Browsing by Author "Amoka, I.S."

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    Application of Geographic Information System for Mineral Exploration in Nigeria
    (Department of Geology and Mining, Nasarawa State University, Keffi, 2010-07-05) Amoka, I.S.; Jatau, B.S.
    Delineation and evaluation of mineral resources are major exploration parameters required for investment decisions. In Nigeria, however, there is acute shortage of such data to ensure rapid mineral development. Recent integration of exploration data with GIS, supported by intelligent systems, has greatly enhanced the acquisition, analysis and interpretation of complex problems of probabilities and decisions involved in mineral projects. Geophysical studies and mineral reserves estimation have been undertaken to illustrate major areas of GIS application in Nigeria’s mineral industry. Resistivity profiles from Ungwar-Doka and Rafin-Gabas, North-central part of Nigeria, were digitized into GIS to delineate tourmaline and chalcopyrite resources. Drill-hole data from Malori and Gurjaji in north-eastern Nigeria were used to generate isopach maps of gypsum quantities from which the reserves were calculated. The results demonstrate the potential of the GIS in speedy and reliable execution of mineral exploration projects.
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    Application of geographic information system in reserves estimation of Oyo-lwa marble deposit, Lokoja Area, Central Nigeria
    (Department of Geology and Mining, Nasarawa State University, Keffi, 2011-11-19) Jatau, B.S.; Amoka, I.S.
    Ore reserves estimation was carried out using GIS modelling on the Oyo-lwa marble deposit in the basement complex of west central Nigeria. Based on topographic, geological, geophysical, and geochemical appraisal, exploratory boreholes and geophysical parameters, distributed on 400m grid pattern were applied. The GIS modelling and delineation using TIN-surface interpolation of the iso-resistivity maps gave approximately 77 million tonnes of marble, while calculations from borehole logs using TIN-surface model, cut and fill method gave approximately 80 million tonnes for a depth recovery of 20m. Using rectangular block method and assuming a recoverable total thickness of 15-20m of the marble, an estimated volume of 24-30 million tonnes is considered to be available for exploitation. With marble bulk density of 2.67t/m3 using rectangular block pattern of estimation, a conservative reserve estimate of 60-80million tonnes of marble is expected to be available for exploitation within the area of investigation.
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    Characterization and Mining of Talc Deposit from Kagara, North Western Nigeria
    (Department of Geology and Mining, Nasarawa State University Keffi, 2015-02-13) Amoka, I.S.; Jatau, B.S.; Ali, M.
    Nigeria's talc reserves are considered suitable for a strong industry for both local and export demands. However, there is only one active talc mining and processing operation, located in Kagara, northwestern Nigeria. The talc resources occur in the schist belts, spread over several geopolitical regions. The deposits occur mainly as massive talcose rocks, usually grayish to greenish in colour. They are predominantly associated with chlorite, tremolite and magnesite. Chemical compositions range from 42% to 60% SiO2, 27 - 32% MgO, 3.5 - 14% LOI, 0.8 – 4.1% FeO and 1.1 – 7% Al2O3. Preliminary beneficiation tests on samples from the mine site show that the quality of the talc deposit can be improved by froth flotation, after pre-concentration by magnetic separation. The milled talc is mainly produced for fertilizers, and minor quantities for ceramics. It is however envisaged that the brighter talc produced by flotation would be suitable for paints, paper, plastics and textile. It is recommended that sub-surface exploration and further flotation studies be carried out to enhance the industrial applications of the talc deposit
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    Petrological and Proximate analysis of Obi-Lafia coal, Nasarawa State, Central Nigeria
    (Department of Geology and Mining, Nasarawa State University Keffi, 2008-11-18) Jatau, B.S.; Amoka, I.S.; Oyeladum, O.A.W
    Preliminary visual examination of Obi/Lafia coal revealed vitrain, clarain and fusain. Petrological studies established that the coal contained vitrinite, extrinite, fusinite (fossil) and mineral substance mostly pyrite.Examination with research microscope(x20) showed vitrinite to be 70%, Extrinite 14%, fusinite 2% and mineral substance (mostly pyrite) 14%. Proximate analysis revealed 4.33% moisture content,35.66% volatile matter. 9.6% ash content and fixed carbon 50.34%. The density of the coal was 1.26 and inorganic matter 16.54%. Ultimate analysis revealed 3.21 % sulphur content. Samples were heated to about 900°C, it forms cake but breaks with slightly strong pressure applied, which indicates it is probably medium coking.
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    SOCIO-ECONOMIC IMPACTS OF ARTISANAL AND SMALL-SCALE MINING (ASM) IN NASARAWA STATE, CENTRAL NIGERIA
    (Department of Geology and Mining, Nasarawa State University, Keffi, 2009-01-26) Jatau, B.S.; Amoka, I.S.
    Artisanal and Small-scale Mining (ASM) has recently received increased local and international attention. This paper aims at providing a balanced overview of the positive and negative impacts of Artisanal and Small-scale Mining (ASM) in Nigeria, with particular reference to Nasarawa State. The benefits and hazards are reviewed and policy response and implementation strategies are suggested. Presently, the hazards of ASM seem to outweigh its benefits in Nasarawa State and generally in Nigeria. However, ASM could make a sound socio-economic and environmentally friendly impact in Nigeria if the operators, stakeholders, authorities, government, financial institutions, donor agencies and non-governmental organizations (NGO) would make concerted efforts to regulate, guide, improve and encourage the industry.
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    WASHABILITY AND FROTH FLOTATION TESTS OF LAFIA-OBI COAL DEPOSIT, NASARAWA STATE, NORTH-CENTRAL NIGERIA.
    (Department of Geology and Mining, Nasarawa State University Keffi, 2013-03-01) Jatau, B.S.; Amoka, I.S.; Fadele, S.I.
    Washability and froth flotation tests on Lafia-Obi Coal deposit Nasarawa State North-Central Nigeria were carried out on samples of the coal deposit obtained from seams 30, 13 and 12 after size reduction using hammer and jaw crush respectively. This is a follow-up research of the proximate analysis conducted with the same samples in the same study area Heavy liquids used for the washability test were carbon tetrachloride CCl4, tannile C6C5 – NH2 nitro benzene C6H5NO3 and Bromoform CHBr3 1.18 to 0.6 micro screened size fractions were adopted for the washability test. 355-600 micro size fractions were used for the trial flotation and +180 to 355 micro size fractions were used for the second trial flotation. From the washability test assuming ash content of 5.7% is acceptable a separating density of 1.6 and a yield of 80% will be obtained. Froth flotation at Ph7 of the coal gave an average ash content of the total float to be 6.64% with the higher ash content reporting in the first float being10.29%. The sulphur, moisture and volatile matter are same as in the raw coal. Froth flotation at Ph9 of the coal gave an average ash content of6.95% with the fine coal reporting first with less ash content of 3.42%. This difference could be probably due to the presence of pyrite which might have been depressed at Ph9. These results support the mediumcoking characteristic of the coal deposit.