Centers for Ethio Mines Development

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Comminution circuit flow sheet Development for Optimum Performance of Iron Ore Processing, in the Case of Sekota, Wagehimra, Northern Ethiopia
(Addis Ababa University, 2023-06) Ephrem Tialhun; Abubeker Yimam (PhD); Megeressa Bedo (Mr.) (Co-Advisor)
Sekota Iron Ore aims to contribute to the economic development of Ethiopia by exploiting and producing high-quality iron ore for both domestic and international markets. The company expects to create employment opportunities and generate revenue for the government, which can be used to invest in other developmental projects. Besides, the establishment of Sekota Iron Ore could also help to reduce the country's reliance on imported iron and steel products, promote local industries and contribute to the growth of the mining sector. Most of the minerals extracted in the nature are founded disseminated with the gangue, this creates a necessity to liberate these particles and reduce the size for principally reach a big concentration of the desired material. As the comminution is by far the largest energy consumer in most mine sites, the study of the mineral processing try to conduct this size reduction with the bigger efficiency possible. comminution flowsheet design is a critical process in the production of iron ore. In this study, the flow rate was fixed at 150t/h with the Crusher specification of a Cedarapids JC24x36 jaw crusher model and a Nordberg Hp 300 S/M cone crusher. Based on the mineralogical information and ore properties provided the AggFlow Version 460.22 software is used to conduct, a comprehensive comminution flowsheet design to achieve the desired particle size distribution and mineral liberation. In the communition of primary crusher stage Iron ore at top size of 42 inches or (1066.8mm) generates 5 different ranges of materials, the first is at a size of 45mm, the second at 10mm, and the third is at 8mm, between 15 and 8mm and between 23.5 and 15mm. The primary crusher, a Cedarapids JC2436 Model Jaw crusher, was required to reduce the feed size with closed side setting of 69.85 mm to a manageable size of end product 21Mtph for further processing. The Nordberg Hp 300 S/M cone crusher was used as a secondary crusher with closed side setting (CSS) of 28mm to further reduce the particle size to 26Mtph. To complete the task several choices analyzed and as final design used 1 jaw crusher Cedarapids Jc 2436, and two cone crushers Nordberg HP 300 S/M. some screening and conveyors placed in the design to increase the reduction ratio of the equipment.
Reverse Flotation as a Method for Beneficiation of Sekota Iron Ore
(Addis Ababa University, 2023-06) Temesgen Demissie; Abubeker Yimam (PhD)
Upgrading low grade Sekota iron ore to reduce the unwanted minerals and improve the quality is necessary to address these issues, in order to produce an acceptable feed for a steel production facility. The primary aim was to use reverse flotation as a beneficiation method for Sekota iron ore, in order to get a last flotation that meets the desired specifications. This process was divided into three stages: crushing, grinding, and flotation. For each of these stages, such as grinding, dosage of collectors, flotation duration, and procedures were determined. In the laboratory, where the samples were obtained, the ore was ground in a size of -0.074mm, using 250 grams of ore, with varying amounts of anionic oleic acid as the collector, 5mg/ton of activator and 5mg/ton of depressant, and floated with 2.0 g/ton of ethanol frother. The slurry was maintained at 10.5 using NaOH throughout the process. Before conducting any optimization tests on the iron ore flotation process, a laboratory procedure was developed to carry out the reverse flotation of the iron ore. The results showed that following these parameters, the flotation process achieved a final concentrate with a grade of 39.16% iron and an iron recovery of 41.29%. In this study, with varying duration of flotation, the iron grade ranged from 40-45% with an iron recovery of approximately 42%.
Study on Flotation Response of Coal from Gamo Zone Southern Ethiopia
(Addis Ababa University, 2023-06) Kibru Woldemariam; Abubeker YImam (PhD)
Based on the log results of pits, geophysical results and areal coverage of coal deposits in Gamo zone, Kuccha woreda, it is roughly estimated to have 744,174.96 tons of coal. The flotation response of a coal is a critical factor in determining the efficiency of coal beneficiation processes. The study investigated the effects of collector dosage, frother dosage, and particle size on the flotation response of Gamo area coal in a 3-liter batch flotation experiment. Kerosene was used as the collector and n-octanol as the frother. Full factorial Design was applied to investigate the effect of collector dosage (10ml, 20ml), frother dosage (2ml, 6ml) and particle size (-250 μm +125μm -125 μm) on the process of flotation using Design expert® 6 software, which shows the significant influence on the value of yield and recovery. The result showed that the optimum condition for the process was 18.3ml, 4.7ml and -125 μm which resulted in 81.7% yield,90% combustible matter recovery and 37.5% flotation efficiency index. The findings suggest that careful optimization of reagent dosages and particle size can significantly improve the flotation response of Gamo area coals, with potential applications in coal beneficiation processes.
