6533b7d9fe1ef96bd126ce13
RESEARCH PRODUCT
Valorisation of industrial iron oxide waste to produce magnetic barium hexaferrite
Manfredi SaeliRui M. NovaisJoão S. AmaralRobert C. PullarJoão A. Labrinchasubject
CeramicsMaterials scienceMagnetic PropertiesFERRITESSettore ING-IND/22 - Scienza e Tecnologia dei MaterialiIron oxideSettore ICAR/10 - Architettura Tecnica02 engineering and technology010402 general chemistrySustainable Chemistry01 natural sciences7. Clean energychemistry.chemical_compoundCeramics; Ferrites; Magnetic Properties; Sustainable Chemistry; Waste preventionFerritesSettore CHIM/03 - Chimica Generale e InorganicaWaste managementMetallurgySettore CHIM/07 - Fondamenti Chimici delle TecnologieGeneral ChemistryBarium hexaferrite021001 nanoscience & nanotechnology0104 chemical sciencesferrite manufacturing building material filler sustainabilitychemistryCERAMICSWaste preventionValorisation0210 nano-technologyWaste preventiondescription
Barium M-type hexagonal ferrite (BaM, BaFe12O19) is an immensely important magnetic material, which we have successfully made from the simple valorisation of Fe-rich industrial waste from steel wire drawing, with addition of BaCO3 and heating in air to 1000 degrees C. The optimum ratio of Fe. Ba (producing 86 wt% BaM) was found to be 11: 1 (non-stoichiometric), and secondary phases of alpha-Fe2O3 (non-magnetic) and ZnFe2O4 (poorly antiferromagnetic) were always present. This material consisted of small submicron platelets. A hard magnetic ferrite was produced with Ms=48.6 A m(2) kg(-1) and H-c=211.5 kA m(-1). The highest density was achieved by sintering samples with Fe: Ba ratios of 11: 1 and 12: 1 at 1200 degrees C /2 hr, with an increase in grain size up to 2 mm. The sintered 11: 1 had electrical conductivity comparable to that of commercial sintered BaM. Such materials are suitable for industrial applications as hard magnets, and EM shielding in architectural and construction materials.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2016-04-01 |