Browsing by Author "Iyakwari, Shekwonyadu"

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    Determination of natural radioactivity levels and radiological hazards in environmental samples from artisanal mining sites of Anka, North-West Nigeria
    (Department of Physics, Nasarawa State University Keffi, 2020-04-04) Akpanowo, MbetAmos; Umar, Ibrahim; Iyakwari, Shekwonyadu; Joshua, Emmanuel Olugbemi; Yusuf, Samson; Ekong, Godwin Bassey
    Artisanal mining of precious metals has become a lucrative venture in Anka, Zamfara State, North-West Nigeria. The use of crude methods of mining and mineral processing and the apparent ignorance of the hazards involved have been linked to some health and environmental consequences. Hence, this study focuses on the assessment of radioactivity levels in rock, soil and sediment samples as well as the radiological hazards of the artisanal mining in Anka. The gamma-ray spectrometry method was employed in the sample analysis. The results show that the estimated mean activity concentrations of 226 Ra, 238 U, 232 Th and 40 K in soil were 37.94 ± 6.01 Bqkg −1 , 41.60 ± 11.06 Bqkg −1 ,151.15 ± 21.09 Bqkg −1 and 380.34 ± 116.41 Bqkg −1 , respectively. The activity concentrations in rocks and sediments were also analyzed. The radioactivity levels were highest in rock samples. ; For rock samples, mean radium equivalent was 499.18 Bqkg −1 , gamma dose rate was 221 ± 35 nGyh −1 , internal and external hazard indices were 1.35 and 1.53, respectively and the radioactivity level index was 3.24. The outdoor and indoor annual effective dose equivalents were 271.03 μSvy −1 and 985.39 μSvy −1 , respectively. The mean indoor and outdoor excess lifetime cancer risk for soil were 0.55 × 10 −3 and 2.18 × 10 −3 . The evaluation of radiological health risks shows that the values obtained in this study were generally higher than admissible recommended limits and the world averages. The results obtained in this study show that the risk of exposure to ionizing radiation is linked to the artisanal mining and mineral processing in Anka
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    QUALITATIVE IDENTIFICATION OF COPPER BEARING MINERALS USING NEAR INFRARED SENSORS
    (Department of Geology and Mining, Nasarawa State University Keffi, 2015-10-21) Oluwaseye, Ismail Folorunso; Iyakwari, Shekwonyadu; Idzi, Amos Ambo; Kehinde, Hussein Okoro; Usman, Halima Osu
    Application of sensors for on-site fast identification and discrimination of dominant ore bearing particles from associated gangues in a complex ore is an important route in minerals exploration and extraction industries. This paper considers identification and discrimination of copper bearing minerals from associated gangues using near infrared sensors. Different copper bearing minerals in the Akiri copper ore are differentiated on the basis of their near infrared spectra behaviour. The near infrared spectra of individual samples are correlated with their mineralogy and chemistry as analysed by X-Ray diffraction and X-Ray fluorescence equipment, respectively. The obtained results indicated that the detection limit of the near infrared sensor is better than that of both X-ray diffraction and X-ray fluorescence equipment used. Hence, in addition to the minerals identified by the X-ray diffraction equipment, other near infrared active minerals with concentration below the X-ray diffraction detection limit were also detected by the near infrared sensors