Centers for Ethio Mines Development

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Characterization and Anionic Reverse Flotation of Boreda Kakisha Iron Ore, Melo Koza, Gofa Zone, South Ethiopia Region
(Addis Ababa University, 2025-06) Wondishaw Wosine; Kebede Gamo (PhD)
Iron ore, a mineral or rock from which metallic iron is extracted, mainly consists of iron in the form of oxides, hydroxides, carbonates, and sulfides. The presence of impurities like silica, alumina, phosphorus, sulfur, and trace elements can affect the ore's quality and suitability for iron and steel production, often requiring processing to reduce impurities. Anionic reverse flotation was used in this work to examine the impurity removal procedure for low-grade BK iron ore. BK iron ore sample is the low-grade and contains Fe2O3 (26.26 – 31.20 wt%, average 29.73 wt %) as iron-bearing mineral and SiO2 (43.16 – 51.78 wt %, average 45.78 wt %) and Al2O3 (11.46 – 13.60 wt %, average 12.42 wt %) as major associated impurities based on AAS analyses. The XRD mineralogical analysis showed that the iron ore sample primarily consisted of hematite and goethite as the main valuable minerals, with quartz being the dominant gangue mineral. The effect of varying particle size range was studied in the flotation test. BK iron ore was upgraded through anionic reverse flotation using the following conditions: 2 ml of 2% corn starch solution, 2 ml of oleic acid, 2 ml of 1% calcium chloride solution, and 2 ml of pine oil, pH of 11 and particle size of -250+150 microns, which is optimal particle size range because of highest concentrate grade due to mineral liberation and less affected by slimes. Under these conditions, a concentrate with 23.92% Fe grade and 97.21% iron recovery was achieved. The average iron (Fe) grade of 20.78% in the ore was increased to 23.17% in the concentrate, while the average iron oxide (Fe2O3) grade of 29.73% in the ore was upgraded to 33.15% in the concentrate. The percentage increase in iron content from the initial ore grade to the final concentrate grade was calculated to be 11.5%. This means that the average iron concentration in the concentrate has increased by approximately 11.5% compared to the original ore. However, further separation is necessary to enhance the iron content and eliminate impurities to meet the minimum iron grade specifications needed for blast furnaces and steel manufacturers.
Characterization and Beneficiation of Coal by Flotation in Sheka Zone Andiracha Woreda Shekibado Kebele, South West Ethiopia
(Addis Ababa University, 2025-05) Temamen Gebo; Melesse Alemayehu (PhD); Abinet Markos (Msc) Co-Advisor
This project successfully characterized and beneficiation by flotation of the coal founding in Sheka Zone Andiracha Woreda, using the proximate analysis and calorific value analysis method for coal detection and evaluation. The study focuses on the characterization and beneficiation of coal using proximate analysis and flotation methods. The parameters for flotation test method are affected by a number of physical and chemical factors, including type and dosage of reagents, pulp, particle size, impeller speed, froth depth, among many other during laboratory experiment. The flotation process can be done with the collector dosages (5ml to 10ml), frother dosages (2ml to 4ml) and particle size (-250 μm +125μm -75μm). Proximate analysis after and before treatment, which includes moisture, ranges from 5.27% to 13.64%, ash content range from 41.15% to 47.69%, volatile matter content ranges from30.46% to 23.46%, and fixed carbon content ranges from 23.13 to 15.22%, is essential for determining coal quality. The calorific value is most crucial component to determine the grade coal which is before flotation value 4002.21BTU/Ib and after flotation value is 6587.05BTU/Ib. The analysis highlights the relationship between coal ranks and calorific value, a critical indicator of energy efficiency and economic potential. By combining proximate analysis with optimized flotation processes, the study provides insights into enhancing the economic and environmental performance of coal from the study area.
Effects of Single and Mixed Collectors in Low Grade Coal Flotation; The Case of Gamo Zone Coal in Southern Ethiopia
(Addis Ababa University, 2025-06) Desta Mulugeta; Zekarias Gebreyes (PhD)
This study investigated the effectiveness of single and mixed collectors in enhancing the flotation efficiency of low-grade coal from the Gamo Gofa Zone of Southern Ethiopia. The research aimed to address the challenges posed by high ash content and impurities in Ethiopian coal, which limit the industrial application. Through controlled laboratory experiments, the performance of single collectors (kerosene, diesel oil, and oleic acid) and mixed collectors in varying dosages was evaluated. The Finding revealed distinct performance characteristics among the collectors. Kerosene demonstrated higher recovery rates (33.7%) but moderate ash content (27.2%), while oleic acid prioritized purity (lowest ash content of 24.9%) at the expense of recovery (27.3%). Diesel oil showed intermediate results. Mixed collector formulations further highlighted the trade-off between recovery and ash content. For instance, the balanced triple-mixed collector C13 (kerosene, oleic acid, and diesel oil in equal parts) achieved a competitive recovery rate of 55.2% with acceptable ash levels (33.7%). In contrast, formulations with higher oleic acid content (C11) yielded the lowest ash content (32%) but reduced recovery (44%). The study underscored the inverse relationship between recovery and ash content, emphasizing the need for tailored collector blends based on specific industrial priorities. For yield-focused processes, Equal-dose blends like C10 (56.3% recovery) are recommended, while purity-focused applications benefit from oleic acid-dominant mixtures like C11. The balanced C13 formulation emerged as a practical choice for scenarios requiring a middle ground.