Mineralogical Assessment of Ashashire Gold Ore to Investigate Its Beneficiation Potential by Flotation Method, In Benshangul Gumuz Western Ethiopia
(Addis Ababa University, 2023-06) Kiross Haile; Bogale Tadesse (PhD); Kaleb Gebreyes (Mr.) (Co-advisor)
Primary and placer gold deposits are found in the Ashashire area, which is an orogenic gold prospect area. These resources are a source of income for both companies and artisanal gold miners. It is located in the Western Greenstone belt of the Precambrian volcano-sedimentary belt, at Kurmuk Woreda, in the western Ethiopian region of Benshangul Gumuz. The region is near to the Sudanese border and is referred to as Ashashire informally. Gold is the most valuable commodity in the world. Due to the significant study that experts from all around the world have done on the history of gold, namely its birth. Ethiopia is a developing country, but it has not yet reached its full potential. Some claims and exploratory activities claim that Ethiopia is rich in precious metals, including gold, which are processed using incredibly archaic methods in many different regions of the country. As a result, the main objective of this research project is to investigate the mineral makeup of Ashashire gold ore in order to assess its potential for flotation-based beneficiation. The geochemistry was validated by both inductively coupled plasma mass spectrometry and fire assay. The petrographic analysis includes a description of the host rock and ore deposit. The host rock mostly consists of chlorite, carbonate, sericite, and quartz, with minor amounts of greenschist to amphibolite facies metamorphic minerals. Pyrite, pyrrhotite, magnetite, sphalerite, chalcopyrite, galena, and gold are found in the ore after petrographic investigation. According to ore microscopic and geochemical study, gold mineralization has strong spatial connections with alteration traits as carbonitization, silicification, sulfidation, and sercitization. The concentration of gold increases with host rocks that have been sericitized, carbonitized, silicified, and sulfurized. According to the ore geochemical data, the gold deposit contains up to 10.3ppm and is contained in chlorite-sericite-carbonate schist in carbonate-quartz veins. This gold deposit's target region is the Ashashire region. It is possible that gold is precipitated from hydrothermal solutions due to the intense wall rock alteration and the strong relationship between carbonate-quartz veins and gold. Every experimental mineralogical examination conducted by organizations and individuals in Ashashire ore mineralogy produces comparable results. It is not economically feasible to concentrate Ashashire gold for the reported gangue minerals using the flotation method. Due to the possibility of large recovery losses and increased chemical reagent consumption from such gangues. Then, prospective approaches for recovering gold from the Ashashire gold deposit include combining processing technologies like gravity separation, flotation processes, and leaching.
Determination Of Work Index of Spodumene from Kenticha Ore, Southern Ethiopia
(Addis Ababa University, 2023-06) Anuwar Mama; Bisrat Kebede (PhD)
From Kenticha, Southern Ethiopia, granite and kenticha spodumene ore were collected and used separately as reference ores. Each test ore was weighed at 2000 grams, and the reference ore was weighed at 500 grams, and all were ground in a lab ball mill under the same conditions. Size analysis of the feed to the ball mill and the output from the ball mill was performed on both the test ore and the reference ore, with the results properly tabulated. The feed and discharge particle sizes for the samples going into the ball mill were calculated using the Gaudian Schumann formula to ensure an 80% passing rate. The work index of the Kenticha spodumene ore was then calculated using Bond's equation, and it was discovered to be 11.391 kWh/t.
