ColTan’. Tantalum is an important element used in the production of electronics and electrical parts. In Nigeria, ColTan deposits are found in association with the pegmatites of the older granites, which also host other precious and semi-precious stones such as beryl, aquamarine and tourmaline. Common occurrences of these ColTan-hosting pegmatites are found in Nassarawa state, towards Jos Plateau, and in selected regions in the southeast, where they are associated with orogenic and hydrothermal events.

Pegmatite hosting columbite and tantalum minerals.

Cassiterite, which is an important source of tin, is found in large occurrences in the Jos Plateau. It is often found in hydrothermal veins or pegmatites. Cassiterite has also been found as nodules and large grain concentrates in placers formed from secondary processes in the oxidation zone of weathered tin deposits. Eta-Zuma Group, Schistbelts Mineral Limited, Greenfield Metals Limited, Western GO Group, etc are active players in the exploration and development of these metallic ores.

Galena and Chalcopyrite

Galena is the main ore of lead, and also an important source of silver. Galena ores in Nigeria typically occurs as hydrothermal veins in association with silver, sphalerite, chalcopyrite, quartz, barites and fluorites. Large-scale veins of galena and associated minerals have been discovered over the years in the Albian Shale and Limestone formations of the Asu River group in the Benue trough. Its distribution is widely controlled by the occurrence of fault systems that provide migration pathways for lead-bearing hydrothermal fluids. These veins along faults have been seen to run for several meters and are of varying thickness, mostly depending on the dip of the fault plane. Huge deposits are being mined in various sites in Ebonyi state such as Ishiagu, Ikwo and Ameka, as well as Taraba, Kwara, Kogi, Plateau, and Nassarawa state. In Ebonyi, Royal salt company is a major operator of several galena-rich mines in Abakaliki area of Ebonyi state.

High grade galena ore extracted from a mine site in Ishiagu, Ebonyi State.

Other important minerals in Nigeria include iron ores, wolframite, sphalerite, magnetite, bismuth telluride, barites, tourmaline, lithium and uranium ores. These resources are widely distributed within the various geological provinces of Nigeria.

Are you considering venturing into the Nigerian Mining space? Then make your way to the Nigerian Mining Cadastre Office, a subsidiary of the Ministry of Mines and Steel Development of the Federal Republic of Nigeria, which manages all the Nigerian mining licenses and mining rights.

References

Kankara, I. A. and Darma, M. R 2016. A Review of Gold Metallurgeny in Nigeria. Int'l Journal of Research in Chemical, Metallurgical and Civil Engg. (IJRCMCE) Vol. 3, Issue 2 (2016) ISSN 2349-1442 EISSN 2349-1450.

Nigeria Geological Survey Agency, (2006). Geological Map of Nigeria. Federal Ministry of Solid Minerals Development.