Determination of Coal Rank and Operational Efficiency through Blending Techniques in the ET-Coal Washing Plant in Dawuro, Ethiopia
(Addis Ababa University, 2025-03) Berhanu Abate; Bisrat Kebede (PhD; Bekele Ayele (PhD) Co-Advisor
The study investigates the impact of blending and subsequent washing and flotation processes on coal quality. Four raw coal samples sourced from different seams were blended to create a uni-form feed before undergoing flotation. The study provides laboratory results of coal samples be-fore and after blending, washed by ET- Washing plant, and flotation treatments, highlighting significant improvements in key quality parameters, such as calorific value, ash content, sulfur levels, moisture content, and volatile matter. The flotation process, in particular, demonstrated considerable advantages in reducing ash and moisture content while increasing calorific value, making the coal more suitable for energy production. However, challenges related to sulfur con-tent and volatile matter remain. Additionally, environmental concerns such as water contamina-tion, air pollution, and solid waste management were addressed, with recommendations for the implementation of flotation circuits, desulfurization, and efficient waste management practices to minimize environmental impact. Economic analysis of the plant’s operation, including capital and operating costs, demonstrated that while the current process is cost-effective, the addition of flotation could enhance coal recovery and overall revenue. The study concludes that flotation provides the most significant improvements in coal quality and efficiency, making it a viable op-tion for enhancing the plant’s overall operational and economic performance.
Beneficiation and Characterization Techniques of Coal in the Western region of Tarcha Zuria Wereda
(Addis Ababa University, 2025-05) Daniel Kassaye; Zekarias Gebreyes (PhD)
Coal stands as the most plentiful and extensively found fossil fuel. Thanks to advanced methods, it can be extracted, moved, and stored efficiently and economically. The global trade of coal is experiencing consistent growth, accompanied by intense competition regarding supply and pricing. Nevertheless, the future commercial viability of coal hinges on its environmental sustainability, particularly on the ability of the power generation sector to minimize sulfur and other harmful emissions. This research examines the extraction methods employed at the Tarcha coal deposit located in Tercha Zuria Wereda, Southern Ethiopia. It utilizes a wet extraction technique to evaluate flotation responses and optimize key factors such as yield percentage and ash content. The primary goal of the study is to enhance the quality of coal by refining flotation processes and minimizing impurities. Laboratory experiments are conducted with varying particle sizes and different ratios of collector to frother in the froth flotation process. The results indicate that the highest coal recovery yields are achieved at a collector-to-frother ratio of 8:4, while also assessing how these variables affect ash content. The data reveal a clear trend of increasing ash content as particle size decreases, highlighting the importance of maintaining specific parameter ranges to optimize yield. Ultimately, this project offers valuable insights that could support local mining operations, particularly the ET-Mining Development Company, which is actively involved in job creation and community development initiatives. The outcomes of this study may also aid Ethiopia in meeting its domestic coal needs, potentially decreasing its dependence on imported coal as the nation advances its coal resource development.
Proximate Analysis and Flotation Performance of Biyo Gurgur Coal, Somali Region, Ethiopia: Effects of Particle size and Collector Dosage on Grade and Recovery.