Reverse Flotation Potential of Bikilal Iron Ore Deposit: A Project Work on Wollega Area Western Ethiopia
(Addis Ababa University, 2023-06) Samuel Getaneh; Mulugeta Sisay (PhD); Guta Legesse (PhD) (Co-Advisor)
Iron is one of the most abundant rock forming elements, constituting about 5% of the earth’s crust. It is the fourth most abundant element next to oxygen, silicon and aluminum and after aluminum, the most abundant and widely distributed metal. Iron is extracted primarily from iron ores. The iron ores mainly include oxides and hydroxides such as magnetite (Fe3O4), hematite [Fe2O3], goethite [FeO(OH)], and limonite [FeO(OH)_nH2O].The primary gangue mineral in iron ores is quartz. The main problem regarding to beneficiate the Bikilal iron ore deposit are the presence of some deleterious gangue minerals such as Phosphorous, Alumina and silica and lack of advanced separation equipment. The aim of this project work is to indicate that the Bikilal iron ore deposit has naturally low grade iron content which is 41.2%Fe and it can be improved by anionic reverse flotation. The method used to upgrade this ore is first the qualitative and quantitative mineralogical analysis has been determined by atomic absorption spectroscopy (AAS) to know the initial amount of iron in the ore. Based on this information reverse anionic flotation has conducted in a batch flotation cell in two size classes at 75μm and 63μm. Oleic acid has been used as a collector whereas Ethanol used as a Frother. Modifiers such as activators, depressants and pH regulators have also used to promote the efficiency of flotation process. The concentrate of flotation has been analyzed again by (AAS) to evaluate the performance of the selected method. The amount from the concentrate has significantly increased from 41.2%Fe average grade to 62%Fe grade. The recovery of iron have been calculated as 65% for under 63μm and 74.4% for under 75μm.The amount of the concentrate for 63μm was 215g and that of 75μm was 250g. Therefore the recovery of iron from 215g under 63 μm is 65.5%Fe which is better than the recovery from 250g under 75μm that is 74.4%Fe. This project work mainly conducted based on (AAS) analysis results but it is not suffifeint to judge the general mineralogical composition and beneficiation process that should be applied in the Bikilal iron ore deposit. Therefore additional investigations and laboratory analysis such as (XRD), (SEM) and (XRF) are recommended to come up with a more tangible and realistic data. This paper have also discusses in detail about the factors that can affect the flotation performance of the ore and the alternative chemical reagents that can go through the mineralogy of Bikilal iron ore deposit.
Determining The Liberation Size of Mekaneselam Iron Ore Southern Wollo Zone, Northern Ethiopia: Implication for Beneficiation
(Addis Ababa University, 2023-06) Getahun Meseret; Dejene Hailemariam. (PhD); Belayneh Digafe (Mr.) (Co -Advisor)
Iron is one of the most important types of ferrous metals that extracted from ore minerals of iron, like magnetite, hematite and others. Ethiopia has a lot of iron ore resources which are located in different parts of the country. Among this, Mekane Selam iron mineralization, which is located in south Wollo zone, Northern Ethiopia, is the target area of this project work. The main objective of this project work was to determine the liberation size of the target iron-bearing ore mineral through mineralogical identification, chemical composition analysis, and examination of the particle size distribution. Atomic absorption spectrometry (AAS), X-ray florescence (X-RF), X-ray diffraction (X-RD) analysis, and sieve analysis, were widely used methods for this project work. The chemical composition of Mekaneselam iron ore consists of 16.55–77.59 % Fe2O3, 7.31–59.02% SiO2, and 1.44–17.38% Al2O3. With an average weight percentage of 48.34%,48.96% of Fe2O3, 34.7%,31.8 % of SiO2, 8.2%,10.68% of Al2O3, and 0.018% , 0.19 % of P2O5 and other minor compositions that resulted from X-RF and AAS compositional analysis respectively. The mineralogical results generated from X-ray diffraction showed that Mekaneselam iron ore consists of major iron-bearing ore minerals of 40–60% hematite, 8–59% goethite, with an average value of 49.13% hematite and 27.85% goethite. The dominant associated gangue minerals are 1–21% quartz with an average value of 11.5% and 1–23.5% kaolinite with a mean value of 8.6%. The examination of the particle size distribution of sizing curves shows that 80 percent passing (P80) of the grinded ore sample is 1100μm. The size-wise chemical compositional analysis of AAS revealed that a higher weight percentage of the target ore mineral was recorded under a sieve size range of (-250μm + 180 μm). This implies that the appropriate liberation size of the target iron-bearing ore mineral is found between (-250μm and +180μm) sieve size ranges. This liberation size range shows a cumulative passing of 38% total particles. The chemical and mineralogical results of Mekaneselam iron ore indicate that the ore is very low grade and can be upgraded to commercial values by using gravity concentration followed by a high-intensity magnetic separator. In addition, it can be upgraded by magnetic reduction roasting (MRR), followed by a low-intensity magnetic separator.
