Halides - Associated problems during the primary zinc production process

Caterina Benigni, Stefan Patscheider, Christoph Pichler, Jürgen Antrekowitsch

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Recycling of zinc containing residues takes place nowadays in Waelz kilns that generate a secondary zinc oxide for the primary zinc industry. Rising complexities of the feeded materials cause a zinc product that is loaded with undesirable elements such as fluorine and chlorine. To reduce the halide content an additional washing step is necessary. To keep the metal loss low soda is charged during washing to create an insoluble metal carbonate and a soluble sodium salt. The alkaline conditions have an impact on the removal of fluorine as well. The target values for halides in the zinc electrolysis are max. 100 mg/L for chlorine and max. 50 mg/L for fluorine. In most cases the washing step is not able to decrease the halides to such low values and therefore, the secondary zinc oxide runs through the whole zinc primary process. The present paper deals with the state of the art soda washing process as well as with alternative possibilities to reduce the halide content to use it directly in the leaching stage.
Translated title of the contributionHalogene - Auftretende Probleme in der primären Zinkgewinnung
Original languageEnglish
Title of host publicationOPMR - Opportunities in processing of metal resources in South East Europe
Subtitle of host publicationProceedings
Pages149-154
Number of pages6
ISBN (Electronic)978-3-200-04893-5
Publication statusPublished - 30 Nov 2016

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