Status : Verified
| Personal Name | Bello, Geleni Shalaine P. |
|---|---|
| Resource Title | Kinetics of the Hydrochloric Acid Leaching of Scandium from Lateritic Blast Furnace Slag |
| Date Issued | July 2024 |
| Abstract | With the increasing demand for scandium in the green technology sector and the prevailing scarcity of its reliable sources, the valorization of secondary and unconventional resources is currently being explored. Ongoing studies in ironmaking in the Philippines have shown substantial scandium concentrations in lateritic slags produced through a simulated blast furnace process. In this study, the recovery of scandium from basic lateritic blast furnace slag through leaching was explored using varied combination settings of diluted HCl concentrations, leaching temperatures, and %solids, optimized using Response Surface Methodology following a Box Behnken Design. Results of the statistical analysis indicate an optimum leaching parameter combination of 2.90 M HCl, 80.00 °C, and 4.00% solids, achieving a theoretical recovery of 64.76% Sc, with impurities of 65.27% Fe, 54.73% Ti, 56.22% Al, and 18.04% Si. Sc leaching was primarily affected by the %solids, followed by the quadratic effect of HCl concentration, and the main effect of leaching temperature, while the main and quadratic effects of %solids and HCl concentration generally influenced the dissolution of the other impurities. By obtaining the solution Eh-pH, the stable species present in the leaching system were identified, further confirming the metal dissolution mechanisms in acidic conditions. The kinetics of the diluted HCl leaching of Sc was found to conform to the Avrami-Erofeev model, wherein the leaching rate of Sc starts rapidly and gradually slows down over time. The rate-determining step of the mechanism is a mixed-face chemical reaction and diffusion-controlled, with an apparent activation energy of 15.26 kJ/mol and a model equation of X_(Sc^(3+)) = 1 - exp [154.97 exp (-15259.60/(8.314 T)) t^(-0.129)]. Furthermore, the leaching residue was characterized by granular aggregates, voids, and cracks, along with some faceted crystals surrounding an unreacted zone, suggesting the disappearance and/or transform |
| Degree Course | Master of Science in Metallurgical Engineering |
| Language | English |
| Keyword | laterites, blast furnace slag, HCl leaching, scandium recovery, kinetics |
| Material Type | Thesis/Dissertation |
Preliminary Pages
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Category : F - Regular work, i.e., it has no patentable invention or creation, the author does not wish for personal publication, there is no confidential information.
Access Permission : Open Access