Identification of Reservoir Rocks, Properties and Structural Mapping of the Abay Basin in Viewing of Petroleum Exploration
(Addis Ababa University, 2023-06) Seid Endrie; Ketsela Tadesse (PhD); Bisrat Kebede (PhD) (Co-Advisor)
The basins has unique geological characteristics and holds different types of sedimentary rocks, such as sandstones, shales, carbonates, and volcanic rocks. The Abay (Blue Nile) Basin is located in the northwestern part of the country and covers an area of over 63,000 square kilometers. The Abay Basins covers a sizable area of the country. It includes Were Ilu, Mechale, and Legehida, which have notable oil seep exhibits. The contribution of the Upper Sandstone reservoir rock data is gathered from prior researchers and written materials in order to develop a relevant relationship between the types of reservoir rocks and structural mapping of the study area. In order to undertake the experimental tests for this study, samples are gathered from the field and sent to laboratory centers. In the laboratory, the chemical composition, porosity and permeability values of the reservoir rocks are determined using a representative sample that was collected from the study area. Based on the results of the experiments, the reservoir rock for the Abay (Blue Nile) Basin formation is an Upper Sandstone reservoir rock with relatively good porosity and excellent permeability. The Upper Sandstone rocks in the Abay basin have porosity values that range from 32.31 to 34.35% and permeability values that range from 1766 to 2350 mD, which suggests that the reservoir quality is generally very good (porosity)and excellent (permeability). During field work, it was discovered that the following fault systems were dominate in the study area. These includes; east-west (E-W) trending faults, northeast-southwest (NE-SW) trending faults, and northwest-southeast (NW-SE) trending faults. The oil and natural gas can be gathered and stored in reservoirs, the geological features called hydrocarbon traps. The presence of a petroleum system in the Abay Basin is strongly supported by the oil seepage at Were Ilu. The study area is characterized by rough structures, so airborne geophysical surveys are advised rather than ground geophysical surveys; seismic lines are needed for the study of the Abay Basin in order to delineate structural traps, stratigraphic traps, and indicate active faulting in the areas where it is possible for seismic line surveys; the basin requires further study regarding the main hydrocarbon fluids reservoir rocks, the total organic carbon contents of the source rocks and the carbonate reservoir rocks.
Characterization of Ore and Gangue Mineralogy at The Ashashire Gold Deposit, Benishangul- Gumz Region, Western Ethiopia
(Addis Ababa University, 2023-06) Getnet Belachew; Melesse Alemayehu (PhD); Basalifew Zenebe (Mr.) (Co-Advisor)
Gold is a precious metal that is highly prized and has been significant throughout human history. It has been used as money and for ornamental purposes. It is a crucial component in electronics, medical equipment, and other industrial uses. Around the world, mining operations have sprung up in response to the demand for gold, and efficient extraction and processing depend on an understanding of the mineralogy of gold deposits. This study aimed to characterize the mineralogy of the Ashashire gold deposit located in the Benishangul Gumuz Regional State, Western Ethiopia. Six representative mineralized core samples were analyzed using fire assay with atomic absorption spectroscopy (AAS), inductively coupled plasma (ICP), quantitative evaluation of minerals by scanning electron microscopy (QEMSCAN) and X-ray diffraction (XRD). The study found that the gold in the deposit occurs primarily as native gold and gold-telluride, with a strong association with tellurium and often found as free particles or in association with gangue minerals such as quartz and pyrite. Pyrite is the dominant sulfide mineral detected in all core samples, with only trace amounts of chalcopyrite detected. The gangue minerals present in the deposit are mainly quartz, ankerite-dolomite, muscovite, chlorite, and albite, with lower levels of paragonite, rutile, magnetite, and calcite. The presence of tellurium suggests that specialized processing techniques may be required to liberate the gold from the tellurides. The degree of liberation, liberation sizes, and recovery of gold are all impacted by the texture of the ore. The gangue mineral composition of the ore can also impact gold processing in several ways, including cyanide consumption, clay coating and gold adsorption, ore hardness, mineralogical complexity, and processing costs. The mineralogical data can be used to develop a suitable processing route, taking into account the ore texture, gold mineralogy, and gangue mineral composition. A combination of techniques such as gravity separation, flotation, cyanide leaching, pressure oxidation, and CIL/CIP could be employed to maximize gold recovery and minimize environmental impact. Further metallurgical testing and optimization are necessary to fully understand and optimize gold recovery from this deposit.
