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1

Estimation of Natural Uranium and Its Risk-Assessment in Groundwater of Bangalore Urban District of Karnataka, India

Ravindra Nai Poojashri, Rajashekara Vinod Alurdoddi, Mudbidre Rajalakshmi

Geomatics and Environmental Engineering

|

2024

|

Vol. 18, no. 2

21--49

EN

In this study, 56 groundwater samples were taken from diverse sources in Bangalore Urban district during the pre-monsoon and post-monsoon seasons to measure the uranium concentration and its correlation with different waterquality parameters. The uranium concentration varied from 0.94–98.79 µg/L during the pre-monsoon season and from 1.38–96.52 µg/L during the postmonsoon season. Except for a few readings, all were within the safe limit of 60 µg/L as prescribed by India’s Atomic Energy Regulatory Board (AERB), Department of Atomic Energy (DAE). Owing to its slightly higher concentration, a study on the radiological and chemical risks that are caused due to the ingestion of uranium was assessed. Based on the radiological aspect, cancer mortality and its risks were assessed, wherein all of the samples were well within the acceptable limit of 10−4; therefore, consuming these water samples was radiologically safe. However, when the risk that was caused by chemical toxicity was assessed, a few samples exceeded the hazard quotient (HQ) value of more than 1, thus illustrating that individuals were vulnerable to chemical risk. This paper features assessments of uranium and its risks to public health in groundwater samples if it exceeded the safe limit. Additionally, it recognizes the value of periodically assessing and treating the area’s drinking water sources.

2

Zastosowanie ICP-MS w jądrowej analizie kryminalistycznej

Chajduk Ewelina

Laboratorium - Przegląd Ogólnopolski

|

2023

|

nr 4

22--25

PL

Jądrowa analiza kryminalistyczna ma kluczowe znaczenie w reagowaniu na działania związane z nielegalnym posiadaniem i obrotem materiałami jądrowymi oraz w przeciwdziałaniu terroryzmowi jądrowemu. W niniejszym artykule przedstawiono zastosowanie spektrometrii mas z plazmą wzbudzoną indukcyjnie w jądrowej analizie kryminalistycznej. Podkreślono jej kluczową rolę w analizie pierwiastkowej - zwłaszcza w oznaczaniu pierwiastków ziem rzadkich - jako znacznika łączącego materiał jądrowy ze złożem uranu. ICP-MS jest niezastąpionym narzędziem do pomiary stosunków izotopowych U i Pu, dostarcza tym samym informacji o historii materiału jądrowego i jego zamierzonym wykorzystaniu.

EN

Nuclear forensics is crucial in responding to suspicious activities related to the illicit possession and trafficking of nuclear materials, and in countering nuclear terrorism. This article presents the application of inductively coupled plasma mass spectrometry in nuclear forensic analysis. Its key role in elemental analysis - particularly in the determination of rare-earth elements - as a marker linking a nuclear material to a uranium deposit is highlighted. ICP-MS is an indispensable tool for measuring the isotopic ratios of U and Pu, thus providing information on the history of a nuclear material and its intended use.

3

Preconcentration of a low-grade betafite ore by dense medium cyclone

Lv Zihu, Wei Min, Zhao Dengkui, Wu Dongyin, Liu Changmiao, Cheng Hongwei

Physicochemical Problems of Mineral Processing

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2022

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Vol. 58, iss. 1

1--14

EN

In order to find an economical and feasible short process for betafite preconcentrating and to provide a reference for the development of similar low-grade uranium deposits, preconcentration of the betafite ore was investigated based on mineralogical characterization study, float-sink tests, and dense medium cyclone (DMC) separation experiments. The float-sink test results revealed that the gravity separation of the betafite ore was feasible, and the expected particle size range was chosen to be 3~0.3 mm. The effect of important parameters of the DMC experiment such as particle size, grade of the feed, separation density, and inlet pressure on the separation performance of betafite ore was studied. Under the optimal experimental conditions, the expanded experiments were performed and the heavy minerals contained 4557 ppm U and 5200 ppm Nb2O5 with a recovery of 88.86% and 79.73%, respectively, were obtained. Besides, the enrichment ratio (E) values of U and Nb2O5 were 14.24 and 12.78 severally, and the tailings discarding ratio (R) value was 93.76%. The results demonstrate that the preconcentration of low-grade betafite by DMC can remove a large number of tailings and obtain a high-grade uranium concentrate.

