Centers for Ethio Mines Development

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Browsing Centers for Ethio Mines Development by Author "Abubeker Yimam (PhD)"

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    Application of Lapidary Technology for Sustainable Gemstone Resource Development In Ethiopia
    (2023-09) Tsion Shumalem; Abubeker Yimam (PhD); Aselefech Mitiku (Ms.)(Co-Advisor)
    Ethiopia is renowned for its mineral abundance and more than 40 varieties of gemstone resources. With the artisanal and small scale miners controlling the production, the phase of the gemstone path abruptly came to a halt, with just a few rough dealers and a few gem cutters remaining, resulting in a very low economic benefit from the sector. The purpose of this study is to look into the function of lapidary technology for sustainable gemstone resource development in Ethiopia. The paper focuses on identifying the country‘s gemstone resource development challenges, the stages of the lapidary process and colored gemstone value chains, lapidary technology and the economic and social importance of lapidary technology in creating various jewelry and decorations using the new technology. In this study, interviews, literature reviews, lapidary work on a selected sample (gemstone from Wegel Tena, Amhara Regional State, Ethiopia), and an economic analysis of rough and value-added gems are conducted to analyze the role of lapidary technology on the industry. Furthermore, it is designed to comprehend the stages of the supply process and gem value chain, as well as to investigate the economic and social ramifications of modern lapidary technology on the development of sustainable gemstone resources. The impact of lapidary on increasing the value of rough gemstones is enormous. An economic analysis made of agate, crystal quartz, obsidian, jasper, and opal found that there is an increase between 400 and 70,000 folds due to the effect of lapidary technology and value added on the rough gemstone. The study’s findings revealed that the fragmented character of the gemstone business attributed to its lag behind other mining industries. Moreover, the study indicated that the gemstone industry in Ethiopia lacks technology, finance, lapidary expertise and a controlled market system. Enabling legislation should be put in place to ensure that the necessary economic return from gemstone resources is attained in order to protect the business and support a successful gemstone cutting and polishing industry.
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    Application of Montmorillonite Type Bentonite Clay From Chacha Area as Alternative for Local Construction Material
    (Addis Ababa University, 2023-06) Addisu Misgana; Abubeker Yimam (PhD); Enatfanta Melaku (Mr.)
    Hollow concrete block are produced from derbanPozolana Portland Cement (PPC), pumice and other aggregates (sand, scoria, gravel and clay). Mixing ratio and composition for HCBs although depend on the availability of materials. It is widely varying among the producers of cottage and industrial scale. However, all producers apply cement as a major constituent for binding. The demand of cement for HCBs and other construction materials is very high while the cement supply is very low. As a result, cost of production and sell price in the market is expensive and becoming not affordable for end users. The objective of this study is to investigate and evaluate the effect in using relatively cheaper bentoniteas cement replacement in HCBs production. Bentonite is available in a bulk when compared to cement. In the process focushas been given for curing and compressive strengthof HCB by varying the amount of cement and bentonite as major constituents in three ways (10kg bentonite replacing 10kg cement, 15 kg bentonite replacing 15 kg cement and 20 kg bentonite replacing 20 kg cement for a single batch /64 HCBs). All HCB samples were produced using 0.84 m3 pumice, 40 liters’ water. In addition silicate analysis (chemical composition) and physical properties (bulk density, moisture content and free swell test) of Chacha clay. Standard Compressive strength tests using (CES24:2013) method for HCBs of six sample replicates with average result on a total of 54 samples tests were made for 14, 21 and 28 age of curing time. For 28days’ age the average compressive strength (N/mm2) of 1.43, 1.27 and 1.23 were achieved by 10%, 15% and 20% bentonite replacement respectively. The compressive strength of HCBs is found to increase with increase of curing age and decreases with increase of the bentonite loading ratio. Generally, replacing of cement with bentonite at 28 days, a 10% bentonite replacement obtained the highest strength value, followed by a 15% bentonite loading ratio and a 20% bentonite loading ratio.
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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.
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    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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    Reverse Anionic Flotation for Potential Beneficiation of Sekota Iron Ore, Northern Ethiopia
    (Addis Ababa University, 2023-09) Tarekegn Dure; Abubeker Yimam (PhD)
    In this project study, hematite ore sample obtained from Sekota area, Northern Ethiopia was used. Main objective of the study is to obtain iron concentrate at possible maximum grade and recovery by using reverse anionic flotation beneficiation method. The effect of oleic acid collector dosage and sieve size fractions were studied and optimized. The chemical and mineralogical characterization of the ore was also determined. Results of chemical analysis using atomic absorption spectroscopy (AAS) showed that the iron ore contains 65.12% Fe2O3 (45.57% Fe). Major gangue minerals were SiO2 (20.62%) and Al2O3 (8.86%) while all other minerals were reported at <1%. Mineralogical descriptions using the X-ray diffraction (XRD) and QEMSCAN BMA showed predominantly hematite and goethite with quartz, kaolinite and clay as gangue minerals while others P and S are in lower amounts. The concentrate 62.96% Fe2O3 with highest grade of 44.07% Fe was obtained with 43.4% Fe recovery in the feed size fraction (−63 μm) adding 3g/t of oleic acid collector. Based on the results obtained from the flotation tests conducted, Sekota iron ore at a sieve size of -75μm and -63μm were able to enhancing both grade and recovery.
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    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%.
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    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.