Selective leaching of zinc from zinc ferrite with hydrochloric acid

• Published in: Hydrometallurgy Vol. 95; no. 3; pp. 179 - 182
• Main Authors: LANGOVA, Sarka, LESKO, Juraj, MATYSEK, Dalibor
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.02.2009; Elsevier
• Subjects: Applied sciences; Exact sciences and technology; Hematite; Hydrochloric acid; Metals. Metallurgy; Production of metals; Steel-making wastes; Zinc extraction; Zinc ferrite; Hydrochloric acid; Hematite; Zinc ferrite; Zinc extraction; Steel-making wastes; Ferrite; Selective leaching; Steelmaking; Extraction; Hydrometallurgy
• ISSN: 0304-386X; 1879-1158
• DOI: 10.1016/j.hydromet.2008.05.040

Zinc ferrite is a major constituent of the steel-making dust and sludge. In the present work the hydrometallurgical extraction of zinc from this material was studied. ZnFe 2O 4 and the sludge were leached in hydrochloric acid at atmospheric and elevated pressure using the microwave heating. More than 90% of zinc can be extracted with diluted acid when the temperature is 250 °C retaining iron in the new oxide matrix. The product resulting from the synthetic zinc ferrite contained 91% of hematite and 9% of zinc ferrite. Dried sludge from an oxygen open hearth furnace was converted into hematite containing 0.18% of zinc and 0.05% of lead. This material can be directly recycled or used as a pigment. Over 99% of the zinc was extracted from the sludge with 0.3 M HCl solution but the amount of iron in the solution was higher than for the pure ferrite treatment because the sludge contained also some magnetite and wustite.