4

Uran i inne substancje promieniotwórcze w wodach spożywanych przez ludzi

Michalski Rajmund

Laboratorium - Przegląd Ogólnopolski

|

2022

|

nr 1

42--48

PL

Uran to radioaktywny metal ciężki, naturalnie występujący w wodzie, a także w niektórych rodzajach gleb i w skałach. Może on znajdować się w różnych produktach żywnościowych, głównie w rybach, warzywach i produktach zbożowych, a także w wodzie przeznaczonej do spożycia przez ludzi.

5

Experimental Study of the Negative Impact on the Environment During the Extraction of Uranium By In-Situ Leaching

Kryakhtunov Alexander V.

Journal of Ecological Engineering

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2022

|

Vol. 23, nr 5

260--270

EN

The purpose of this study was a detailed analysis of all aspects related to the impact of objects and structures of the planned economic activity on the environment on the territory of the Semizbay deposit in the Republic of Kazakhstan. In the course of the work, the geoecological characteristics of the Semizbay deposit were presented. The analysis of data on the state of the components of the natural environment, based on the materials of earlier studies at the facility, was carried out. On the basis of the actual material, a list of priority pollutants subject to monitoring was compiled. The methodology and organization of the projected works are given. The types, conditions, scope of work were indicated. During the study, the following were carried out: soil sampling was carried out in the vicinity of the deposit, radiochemical analysis, and X-ray diffraction analysis. As a result of the study, a program of geoecological research was developed on the territory of the deposit: the content of radionuclides and the mineralogical composition of the sample were determined, which can become an alternative for further research on the territory of the enterprise.

6

Studies on uranium recovery from a U-bearing Radoniów Dump

Kiegiel Katarzyna, Roubinek Otton, Gajda Dorota, Kalbarczyk Paweł, Zakrzewska-Kołtuniewicz Grażyna, Chmielewski Andrzej G.

Nukleonika

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2021

|

Vol. 66, No. 4

115--119

EN

This work reports the possibility of uranium recovery from a post-mining uranium ore dump in Poland by a bioleaching method. The studies were conducted on the dump leaching model with the mass of 570 kg of uranium bearing mineral material from Radoniów pile and in the periodic bioreactor with a work volume of 80 dm3 and with mechanical mixing and aeration of the charge. The uranium concentration in the examined material was about 800 ppm. In this process, the consortium of microorganisms isolated from former mines was used. It was composed of the following microorganisms: Bacillius, Pseudomonas, Sphingomonas, Thiobacillus, Halothiobacillus, Thiomonas, and Geothrix. The effi ciency of the uranium bioleaching process was 98% in the reactor, and a yield of 70% was obtained in the dump leaching model. The post-leaching solution contained signifi cant amounts of uranium ions that were separated in two stages: (1) by ion chromatography and then (2) by a two-step precipitation method. The resulting solution was a source of ammonium diuranate, the precursor of yellowcake (uranium oxides).

7

Radiological characterization of the phosphate deposit in Al-Jalamid phosphate mining area, Saudi Arabia

Alhawsawi Abdulsalam M., Shababa E. I., Qutub Maher M. T., Banoqitah Essam M., Kinsara A. A.

