Centers for Ethio Mines Development

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Browsing Centers for Ethio Mines Development by Author "Anteneh Marlign (PhD)"

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    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.
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    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.