(Addis Ababa University, 2025-02) Yahye Ahmeda; Mulugeta Sissay (PhD)
This study investigates the proximate Analysis and flotation performance of coal from the Biyo Gurgur area in the Somali Region of Ethiopia to assess its quality and industrial potential. Despite Ethiopia’s heavy reliance on imported energy, domestic coal resources such as those in Biyo Gurgur remain underutilized due to limited characterization and beneficiation data. This study’s main objective was to evaluate the coal quality in the Biyo Gurgur region using flotation experiments, calorific value, and proximate analysis. ASTM standards determine important factors such as moisture, ash, volatile matter, fixed carbon, calorific value, and sulfur content. Proximate analysis showed that the coal is low-grade lignite with high ash content (19.3%-63.2%), moderate volatile matter (19.5%), and low fixed carbon (13.2%-50.6%), resulting in a calorific value of 1626.48cal/gm. With a sulfur content level of 0.16%, there was little risk of sulfur emission to the environment. Flotation experiments were carried out to evaluate the effects of particle size and collector dosage on grade and recovery. The findings showed that both parameters significantly influence efficiency. The highest recovery (11.84%) and grade (97.85%) were achieved at a particle size of -125+75 with a 10mL collector dosage, while coarser particles exhibited lower recovery rates. The flotation process effectively separated hydrophobic coal particles from hydrophilic ash-forming minerals, highlighting its potential as a beneficiation technique to improve coal quality. These results demonstrate the coal’s limited energy potential and significant impurity levels, which restrict its industrial use in its unprocessed form. However, flotation and other beneficiation techniques can improve its quality for industrial and energy applications. The study concludes that although biyo gurgur coal has limited application in its raw state, beneficiation through flotation can significantly improve its quality for industrial and energy uses.
Flowsheet Design of Pilot Beneficiation Plant for Melka Arba Iron and Some Essential Minerals in Ethiopia Using METSIM
(Addis Ababa University, 2025-06) Asmamaw Mulugeta; Mulugeta Sisay (PhD); Ijara Tesfaye
Despite having abundant natural resources, including coal, iron, lithium, niobium, chromium, gold, and tantalum, Ethiopia has a difficult time efficiently using these resources for economic development. The absence of dedicated simulating flowsheet of pilot mineral beneficiation facilities has hindered essential research and development activities, limiting the optimizat ion of extraction and beneficiation techniques. This study proposes common simulating flowsheet design of a pilot benefici ation plant for essential mineral s in Ethiopia using METSIM simulation software, and testing the designed flowsheet by simulating the beneficiation of Melka Arba Iron using magnetic separation method. The study was conducted by assessing the literature to ascertain the equipment demands and using mineralogical analysis to select suitable Ethiopian minerals for beneficiation in order to acquire laboratory equipment in compliance with established specifications. Then, simulate the magnetic separation of Melka Arba iron ore for testing the designed flowsheet using METSIM software. The choice of equipment is crucial to the effectiveness of the procedure. In order to accommodate the distinct mineralogy of Ethiopian ores, the design carefully integrated industry-standard equipment, such as jaw and cone crushers, ball mills, and separation technologies, such as magnetic, gravity, and flotation techniques. Operations are streamlined and redundancy is reduced because to this integration. With a magnetite recovery of almost 95%, METSIM's simulation of the beneficiation of Melka Arba iron ore validated magnetic separation as a very successful concentration technique. The effective separation of magnetite from accessory and gangue minerals was confirmed by mass balance findings. These simulation results offered a strong basis for additional process modification, allowing for enhancements in recovery rates, operational effectiveness, and the overall viability of the Melka Arba iron ore beneficiation process from an economic standpoint. In conclusion, the novel pilot process design that has been introduced here provides a scalable model for modernizing Ethiopia's mineral processing industry, tackling present issues associated with the absence of standardized beneficiation methods.
Beneficiation of Lithium Ore Using Flotation Technique, In case of Erar Area, Harar Region, Ethiopia.
(Addis Ababa University, 2025-05) Taju Mohammed; Bisrat Kebede (PhD); Mamaru Genetu (Mr.) Co-Advisor
Enhancing the recovery of lithium from its ores is vital for supporting the growing demand for lithium-ion batteries used in electric vehicles and energy storage systems. This research investigates the beneficiation of lithium ore from Ethiopia’s Harar region through the froth flotation method, focusing on how varying reagent dosages affect flotation performance. Flotation tests were carried out by adjusting the amounts of collectors, frothers, and activators to study their effects on both the yield (concentration weight) and the purity (grade) of the lithium concentrate. The findings indicate that the amount of reagents used significantly influences flotation efficiency. The optimal result was obtained in experiment number 3, which used 5 mL of frother, 7 mL of collector, and 10 mL of activator, achieving the highest concentration weight. A steady increase in concentrate yield was observed from the first to the third experiment, followed by a decline through the ninth experiment. These results highlight the importance of precise reagent dosage control to maximize both the quantity and quality of lithium recovery. The study offers practical insights into improving the effectiveness and sustainability of lithium ore processing in the Harar region.