Nukleonika

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2021

|

Vol. 66, No. 1

35--44

EN

It is a known fact that phosphate rocks have high levels of natural radioactivity due to the presence of large concentrations of radionuclides. This work aims to estimate radiation exposure and dose levels at Al-Jalamid site in northern Saudi Arabia. Al-Jalamid area is one of the largest reserves of phosphate worldwide. Ma’aden, a Saudi Government public company, owns the mine and is responsible for all mining activities. Phosphate and soil samples collected from Al-Jalamid phosphate mining area have been analysed for their uranium and thorium content by an α-spectrometer using radiochemical techniques. The quantity of radon gas was measured both in groundwater and in the atmosphere (indoor and outdoor) at the site using a portable radiation survey instrument. Groundwater samples collected from wells surrounding the mining area were analysed using a liquid scintillation counter in addition to an α-spectrometer. Finally, it is found that phosphate rock concentrate products cannot be utilized economically based on the standards set by the International Atomic Energy Agency (IAEA), since the average activity concentration does not reach the limit set by IAEA and hence are not commercially feasible.

8

New minerals and the first mineral occurrences in the Kupferschiefer (U, REE, HgS, chloride minerals PtAs2, Pt(Sb,Bi)2, PtBi2), Poland, and their genetic meaning

Kucha Henryk “Harry”

Mineralogia

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2021

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Vol. 52, iss. 1

31--42

EN

Main U minerals in the Lubin and Polkowice mines in decreasing order of abundance are: uraninite, brannerite, metazunerite, metauranospinite, uranospinite, thucholite, monazite-huttonite, coffinite, and becquerelite. All these minerals are associated mainly with noble metal mineralization at the redox interfaces. Main minerals of REE are: (i) brannerite, monazite-huttonite in Noble Metals Bearing Shale (NMBS), (ii) fl orencite in Mo-Re shales and (iii) minor phospates in Cu-black shales derived from oxidation of organic matter. The latter, however, are controlling no more than 1/5 of the REE budget. Chloride minerals and sulphates are ubiquitous phases associated with Cu sulphides. They are represented by chlorargylite, cotunnite and penfeldite. Halite and sylvite form cubic inclusions in gypsum, up to 3 mm in chevrel compound, where they occur together with thiosulphates, annabergite and erithrite and Ni-Co-diarsenides. Sylvite is most common in lensoidal accumulations of semi massive kaolinite + chalcocite + gypsum at the contact between black shale and the top part of white sandstone. Such lenses have been traced over a distance of up to 30 m in the Lubin West and Polkowice East mines. Sylvite and halite have been so far overlooked during investigations of the Kupferschiefer because of applying standard cutting and polishing procedures using water as a lubricant. The Au content in native gold may reach exceptionally up to 97.40 wt% in a dolomitic reef from the Lubin West Mine. Gold forms four characteristic micro to nano-textures. Organic matrix of thucholite indicates correlation of Pt-Ni-V suggesting substitution of Pt in tetrapyrrole ring. Sperrylite, geversite and insizwaite appear at the western perimeter of Cu-sulphide deposit, where the redox gradient is so strong that almost all organic matter is gone. Platinum has forms its own minerals trapped in microfractures in anilite-digenite-spionkopite-yarrowite-bornite composite grains present in the reddened NMBS. Celestine-barite solid solution is one of the main accessory minerals in the Kupferschiefer. It has Sr/Ba ratio around 2.5 and 7.5. Euhedral uraninite associated with celestine-barite yielded U/Pb age of 84 ± 1 Ma, based on four grains measurements.

9

Elektrownia Jądrowa Cernavoda – rumuńskie doświadczenia z technologią CANDU

Nowicki Jacek

Energetyka

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2021

|

nr 1

26--41

PL

W Rumunii pracuje jedyna na kontynencie europejskim Elektrownia Jądrowa Cernavoda (rum. Centrala Nucleară de la Cernavodă) wykorzystująca kanadyjską technologię reaktorów energetycznych CANDU 6. W reaktorach tego typu paliwem jest niewzbogacony uran, zaś chłodziwem i moderatorem ciężka woda. EJ Cernavoda pokrywa około 20% zapotrzebowania na energię elektryczną w krajowym systemie elektroenergetycznym Rumunii, przyczyniając się do redukcji emisji CO2 o około 10 milionów ton rocznie. Obecnie w elektrowni pracują dwa bloki jądrowe, każdy o mocy elektrycznej 706 MW, uruchomione kolejno w latach 1996 i 2007. Pierwotne plany przewidywały budowę jeszcze trzech kolejnych jednostek, z których w przyszłości ostatecznie powstać mają jeszcze dwie. W artykule opisano historię powstania EJ Cernavoda i jej dotychczasową eksploatację. Obszernie scharakteryzowano kanadyjską technologię reaktorów energetycznych CANDU.

