IBBU-MINISTRY OF MINES AND STEEL DEVELOPMENT EXPLORATION AND UTILIZATION STUDY OF NIGERIAN COAL DEPOSITS

Report submitted December 2018
Coal deposits at Okaba (Northern Anambra Basin) and Gombe (Upper Benue Trough) were selected for study of their energy conversion efficiencies and as raw materials for the production of smokeless coal fuel, electricity generation and coking coal blending for steel production. Local combustion, organic geochemical Leco CS and Rock-Eval data were generated on the coals. Combustion studies recording the time it takes same quantities of water to attain boiling point using same quantities of coal show that the Okaba coal is the most efficient with 10.0 minutes while the Gombe coal recorded 12.5 minutes. Juxtaposed against earlier studies, the Omelehucoal (Northern Anambra Basin) took 11.4 minutes, Owukpa(Northern Anambra Basin)16.4 minutesand the Lafia-Obi coal (Middle Benue Trough) never brought the water to boiling point. Leco CS shows that higher TOC values equivalent to burnable carbon are recorded in the Okaba coals. Rock-Eval data show that highest Hydrogen Index (HI) values equivalent to fuel contents are also recorded in the Okaba. Integrating and combining the results, the coals from Okaba have the best energy conversion efficiency and therefore most efficient for use in smokeless fuel production and electricity generation, in the present form, with little negative impacts on man and the environment. Both the Okaba and Gombe coal deposits, based on the relatively high hydrogen index contents are suitable blenders with imported anthracite and/or bituminous coals for coke making. Defusinization experiments in which samples were digested with eight types of organic acids gave results that show that Benzoic and Formic acids can be used to clean the coals to make them more suitable for smokeless fuel production, electricity generation and coke making as the compositional requirements for all three applications lie in high HI and low OI values. The results obtained align with the Roadmap for the growth and development of the Nigerian mining sector developed by the Ministry of Mines and Steel Development. The generation of more electrical power from coals and the commercial production of smokeless coals for domestic cooking will make more power available for domestic and industrial purposes while assisting also to curb the alarming rate of deforestation in Nigeria. The results also benefit the search for blendable coals for coke making for the Nigerian iron and steel industry.