Mineralogical Characterization and Comminution Energy Requirement of Lithium-Bearing Pegmatite in Burkuke, Sidama Regional State, Ethiopia
(Addis Ababa University, 2025) Deneke Gizaw; Kebede Gamo (PhD)
This study focuses on the mineralogical characterization and comminution energy requirement of lithium-bearing pegmatite located in the Burkuke locality in Sidama Regional state, Ethiopia. The increasing request of lithium around the world, used especially for batteries and renewable energy technologies, requires a deeper knowledge of mineralogical and chemical characteristics of pegmatites that is fundamental to develop the most efficient extraction techniques. The X-ray diffraction (XRD) analysis indicates that all three samples consist of multiple mineral phases and their compositions and abundances of minerals are different between the samples. XRD analysis confirmed the presence of critical lithium-bearing minerals Spodumene Present in all three samples (DE01: 30.1%, DE02: 10.3%, DE03: 12.6%), indicating moderate to significant lithium potential. Associated gangue minerals: Quartz, feldspar, albite, muscovite, and biotite, which can affect the liberation and separation processes. According to the results of the Atomic absorption spectroscopy (AAS) analysis the content of lithium oxide in the concentrates is relatively low (0.09%) and this is an integral factor in taking into account of the possibility of lithium extraction from this pegmatite. The findings indicate that although fine grinding enhances mineral liberation, energy consumption requires particular attention when processing operations are performed on an industrial scale. From grinding data, it is found that the feed size, the milling speed, and the amount of consumed energy affect the size reduction phenomenon. Sample 1 (350 rpm, 3.35 kWh/ton, P80 320 μm), Sample 2 (700 rpm, 5.01 kWh/ton, P80 200 μm), Sample 3 (1050 rpm,1.53 kWh/ton, P80 620 μm), and Sample 4 (3.365 kWh/ton, P80 1.3 mm).
A Masters Project on Utilization and Quality Enhancement of Local Kaolin Clay Minerals Through Beneficiation
(Addis Ababa University, 2023-02) Abiyot Ayalew; Anteneh Marlign (PhD); Meseret Aregahegn:-Co-Advisor
Recently, some researchers labeled industrial minerals as ‘Development Minerals ‘because of their crucial role for fast local economic development and their necessity in the industrialization. The commercial term “Kaolin “is one of the most versatile industrial clay minerals composed essentially of kaolinite (Al2O3.2SiO22H2O). Kaolin What we call it as “China clay” have been found in Ethiopia as huge reserve estimated (20 million tons), throughout in the different parts of country. However, manufacturing industries import commercially value-added Kaolin from foreign countries due to the low qualities of local kaolin which have major impurities. The impurities of Kaolin from literatures and from XRF characterization of Raw Kaolin (RK) are quartz, mica, feldspar, iron oxide and titanium oxide minerals. Here my interest was to improve the qualities of this local kaolin through physical, thermal and chemical beneficiation to substitute imported commercial Kaolin. The two principal objectives of kaolin refining were the removal of impurities and the production of the desired particle-size distributions. Possibly to meet some industrial requirements, the coloring impurities (mainly iron oxides and other small amounts of fuxing components) must be removed. Based on the XRF analysis, the raw kaolin ore from AlemTena, Ethiopia containing 64.135 wt% SiO2, 25.747 wt% Al2O3, 4.838 wt% Fe2O3, and 8.22 wt% loss of ignition (LOI). Then it was physically beneficiated, chemically leached, and thermally treated for possible industrial use, especially for ceramic applications. The leaching experiments were carried out using oxalic acid solutions as leaching reagents for the iron extraction and colour enhancement process. A substantial reduction of iron oxide (4.838 to 3.107 wt %) and silica (64.135 to 57.285 wt%) SiO2 on the other hand a substantial increment of alumina (25.747 to 33.662 wt%) Al2O3 from the raw kaolin was observed at operating conditions of 2.0 M oxalic acid, the temperature of 90 °C, and contact time of 120 min. From Chemically leached kaolin we observed a significant whiteness and brightness. In other way the thermally treated kaolin was observed an increment of iron oxide (4.838 to 6.605 wt %) and also it lost its crystalline structure and becomes an amorphous phase but still its alumina and silica contents improved. Generally, from my study I understood that, the physically beneficiated, chemically leached, and thermally treated kaolin raw material can used to fabricate low-cost kaolin-based ceramic products.