EN

Cernavoda Nuclear Power Plant (Centrala Nucleară de la Cernavodă) in Romania – using the Canadian technology of power reactors CANDU 6 – is the only one of this type working on the European continent. In such reactors the fuel is natural uranium and heavy water works as the coolant and the moderator. NPP Cernavoda covers about 20% of electric energy demand in the Romanian national power system, contributing to the CO2 emission reduction by around 10 million tonnes per year. At present, there are two nuclear units (of 706 MW capacity each) working in the plant, commissioned in the years 1996 and 2007 respectively. It was originally planned to build three more units but finally it was decided to build only two in the future. Presented is the history of how the NPP Cernavoda originated and its up to now conducted operation. Described is extensively the Canadian technology of CANDU power reactors.

10

Effect of gender and occupations on uranium concentration in human blood and soil samples collected from Babylon, Iraq

Showard Ansam F., Aswood Murtadha Sh.

Polish Journal of Medical Physics and Engineering

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2020

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Vol. 26, Iss. 3

143--148

EN

Uranium concentrations of human blood and soil samples have been studied at different ages and occupations in Babylon, Iraq. The technique of nuclear track detectors CR 39 with nuclear fission track analysis has been used to determine the uranium concentrations in this study. Results have shown that the concentrations of uranium ranged from 0.56 ± 0.06 to 1.24 ± 0.29 ppb with an average of 0.83 ± 0.18 ppb in blood samples. On the other hand, the concentrations of uranium in soil samples ranged from 0.93 ± 0.20 to 2.59 ± 0.15 ppm with an average of 1.72 ± 0.19 ppm. Moreover, the highest averages of concentration have been found in the city center of Babylon, reaching 1.09 ± 0.22 ppb and 2.10 ± 0.23 ppm in blood and soil samples, respectively. The results have further proved that gender and occupations have an effect in increasing the concentrations of uranium. In addition, the concentrations in blood samples are generally lower than the concentration in soil samples.

11

Hydrometallurgical removal of uranium and thorium from Ethiopian tantalite ore

Cheru Mulugeta Sisay, Albertodel Rosario Alberto Velázquez, Yimam Abubeker, Tadesse Bogale, Berhe Gebreyohannes Goitom

Physicochemical Problems of Mineral Processing

|

2019

|

Vol. 55, iss. 2

448--457

EN

This study focused on the leaching of uranium and thorium from a high grade Ethiopian tantalite ore using sulfuric acid. The effects of variables such as acid concentration, temperature and leaching time were studied. In general, the leaching efficiency of uranium increases with increasing temperature from 100 to 300°C whereas the opposite trend was observed for thorium. The amount of uranium leached increased from 69.1% at contact time of 1 hr to 88.6% when the tantalite ore was leached for 3 hrs. On the other hand, for the experiments conditions considered in this study, the leaching behavior of uranium and thorium did not change significantly with varying sulphuric acid concentration from 70 to 90 wt%. Overall, the highest dissolution of uranium and thorium were achieved at 100°C, 70 wt% H2SO4 concentration and 1 hr contact time.

12

Uran w szkle historycznym

Kunicki-Goldfinger J. J.

Szkło i Ceramika

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2018

|

R. 69, nr 1

16--21

PL

W pracy omówiono wybrane zagadnienia związane z występowaniem uranu w szkle historycznym, takie jak: naturalna zawartość uranu w szkle, historia szkła uranowego, jego wybrane właściwości oraz radioaktywność szkieł historycznych ze szczególnym uwzględnieniem szkieł uranowych.

EN

The paper discusses selected issues related to an occurrence of uranium in historical glass, such as a natural occurrence of uranium in glass, history and selected properties of uranium glass as well as radioactivity of historical glasses with a particular attention to uranium glasses.

