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Research Article
Influence of the Treatment of Bingerville Clayey Sands with a Batard Binder Mixture (Lime-cement) for Use in Road Engineering
Issue:
Volume 14, Issue 6, December 2025
Pages:
252-262
Received:
27 October 2025
Accepted:
11 November 2025
Published:
9 December 2025
Abstract: In tropical countries, clay soils used in construction have unfavorable geotechnical properties and degrade prematurely due to their low bearing capacity and sensitivity to water, such as those of Bingerville, in southern Cote d'Ivoire, where these soils are the raw material for infrastructures projects. The use of improvement techniques such as treatment with hydraulic binders can improve the geotechnical properties of these soils by increasing their physical and mechanical strength in many countries where these materials are abundant, thereby reducing material transportation costs and environmental pollution. This study characterizes the clay soils of Bingerville in their natural state for their identification and suitability for treatment before subjecting them to lime and cement mixtures. The results of this study showed that the clay soils of Bingerville are clayey sands. After analysis, they are suitable for mixed treatment (lime-cement) in order to increase their geotechnical properties for their use in road techniques. Laboratory tests identified an optimal mixture of 3% lime and 6% cement. The experimental results made it possible to obtain, on clayey soils in the initial state, the total organic matter content (TOC), equal to 0.15%, a very low value, less than 1%, showing that these soils can support any load without deforming under the influence of water, therefore suitable for binder treatments. The plasticity index (PI) equal to 23.7%, a value greater than 12%, suggests that these clayey soils are subject to mixed Batard treatment (lime-cement). After treatment of Bingerville clay soils with lime and cement mixtures, dry densities increased from 1.83 to 2.03, with the 95% California Bearing Ratio (CBR) of the Modified Optimum Proctor (MOP) at 4 days of immersion increasing significantly from 14 to 94. These results are consistent with the recommendations for their use as treated local soils in low to medium traffic road projects.
Abstract: In tropical countries, clay soils used in construction have unfavorable geotechnical properties and degrade prematurely due to their low bearing capacity and sensitivity to water, such as those of Bingerville, in southern Cote d'Ivoire, where these soils are the raw material for infrastructures projects. The use of improvement techniques such as tr...
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Research Article
Blasting Method for Improving the Secondary Combustion Efficiency in the Romelt Process Using CFD Analysis
Issue:
Volume 14, Issue 6, December 2025
Pages:
263-269
Received:
26 August 2025
Accepted:
30 October 2025
Published:
11 December 2025
Abstract: The Romelt process is called liquid-phase smelting reduction process because in the metallurgical processes the reaction of coal and iron occurs in the liquid slag layer, which is boiling vigorously by oxygen-enriched air flow blown into the liquid slag. The bath of the furnace is charged with coal and iron ore, and an oxygen nozzle for secondary combustion is installed on both sides of the bath cavity to burn out the CO and H2 gases generated in the bath. CO and H2, rising from the boiling slag bath, are completely burned by oxygen blown into the secondary nozzle in the combustion chamber. The heat from this combustion reaction plays an important role in the Romelt process. 60-80% of the secondary combustion heat is transferred to the bath and becomes the heat source of the main process. At present, the Romelt process has a high CO content in the exhaust gas due to the low efficiency of combustion by oxygen blown into secondary nozzle and low oxidation of CO. This paper analyses the reason of the low efficiency of combustion by oxygen blown into conventional secondary nozzle using CFD, and based on it, suggests the blasting method to increase the secondary combustion efficiency by oxygen blown into the upper tuyere of the Romelt furnace. To improve the secondary combustion efficiency, a new type of catalyst for enhancing the oxidation of CO was investigated and more than 90% of efficiency of secondary combustion was achieved. At this time, oxygen concentration should be at least 95%.
Abstract: The Romelt process is called liquid-phase smelting reduction process because in the metallurgical processes the reaction of coal and iron occurs in the liquid slag layer, which is boiling vigorously by oxygen-enriched air flow blown into the liquid slag. The bath of the furnace is charged with coal and iron ore, and an oxygen nozzle for secondary c...