Analyzing the Effect of Operational Parameters on the Breakage Mechanisms of Spodumene Mineral to Optimize the Comminution Processes of Lithium Bearing Pegmatite in Kenticha, Ethiopia
(Addis Ababa University, 2023-06) Abdu Ebrahim; Alberto Velazquez Del Rosario (Prof); Ijara Tesfaye (Mr.0
This study is aimed to investigate the optimal operational conditions for breaking down the Kenticha, Ethiopia Li-pegmatite,which contains lithium minerals, particularly spodumene. The goal is to produce high-quality spodumene concentrate by achieving the desired particle size, particle distribution, which are crucial for efficient separation during the physical separation and subsequent froth flotation steps. To achieve this, one sample from Kenticha Li-pegmatite replicated four times were characterized using X-ray diffraction (XRD) and atomic absorption spectroscopy (AAS) techniques for mineralogical and geochemical analysis respectively. XRD analysis confirmed that the ore was predominantly composed of spodumene, with minor amounts of quartz, mica and feldspar. AAS analysis showed that the ore contained a moderately high level of lithium (approximately 2.5%) as well as other trace elements such as iron, and very low amount manganese and phosphorus. The results indicated that the ore had the potential to be a valuable source of lithium for industrial purposes. The sample then were crushed using a Laboratory Jaw Crusher in primary step and the study was conducted for different conditions parameters of grinding as a secondary step using a Laboratory Ball Mill. Optimal breakage mechanism was determined to achieve the desired spodumene concentrate.The results showed that the optimal conditions under the experimental analysis identified as milling power: 41 W, amount of feed: 250 g and the milling speed: 500 rpm, could produce narrow size distribution and the desired particle size for high spodumene concentration. This research has significant implications in the field of lithium mineral processing, providing important insights into the operational parameters that can achieve high-quality spodumene concentrate.
Effect of Particle Size on Coal Cleaning by Froth Flotation Method in Didaye Woreda, Wolaita Zone
(2023-06) Tiruye Kassaw; Bogale Tadesse (PhD); Guta Legesse (PhD) (Co-Advisor)
The aim of this study is to investigate the effect of particle size on the efficiency of coal cleaning process by froth flotation. Coal cleaning is an important process, which involves removing ash, and other impurities from coal to improve its quality for energy and industrial use. Froth flotation is a widely used method for coal cleaning, which relies on the difference in surface properties between the coal particles and the mineral matter. However, the efficiency of froth flotation is greatly affected by the size of coal particles. In this study, four different sizes range of coal particles (-500μm+350πm, -350μm+225μm, -225μm+180μm and-180mμ+100μm) were tested for their ability to float in the froth flotation process. Results showed that the efficiency of coal cleaning was highest for particles ranging from at this particle size -350μm+225μm, while particles above +350μm showed the poorest performance. The results suggest that particle size is a critical factor in the success of coal cleaning by froth flotation, and -350μm+225μm coal particles are more amenable to this process. The findings of this study will help in optimizing the coal cleaning process to improve its efficiency index, combustible recovery and ash rejection.
Biostratigraphy, Burial History and Thermal History of Gambella Basin, Ethiopia; Implications for Source-Reservoir Interaction and Hydrocarbon Generative Potential
(2023-06) Changkuoth Dhan; Samuel Getnet (PhD)
The Gambella Basin, located in southwestern Ethiopia, near the Sudan border, covers an area of about 15,350 sq.km. It has a NW-SE elongated outline, and it is presumed to be the southeastern extension of the Melut Basin of South Sudan. Geological data review indicates that sedimentation in the interior Basins of the South Sudan is controlled by intermittent rifting phases that continued up to Mid Miocene. Biostratigraphy, Burial history and Thermal history evaluation of Gambella area, analysis include the Palynological and Paleoenvironment analysis on 104 cuttings samples and 16 sidewall cores from the interval of 60-3500 mKB in Jekow well and carried out on seventy 70 ditch cuttings from the interval 745-3250 in Jacaranda well (PCOB report, 2007 ). The exploration wells, Jekow (in the East) and Jacaranda (in the West) Gambella, Ethiopia which have penetrated the target zone of Sothern Melut Basin extension of the South Sudanese rift Basin. The source rock screening, Thermal Maturity, zonal layer, geologic section, the vitrinite reflectance and the age have target the interest of burial history and the hydrocarbon generative of the Basin. A one-dimensional modeling of Burial history and Thermal history was performed in Jekow and Jacaranda locations using one PetroMod 1-Dimensional modeling of Integrated Exploration Systems of Gesellschaft mit beschränkter Haftung, (GmbH-IES), Germany. However, due to unsuccessful exploration campaign in South Melut Basin where Gambella Basin is extended and in addition to the poor quality seismic data implied that the risk for the petroleum system in the West Gambella Sub-basin is still very high.
