Cost-effective integrated strategy for the fabrication of hard-magnet barium hexaferrite powders from low-grade barite ore

• Published in: International journal of minerals, metallurgy and materials metallurgy and materials, 2016-09, Vol.23 (9), p.991-1000
• Main Authors: Sanad, M. M. S., Rashad, M. M.
• Format: Article
• Language: English
• Subjects: BaFe12O19; Barite; Barium; Barium hexaferrite; Ceramics; Characterization and Evaluation of Materials; Chemistry and Materials Science; Composites; Coprecipitation; Corrosion and Coatings; Crystallites; Extractive metallurgy; Fabrication; Ferric chloride; Glass; Hydrogen peroxide; Magnetic measurement; Magnetic properties; Materials Science; Metallic Materials; Natural Materials; Oxidizing agents; Sodium hydroxide; Solid phases; Surfaces and Interfaces; Thin Films; Tribology; Ultrafines; X-ray diffraction; 低品位; 制备; 扫描电子显微镜; 振动样品磁强计; 粉末; 重晶石矿; 钡铁氧体
• ISSN: 1674-4799; 1869-103X
• DOI: 10.1007/s12613-016-1316-y

Ultrafine barium hexaferrite（BaFe12O19） powders were synthesized from the metallurgical extracts of low-grade Egyptian barite ore via a co-precipitation route. Hydrometallurgical treatment of barite ore was systematically studied to achieve the maximum dissolution efficiency of Fe（～99.7%） under the optimum conditions. The hexaferrite precursors were obtained by the co-precipitation of BaS produced by the reduction of barite ore with carbon at 1273 K and then dissolved in diluted HCl and FeCl3 solution at pH 10 using NaOH as a base; the product was then annealed at 1273 K in an open atmosphere. The effect of Fe^3＋/Ba^2＋ molar ratio and the addition of hydrogen peroxide（H2O2） on the phase structure, crystallite size, morphology, and magnetic properties were investigated by X-ray diffraction, scanning electron microscopy, and vibrating sample magnetometry. Single-phase BaFe（12）O（19） powder was obtained at an Fe^3＋/Ba^2＋ molar ratio of 8.00. The formed powders exhibited a hexagonal platelet-like structure. Good maximum magnetization（48.3 A×m^2×kg^–1） was achieved in the material prepared at an Fe^3＋/Ba^2＋ molar ratio of 8.0 in the presence of 5% H2O2 as an oxidizer and at 1273 K because of the formation of a uniform, hexagonal-shaped structure.