By Mustapha A. Raji
Nigeria located in West Africa lies between latitudes 4°N and 14°N, and longitudes 3°E and 15°E with an estimated population of approximately 170 million, is the most populous country in Africa. Apart from its crude oil estimates, Nigeria is also abundantly blessed with vast reserves of solid minerals with approximate reserves include iron, cassiterite, marble, limestone, gemstones, lead, zinc, wolframite, chromite, among other minerals. The aforementioned minerals are pertinent strategic and industrial raw materials useful in defence, high-tech, chemicals, domestic, and allied sectors. Additionally, the country has numerous opportunities for investing in mineral sectors due to the approximate reserves of untapped mineral potentials. However, it is saddening that these potentials have been side-lined since the first discovery of crude oil in 1957.
Recently, the decline in the global crude oil price due to the Covid-19 pandemic has translated to the interest shown by the Federal Government of Nigeria in its effort to diversify the country’s economy from crude oil exploration to other sectors of the economy to the mineral sector among others. There is hope that the use of abundant domestically-sourced solid minerals for our indigenous industries would contribute to the nation’s growth and economic sustainability.
Up to date, energy crises are one of the major issues facing many emerging markets, notably, the most common source of energy; coal which is depleting fast due to the emission of greenhouse gases that leads to climate change. Unequivocally, as far as Nigeria is concerned, nuclear energy production and consumption are expected to be on the increase in the next few years. Considering the above-stated factors, it appears very essential to explore alternative sources of energy (which are clean and do not have much detrimental effect on the environment) such as solar, wind, tidal, nuclear, and hydrothermal energies; nuclear power plants are among the said alternative sources of energy, and they make use of main uranium. Similarly, nuclear power plants constitute one of the economical and carbon-free energy sources.
Economically, Nigeria as a developing country has recently signed an agreement with the Russian State Atomic Energy Corporation (ROSATOM) with a mandate to construct its power plant by 2025 – for possible diversification of its energy generation from hard-earned crude oil for electricity generation to nuclear power that is carbon-free tackle air pollution problems, boost industrialization, and revenue generation which would be a plus to Nigeria’s economic growth and development. Interestingly, there abound many other existing but untapped indigenous uranium ores for industrial value addition which Nigeria can utilize effectively.
Hence, owing to the increasing demands for the metallic minerals such as gold, manganese, copper, cassiterite as well as uranium in power and chemical industries, there is the urgent need to explore new routes capable of emanating fewer gangues, affordable, low intensive energy, and eco-friendliness for producing compounds that would find a wide array of utilization in our industries.
As far as mineral processing is concerned, the extraction and the purification of precious metals from their ores for industrial value additions are commonly performed either by pyrometallurgy, hydrometallurgy, or the less efficient bio-hydrometallurgy routes. On one hand, the pyrometallurgy route, as a unit operation, involves thermal treatment of ores at a very high temperature to bring about physical and chemical transformations. As a result of these high energies and transformation, the pyrometallurgy route tends to contribute massive waste or emissions of toxic gases into the atmosphere. However, this technique involves preliminary treatments such as roasting, calcining, and smelting. On the other hand, the hydrometallurgy route involves leaching, solvent extraction, and precipitation methods. Here, the metal of interest and all other associated gangues are dissolved into the leaching solutions in acidic or alkali media. Thus, the metal of interest is separated from the associated gangues in the pregnant solution by solvent extraction and precipitation. These routes are mostly adopted due to metallic products of high purity coupled with fewer environmental hazards.
It is pertinent to note that primary (mineral ores) and secondary (e-waste, button cell batteries, medical wastes, Ni-Cd batteries, etc.) are the main sources for the recovery and separation of precious metals such as uranium, tungsten, manganese, iron, copper, and zinc. Therefore, for possible purification and beneficiation of these precious metals, the utilization of hydrometallurgy which comprises of leaching, solvent extraction, and precipitation routes is mostly adopted due to its economic and safety perspectives. This technique owing to its ease of design with profitable kinetics is what the Hydrometallurgy and Mineral Processing Unit of the Department of Industrial Chemistry, University of Ilorin, Nigeria has been using to record significant progress, globally-acclaimed various contributions coupled with tremendous success and glorious awards to the glory of Prof. Alafara A. Baba (Head, Department of Industrial Chemistry) and Prof. Folahan A. Adekola (Immediate Past Dean, Faculty of Physical Sciences).
Nigerian governments both at state and federal levels need to look closely into the various mineral ore processing for economic sustainability and development. Specifically, of note is the treatment and recovery of Nigerian uranium ores as nuclear fuel in the power sector which will further strengthen the revolution in the dreadful power generation and supply in the country since limited data exist in this regard. However, it would be worthy of note for the Federal Government of Nigeria coupled with its dream to be supervised by its solid mineral sectors to expect the contributions of solid minerals to the nation’s growth and development as there exist abundant uranium mineral deposits of high industrial values and proven reserves in the country.