13

Zasoby uranu w Polsce – możliwości pozyskiwania uranu ze źródeł niekonwencjonalnych

Kiegiel K., Zakrzewska-Kołtuniewicz G.

Postępy Techniki Jądrowej

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2018

|

z. 2

17--22

PL

W artykule omówiono niekonwencjonalne zasoby uranu w Polsce oraz przedyskutowano możliwość ich eksploatacji. Polska posiada jedynie złoża ubogich rud uranu. Najbardziej perspektywiczne zasoby to ordowickie łupki dictyonemowe o koncentracji uranu w zakresie 75-250 ppm oraz piaskowce syneklizy perybałtyckiej, gdzie koncentracja tego pierwiastka dochodzi miejscami nawet 1,5%. Uran może być również odzyskiwany z odpadów przemysłowych różnego pochodzenia, m. in. z przemysłu miedziowego i produkcji nawozów fosforowych.

EN

The article presents the unconventional resources of uranium in Poland and discusses the possibility of their exploitation. In Poland there are only low-grade uranium ores. The most perspective resources of uranium are the Ordovician dictyonema shale with uranium concentrations in the 75-250 ppm range and the sandstones of Peribaltic Syneclise, where the concentration of this element reaches locally up to 1.5%. Uranium can also be recovered from industrial waste of various origins, inter alia, waste from the copper industry and from the production of phosphate fertilizers.

14

Organic and inorganic geochemical study of the Lower Permian Walchia shale of the Intrasudetic Basin (SW Poland)

Bilkiewicz E., Pieczonka J., Piestrzyński A.

Geological Quarterly

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2018

|

Vol. 62, No. 3

631--643

EN

The Lower Permian Walchia shale of the Intrasudetic Basin is lacustrine sediment enriched in organic matter and base metals. Rock-Eval geochemical analysis was conducted on 110 drill-core rock samples of the Walchia shale in order to characterize the quantity, genetic type and maturity of dispersed organic matter. Concentrations of U, Th, Cu, Ni, V, Pb, Zn, Co, Mo, Cr, P, S and Fe were determined and microscopic studies to recognize mineral composition were performed on selected samples. Organic matter of the Walchia shale is immature and dominated by terrestrial type III kerogen with an admixture of planktonic type II kerogen. The Walchia shale is generally poor source rock, but some parts of the profile exhibit good and even excellent hydrocarbon potential. The average concentrations of analysed metals are higher than the average reported for black shales. The concentrations of base metals do not correlate with TOC contents, suggesting that their presence is associated with inorganic features of the Walchia shale or they could have been related primarily to organic matter which was subsequently oxidized and altered. Uranium may be partly associated with phosphates. Results of microscopic investigations revealed the lack of detectable radioactive minerals, abundance of framboidal pyrite, and prevalent galena, sphalerite and chalcopyrite.

15

Wybrane aspekty procesów inżynierii chemicznej od wydobycia rud uranowych do wzbogacania uranu

Szołucha M., M.

Postępy Techniki Jądrowej

|

2017

|

z. 2

22--36

PL

W artykule przedstawiono wybrane aspekty procesów inżynierii chemicznej znajdujących się na początku cyklu paliwowego, rozpoczynając od wydobycia uranu a kończąc na procesach wzbogacania uranu.

EN

This paper presents selected aspects of chemical engineering processes applied in early stages of a fuel cycle, begins with the mining of uranium and ends with the uranium enrichment processes.

16

Features of distribution of uranium and thorium in red mud

Gu H., Wang N., Yang Y., Zhao C., Cui S.

