Review Article
Geological Occurrence, Mineralogical Characteristics, Industrial Applications, and Development Potential of Ethiopian Bentonite Deposits: A Review
Issue:
Volume 15, Issue 4, December 2026
Pages:
81-93
Received:
14 October 2026
Accepted:
23 October 2026
Published:
6 November 2026
DOI:
10.11648/j.jenr.20261504.11
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Abstract: Ethiopia hosts substantial bentonite resources totaling over 141.5 million tonnes, distributed across the Cenozoic Afar Depression and the Main Ethiopian Rift. This comprehensive review systematically synthesizes the geological occurrence, mineralogical and chemical characteristics, physical properties, industrial application suitability, and development potential of Ethiopian bentonite deposits. Major deposits include Gewane (77.03 Mm3 / ~70 Mt), Warseiso (7.01 Mm3), Ledi (1.78 Mm3), Hadar Basin (Kada Hadar & Ounda Hadar, 0.93 Mm3), and Gidicho Island (>9.4 Mt / 3.46 Mm3), all formed through the low-temperature alteration and diagenesis of Cenozoic volcanic ash and vitric tuff in alkaline lacustrine environments. Mineralogically, X-ray diffraction (XRD) demonstrates that Ethiopian bentonites are predominantly calcium montmorillonite (Ca-montmorillonite) accompanied by minor kaolinite, quartz, albite, and trace zeolites. Complete major oxide geochemistry by XRF reveals SiO2 contents ranging from 48.78% to 61.93% and Al2O3 from 11.06% to 16.40%, with distinct Na2O/CaO zonation reflecting alkaline depositional water chemistry. Physicochemical testing indicates exceptionally high cation exchange capacity (CEC) values ranging from 77.0 meq/100g (Gidicho) to 82.1 meq/100g (Warseiso), exceeding standard commercial calcium bentonites. Natural swelling indices reach 17.1 mL/2g for Gidicho bentonite, which competes closely with international drilling-mud benchmarks. Beneficiation and chemical activation pathways including sodium carbonate activation for API 13A drilling muds, acid activation (0.8M HCl) for bleaching earth and catalysis, and thermal activation (300°C) for surface area expansion (increasing from 57.6 to 81.74 m2/g) substantially upgrade industrial performance. Systematic evaluation against international standards (API 13A/ISO 13500, UNIDO, JB/T 9227) confirms high suitability for drilling fluids, foundry sands, iron-ore pelletizing, civil engineering sealants, and environmental sorbents. Strategic domestic exploitation can completely replace expensive imports, conserve foreign currency, foster regional industrial growth, and drive value-added mineral export development in East Africa.
Abstract: Ethiopia hosts substantial bentonite resources totaling over 141.5 million tonnes, distributed across the Cenozoic Afar Depression and the Main Ethiopian Rift. This comprehensive review systematically synthesizes the geological occurrence, mineralogical and chemical characteristics, physical properties, industrial application suitability, and devel...
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Research Article
The Impact of South Sudan Petroleum Fiscal Regime on the Generation of Government Revenue
Chol Stephen Jok,
Jacob Dut Chol Riak*
Issue:
Volume 15, Issue 4, December 2026
Pages:
94-109
Received:
11 October 2026
Accepted:
22 October 2026
Published:
6 November 2026
DOI:
10.11648/j.jenr.20261504.12
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Views:
Abstract: The petroleum fiscal system is a key component of economic dynamics because it controls how investors and host governments divide risks and rewards. South Sudan’s petroleum fiscal system remains the central determinant of the state’s economic viability. petroleum accounts for approximately 70% of government revenue and 95% of exports. Under the existing Exploration and Production Sharing Agreements (EPSAs), the Joint Operating Companies (JOCs) recover costs and profit oil at rates that leave the government with a diminished share of its own resource wealth. South Sudan pays Sudan approximately $11 per barrel in transit and processing fees. Following the Rapid Support Forces’ captured of the Heglig area in December 2025, a tripartite arrangement of transit fees became a burden to the government of South Sudan. Based on Monte Carlo simulations, the study proposed a revised fiscal framework that links the R-factor to production. In comparison to the current fiscal regime, the proposed model yields a large rise in average government take of 40% to 73.39%, excluding divorce and transit fees. The payback time shortens from the current 7 years to 6.81 years. Following the sensitivity analysis, the government's Net Present Value (NPV) is positively impacted by oil prices, whilst the discount rate has a negative impact. This study recommends the use of a R-factor to production in contrast to the progressive sliding scale that South Sudan has been using for the last ten years. With its more equitable distribution of risks and rewards, the proposed fiscal framework encourages win-win outcomes. The study offers major insights for scholars, financiers, and public policymakers in South Sudan who seek to enhance their petroleum-related fiscal framework for sustainable long-term growth and fair profits.
Abstract: The petroleum fiscal system is a key component of economic dynamics because it controls how investors and host governments divide risks and rewards. South Sudan’s petroleum fiscal system remains the central determinant of the state’s economic viability. petroleum accounts for approximately 70% of government revenue and 95% of exports. Under the exi...
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,
Getnet Belachew
