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Journal of Minerals and Materials Characterization and Engineering 2024年第6期12卷 281-298页

作者： Oumar Keita Mory Diane Department of Hydrology University of Nzrkor Nzrkor Guinea guinea bauxite company Kamsar Guinea

The Sangarédi bauxite deposit in the Republic of guinea contains several bauxite types depending on their litho-genetics. For rational and sustainable exploitation, determining the physical and mechanical properties of these different bauxite types is essential for mining companies. This paper presents a model for the physico-mechanical characterization of Sangarédi bauxites according to their litho-genetic type. Eight pits were drilled, and samples were collected from different layers at different depth intervals for each bauxite type. Physical and mechanical characterization tests were then carried out on 27 samples to determine the following parameters: water of absorption (%), compressive strength (kgf/cm2) and dynamic tensile strength (kgf/cm2). The effect of depth of sampling on these physico-mechanical parameters was evaluated. An average value of the parameters was made for each bauxite type. The results showed that the physico-mechanical characteristics of bauxites depend on the depth of sample collection, and the average value of the parameters constitutes the representative values of the bauxite type. Finally, a comparative study of the average value of the physico-mechanical parameters of the different bauxite types was carried out.

关键词： bauxites Litho-Genetics Physico-Mechanical Compressive Strength Dynamic Tensile Strength

Study of the Chemical and Mineralogical Composition of Kindia bauxite in the Republic of guinea: The Case of the Saföfö Site

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Journal of Materials Science and Chemical Engineering 2024年第10期12卷 62-71页

作者： Mouctar Camara Mamadouba Aboubacar Fofana Mohamed Dubréka Sylla Alpha Madiou Diallo Aboubacar Diallo Aly Hawa Camara Sékou Traore Department of Chemical Engineering Gamal Abdel Nasser University of Conakry Conakry Republic of Guinea Department of Physics University of NZerekore NZerekore Republic of Guinea Department of Chimie Gamal Abdel Nasser University of Conakry Conakry Republic of Guinea Institut Superieure dArchitecture and lUrbanisme (ISAU) Conakry Republic of Guinea National Laboratory of the Geology Department from Mines and of the Geology Conakry Republic of Guinea

The chemical and mineralogical composition of bauxite deposits is a key factor in the profitability of refining processes. The study of bauxites from the Saföfö site has assessed variations in chemical and mineralogical composition under various conditions, as well as the optimum conditions for their exploitation. The methodologies used in this study include experimental methods for determining moisture content, chemical composition, mineralogical composition, and specific density of bauxite. The results show significant variation in moisture content among the bauxite samples, with values ranging from 2.90% to 17.80%. The silica percentages in the samples range from 1.69% to 8.14%, while alumina percentages vary from 36.81% to 54.03%. After calcination, alumina oxide percentages range from 40% to 75%. After chemical activation, alumina oxides Al2O3 range from 40% to over 50%. Gibbsite is the most abundant mineral, accounting for about 60% - 70% of the total composition of the bauxite samples. Samples A to F have bulk densities varying between approximately 3.6 and 3.9. Sample B has the highest density, around 3.9, while sample C has the lowest, at around 3.5. bauxite mining at the Saföfö site offers significant potential for the alumina industry, provided appropriate processing methods are selected to maximize quality and profitability while minimizing environmental impact.

关键词： bauxite Chemical Composition guinea Mineralogy and Saföfö

Characterization of Zeolite Types Contained in Sangaredi bauxite in the Republic of guinea

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Journal of Materials Science and Chemical Engineering 2024年第11期12卷 1-14页

作者： Mohamed Dubreka Sylla Oumou Kourouma Mamadouba Aboubacar Fofana Mouctar Camara Alexandre Lucien Richard Department of Chemical Engineering Universit Gamal Abdel Nasser de Conakry Conakry Republic of Guinea Ecole Doctorat en Sciences et Technique Universit Gamal Abdel Nasser de Conakry Conakry Republic of Guinea