Investigation of Reverse Flotation Response for The Beneficiation of Iron Ore Around Dawa-Moyale, Somali Region, Ethiopia
(Addis Ababa University, 2025-05) Abdifatah Maktel Abdullahi; Zekarias Gebreyes (PhD)
Iron (Fe) is the fourth most abundant element in the Earth’s crust and constitutes approximately 6% of its composition, which is fundamental to the industrialization and civilization of any nation, including that of the Federal Democratic Republic of Ethiopia. The Dawa-Moyale area in the southern metamorphic terrain of Ethiopia has been recognized as a region rich in iron ore deposits. Therefore, this study aims to investigate the beneficiation potential of Dawa-Moyale iron ore in the Somali region of Ethiopia using the reverse flotation method. The study employed a two-level full factorial experimental design using Stat-Ease 360 software (Trial version) to model the influence of various experimental factors on flotation performance. The flotation experiments focused on feed particle size, pH value, and collector dosage as the independent variables, while iron grade and recovery were designed as process responses. The results of the experimental tests indicated that the models for iron grade and recovery were statistically significant, where the predicted values aligned well with the experimental results, with R-squared (R²) values of 0.972 and 0.9962 for iron grade and recovery, respectively. The findings revealed that collector dosage (oleic acid), pH value, and the interaction between particle size and collector dosage significantly influence the Fe grade, whereas feed particle size is the sole experimental factor with a statistically significant effect on iron recovery. The maximum iron grade and recovery of 46% and 94.7%, respectively, were achieved under the flotation conditions determined as follows: a particle size of -150+63μm, a collector dosage of 125g/t, and a pH of 9.5. The results of this study provide valuable insights into the beneficiation potential of Dawa-Moyale iron ore and contribute to the development of the iron ore industry of Ethiopia.
Evaluation of Borax as an Alternative to Mercury in Gold Recovery: A Case Study of Benishangul Gumuz Region, Assosa Area, Western Ethiopia
(Addis Ababa University, 2025-05) Zeryihun Hailu; Bisrat Kebede (PhD); Enatfanta Melaku (Mrs.) Co- Advisor
Artisanal and small-scale gold mining (ASGM) plays a critical role in the Ethiopian economy, particularly in rural and resource-endowed regions like the Benishangul Gumuz Region, where it forms a mainstay of livelihood for many households. However, the extensive use of mercury for gold recovery in ASGM operations has raised serious environmental and public health concerns, such as soil and water contamination and toxic exposure that affect not only miners but also adjoining communities. The goal of this study was to evaluate borax as a safer and more environmentally friendly alternative to mercury in the gold extraction process, with a focus on the Assosa Zone. The study adopted comparative experimental analysis with ore samples collected from two geologically different mining areas: Agosha Kebele (quartz-vein-hosted primary ores) and Mukufute Kebele (alluvial placer deposits). Through the adoption of borax smelting and conventional mercury amalgamation techniques, the effectiveness of gold recovery was analyzed using statistical methods, including descriptive analysis, Wilcoxon Signed-Rank tests, and ANOVA. The results revealed that borax smelting yielded significantly better gold yields, with a mean recovery of 0.6125 g, compared to 0.2345 g from mercury amalgamation, while at the same time avoiding the toxic emissions and residual pollution associated with mercury. Borax also proved versatile for both ore types and showed practical advantages regarding safety, cost-effectiveness, and environmental preservation. This study confirms the technical and economic viability of introducing borax in Ethiopia’s ASGM industry and informs the wider effort towards reducing mercury use in small-scale mining. The study concludes by advocating for the adoption of borax through policy support, stakeholder training, and awareness creation, while also proposing areas of future research to determine its long-term environmental effects, socio-cultural acceptability, and potential for scalability in other mining areas.
Talc Beneficiation through Flotation Techniques in Ethiopia: A Case Study of Sidama Regional State, Hoko Woreda
(Addis Ababa University, 2025-03) Wakjira Tesfaye; Anteneh Marlign (PhD); Desisa Yadeta (PhD) Co-Advisor
Talc is a hydrated magnesium layered silicate mineral. The major uses are in the plastics industry, rubber, cosmetics, ceramics, and pharmaceuticals. Properties include increasing stiffness and resistance to heat and are suitable for talcum powder and tablet formulations since it is soft and inert. This project discusses the flotation parameters of talc beneficiation, sourced from the Sidama Regional State in Ethiopia, using high-grade and high-recovery outputs. The flotation techniques have always remained favorable for talc-beneficiating processes, especially because the process achieves gangue mineral separation. The experiments showed that under optimum conditions, the pH was 11, the collector dosage was 1.2 kg/ton, and the depressant dosage was 1.0 kg/ton, maintaining the pulp density at 200 g/l and an impeller speed of 1100 rpm. Under these conditions, the talc recovery was 74.25% in the flotation process. The chemical analysis of the resulting talc concentrate showed significant improvements: SiO₂ increased from 58.2% to 73.01%, while MgO increased from 24.22% to 24.62%. The Fe₂O₃ content decreased remarkably from 14.37% to 1.66%, reflecting a successful removal of impurities and a substantial increase in the purity of the final product. Results indicate that oleic acid and kerosene oil, with sodium hexametaphosphate as a depressant and propyl glycol as a frother, gave the best recovery with a grade improvement. Such a scheme of optimization of flotation conditions to improve talc quality is important in fulfilling these industrial applications in the industries of ceramics. This work contributes to an understanding of talc beneficiation techniques and forms the ground for further research on enhancing the talc recovery methods in Ethiopia and meeting the requirements of various industries for economic development.