Applicability of Gravity Separation Method on The Ashashire Gold Ore Deposit from Benishangul Gumuz Region, Ethiopia
(Addis Ababa University, 2023-06) Misganu Kabeta; Mulugeta Sisay (PhD); Abaynesh Mitiku (Mr.) (Co-Advisor)
The current Project of applicability of gravity separation method for gold ore deposit was conducted in Ashashire locality of Benishangul gumuz region, North western Ethiopia. The purpose of this project is beneficiating the Ashashire gold ore deposit by applying the gravity separation. The Ashashire composites were produced to provide sufficient mass for this study and experiment includes sample preparation, head assay analysis of gold and multi-element, gravity concentration and mineralogical analysis. The study conducted to determine the applicability of gravity separation method by using KC on the Ashashire gold ore deposit. The samples were moderately ground to the standard grind size of P80 - passing 106, 75, 53 μm and this nominal size was selected for the preliminary assessment for Concentration optimization. During the study, a grind optimization was conducted on the composites sample with varying grind size to evaluate the effect of grind size on gold recovery. The gravity testing comprised three-stage concentration by centrifugal knelson concentrator to produce gravity concentrate. High recovery of gold from the gravity concentrates was achieved from the second gravity concentration. Based on the results from laboratory experiments, a grind size of P80 75 μm is selected as optimal size for the ashashire deposit using KC gravity methods. Increasing the grind size from P80 of 75 μm to106 μm decrease recovery rate from 75 % to 54 % or decreasing the grind size from P80 of 75 to 53 μm decrease gold recovery rate to 37%. It was observed that repeat gold head assays varied, indicating the presence of coarse gold particles and uneven gold particle distribution. The native gold grain in the ores is mostly associated with quartz and Fine gold is closely associated with pyrite, forming inclusions and dispersed within pyrite. According to the fire assay, chemical, and mineralogical analyzes data, only gold and telluride is commercially valuable component in the ores. Presence of 2.13 ppm Te was detected in the composite sample during head assay analysis. The differences between assayed head grades and calculated head grades would indicate that the gold is not evenly distributed within the ore and occurs as localised spots. Gold was identified to occur predominantly in the native form and as Au-Te. The sample subjected to gravity separation assayed about 2.6 g/t Au.
Upgrading The Iron Grade of Bikilal Iron Ore Using Magnetic Separation Method with Frantz Laboratory Magnetic Separation
(Addis Ababa University, 2023-06) Deagaga Amenu; Dejene Hailemariam (PhD); Wondefrash Mamo (Mr.) (Co -Advisor)
The iron ore deposit of the Western Oromia Region of Ethiopia, at Bikilal, is a huge deposit, but it is low in grade. It assays 19.50 % Fe2O3 and 45.66% SiO2. The present study is an attempt to investigate the potential of this ore for upgrading at laboratory scale. Based on the appreciable differences in magnetic susceptibility between the desired iron minerals and gangue minerals, it was suggested that magnetic separation may be useful to concentrate this type of iron ore. The study used two feed size fractions (-500+75 micrometers; -300+75micrometers) and two currents 0.4 ampere; 0.8 ampere), and performed four experiments by adjusting these operating factors. The iron grade and recovery were measured and recorded for each combination of tests. For run 1and 2, that received -500+75μm and 0.8 and 0.4 ampere respectively, the results of iron grade and recovery, in % were 25.02; 83.73% and 20.84;68.63%. For run 3 and 4, that received -300+75μm and 0.8 and 0.4ampere, the obtained iron grade and recovery were 31.18;90.17 % and 26.64;75.63%. Factorial Design, particularly, Two Level Factorial Design was applied to investigate the effects of feed size (-500+75 and -300+75μm) and current (0.4 and 0.8 ampere) on the process of Frantz laboratory magnetic separator using Design expert v13 software, which shows the significant influence on the values of Fe grade and recovery at roughing stage of the concentrate. The results showed that both feed size and current had a significant effect on the iron grade and recovery, and their interaction had not significant. The optimal condition was found to be using a feed size fraction of -300+75 micrometer and a current of 0.8 ampere, which gave an iron grade of 31.2 % and an iron recovery of 90.2 %. The study demonstrated that the Frantz® Low Field Control Model LFC-2 is a useful accessory for separating ferromagnetic materials according to differences in their magnetic properties. The study also provided some insights into the trends and correlation among the factors and responses, which can help to understand and optimize the magnetic separation process.
