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Contact Name
Andri Agus Rahman
Contact Email
jurnal@rmpi.brin.go.id
Phone
+6282120080815
Journal Mail Official
eksplorium@brin.go.id
Editorial Address
Gd. 720, KST BJ Habibie, Kawasan Puspiptek Serpong, Tangerang Selatan 15314
Location
Kota bogor,
Jawa barat
INDONESIA
Eksplorium : Buletin Pusat Pengembangan Bahan Galian Nuklir
ISSN : 08541418     EISSN : 2503426X     DOI : https://doi.org/10.55981/eksplorium
EKSPLORIUM is published to deliver the results of studies, research and development in the field of nuclear geology. The manuscripts are the result of study, research and development of nuclear geology with scope: geology, exploration, mining, nuclear minerals processing, safety and environment, and development of nuclear technology for the welfare.
Articles 172 Documents
Lithological Discrimination Based on Radiometric Data: Case Study of Rabau Sector, West Kalimantan and Salumati Sector, West Sulawesi Maulana, Muhammad Wira; Ciputra, Roni Cahya; Iskandarsyah, Iskandarsyah; Adimedha, Tyto Baskara; Sukadana, I Gde; Indrastomo, Frederikus Dian; Syaeful, Heri; Pratiwi, Fadiah; Rachael, Yoshi; Mardania, Faneza Nur; Kamajati, Dhatu; Rahmawati, Putri; Garwan, Mirna Berliana
EKSPLORIUM Vol. 46 No. 1 (2025): MAY 2025
Publisher : BRIN Publishing

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.55981/eksplorium.2025.11475

Abstract

This study evaluates the applicability of radiometric methods for lithological discrimination in tropical environments, with a focus on two uranium exploration sites in Indonesia: the Rabau Sector in West Kalimantan and the Salumati Sector in West Sulawesi. These locations were selected to represent various lithologies within the uranium exploration program. The aim is to determine whether gamma-ray spectrometry, commonly effective in arid environments, can also delineate lithological boundaries and alteration zones under conditions of intense weathering and dense vegetation cover of tropical area. Ground-based radiometric data were collected using the RS-125 gamma spectrometer to record the concentration of potassium (K), equivalent uranium (eU), and equivalent thorium (eTh). Data processing involved anisotropy analysis, geostatistical interpolation using ordinary kriging, ternary RGB composite mapping, and delineation of radiometric domains. The resulting radiometric maps were then qualitatively compared with existing geological maps for validation. The results show that radiometric signatures, particularly eTh and eU, can effectively distinguish rock units with differing genesis or degrees of alteration, despite tropical conditions. In Rabau, where lithologies share a common protolith, elevated eU concentrations correspond to hornfels, while metatuff and metasiltstone remain indistinguishable, indicating the influence of thermal metamorphism on radiometric responses. In Salumati, eTh and eU zoning within phonolite suggest compositional variability or differential alteration, and elevated eU in altered tuff reflects uranium remobilization in smectite-rich zones. These findings demonstrate that, despite the challenges posed by tropical climates, radiometric mapping remains a viable tool for lithological discrimination and early-stage uranium exploration in Indonesia. This work extends the application of radiometric techniques beyond arid environments and underscores the need to integrate radiometric interpretation with genetic, provenance, and alteration context in tropical geological mapping.
Adsorption of Uranium onto Delaminated Amino Talc-Like Clay Saputra, Dwi Luhur Ibnu; Purwaningsih, Henny; Farid, Muhammad; Basuki, Triyono; Nakashima, Satoru; Rachmadetin, Jaka; Laksmana, Roza Indra; Sihotang, Juan Carlos; Noerpitasari, Erlina
EKSPLORIUM Vol. 46 No. 1 (2025): MAY 2025
Publisher : BRIN Publishing

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.55981/eksplorium.2025.12136

Abstract

Uranium-containing waste is generated as a by-product of nuclear power plants, radioisotope production, nuclear fuel fabrication, and mineral processing. A radioactive waste treatment plant treats radioactive liquid waste using various methods, including evaporator technology, ion exchange resins, and adsorbents. Various adsorbents have been investigated for the removal of uranium from aqueous solutions. Negatively charged adsorbents, such as natural clay, biomass-based adsorbents, and polymers, have been utilized for uranium adsorption. Previous research on uranium adsorption by amino clay, which has a positively charged surface, was still very limited compared to other adsorbents. In the present study, the application of Delaminated Amino talc-like Clay (DAC) for removing uranium from aqueous solutions was examined. DAC with amino propyl on the tetrahedral sheet surface is easily protonated to form a positively charged R-NH3 that may influence its interaction with uranium. The speciation and reaction kinetic order were studied in aqueous solution with pH and contact time as the variables. The adsorption of uranium onto DAC, which is likely due to physicochemical interactions and ion trapping, was evaluated. The maximum removal efficiency (84.5%) and adsorption capacity (113.06 mg/g) were achieved at pH 4 after approximately 60 minutes. The uranium adsorption capacity is low at pH 2 and 3 (10%), which is due to the repulsive interaction between the positive surface charge of DAC and (UO2)2+ as the dominant uranium species. Uranium adsorption capacity is high at pH 4 and 5, because the predominant species of uranium, such as (UO2)2+ and [(UO2)2(OH)2]2+, were probably adsorbed by DAC through chemisorption with R-NH2. The adsorption of uranium on the DAC was found to follow the pseudo-second order kinetic model.