Physicochemical Problems of Mineral Processing

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2017

|

Vol. 53, iss. 1

110--120

EN

Natural radioactive elements such as uranium and thorium restrict the use of red mud as building materials or additives, and may cause environmental problems. The distribution features of U and Th in red mud was studied from micro and macro analysis, using EPMA, LA-ICP-MS, and methods of mineralogy and beneficiation. Based on the micro-area scanning analysis, main chemical compositions in red mud, such as Ca, Al, Si, Na, and K are dispersive while Fe and Ti mainly tend to concentrate in granular phases. Based on the in-situ analysis, the distribution of main elements and most trace elements in micro-zone of red mud was homogeneous. In micro-zone area, the variation tendency of thorium content was similar with Y in red mud samples. By means of the methods of mineralogy and beneficiation, red mud samples were separated into different fractions. U and Th tend to be enriched in the low density fraction of the red mud. Th presented a high concentration in the finest particle size fractions of the red mud. Neither U or Th was regularly distributed in various magnetic red mud fractions. Thorium fingerprint peaks were determined in perovskite by EDX under TEM, which is proposed to be one of the radioactivity sources in Bayer red mud.

17

A comparison of uranium recovery from low-grade ore by bioleaching and acid leaching

Szolucha M. M., Chmielewski A. G.

Physicochemical Problems of Mineral Processing

|

2017

|

Vol. 53, iss. 1

136--149

EN

The objective of this work was to compare the bioleaching with the acid leaching of uranium under similar process conditions within 65 days. The low-grade uranium ore used in the experiments was collected from Radoniow’s ‘small’ dump, Poland. Bioleaching and acid leaching studies were carried out in identical columns. The isolated bacterial consortium from the Radoniow’s mine was used for the bioleaching process. A solution of sulphuric acid and H2O2 as oxidizing agent was used for the acid leaching. The extraction of uranium under acid leaching conditions reached maximum of 64±13 % w/w after 31 days. The bioleaching of uranium achieved a maximum extraction of 75±15 % w/w after 55 days. In this study an attempt was made to demonstrate the relationship between the shrinking-core model and the experimental data by plotting the fractional conversion of uranium against time.

18

The Atomic Energy Lab – zabawa z promieniowaniem

Pasieka E., Cieślik T.

Inżynier i Fizyk Medyczny

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2017

|

Vol. 6, nr 4

225--229

PL

Gilbert´s U-238 Atomic Energy Lab to zestaw edukacyjny zaprezentowany wiosną 1950 roku w Stanach Zjednoczonych przez wszechstronnie uzdolnionego Alfreda Carltona Gilberta, pomysłodawcę wielu zabawek dla dzieci. Celem pracy jest scharakteryzowanie poszczególnych elementów zestawu na podstawie przeglądu piśmiennictwa. Komplet składał się z próbek radioaktywnych minerałów i urządzeń do detekcji promieniowania jonizującego, które miały pozwolić Amerykanom na zapoznanie się poprzez zabawę z ogólnie pojętą energią atomową. Jego posiadacze mieli do dyspozycji między innymi licznik Geigera-Müllera sygnalizujący obecność promieniowania za pomocą dźwięków, a także spintaryskop sygnalizujący obecność promieniowania za pomocą błysków. Wśród minerałów znajdował się: torbernit, uraninit, autunit i karnotyt. Oprócz wymienionych elementów do każdego zestawu dołączano podręcznik obsługi oraz komiks Learn How Dagwood Splits the Atom. Historia rysunkowa miała zapoznać obywateli z promieniotwórczością, a także zminimalizować strach zwłaszcza po tragicznych wydarzeniach z Hiroszimy i Nagasaki. Cały zestaw spełniał rolę edukacyjną i był formą rozrywki, a dzięki starannemu przygotowaniu i jakości przyrządów mógł stać się inspiracją dla wielu młodych ludzi do wyboru kariery zawodowej związanej z wykorzystaniem energii atomowej.

