Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7148

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Subject: search.filters.subject.Iron oxide

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  • Article
    Citation - WoS: 13
    Citation - Scopus: 17
    Characterization and Beneficiation of Ethiopian Kaolin for Use in Fabrication of Ceramic Membrane
    (IOP Publishing, 2021) Zewdie, Tsegahun Mekonnen; Prihatiningtyas, Indah; Dutta, Abhishek; Habtu, Nigus Gabbiye; Van der Bruggen, Bart
    Kaolin (china clay) is a rock material that is very rich in kaolinite. A kaolin ore from Debre Tabor, Ethiopia containing 59.2 wt% SiO2, 24.9 wt% Al2O3, 2.4 wt% Fe2O3, and 8.22 wt% loss on ignition (LOI) was physically beneficiated, chemically leached, and thermally treated for possible industrial use, especially for ceramic membrane fabrication. The leaching experiments were carried out using oxalic acid solutions as leaching reagents for the iron extraction process. The effect of acid concentration, reaction temperature, and contact time on iron leaching was investigated. It was determined that the rate of iron extraction increased with the oxalic acid concentration, leaching temperature, and contact time. A substantial reduction of iron oxide (2.4 to 0.36 wt%) from the raw kaolin was observed at operating conditions of 2.0 M oxalic acid, the temperature of 120 degrees C, and contact time of 120 min. A maximum kaolin whiteness index of 81.4% was achieved through this leaching process. Finally, the physically beneficiated, chemically leached, and thermally treated kaolin raw material was used to fabricate a low-cost kaolin-based ceramic membrane. After firing at 1100 degrees C the ceramic membrane was found to have a mass loss of 11.04 +/- 0.05%, water absorption of 8.9 +/- 0.4%, linear shrinkage of 14.5 +/- 0.05%. It was demonstrated to be chemically stable, having less than 3% mass loss in acid solution, and less than 1% mass loss in alkali solution. The newly developed membranes have thus properties comparable to commercial ceramic membranes.
  • Article
    Citation - WoS: 31
    Citation - Scopus: 32
    Evaluating the Critical Roles of Precursor Nature and Water Content When Tailoring Magnetic Nanoparticles for Specific Applications
    (American Chemical Society, 2018) Cotin, Geoffrey; Kiefer, Celine; Perton, Francis; Boero, Mauro; Özdamar, Burak; Bouzid, Assil; Begin-Colin, Sylvie
    Because of the broad range of application of iron oxide nanoparticles (NPs), the control of their size and shape on demand remains a great challenge, as these parameters are of upmost importance to provide NPs with magnetic properties tailored to the targeted application. One promising synthesis process to tune their size and shape is the thermal decomposition one, for which a lot of parameters were investigated. But two crucial issues were scarcely addressed: the precursors nature and water content. Two in house iron stearates with two or three stearate chains were synthesized, dehydrated, and then tested in standard synthesis conditions of spherical and cubic NPs. Investigations combined with modeling showed that the precursors nature and hydration rate strongly affect the thermal decomposition kinetics and yields, which, in turn, influence the NP size. The cubic shape depends on the decomposition kinetics but also crucially on the water content. A microscopic insight was provided by first-principles simulation showing an iron reduction along the reaction pathway and a participation of water molecules to the building unit formation.
  • Article
    Citation - WoS: 60
    Citation - Scopus: 67
    Removal of Aqueous Rare Earth Elements (rees) Using Nano-Iron Based Materials
    (Korean Society of Industrial Engineering Chemistry, 2013) Ünal Yeşiller, Semira; Eroğlu, Ahmet Emin; Shahwan, Talal
    The uptake of REEs was investigated using nano-zero valent iron (nZVI) and alumina-supported nZVI (Al-nZVI). The results indicated fast uptake, with saturation approached within 10 min of contact between solutions and solids. Upon using nZVI, the uptake of REEs seemed to be quantitative over the studied range of concentration; 1.0–100.0 mg L−1. When Al-nZVI was used, complete removal was achieved within the range of 1.0–10.0 mg L−1. The solids demonstrated stable performance beyond pH of 2.0, up to neutral pH conditions. Fractionation of REEs on Al-nZVI was observed. The REE ions seem to be fixed to oxide and oxyhydroxide surface groups.