[ Évaluation des teneurs en alumine et en silice de la bauxite de Sangarédi et leur impact sur la qualité des produits destinés à l’export, République de Guinée ]
Volume 82, Issue 2, January 2026, Pages 101–113
Ibrahima Kalil Kourouma1, Alain Gbilimou2, Soriba Bangoura3, and Oumou Hawa Bah4
1 Institut Supérieur des Mines et Géologie de Boké, Tamakènè, Guinea
2 Institut Supérieur des Mines et Géologie de Boké, Tamakènè, Guinea
3 Institut Supérieur des Mines et Géologie de Boké, Tamakènè, Guinea
4 Institut Supérieur des Mines et Géologie de Boké, Tamakènè, Guinea
Original language: French
Copyright © 2026 ISSR Journals. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
This research focused on assessing the chemical constituents of bauxite from Sangarédi, the dominant mining locality of Compagnie des Bauxites de Guinée (CBG), in an effort to assess the contributions of the constituents in deciding the final quality of exported products. Sampling was performed as a whole (from the deposit and intermediate stockpiled, and stockpiled for sale); then selected samples underwent analysis by x-ray fluorescence (XRF) in the laboratory. The study was completed based on alumina (Al2O3), and reactive silica (SiO2) whose variation can affect the sustainability and ultimately the profitability of a bauxitic ore in the Bayer process, which is the valorisation process of the ore. The study results indicate that alumina is relatively stable, with an average content of 49.66 %, which is very much like the contractual specification of 50.01 ± 1.5 %; approximately 90 % of the samples fall within the acceptable tolerance range, and it shows that the ore has good export quality. However, reactive silica is unstable and too high, with an average content of 2.38 %, which exceeds the contractual specification of 2.01 ± 0.3 %; only 40 % of the samples conform with the standard, while 60 % are above the standard. This non-conformance created over-consumption of caustic soda and reduced alumina yield, which was detrimental to the international competitiveness of Sangarédi bauxite. The proposed corrective actions are strengthening continuous quality control, improving stockpile homogenization, avoiding contaminations during handling and transport, and implementing differentiated deposit management. In sum, this study has shown that controlling the variability of reactive silica is a tactical lever for better compliance with contractual specifications, enhancing the value-added of exported products, and consolidating Guinea’s role as the leading bauxite producer in the world.
Author Keywords: Bauxite, Sangarédi, alumina, reactive silica, quality control.
Volume 82, Issue 2, January 2026, Pages 101–113
Ibrahima Kalil Kourouma1, Alain Gbilimou2, Soriba Bangoura3, and Oumou Hawa Bah4
1 Institut Supérieur des Mines et Géologie de Boké, Tamakènè, Guinea
2 Institut Supérieur des Mines et Géologie de Boké, Tamakènè, Guinea
3 Institut Supérieur des Mines et Géologie de Boké, Tamakènè, Guinea
4 Institut Supérieur des Mines et Géologie de Boké, Tamakènè, Guinea
Original language: French
Copyright © 2026 ISSR Journals. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
This research focused on assessing the chemical constituents of bauxite from Sangarédi, the dominant mining locality of Compagnie des Bauxites de Guinée (CBG), in an effort to assess the contributions of the constituents in deciding the final quality of exported products. Sampling was performed as a whole (from the deposit and intermediate stockpiled, and stockpiled for sale); then selected samples underwent analysis by x-ray fluorescence (XRF) in the laboratory. The study was completed based on alumina (Al2O3), and reactive silica (SiO2) whose variation can affect the sustainability and ultimately the profitability of a bauxitic ore in the Bayer process, which is the valorisation process of the ore. The study results indicate that alumina is relatively stable, with an average content of 49.66 %, which is very much like the contractual specification of 50.01 ± 1.5 %; approximately 90 % of the samples fall within the acceptable tolerance range, and it shows that the ore has good export quality. However, reactive silica is unstable and too high, with an average content of 2.38 %, which exceeds the contractual specification of 2.01 ± 0.3 %; only 40 % of the samples conform with the standard, while 60 % are above the standard. This non-conformance created over-consumption of caustic soda and reduced alumina yield, which was detrimental to the international competitiveness of Sangarédi bauxite. The proposed corrective actions are strengthening continuous quality control, improving stockpile homogenization, avoiding contaminations during handling and transport, and implementing differentiated deposit management. In sum, this study has shown that controlling the variability of reactive silica is a tactical lever for better compliance with contractual specifications, enhancing the value-added of exported products, and consolidating Guinea’s role as the leading bauxite producer in the world.
Author Keywords: Bauxite, Sangarédi, alumina, reactive silica, quality control.
Abstract: (french)
Cette recherche s’intéresse à l’évaluation des espèces constitutives de la bauxite de Sangarédi, principal site d’exploitation de la Compagnie des Bauxites de Guinée (CBG), en vue d’analyser leur rôle dans la qualité des produits exportés. Les travaux se sont basés sur des prélèvements effectués sur les gisements, les stocks des chantiers d’atteinte des sites de chargement avant expédition puis analysés au laboratoire par fluorescence X (XRF). Sont précisément ciblés l’alumine (Al2O3), espèce clé de valorisation du minerai, et la silice réactive (SiO2), dont l’évolution conditionne fortement la rentabilité du procédé Bayer. Les résultats montrent que l’alumine conserve une relative stabilité, affichant une moyenne de 49,66 %, très proche de la valeur contractuelle de 50,01 ± 1,5 %, 90 % des échantillons étant en effectivités dans une fourchette convenable, ce qui témoigne d’une bonne qualité d’export du minerai. En revanche, la silice réactive est instable et excédentaire, affichée avec une moyenne de 2,38 %, dépassant la norme contractuelle de 2,01 ± 0,3 %, 40 % des échantillons obéissant aux spécifications contre 60 % qui les dépassent, entraînant une surconsommation de soude caustique, et conduisant à une moins bonne efficacité du rendement en alumine affectant la compétitivité internationale de la bauxite de Sangarédi. Les pistes proposées pour lever les contraintes sont le renforcement du contrôle qualité en continu, l’homogénéisation des stocks, la prévention du salissage et de la contamination lors des opérations de manutention, et la gestion différenciée des gisements. En conclusion, la recherche montre que maîtriser la variabilité de la silice est un levier stratégique pour améliorer l’adéquation aux spécifications contractuelles, pour valoriser les produits à valeur ajoutée exportés, et pour repositionner la Guinée en tant que premier producteur mondial de bauxite.
Author Keywords: Bauxite, Sangarédi, alumine, silice, contrôle qualité.
How to Cite this Article
Ibrahima Kalil Kourouma, Alain Gbilimou, Soriba Bangoura, and Oumou Hawa Bah, “Evaluation of the alumina and silica contents of the Sangarédi bauxite and their impact on the quality of export-products, Republic of Guinea,” International Journal of Innovation and Scientific Research, vol. 82, no. 2, pp. 101–113, January 2026.