EN

Gilbert´s U-238 Atomic Energy Lab is an educational set, which was presented springtime 1950 in the United States by versatile talented Alfred Carlton Gilbert – the originator of many toys. The aim of this paper is a review of literature to characterized components of the set. This set was composed of instruments for measuring ionizing radiation and samples of minerals, which would let Americans to introduce with generally known nuclear energy in form of entertainment. The owners of the set had in their hands: Geiger-Müller counter, which pointing with sound a presence of radioactivity materials and spinthariscope signaling a presence of radiation with flashes. Amongst minerals there were: torbernite, uraninite, autunite and carnotite. Except above-mentioned elements to each set was included a product manual and a comic book Learn How Dagwood Splits the Atom, which let civilians to introduce with radioactivity in an accessible form and to minimize a fear after tragic occurrences in Hiroshima and Nagasaki. The whole set had an educational role and was a form of entertainment, a careful preparation and a high quality of components of the set could be an inspiration for many young people to choose their occupational career related with a nuclear energy.

19

Removal of uranium(VI) from aqueous solution by rice husk

Xia L., Li R., Xiao Y., Zheng W., Tan K.

Environment Protection Engineering

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2017

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Vol. 43, nr 4

41--53

EN

Basic aspects of uranium adsorption by rice husk have been investigated. The influences of various experimental parameters such as pH, time, adsorbent dosage, rice husk size, temperature and various concentrations of uranium on uptake were evaluated. The thermodynamics and kinetics of adsorption were analyzed by FT-IR and SEM. The adsorption capacity for uranium on rice husk increased upon increasing initial concentration of uranium and temperature, while decreased with the increase of the amount of rice husk. Maximum uranium adsorption was observed at pH = 3 and particle size between 120 μm and 150 μm. Adsorption equilibrium was achieved within 60 min. At 25 °C, the saturated adsorption capacity qmax was up to 15.14 mg/g when the initial concentration of uranium ranged from 10 to 400 mg/dm3. The adsorption of uranium followed Langmuir adsorption isotherm and according to quasi-second order kinetic equation. The calculated values of ΔH°, ΔS°, and ΔG° indicated that the biosorption process was endothermic and spontaneous. Based on FT-IR spectra it may be concluded that hydroxyl, carbonyl, P–O and Si=O groups are the main active sites.

20

Combined high-resolution aeromagnetic and radiometric mapping of uranium mineralization and tectonic settings in Northeastern Nigeria

Adepelumi A. A., Falade A. H.

Acta Geophysica

|

2017

|

Vol. 65, no. 5

1043--1068

EN

Geological lineaments, depths to the basement, uranium concentra-tions, and remobilization in parts of the Upper Benue Trough, covering about 55 × 55 km2 (longitudes 11°30′–12°00′E and 10°30′–10°30′N), Northeastern Nigeria were investigated using integrated High-Resolution Aeromagnetic Data (HRAD) and radiometric data. This was with a view to identifying the potential zones of uranium occurrence in the area. The HRAD was processed to accentuate anomalies of interest and depths es-timate of 150–1941 m were obtained from source parameter imaging technique. The results from the superposition of the horizontal gradient magnitude, analytical signal amplitude, first vertical derivative, and 3D Euler solutions of the HRAD revealed that the study area was dissected by linear structures that trend ENE–WSW, NE–SW, E–W, NNE–SSW, WNW–ESE, and NW–SE; among which the ENE–WSW and NE–SW trends dominated. Analyses of radiometric data showed that uranium ores in the study area were possibly remobilized epigenetically from the granitic rocks, and were later deposited into sedimentary rocks (Bima formation). Burashika group (Bongna hills) and Wawa area of the study area showed vein-type deposits, while the anatectic migmatite in the northeastern region and the uranium rich Bima formation showed both fault/fracture and contact types of deposition. It was also observed the northwesterly and southeasterly, dominant dip direction, dipping faults dip in the same direction as the paleocurrent direction (direction of depositions of sediments), and trend in a direction perpendicular to the hypo-thetical direction of uranium deposition. The study concluded that the studied area is dissected by several linear structures and the studied area possibly contains deposits of uranium ore, which are likely to be found in: the Bima Sandstones of Wade, Shinga, Bima hill, Wuyo, Teli, Bryel, Dali, Barkan, Gasi, Kunkun, Boragara, Deba, and Gberundi localities; the anatectic migmatite at Kubuku, Whada, and Hyama; and the Bongna hills and agglomerates around Burashika, Kawaba, and Galu.