Enhancing The Caloric Value of Coal Deposit Using Flotation Method in Lalo District, South-Western Ethiopia
(Addis Ababa University, 2025-02) Megersa Biratu; Melese Alemayehu (PhD); Bekele Ayele (PhD) Co-Advisor
Lalo coal reserves are mainly lignite and contain high ash coals therefore, it is important to enhance these low-quality coals. Coal applications are impacted by high ash content; hence improvements are required to lower the ash content of coal in our nation. Tests were carried out to investigate and determine the effect of parameters like particle size and collector dosage on reducing ash content from coal. The particle size observed to have the most significant role in coal ash, followed by the collector dosage. The optimum particle size and collector dosage values were -100+75μm and 7ml respectively. The results from the flotation study on a laboratory scale at optimized conditions revealed an increase in carbon content from 26.16% to 39.07%, decrease ash content and sulfur content from 25.75% to 20.09% and 0.47% to 0.21% respectively. Using a high ash content coal sample from the Lalo district coalfield, flotation is used in this study to improve the quality of coal samples to remove the ash and impurities.
Evaluation of Flotation Efficiency for Ela -Hanchano Coal in The Konta Zone, Southwestern Ethiopia Region, Ethiopia
(Addis Ababa University, 2025-02) Mebratu Menu; Melesse Alemayehu (PhD); Bekele Ayele (PhD)
The study focused on evaluating the efficiency of flotation processes in recovering coal from the Ela-Hanchano deposit in the Konta Zone of Southwestern Ethiopia. The work aims at improving recovery levels and upgrading the quality of coal by applying froth flotation, a physic-chemical method widely used for coal particles from associated impurities. This work considers critical parameters such as particle size distribution, the dosages of collector and frother, and their influence on flotation recovery, the grade of the concentrate, and the overall performance of coal beneficiation. Experimental work involved the preparation of coal samples through crushing and grinding, followed by sieving to the required particle size fractions (-500+250μm,-250+125μm and -75μm). Flotation tests were conducted using a laboratory flotation cell with kerosene as a collector and n-octanol as a frother. Recovery efficiency was evaluated at different reagent dosages and particle sizes. Proximate analyses were carried out to establish the physio-chemical characteristics of the treated coal, including moisture content, ash content, volatile matter, fixed carbon, sulfur content, and calorific value. Results showed that finer particle sizes significantly improved flotation recovery, and the highest efficiency was obtained as 87.58% for particles of under 75μm. The optimum collector (5ml) and frother (4ml) dosages improved the flotation process in terms of enhancing coal concentrate quality. Treated coal showed a reduction in ash content from 12.90% to 10.95%, a decrease in moisture content from 21.54% to 2.60%, and an increase in fixed carbon from 34.14% to 46.41%. The calorific value of the coal improved remarkably from 4,804.07 Cal/g (8,647.33 Btu/lb.) for raw coal and 6,418.15 Cal/g (11,552.67 Btu/lb.) for treated coal. This research underlines the importance of flotation parameters in the optimization of coal beneficiation and presents a framework that will help to improve the exploitation of Ethiopia’s coal resources.
Categorization of Coal Based on Composition and Mineralogical Analysis for Evaluation of Quality Indicators; A Case Study of the Botor Tolay Area, Jimma, Southwestern Ethiopia
(Addis Ababa University, 2025-05) Likasa Bakala; Kebede Gamo (PhD); Bekele Ayele (PhD) Co Advisor
The classification of the coal's composition from the Botor Tolay deposit and its implications for coal quality indicators are the main goals of this study. The project research employs analysis of coal samples collected from five points within the studied area, utilizing techniques such as proximate, calorific value, sulfur content, XRD, XRF, and FTIR analysis methods to determine key compositional elements. The results reveal distinct categories of coal based on their calorific value, sulfur presence, moisture content, ash content, volatile matter, fixed carbon, and fuel ratio. Accordingly, calorific value ranged from (7,406.54 to 9,783.46Btu/lb), sulfur content (0.17 to 0.21%), moisture content (1.12 to 1.46%), ash content (33.99 to 48.52%), volatile matter (19.13-21.94%), fixed carbon (30.84 to 42.88%) and fuel ratio (1.61 to 1.95%). Hence, all the studied coal samples fall within the sub-bituminous coal category based on calorific value categorization. One of the coals sample BT-1 has the highest percentage of fixed carbon (42.88%), which made it to have a high fuel ratio, enabling it to be more combustible. Major element analysis of the coal sample indicates it contains the maximum amount of SiO2 (67.668% by wt.), and Al2O3 (24.194% by wt.) followed by Fe2O3 (4.472% by wt.) and (TiO2 (1.296% by wt.). Functional group analysis indicated the presence of the peak of the -OH stretching vibration group and the peak in the spectra of coal found between 1100 and 400 cm−1, which are assigned to clay minerals such as quartz, kaolinite, and illite. The Crystal chemistry structure analysis of the coal sample revealed the presence of silicon dioxide (SiO2) and pyrite (FeS2), which may contribute to increased ash content.