Since their discovery, zeolites have generated significant interest in various technological fields, such as molecular sieves, ion exchangers, catalysts, and especially as adsorbents. This article focuses on characterizing the types of zeolites present in Sangarédi bauxite. To achieve this objective, we conducted a physico-chemical characterization (moisture, particle size, volumetric density, porosity) and determined the optimal conditions for activating the zeolite samples (15% H2SO4 concentration, L/S ratio of 2, temperature of 70˚C, duration of 3 hours). Techniques used to characterize the samples included desiccation gravimetry, mechanical sieving, X-ray fluorescence (atomic percentage), X-ray diffraction, BET method, and water pycnometry. Additionally, we assessed the adsorption capacity of zeolites activated by the elimination of methylene blue in an aqueous solution, which was selected as a model water pollutant. According to X-ray fluorescence and diffraction data, there are nine types of zeolite in Sangarédi bauxite, divided into five families. Regarding physical activation, a good porous structure was observed at a temperature of 300˚C to 340˚C for 4 hours. Above this range, material condensation occurs, leading to a sudden increase in mass loss, which can be explained by a change in their crystalline structure. After treatment with sulfuric acid, the activated samples showed an increase in specific surface area (from 72 to 130.25 m2∙g−1 on average) and porosity (from 0.07% to 0.3%), as well as an increased susceptibility to methylene blue discoloration (from 13.58% to 30.35%). These results confirm the improvement in the microporous structure and the formation of a more developed molecular sieve network. Thanks to the identified structural and textural characteristics, it can be concluded that the activated zeolites obtained are extremely reactive materials and can be used effectively in water treatment.

关键词： bauxite Characterisation guinea Sangarédi Zeolite

Petrological and Statistical Studies of the Limbiko bauxite Deposit, Republic of guinea

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International Journal of Geosciences 2023年第4期14卷 351-376页

作者： Abdoulaye Kadiatou Diallo Mohamed Samuel Moriah Conte Oumar Barou Kaba Aly Soumah Mohamed Camara Laboratory for Applied Research (LAR) Fundamental Geology and Prospection Research Unit (FGPRU) Emerging Centre for Mines and Society (ECMS) of the Institute Superior of Mines and Geology of Boke (ISMGB) Boké Republic of Guinea Laboratory for Applied Research (LAR) Research Unit Mining and Resource Development (RUMRD) Emerging Centre for Mines and Society (ECMS) of the Institute Superior of Mines and Geology of Boke (ISMGB) Boké Republic of Guinea

The increasing demand for Aluminium pushes the miners to multiply the research in order to answer this demand. The objective of this work is to characterize the bauxitic deposit of Limbiko. The methodology consists in collecting samples, and establishing stratigraphic logs, sections and geological maps. The analyses were carried out in the laboratory of the company des bauxites de guinea. Statistical methods were used to process the geochemical data. The study area is characterized by sedimentary formations of the Devonian, in which the dolerites of the Mesozoic were injected. It is on these Devonian and Mesozoic formations that the Limbiko bauxite deposit was developed. The stratigraphic logs show the succession of formations. The parent rock is surmounted by an alteration crust. The petrographic study is based on the bauxitic and transitional zones characterized by ferruginous laterites. Both zones contain some ferriplantite. Mineralogical analysis shows the presence of gibbsite, goethite, alumogoethite, rutile and clay minerals. The geochemical study of the major elements shows that the more the contents of SiO2, Fe2O3 decrease, the more the content of Al2O3 increases and those of TiO2, Al2O3 increase in the same direction. The PCA confirms the mineralogical results by classifying the samples into clay, bauxite and ferrite.

关键词： bauxite Alteration Crust Aleuro-Argillite Dolerite Gibbsite

Physicochemical Characterisation for Potential Uses as Industrial Mineral of bauxite from Débélé, guinea

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Journal of Materials Science and Chemical Engineering 2021年第3期9卷 9-22页

作者： Mamadou Yaya Balde Chantale Njiomou Djangang Ramatoulaye Binta Diallo Philippe Blanchart Daniel Njopwouo Department of Inorganic Chemistry University of Yaounde I Yaounde Cameroon Department of Chemistry University Gamal Abdel Nasser of Conakry Conakry Guinea Institute of Research for Ceramics—IRCER Limoges France

Assessing the potential uses as industrial mineral, bauxite from Débélé, guinea, has been characterised by chemical and mineralogical analyses, the determination of the amorphous content, the rate of portlandite consumption in an aqueous solution, the strength activity index, and the thermal behaviour up to 1200°C. It was evidenced that the raw sample is gibbsite-rich type bauxite with about 45.06 wt% of alumina, 23.80 wt% of iron oxide, and 1.74 wt% of silica. It meets the chemical composition required for bauxites used for refractory cement. During heating, the raw bauxite undergoes high densification with low linear shrinkage, motivating a potential use in dense ceramic compositions with high thermal stability. Also, the heating at only 600°C gives a significant pozzolanic activity in combination with Portland cement. The correlation between the pozzolanicity, the amorphous phase content, and the specific surface area indicated that the raw and the calcined materials present an interesting reactivity for using them in alternative cement formulations.

关键词： bauxite Characteristics Industrial Mineral guinea