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Research Article
Research on Precise Classification Technology of Tailings Sand
Issue:
Volume 14, Issue 6, December 2025
Pages:
270-278
Received:
11 November 2025
Accepted:
21 November 2025
Published:
29 December 2025
DOI:
10.11648/j.ijmsa.20251406.13
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Views:
Abstract: It is difficult to achieve dry and precise classification for fine sand characterized by small particle size, high content of micro-powder, and unstable gradation. In this study, a rectangle swing screen assisted by airflow & ultrasonic was employed to achieve precise classification of fine tailings. Through detailed process calculations and sample analysis, the following conclusions can be drawn: The movement trajectory of the fine sand within the rectangle swing screen follows a 360° parabolic path. The current theoretical formula for calculating the resistance coefficient of the transitional flow field within the airflow-assisted rectangle swing screen should be revised. After pre-dried, the magnetic tailings, vanadium-titanium magnetic tailings and molybdenum tailings were precise classified by the new multi-field coupled classifiers. The new classifiers enables the production of products with a mixed-grade rate of less than 5%. The classification efficiency is influenced by the inclination angle of the screen, the length of the sieve, the air velocity, the ultrasonic amplitude & etc., and parameters can be reasonably set according to engineering requirements. Furthermore, the prepared products have been successfully applied in the production of dry-mixed mortar and can be manufactured on a batch scale. The dry-mixed mortar containing tailings has been applied in urban renewal projects and has achieved good results.
Abstract: It is difficult to achieve dry and precise classification for fine sand characterized by small particle size, high content of micro-powder, and unstable gradation. In this study, a rectangle swing screen assisted by airflow & ultrasonic was employed to achieve precise classification of fine tailings. Through detailed process calculations and sample...
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Research Article
Exploring the Biological Activity of Organically Ligated Metal–Peroxo Complexes
Jahanara Nasrin*
Issue:
Volume 14, Issue 6, December 2025
Pages:
279-288
Received:
16 November 2025
Accepted:
10 December 2025
Published:
29 December 2025
DOI:
10.11648/j.ijmsa.20251406.14
Downloads:
Views:
Abstract: Metal-based complexes have attracted considerable attention due to their diverse biological activities and potential applications as antimicrobial agents. In this study, a series of previously synthesized metal complexes of Molybdenum(VI), Uranium(VI), Zirconium(IV), and Thorium(IV) were systematically evaluated to investigate their antifungal, antibacterial, and cytotoxic properties. The primary objective of this work was to assess the bioactive potential of these complexes and to identify promising candidates for antimicrobial applications. The antifungal activity of the complexes was examined against Aspergillus niger, A. fumigatus, and A. flavus using the agar diffusion method. Antibacterial efficacy was determined by minimum inhibitory concentration (MIC) assays against both Gram-negative (Pseudomonas aeruginosa and Escherichia coli) and Gram-positive (Streptococcus β-haemolyticus and Bacillus subtilis) bacterial strains. Cytotoxicity was evaluated using the brine shrimp lethality assay as a preliminary indicator of biological safety. The results demonstrated that all tested complexes exhibited varying degrees of antifungal and antibacterial activity. Notably, the Mo(VI) complex 2 showed the highest antifungal activity against A. flavus, producing a zone of inhibition of 14 mm. In antibacterial studies, Mo(VI) complex 4 displayed the lowest MIC values, indicating superior antibacterial potency, followed by the U(VI) complex 8, while Th(IV) complexes showed comparatively weaker activity. Cytotoxicity assessment revealed that Mo(VI) complex 5 exhibited the highest toxicity, whereas complexes 1 and 2 were comparatively less toxic. Overall, the findings suggest that Mo(VI) complexes possess significant antimicrobial potential and represent promising candidates for further development as bioactive agents.
Abstract: Metal-based complexes have attracted considerable attention due to their diverse biological activities and potential applications as antimicrobial agents. In this study, a series of previously synthesized metal complexes of Molybdenum(VI), Uranium(VI), Zirconium(IV), and Thorium(IV) were systematically evaluated to investigate their antifungal, ant...
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