Process Enhancement of Sapphire Gemstone from Borena Zone, Oromia Region, Southern Ethiopia
(Addis Ababa University, 2025-04) Kibirite Mokonen; Mulugeta Sisay (PhD); Aselefech Mitiku (Mrs.) Co-Advisor
The Borena Zone in the Oromia Region of Southern Ethiopia has recently emerged as a significant source of sapphires. Despite the region's potential, local processing methods remain rudimentary, often relying on manual labor and traditional techniques that limit the quality and market value of the gemstones. This study explores the current state of sapphire processing in the Borena Zone and proposes technological enhancements to improve the efficiency and quality of the final product. From Mining Engineering point of view, integrating advanced processing techniques, such as cabochon style and Faceting, the sapphire industry in this region can significantly elevate its quality of the mineral; Sapphire. Successful case studies from other regions, including Sri Lanka and Madagascar, highlight the transformative impact of modern processing technologies. Implementing these advancements in the Borena Zone has the potential to not only increase the value of Ethiopian sapphires but also foster the quality. and strengthen the local gemstone industry's global competitiveness. This project work underscores the critical need for technological investment and skill development to achieve substantial process enhancements in the Ethiopian gemstone sector.
Beneficiation of Blended Coal by Froth flotation Technique, In The case of Kripto Coal Mining and Chemicals PLC Elasanchano Woreda Konta Zone South West Region of Ethiopia
(Addis Ababa University, 2025-03) Ewunetu Mitku; Mulugeta Sisay (PhD); Mamaru Genetu (Mr.) Co-Advisor
Beneficiation of blended coal in the case of Kripto coal mining and chemicals plc located Elasanchano woreda konta zone, south western part of Ethiopia using kerosene as a collector n-octanol as afrother sodium silicate as a depressant with aeration speed of 1850 r/pm to facilitate the formation of small bubble enhance the calorific value of blended coal in the three flotation parameters studied in this project. which is particle size, frother dosage and flotation time is investigated. The optimal particle size we get maximum combustible recovery and quality is +125+-250 μm particle size which have 35.699% recovery and its heating value measured in boom calorimeter is 6,047.5781Ca/gram. The optimal frother dosage we get maximum recovery and grade is 6ml of n-octanol which have 65.157% recovery and its heating value is 6,412.7735 Ca/gram. The optimal flotation time we get high combustible recovery and quality of coal is 10 minute which have 70.426% of recovery and its calorific value is 5,894.4779 Cal/gram. Generally, froth flotation technique is good for environmentally friend method for the reduction of sulfur content in coal which reduce the release of SO2 gas cause for the formation of acid rain and health risks including lung cancer in humans. This project reduces the sulfur content of blended coal 0.68% to 0.44%. So, froth flotation is an appropriate method for the enhancement of heating value and proximate and ultimate characteristics of coal by removing the impurities from coal.