Investigating the Potential of the Magnetic Separation Method as an Auxiliary Technique for Upgrading Lithium Ore Mineral from Kenticha Pegmatite Deposit in Guji, Southern Ethiopia
(Addis Ababa University, 2023-06) Berhanu Adugna; Sisay Degu(PhD)
Lithium has become a critical mineral in the energy industry, with significant increases in usage due to the global shift towards green energy alternatives over the past decade. The Kenticha pegmatite deposit in Ethiopia is known to have a feasible content of Li2O, making it a potentially valuable resource for lithium extraction. However, the beneficiation of lithium-bearing minerals is a crucial stage in upgrading the lithium oxide content of the ore and enhancing its economic value. The presence of gangue minerals such as microcline, albite, quartz, muscovite, and iron silicate minerals can complicate the process. Frantz magnetic separators were employed to conduct magnetic separation tests. Samples were collected from four different locations within an upper lithium-rich pegmatite deposit and subjected to analysis, revealing varying percentages of lithium oxide and iron oxide. The effectiveness of a Frantz magnetic separator was examined using feed size fraction and intensity as independent variables, with various combinations of factors tested. The resulting data was analyzed using AAS and XRD techniques to gain valuable information about the separation process and lithium mineral liberation. The separation effectiveness was evaluated based on the results, which indicated that high-intensity magnetic experiments with fine feed size fractions achieved better recovery of lithium oxide and less iron-bearing minerals. The potential for using the magnetic separator as part of a larger processing plant was also discussed, with comparisons magnetic separation method to other conventional lithium processing methods that employed magnetic separation. Finally, potential types of magnetic separators were suggested for the LCT Kenticha pegmatite deposit.
The Flotation Response of Dedo Coal Deposit, Jimma Ethiopia: Implication to Improve the Quality of Coal
(Addis Ababa University, 2023-06) Dejene Amane; Melesse Alemayehu (PhD)
The purpose of this study was to investigate the flotation response of the Dedo coal deposit and to improve its quality. In this project, chemical reagents were used to induce hydrophobicity in hydrophilic coal particles present in coal slurry, and particularly froth flotation techniques were employed. To obtain a general understanding of the floating response of coal from the study area, the yield of floated coal was estimated. The quality of coal before beneficiation (froth flotation) in this project was characterized by a moisture content of 13.63%, volatile matter of 33.45%, ash of 25.66%, sulfur of 0.36%, and calorific value of 4806 cal/gm. After beneficiation, the moisture content was 11.06%, volatile matter was 25.63%, ash was 20.28%, sulfur was 0.25%, and calorific value was 5029.38 cal/gm. These results indicate that impurity contents such as ash, mineral matter, and sulfur resources were reduced, and the calorific value of coal was increased by applying successful froth flotation
Grindibility and breakage characteristics of Sekota iron ore deposit in Wag-Himra Zone, Northern Ethiopia
(Addis Ababa University, 2023-06) Yohanes Belachew; Bogale Tadesse (PhD); Birtukan Yenealem (Co-Advisor)
In this study, the influence of mill rotation speed and grinding time were investigated on Sekota iron ore grinding process in a batch mill with length 150 mm and inner diameter 150 mm. The particle size distribution of the feed was carried out by an electric sieve and the bulk feed was classified into three samples to perform the grinding test. Three distinct iron ore feed size fractions between -335mm to +0.71mm, -0.71mm to +0.15mm and -3.35 to -0.075mm separated by a series of √2 gaps were prepared. The fractions were milled at different grinding times (5, 15, 25, 35, 45 and 60 min) at 450 rpm and at different mill rotational speeds (250, 300, 350, 450 and 550 rpm) at 25 min. The mill rotation speed and grinding time affect the energy consumption, the desired grind size and the P80 of the feed size fraction. When grinding time increased from 5 to 60 min, the percentage of cumulative mass of target size increased from 8.5 to 31.1%, from 7.1 to 22.8% and from 10.6 to 26% for coarse, fine and mixed iron ore size fractions, respectively. Likewise, a significant amount of the desired grind size is produced as the grinding speed increases until the maximum critical speed is reached. For all feed size fractions, the required grind size amount (-0.075 mm) is not achieved at grinding times from 5 min to 60 min and at maximum mill rotation speed (450 rpm). The product size distribution of the three iron ore feed size fractions were also affected as the grinding time and the mill rotation speed increased from 5 to 60 min and 250 rpm to the maximum speed (450 rpm). The P80 values of all feed size fraction generally decreased both milling time and mill speed are increased from 5 to 60min and 250 to 450 rpm respectively. Unlike the P80, the energy consumption of the ball mill increases significantly as the mill speed and grinding time increase from 250 to 450 rpm and from 5 to 60 minutes respectively.