Mineralogical characterization of Bikilal Iron ore of Western Wollega, Gimbi, Ethiopia
(Addis Ababa University, 2024-09) Jebessa Mammo; Melesse Alemayehu (PhD)
The Bikilal Iron Deposit is located in Gimbi, West Wollega zone of Oromia National Regional State, 440 kilometers west of Addis Ababa and is found at 25 kilometers northeast of Gimbi town. Its iron ore deposit is a Kiruna-type magnetite – ilmenite deposit that consists of magnetite, ilmenite, hematite, sulphides, and apatite. The principal ore minerals are magnetite and ilmenite. Bikilal iron ore with 57 million tons of magmatic origin. Its iron ore accounts 23.3% magnetic iron content and with 41% total iron. The main objective of the project is to characterize the mineralogy of Bikilal iron ore so as to identify the main valuable minerals, gangue minerals, and their relationships, as well as the grain size in the various ore phases.To study the mineralogy of Bikilal Iron Ore secondary data were collected. Primary data were gained from laboratory analysis for thin section and polish section (One sample each) done at Ethiopian Geological Survey of Ethiopia, X-Ray Diffraction analysis done at Adama Science and Technology University Laboratory. The Polish section analysis indicates that mineral compositions were 10% Pyrite, 15% Ilmenite, 20% Magnetite and 1% Chalcopyrite with xenoblastic texture and 54% gangue. Thin section analysis also indicate that the description of the ore were dark gray in color and fine to coarse grained in texture and its mineral compositions were 62% plagioclase, 30% hornblende, 5% Opaque, and 3% Biotite.. Six Chemical composition analysis by atomic absorption Spectrophotometry (AAS) were taken from secondary data (Zewdneh Tassew, 1990) and (Debebe Tafesse, 1995) to analyze the major oxides present in the ore and their average results were 48.55% SiO2, 0.85% TiO2, 9.47% Fe2O3, 17.08% Al2O3, 8.68% MgO, 10.53% CaO, 2.35% Na2O, and 0.308% P2O5. Additionally, Seven X-ray florescence (XRF) results were taken from (tesfa Lemu, 2013) and the average results were 47.97% SiO2, 0.91%TiO2,17.52%Al2O, 9.65%Fe2O3, 0.13%MnO, 8.58%MgO, 12.03%CaO, 2,52%Na2O, 0.09%K2O, and 0.312%P2O5. Three samples were analyzed by the X-ray diffraction (XRD) on the Bikilal iron Ore at Adama Science and Technology University Laboratory. The phases were identified as 52.2% Hornblende, 1.2%Biotite, 27.8% Actinolite, 6.3% Titanomagnetite, and 12.6% amphibole. The elemental composition of the XRD analysis were O, Si, Fe, Ca, Mg, Al, K,Ti with negligible amount of F and V. From analysis results above SiO2, TiO2, and Al2O3 make up the majority of the gangue minerals in Bikilal iron ore, with an unacceptably high concentration of the harmful element phosphorus. One explanation for the indication of a decrement in the amount of the key mineral in the ore (Fe2O3) is the relatively high silica content of the Bikilal iron ore, even when compared to the iron mineral hematite. This indicates the amount of the gangue is very high that exceeds the amount of the important mineral present in the ore. Others impurities found in the ore include MgO, CaO, Na2O, K2O, TiO2 and albeit in smaller amounts. The commercial ore should contain fewer than 6% and 4% of silica and alumina, respectively (Joan J. Kiptarus et al., 2015) but the Bikilal iron ore SiO2 and Al2O3 average content are 36.2% and 6.4% respectively, that is very big difference in respect to gangue contents. Alumina is a particular target during the beneficiation of iron ore and is a representation of pollution in the steel-making process. As a result, the Bikilal iron ore deposit's average quality is below the needed requirement, which is less than 40%, and is not comparable to the top iron ore nations, leading to the low-grade ores. The deposit of the ore can be exploited for multiple sources of different valuable commodities in addition to iron ore like phosphorus, Gold, Aluminium and Titanium.
Flowsheet Development Studies for Lega Dembi Gold Process Plant
(Addis Ababa University, 2023-09) Adinew Abebe; Abubeker Yimam (PhD)
This flowsheet advancement of Legadambi processes for gold plant contain different unit operation and unit process. Legadambi gold process plant use different beneficiation mechanism to extract and recover the valuable metal or element of interst from associated mineral or gangue. The process consists seven consecutive and interdependent but segregated unit operating process and unit process. Process those implmented in Legadembi were comminution (crushing and grinding), Thickening and reagent leaching (Extraction), both adsorption and Desorption (stripping), Electrowinninng and gold Smelting,Tailing dam and Detoxification plant. The flowsheet consists two crushing circuits each consists a primary, secondary and tertiary stage crusher that produces a crushed ore product, which is then conveyed to feed the grinding unit. Grinding unit is configured in two single stage mills with cyclone classification to confine the particle size reduction within requirement range. Grinding unit consist circuit discharges ore slurry through desanding screen to thickening unit; screen removes trash material from overflow slurry. Flowsheet of thickener and reagent unit utilizes flocculent chemicals to increase/enhances settling rate of solid in grounded ore slurry for gold and silver leaching process. Leaching circuit uses sodium cyanide to extract gold. In the pulp procedure, activated carbon and gold from the ore are utilized to adsorb the recovered gold from solution in carbon. The carbon is gathered and processed in the elution circuit, which separates the carbon and gold, after the CIP circuit. While the gold is extracted from solution during the electrowinning process, the carbon is renewed and utilized again in the CIP circuit. To create gold Dore bars, the stripped and electrowonted gold is melted in a gold chamber. For the purposes of final deposition, recovering decant water, and the detoxifying process, process tailg ravitate to a tailing storage facility. Process tails solution detoxified in cyanide destruction plant before being discharged to the environment. Finally, Production process of each unit described with block and process flowsheet.

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