Characterizing the Ore Mineralogy of Kenticha Pegmatite for Lithium Beneficiation, Southern Ethiopia
(Addis Ababa University, 2023-06) Gutema Mekonen; Alberto Velazquez (Prof.); Kaleb Gebreyes (Mr.) (Co-Advisor)
Lithium is a highly sought-after resource crucial for rechargeable batteries, and the Kenticha pegmatite ore deposit in Ethiopia holds potential as a source of this valuable element. The focus of this study was to investigate the mineralization of Kenticha, specifically the spodumene ore, and its suitability for beneficiation processes. Through XRD, AAS, and petrographic microscope analysis, the study identified the minerals present in the spodumene pegmatite ore, their average composition, and mineral texture for spodumene concentrate liberation. Spodumene was found to be the most abundant mineral, but its low degree of liberation from other minerals required additional processing steps for high yield. Weathering significantly impacted mineral identification and quantification, affecting diverse mineral morphology and liberation. The study's findings have implications for mining operations, exploration, and processing strategies, suggesting additional processing steps for spodumene recovery and highlighting the impact of weathering on mineral characterization. The study provides valuable information on mineral texture and liberation for selecting processing methods for beneficiation, contributing to a better understanding of the Kenticha pegmatite ore deposit's mineralization potential for lithium extraction.
Evaluation of the Nature of Porosity in Carbonate Rock Of Hamanlei Formation, Ogaden Basin, Ethiopia: Implications For Prediction of Reservoir Quality
(Addis Ababa University, 2023-06) Yimam Ali; Solomon Kassa (PhD)
The Ogaden basin is the largest sedimentary basin in Ethiopia having 350,000 km2 areal coverage. It is also the most studied sedimentary basin in Ethiopia. Nonetheless, the amount of data gathered from this baisn is not enough to better comprehend the petroleum system of the basin. The Hamanlei carbonate rock in the basin makes good reservoir rock. The nature of this reservoir rock is complex owing to various factors. Despite detail studies were conducted to understand the reservoir property, particularly core and wireline log study, further studies are needed for better characterization of this reservoir rock. To further characterize the reservoir property, i.e. porosity, of this rock and prediction for reservoir quality, petrographic and image analysis were performed. The outcome of this study provides valuable insights into the mineralogy and texture of the studied rocks. Furthermore, it highlights the importance of understanding the different pore types that enables to better interpret the reservoir quality and potential flow characteristics of the studied rocks. Generally, the porosity value of the reservoir rock is too small which is caused by the dominant proportion of matrix and cement
Value Addition of Ethiopian Gemstones
(2023-06) Mehatebe Gebrewold; Abubeker Yimam (PhD); Aselefech Mitiku (Ms.) (Co-Advisor)
Ethiopia is well recognized for producing gemstones. Numerous high quality gemstone varieties, such as opals, emeralds, sapphires, amazonite, amber, rubies, tourmalines, aquamarines, chrysoprase, peridot, chalcedony, obsidian, agate (scapolite agate), jasper, petrified wood, and various types of quartz, including precious quartz, are the main gemstones mined in the nation. However, the industry continued to generate little appreciable economic advantage because the country mostly exported rough gemstones with no added value. This project study intends to demonstrate the technology needed for adding value to various Ethiopian gemstones and the associated financial advantage. The following measures were taken in order to add value: Sorting the chosen gemstone by specie, selecting clean, color-full, large (excellent size to cut) pieces from the rough collection, cutting, polishing, and ultimately faceting of the chosen gemstone. The value added gemstones are then each given a physical description based on their Color, Clarity, and Cut. Finally, a price estimate has been generated for the gemstones with enhanced value. The project's findings showed that enhancing the value of the rough gemstone might produce earnings of up to 1,610,590 ETB/Kg of Opal, 293,560 ETB/Kg of Crystal Quartz, 213,040 ETB/Kg of Green Obsidian, 48,565 ETB/Kg of Jasper, 43,730 ETB/Kg of Agate and 43,675 ETB/Kg of Black Obsidian. As a result, small-scale gemstone business owners can profit from the high prices of their products and the country can increase the foreign currency revenues from selling the value-added gemstones by adding value to the rough gemstones through the use of relevant technology.

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